U.S.S. TRIGGER (SS-237) — war patrol report SS-237_TRIGGER_Part1.pdf

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A refit period at Pearl Harbor proceeded her departure on her second war patrol on 23 September with Commander Roy S. Benson, as her new skipper. With a stop at Midway to top off her fuel bunkers, TRIGGER entered enemy-controlled waters and made her first contact west of Japan on 5 October. A dark spot in the grey dawn appeared to be smoke from a small vessel and the doughty sub sped on the surface with her deck guns manned. When the range was closed to 1500 yards, she pulled the trigger on the ship and sprayed her decks with machine gun fire and opened up with her 3-inch guns. Guns from the Jap ship returned the compliment and as the shells and bullets whistled close aboard, TRIGGER submerged for a torpedo shot on the ship which seemed about 4,000 tons.

Both vessels ceased firing and the freighter zig-zagged radically on a retiring course. The hot pursuit of TRIGGER came up for quite a jolt when it was discovered that in her radical turns the freighter had turned around in her flight and was now racing straight toward TRIGGER in an obvious attempt to ram her. It was now time for the submarine to manoeuvre the Jap out of position to avert a collision. The vessels passed each other on opposite and parallel courses as machine gun fire rattled down at the sea. The close to torpedo in passing, TRIGGER finally sent two torpedoes after the freighter. A rumble and a roar indicated that the second torpedo struck home. The sound man picked up the rhythmic vibration of an approaching patrol ship and a dive was ordered. Although TRIGGER was anxious to see the show, the price of admission was too high and the skipper decided to stay below.

Pursuit of the crippled freighter was continued after the atmosphere had cleared. The smoke from the Jap's stack could be seen distinctly as TRIGGER closed the range. Several large puffs of smoke billowed over the ship and then nothing was seen. The Jap freighter was not designed to submerge, but encouraged by torpedoes, she exceeded the designers expectations on this occasion.

It was off the coast of Burge Sudo that TRIGGER made her next kill in the early morning of 17 October. Sighting the tell-tale smoke of a Jap ship close inshore, a surface approach was made in the darkness and two torpedoes leaped out of the bow tubes after the enemy. Both hit! The ship went down by the bow and her deck gun began to flash in anger.

The sub drew out of the range of the stricken vessel and observed flashlights blinking along the weather decks. The ship was apparently not sinking and several more torpedoes were sent after her by way of persuasion. But no further "persuasion" was necessary for the bow went under, the stern went up and a 5,000 ton freighter was heard to crumble as the dark ocean depths crushed her sides.

That very afternoon, TRIGGER cautiously approached another 5,000 ton freighter, attained a perfect firing position and sent three torpedoes straight and true for the target. Submariners don't like disappointment but they accept the bitter with the sweet and keep on.

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trying. Why three perfectly fired torpedoes should produce nothing is inexplicable and a source of utter chagrin. That is what happened to this Jap ship—nothing! . Just nothing! The skipper could be forgiven if he slammed his cap on the deck.

There were better days ahead for the TRIGGER and 20 October 1942, was one of them. The smoke from a 10,000 ton loaded tanker started another chase in the early evening and finished in the bright moonlight. By figuring out the zig-zag plan and base course of the tanker, TRIGGER closed the range to fire four torpedoes for two hits. The target headed for the sub to ram her, but TRIGGER went to a depth of 100 feet. The tanker churned right overhead, dropping a depth charge as she passed. It was her last pass, for the TRIGGER had already thrown the lucky pair. A violent eruption; silence from the vessels' screws; the crackling noise of a ship breaking up; a clear horison. That is how a ship is lost. That is how this one went down.

Bungo Sudo was a heavy traffic lane for Japanese tankers and the morning of 24 October brought another torpedoes out at her cap ship. Three hits! One caught her right in the stern, stopping the capships as she turned away. Heavy white smoke streamed out of her after parts and a deck gun started banging away. A last torpedo was saved for the "Coup de Grace" but no explosion was heard. Two bombing planes were sighted and with the shock of two exploding bombs bidding her farewell it was the target. TRIGGER left the tanker down by the stern, her fate in the lap of the gods.

In company with the submarine DRUM, TRIGGER's diesel engines purred into the channel at Pearl Harbor on 8 November for a refit. Parceled to gird her for further combat. TRIGGER could hold her head higher now. Each patrol increased the respect felt for her among the men of the "silent service". The third patrol was no exception.

Quietly slipping out of Pearl Harbor on 3 December, TRIGGER pulled into Midway 7 December. It was a day to be remembered; a day to be avenged. And vengeance was forthcoming. Her first objective was the laying of mine fields near Inubo Sakii.

It was after the first mine field had been laid and TRIGGER was laying a second on the night of 23 December. Two dark forms approaching across the water directly toward the sub were identified as an 8:30 ton freighter with escort. A perfect torpedo set-up was passed up out of deference to the important task of completing the minelaying operations.

It was a case of having your cake and eating it too when the freighter apparently nudged one of the mines and a violent explosion ripped skyward taking the midships section of the freighter up like a giant and dropping her back down with a broken back. In seconds the ship was 90 degrees from her former course, lying in the trough of the heavy seas, and rolling in the ground swells. The main deck was soon awash and she was unceremoniously flushed to the bottom of the sea.

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Two days later a cloud of smoke attracted the eager eyes of TRIGGER and a 5,000 ton freighter hove into view zig-zagging on 60 degree legs. Just as she steadied on a new course, TRIGGER cut loose with a spread of three of her best. One hit was made just forward of the bridge and she settled down by the bow, tooted her whistle and turned away. At this time the TRIGGER was only two miles off Nojima Saki and the current was setting her toward the beach, forcing her to turn to seaward.

Approximately six seaplanes were sighted, one of them right over the target. The crippled ship was trying hard to make it back to port but her dock forward was awash and her screws were nearly out of water, spinning rapidly. As the range was opening, it was decided that one more torpedo would bring a quik end. The last torpedo streamed toward the freighter and struck homo. With planes in the air dropping bombs, it was decided to clear the area since there was no more doubt that the ship was sunk.

It was the day after a Christmas spent in the usual patrols, that a convoy of Japanese ships was sighted approaching the mine fields which TRIGGER had recently laid. As the lead ship approached the exact spot of the mine field, profuse smoke billowed up from the ship and the other ships of the convoy scattered and started down by the bow. It was safe to consider that a 5,000 ton ship was either sunk or damaged by that mine.

The last day of the year was a profitable one for TRIGGER. Mountainous seas spilled over the periscope sight and only a momentary glimpse of a target ship could be seen. That glimpse was enough to reveal a large ship with a cargo of planes on her stern. Despite the raging seas, three torpedoes were fired at the Jap freighter for two hits. The ship took a list to starboard and started down by the bow. Her propeller stopped and a heavy internal explosion was heard.

The ship could not be seen through the periscope and TRIGGER surfaced to see what the score was. About 4,000 yards away the ship's stern was up in the air and with two-thirds of her already submerged, she soon disappeared. The ship appeared to be a seaplane tender and may have been the last blow struck at the enemy in the year 1942.

The new year started out slowly for the contacts seemed to be too close in shore or too small. The tempo was soon to liven, for on 10 January a vessel was approaching bows on and it was not until she started zigzagging that TRIGGER could identify a Japanese destroyer coming at her. Three torpedoes were fired. One hit just under the well deck and the explosion folded the forecastle up at an angle of 45 degrees. The second hit scored toward the stern. As soon as she fired, TRIGGER executed a high speed turn to bring the stern tubes to bear.

About three dozen fishing vessels approached the sinking destroyer from the shore but they were of little help. With her bow turned up like an old shoe, the destroyer sank on an even keel. This, her

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last kill of the third war patrol also marked her first victim of the year 1945. The patrol ended as TRIGGER arrived at Midway for a refit period.

The fourth war patrol was very active with a total of thirteen contacts made. Although TRIGGER performed in her usual determined way, the effectiveness was hampered by rain squalls, darkness and other factors.

On 15 March a convoy of five freighters with two escorts was picked up. The ships were in two columns and TRIGGER boldly worked into a position ahead of the convoy and proceeded to run right down the middle of the groups. Three torpedoes were fired at the lead ship in the right hand column. While these torpedoes were on their way, a set-up was just developing on the left hand column when TRIGGER's presence was betrayed by the wake of the torpedoes in the glassy sea.

The second target headed straight for the TRIGGER and she sent three torpedoes down the ship's throat. Two hits were scored and the sub was forced down deep as the escort vessels raced in to give her a working over with depth charges. Breaking up of the ship was indicated from noises coming from the direction of the first target. Later in the day, TRIGGER surfaced and, upon looking around, sighted what appeared to be the second target ship with a smaller ship alongside to provide buoyancy and propulsion. They were creeping along at 2 knots with two small destroyers or corvettes protecting them. Three bow tubes were emptied at 700 yards but no explosions followed although the escorts maneuvered around wildly with the knowledge that torpedoes were being fired at them, but now knowing where to look.

Shortly after noon on 20 March a rain squall suddenly opened, lifting the curtain on a convoy. TRIGGER quickly submerged and commenced an approach which resulted in a spread of three torpedoes racing toward the leader; a 7,000 tonner. On torpedo hit with a low order detonation caused the ship to list to port. She stopped and fired three other ships circled her as they dropped depth charged and fired their deck guns at the periscope.

The stricken vessel corrected her list, started up again and surprisingly rejoined as third ship in column formation and steamed on. TRIGGER could not give chase for her fuel was low and with only two stern tube torpedoes left she arrived at Pearl Harbor 6 April 1943.

It was the slender snout of a seasoned veteran that pushed the water aside on her way out of Pearl Harbor on 30 April. And it was well that the big opportunities ahead fell to a wary fighter like TRIGGER. She knew she was in the big league when contact was made with an array of destroyers, cruisers, battleships and a carrier during the merry Month of May. Our doughty submarine could have been murdered a dozen times over if she had been detected. In her anxiety to torpedo a carrier in a large battle force, she almost lost the initiative to a destroyer.

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TRIGGER's first torpedo in the fifth war patrol, however, was destined for a tanker which appeared suddenly from the mist of 28 May. Quick, split - second timing was necessary to get off three torpedoes at the 7,500 ton tanker. One hit was scored aft on the ship and a quick set up was being made on a following tanker. Both ships turned away and TRIGGER was welcomed by a loud explosion nearby which indicated possible air patrols and her wisest move was to dive out of danger.

The first of June started with a bang as a contact developed into two freighters off the coast of Nojima Sakii. One torpedo out of the three fired at the first ship caught her toward the after part of the ship and she settled down to the main deck aft and her screws stopped turning; never to turn again. The second ship started radical course changes and spoiled whatever chance there was of tagging her with a torpedo.

TRIGGER was patrolling off Tokyo on 10 June when the alert officer of the deck sighted something that looked like smoke on the horizon. The next observation revealed it to be the island of a huge aircraft carrier. The "Bong, Bong, Bong" of the general quarters alarm set all hands racing to their battle stations. The captain made a quick appraisal and announced to the men that the target was the biggest thing that they had yet seen. It was a tense moment! The carrier was coming down on TRIGGER at 21 knots and the sub was ready to let go with everything she had.

Destroyers were streaming through the water on both bows, the whole trio zigzagging radically. Things began to happen fast! The periscope shot up. Bearing, range and angle on the bow were reported crisply. There was not a superluminous word spoken. It was "Irig for depth charge, rig for silent running---right full rudder---new course 060." TRIGGER fortunately lay ahead of the base course. Hearts were beating faster and the minutes ticked on.

A destroyer was bearing down on the submarine, the "Thum, thum, thum, thum" of the whirling screws swept right over head. A sigh of temporary relief swept through the sub and the sound of the heavier screws was picked up. There was no time left now. The crisp orders to fire were repeated six times and each time a swish responded that sent a deadly torpedo on its way. Four solid detonations echoed back to the sub and the carrier's screws stopped. A quick look showed the huge giant drifting and listing. Little white-clad forms scurried madly about the decks, and it was observed that the carrier was brand new. The periscope spun around and picked up the destroyers furiously racing toward the periscope.

"Take her down!" It was TRIGGER's turn for a beating now, and it was quick in coming. A beautifully coordinated attack by the destroyers scored one bull's-eye after another. Bits of paint, cork and dust filled the air as every plate, bulkhead and pipe vibrated with the explosions. The lights went out and everyone was knocked down and

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and left groping after something to cling to. The heavy_slides of the submarine squeezed in with each reverberating shock and the deck palings and gratings clattered around dangerously.

Way down below the surface the unmerciful pounding continued. The temperature soared, the humidity hit the saturation point and the men worked to the point of exhaustion controlling the flooding which resulted from the tortured sea valves and fittings.

It was well after midnight before the TRIGGER surfaced and got away. Fresh cool air never felt so good and the men knew the gratefull feeling of returning from the shadow of death. TRIGGER had worn out her welcome in the area and was glad to leave.

The Japanese aircraft carrier did not sink from the four hits distributed along her length, but the sight of seeing their proud carrier return to port in a few hours at the end of a tow line must have been very depressing to the Japs. It meant months of work, tons of valuable material and the occupation of a badly needed drydock. It was over a year later that one of the reconnaissance planes photographed the hapless carrier. What a set-back the TRIGGER had caused!

She arrived at the Submarine Base at Pearl Harbor on 22 June for a much needed refit period. The poor condition of the main engines made a Navy Yard overhaul necessary.

The short but highly successful sixth war patrol commenced with TRIGGER's departure from Pearl Harbor on 1 September. Her patrol area was in the East China Sea. Two unescorted frigates were steaming together at a wide distance apart. The bigger one was selected as the first target and a perfect set-up resulted in two duds thumping the ship's side with nothing more accomplished than putting the Japs on the alert.

By pursuing the contact through the night, TRIGGER fired four torpedoes with one sure hit which had the remarkable effect of sinking the ship in about three minutes. Seconds later, her boilers blew up with a tremendous force.

The afternoon of 21 September brought the masts of a six-ship convoy into the sights of the periscope and TRIGGER trailed them until she was able to conduct a surface attack that night. As she approached the convoy with a carefully planned attack, three torpedoes each were shot after tanker #1 and tanker #2. One hit on the first tanker sent flames shooting 500 feet into the air, illuminating the entire area. The second torpedo hit her and smashed it, with the furious holocaust already taking place, it added little to the complete confusion. Crew members in white uniforms were sprinting forward on her decks ahead of the rapidly spreading flames as the burning funeral pyre forged on. A gun crew tried to man the bow gun but after three or four shots, their efforts were obscured by the yellow-red flames which blazed over her entire length.

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A flash amidships on tanker #2 sent up a column of smoke and water and she turned away as fire broke out immediately. The freighter #2 in the opposite column also took a torpedo amidships. She broke in half beneath the stack and disappeared below the surface almost immediately.

The first freighter in the column was holding course and the third freighter started to turn away. The remaining freighter and tanker were firing their deck guns and with tanker #3 bearing down on the sub she swung around and emptied a stern tube which scored a hit on the starboard bow. The shells from the deck guns were whistling overhead now; too close for comfort and TRIGGER was forced to dive.

The skipper lost his footing while the ship was diving and fell into the periscope well. The quartermaster commenced lowering the periscope but the skipper called out in time to avert disaster. In the meantime, the tanker was expected to rumble overhead and possibly drop depth charges, but nothing was heard from the surface.

Upon surfacing, TRIGGER made a quick appraisal of the situation and found that two tankers were burning, the third one damaged and down by the bow, one freighter sunk, the second one undamaged, and standing by the badly burning tanker and the third freighter was undamaged and making tracks in a northerly direction. TRIGGER took after the latter ship.

As the chase began, the stern of a ship was sighted pointing vertically into the air, probably tanker #3 which had taken a hit on her bow. As the stern of the ship sank, the blowing red hull of the burning tanker beyond came into full view. The freighter #3 was the next victim and the bow torpedoes attacked out after her. Both of them ripped into the bow of the freighter and she settled by the bow immediately.

A light came on, on the bridge and signals started blinking as the ship commenced thumping out shells from her deck gun and the guns of the fire fighter joined in the chorus. The "music" was quite sour as the ships were apparently firing in the opposite direction of the sub. As TRIGGER closed in boldly to administer the merciful end, the Japs spotted her and turned their guns around in the right direction. Two stern shots at the freighter produced nothing more than the realization that one of them was a dud. By this time the Japs were getting pretty handy with their deck gun and TRIGGER went below.

The last two torpedoes aboard were fired at Freighter #3. One hit--the other missed. The one that hit was a dud! It is possible that some strong language was exchanged over this most exasperating dud.

With all torpedoes expended, a quick pow-wow was held to discuss the chances of a surface battle. It was decided against for the deck gun had never in its history fired five consecutive shots without

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jamming and one apologetic gun was a poor match against armed vessels and there was still a good chance that the targets would eventually sink.

The whole action covered a period of 3½ hours and took place within a circle of 8,000 yards of the brilliantly burning tanker. The light from this fire was intense for the flames leaped for most of the time a hundred feet above the masts. Minor explosions continuously erupted and the breeze carried a plume of smoke twenty miles across the ocean.

TRIGGER set her course toward the edge of the patrol area, her torpedoes having been quickly and well expended. In about 10 minutes a glow flared up beyond the burning tanker. It was tanker #2 blowing up. Huge fires billowed into the air and the bow, bridge and stern of the tanker were incandescent. The hull of the first tanker disappeared and the place where she had been was still burning fiercely with flames lashing up 50 to 100 feet high. Crew members came up the bridge one at a time to view the holocaust the TRIGGER was leaving behind her.

RESULTS OF THE ATTACK

Freighter #1 (Kohuku Maru type) escaped undamaged.
Freighter #2 (Argun Maru type) Sunk--Broken in half.
Freighter #3 (Lima Maru type) Damaged--two hits on bow--forecastle awash.

Tanker #1 (Nippon Maru type) Sunk--Blow up immediately
Tanker #2 (Syoyo Maru type) Sunk--Blow up after burning several hours.

Tanker #3 (San Pedro Maru) Sunk.

Arriving at Midway 30 September 1943, TRIGGER completed her refit period and departed on her seventh war patrol 22 October. By the 1st of November TRIGGER was hot on the trail of another convoy which was protected by st least two escort vessels. Several good approaches were spoiled by untimely course changes, but two freighters finally presented overlapping targets. Both were three-Island type freighters of about 7,000 tons. Sixty seconds after firing three torpedoes, freighter #1 caught one on the bow. A large column of spray and smoke enveloped the forward part of the ship and she went down bow first.

Freighter #2 was stopped short when a torpedo ripped into her amidships with a terrific explosion. The smoke and debris which completely covered the ship enshrouded her demise and she never came into view again. Two patrol vessels with spray flying from their bows raced in toward TRIGGER and it was time to dive. Twenty depth charges shocked the water around the sub before they lost contact.

The early morning of 2 November brought another 7,000 ton freighter into view and one solid hit brought a cloud of smoke and steam out of the ship's tortured hull. A few minutes observation indicated that

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the ship was not sinking and the TRIGGER waded in for round two. The
freighter's guns started popping in the direction of the sub but the
marksmanship was something less than expert. Two more hits proved too
many for the ship and she went into a vertical plunge to the ocean
floor.

Following up another radar contact brought an 8,000 ton tanker
into range for a three-torpedo spread. All three hit! The tanker was
torn apart with her bow broken off and her decks awash. The bow sank
at once and the after two-thirds of the ship went under in a flat dive
to join the rest of the ship at the bottom. In the dark of the night,
TRIGGER ran through a large oil slick and heard indescribable screaming
and yelling from ahead. A group of life boats and rafts appeared
momentarily and upon reversing course to search for survivors, the sub
found only a shattered life raft. The entire day passed and just before
midnight, yells and moans on the port beam attracted attention
to three men on a raft. TRIGGER maneuvered to bring them closer but
they made no effort to swim toward the ship. While maneuvering in the
darkness, the raft drifted away and all efforts to regain contact were
unavailing. The high wind and heavy seas which followed made their
survival very doubtful.

An attack on a convoy on 5 November was fouled by aggressive
patrols but on 9 November the bright moonlight showed the smoke of
several ships. From her position ahead of the convoy, TRIGGER made
a periscope approach right for the center of the convoy by passing
between the patrolling screen. The convoy made a zig white torpedoes
the sub directly between two columns of ships. With no bow torpedoes
remaining, TRIGGER lined up a stern shot on the largest ship.

Of the four torpedoes fired, one hit under the stack and the
second hit aft as an approaching patrol vessel forced TRIGGER down
under. Five excellently placed depth charges jolted the sub before
the ship lost contact. Several another shots later, when TRIGGER could sur-
face she saw a destroyer and another ship still picking up survivors
with a patrol plane circling over the scene of the disaster. The
sunken ship was a large, now-type passenger-cargo ship carrying a
large deck load and so many troops that it took five hours to pick
them up.

It was very dark on the night of 21 November and TRIGGER followed
up a radar contact until she was tracking directly ahead of a 5,000
ton freighter. When the range had decreased to 2,000 yards, she pulled
off the track, swung her stern around and fired four torpedoes for two
resounding hits. The ship started down by the bow until she was
straight up and down with her bow pushing into the bottom. The stern
slowly sagged and the ship finally sank with a rush. With her torpedoes all expended, TRIGGER arrived at Midway on 3 December, a very
successful patrol ended.

On the first day of 1944 TRIGGER departed Pearl Harbor for her
eighth war patrol which was conducted in the Truk-Guam areas. A Japanese submarine was contacted on 27 January and a salt water game

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ensued in which both subs tried to slip a torpedo into each other but the game ended in a stalemate as they lost contact.

A radar contact started off an approach on a convoy of three large ships with two escorts on the night of 31 January. It was a clear night with no moon but bright stars and the first three torpedoes scrved to make one of the destroyers disappear in a cloud of smoke and debris as two hits tore into her. The nearer destroyer turned on TRIGGER and three more torpedoes entered a bid for a similar fate for her. Fate would not cooperate, even when encouraged by four more expensive torpedoes. The destroyer went wild turning to the left and then to the right all the while dropping depth charges and firing guns.

TRIGGER went below and turned in the direction of the convoy. The destroyer raced past the sub trying to get back to the convoy. By the time TRIGGER caught up with the group, the four ships were in column with the destroyer in the lead. All were zigzagging radically. Four torpedoes streaked through the water toward the last ship. Two explosions sent tongues of yellow flame leaping toward the masthead and minor explosions with bursts of flame bid a spectacular farewell before the inscrutable ocean closed over the big ship.

The destroyer commenced dropping depth charges from a seemingly inexhaustible supply and headed for the scene of the sinking. She was flashing the numeral "five" repeatedly as she approached a patch of blinking lights in the water where survivors bobbed helplessly.

TRIGGER commenced an approach on the remaining two ships but it was impossible to close the range before dawn and on 19 February and up. The patrol ended as the sub arrived at Midway on 19 February and entered Pearl Harbor 23 February for a refit and training period. Commander R. E. Dornin was relieved by Lieutenant Commander F. J. Harlfinger. Several new officers were taken aboard before the Ninth War patrol steered with TRIGGER's departure on 23 March 1944.

A radar contact in the dark early hours of 8 April started an approach which revealed a convoy of four columns of large ships accompanied by a terrific escort force. By working her way among the ships, TRIGGER was about to unleash ten torpedoes in a mass killing, when a Jap destroyer suddenly loomed up 50 yards away with a machine gun firing through a window on the bridge. As the destroyer churned the water across her bow in an attempt to ram, TRIGGER cut loose with four torpedoes as soon as a path through the water was open to the target ship.

At this time four of the escorts had the submarine trapped. As one had tried to ram, the second followed him up with depth charges and the other two were lined up on either quarter. Just then, two hits were heard on a huge, heavily loaded tanker and two more hits were heard on a ship elsewhere in the convoy. An appraisal of the damage inflicted was impossible in the face of her dangerous position and TRIGGER plunged to the depths to take the inevitable working over by the Japanese destroyers.

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Six very close depth charges shook the sub and left no doubt that TRIGGER was hurt. Six anti-submarine vessels hounded her for 17 hours while she went deep with silent running from 0350 to 1900. The heavy steel sides of the submarine buckled in and out under the terrific pressure. The pipes and bulkheads vibrated like guitar strings and locker doors sprung open scattering the contents over everything. The intense heat and humidity sent rivulets of perspiration rolling down the faces and bodies of the crew until their clothes were drenched and socks and shoes soggy. Leak of oxygen in the air and the nervous strain of the unrelenting depth charges brought some to the verge of collapse.

When TRIGGER finally surfaced at night, the forward torpedo room was flooded to the floor plates and all other compartments were flooded to the lower flats except the battery compartments and the after torpedo room. The bow planes, trim pump, sound gear and both radars were out of commission. Most of the auxiliary machinery was out of alignment and the sub was unable to transmit radio messages because of the radio antennae was grounded. The ingenuity and fighting spirit of the TRIGGER man manifested itself again and she recovered from the worst beating she had ever had by mustering spare parts and baling wire to effect numerous repairs and start out to hunt down the Japanese. She took a terrific beating but she came up with her same dauntless, fighting spirit.

Making contact with the submarine TANG, TRIGGER exchanged information and borrowed some spare parts and made plans for a coordinated patrol. On 26 April, radar contact was made with a convoy of ships near Palau. TRIGGER slipped in to 2,600 yards and lined up overlapping targets of four ships so that a solid mass of ships stretched about 20 degrees across her bow. Six torpedoes were fired at all four ships and the sub turned around to bring her stern tubes to bear.

Four hits were seen and heard; two hits on the near ships and two others apparently on the two ships on the far side. One of the closer ships blew up from an explosion on her after parts and one of the far ships was seen straight up and down with her course set for the bottom. The remaining ships and escorts began milling around in a state of hopeless confusion that was not unpleasant to see. Four more torpedoes were fired at the group of ships including the destroyer in the foreground. The torpedoes streaked past the destroyer and scored a hit on a freighter.

Of the four freighters in the leading group, only one was able to get under way and she was down by the bow steaming at a reduced speed. A fifth freighter joined the cripple and with her reloading completed, TRIGGER noticed that the third freighter was sinking and took out after the two remaining two freighters.

The damaged freighter finally stopped and the loaded ship hove to close aboard. As TRIGGER prepared to fire at both of them the undamaged freighter got underway and two hits were scored on the damaged ship. With three torpedo hits in her and afire, the ship had no chance of remaining afloat.

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By this time the three escorts were formed in a close group with their blinkers signalling back and forth. TRIGGER decided to add a little more confusion to their conference with three torpedoes. A cloud of smoke shot into the air where the middle destroyer had been and the ship disappeared. The last thing heard from the ship was her load of depth charges erupting in rapid-fire order way down below.

Pursuit of the undamaged freighter continued to no avail and TRIGGER, with one more torpedo left, decided to return to the burning ship to see if she could use it. An old type destroyer was prowling around and the freighter, down by the bow and listing to the starboard was ablaze from stern to stern. There was no question about the ship's future; it had none. Plumes shot hundreds of feet into the air, and frequent explosions blew great masses of glowing debris into the air. As TRIGGER departed from this vale of desolation, the ensuing ship was still visible from 50 miles away with huge flashes skyrocketing upward.

The same for the car-fleet freighter and one escort vessel sunk one freighter and two escorts, both ships of the patrol, were lost in the morning of 15 May 1944.

After the merciless pounding absorbed by the rugged submarine, it was necessary for TRIGGER to undergo a major overhaul at Hunters Point, San Francisco, California. In excellent and thorough job was performed on TRIGGER and when she finally departed Pearl Harbor on 24 September for her 10th war patrol, she was in good fighting condition.

The tenth war patrol was conducted in two phases. The first phase was a coordinated attack off the east coast of Formosa and the Southern Islands of the Nansel Shoto, in company with the submarines SILVERSIDES and SALMON. During the phase, TRIGGER rescued a pilot from the water and helped in escorting the damaged SALMON back to Saipan. The second phase was conducted off the Benin Islands as TRIGGER became one of seven submarines in a wolf pack. Although two task forces were contacted, it was impossible to close for an attack.

The tops of ship's masts started an approach by TRIGGER on 30 October, which brought into view a large fleet tanker with four escorts. By smart maneuvering the ships forced a chase for nine hours before TRIGGER scored three hits on a tanker. All hits were near the stern and the after part of the ship was obliterated by smoke and debris. When the smoke had cleared, the tanker appeared with part of her stern missing and her screws stopped forever. A fourth torpedo hit while the periscope slights brought into view a patrol vessel bearing down angrily on TRIGGER and she was forced to dive and take a complete treatment of depth charges which last an hour in which 78 depth charges rumbled around her, none of them far from scoring a bull's-eye.

— page 16 —
14 - USS TRIGGER (SS 237)

Several patrol craft were attacked in the later part of the patrol by guns and torpedoes, but heavy seas and the shallow draft of the ships saved them from the wrath of the TRIGGER. The patrol ended as the sub moored alongside the subdder HOLLAND at Saipan on 3 November 1944.

The eleventh war patrol of TRIGGER commenced on 28 December and ended on 3 February 1945. Conducted in the Bungo-Suido-Ki1 Suido Area, the patrol, like her previous ones, was carried on with an aggressive spirit and a thoroughness associated with TRIGGER. However, contacts with the enemy were few and the air and radar anti-submarine measures thwarted the submarine's attempts to score with her torpedoes. This was particularly discouraging when contact was made with a large convoy on 29 January. Time and time again aircraft overhead spotted the submarine closing in for a kill and forced her to dive.

Trouble with her main motors on 2 February climaxed a patrol characterized by few ship contacts and many enemy aircraft. TRIGGER moored at Apra Harbor, Guam as the patrol ended on 3 February 1945.

Perhaps fortune ceased to smile on TRIGGER altogether at this point in her brilliant career. She was to join the submarine TIRANTE on her twelfth war patrol. A radar call was sent out from TIRANTE calling TRIGGER. Silence was the only answer--a silence that has never been broken; a silence that told a wordless story. The call for the TRIGGER is still echoing through the ocean depths; echoing in the hearts of those who know her for the gallant ship she was. The spirit of the TRIGGER lives on. It will never die!

USS TRIGGER (SS 237) earned eleven Battle Stars on the ASIATIC-PACIFIC Area Service Medal, for participating in the following operations:

1. Star/Leyte Operation
   Northern Luzon and Formosa Attacks -- 11 to 14 October 1944

2. Star/Iwo Jima Operation
   Assault and Occupation of Iwo Jima -- 15 February to 16 March 1945

3. Star/Submarine War Patrol - Pacific -- 23 September to 8 November 1942

4. Star/Submarine War Patrol - Pacific -- 3 December 1942 to 22 January 1943

5. Star/Submarine War Patrol - Pacific -- 13 December 1942 to 6 April 1943

6. Star/Submarine War Patrol - Pacific -- 30 April to 22 June 1943

7. Star/Submarine War Patrol - Pacific -- 1 to 30 September 1943

— page 17 —
15 - USS TRIGGER (SS 237)
1 Star/Submarine War Patrol - Pacific -- 22 October to 8 December 1943
1 Star/Submarine War Patrol - Pacific -- 1 January to 23 February 1944
1 Star/Submarine War Patrol - Pacific -- 23 March to 15 May 1944
1 Star/Submarine War Patrol - Pacific -- 24 September to 23 November 1944

She also earned the Presidential Unit Citation on the following operations:

Fifth War Patrol - Pacific -- 30 May to 22 June 1943
Sixth War Patrol - Pacific -- 1 to 30 September 1943
Seventh War Patrol - Pacific -- 22 October to 8 December 1943

STATISTICS

OVERALL LENGTH 312 feet
BEAM 27 feet
SPEED 20 knots
DISPLACEMENT 1,525 tons

Restencliffed August 1951

— page 21 —
11 July
(Contact Ho. 4). Changed course to close range and identified two destroyers. Submerged to attack but destroyers were heading away with 1700 starboard angle on bow. Delivered this destroyers had escorted above tactics from Kiska to Jitui and was returning.

Scrubbed Jereza Tor, Chief of Harbor and Holtz Bay. Inertial information.

12 July
0058 sent contact report to San recording day (3sec paragraph 10). Returned to search plane on Jitui. Returned to search plane

— page 23 —
24 July
Subject: U.S.S. TRIDENT (CINCPAC 2) 12/15/45
- 0056 received Contraband 0.5% 2/1/55 di-
  rection patrol be conducted as on 22 July
  and asking for weather report prior to day-
  light. 0.37 sent our 24/512 via U.S. (Kansuilu).
  Could not raise U.S. (Dutch Harbor) on 4/25 KOS.
  1339 obtained fix on Buldir Island and checked
  closely with radar range at 11 miles. This fix,
  after 52 hours of dead reckoning running, in-
  dicated a current set at 079°(T) and a drift
  of 0.33 knots, in this area.

25 July -
8 August
Patroling off Bolita Bay, Chichagof Harbor and
Jarana Bay, Alaska.

25 July
0132 received Contraband 0.5% 2/1/55 distri-
buting 27 July as tentative Patrol Day. It is over-
drawn 0.44. 0.42 received Contraband 0.5% 2/1/55
24/7/45 directed to patrol area to be under-
way. This patrol was conducted at 12:00 AM.

26 July
Later enemy patrols and radar range covered
with fog. Chief of Patrol and air attack to
Bay searched. Inactive in area.

1241 while 5 miles north of Jarana Bay started
small patrol to be bearing 1750(1), Clatsop
coast 3 miles, 0.4 miles. 0000(2) 22/1/45 at
Hatch. (Contact 10, 6). Passed about 4
range of 400 yards. To attempt to attack
made due to fog, but not at all. The
it was there to secure scuttling ammunition, pro-
vided the crew due here on 28 July. The boat
disappeared into Bolita Bay. Course was re-
versed to search Bolita Bay but the inner
anchorage was not visible.

- 5 -

- 1

— page 24 —
26 July (Cont'd)
In general appearance this patrol boat was similar to our "World War submarines. It had trim lines, second capable of high speed, carried one or more depth charge racks aft and a gun on the forecastle. This gun appeared smaller than a 3 inch, and probably about 37 millimeter.

27 July
At daybreak, patroling 10 - 15 miles north of Red Head searching for Iraq that night he arrived a day earlier; since patrol boat was sighted yesterday. Then patrolled off north-east coast to the eastward of Ceram Sea to intercept anything that might have been chased out of Asia by today's battleship.

28 July
0221 intercepted "TITAN" 23:30 to Cantacuzene group 3.5 miles southwest of Ceram Sea. Visibility was poor. Visibility

— page 29 —
4. NAVIGATIONAL AIDS

There were no lights, lighthouses, or similar navigational aids in this area.

The only Navalistical Chart of Arbu available was U.S.C. & G.S. Chart No. 9102. The inadequacy of this chart is undoubtedly recognized and will therefore not be commented on. It was found that the main points of northern Arbu such as Cape Wrangell, Kresta Point, Red Head and Chirikov Point appear to be correctly positioned on the chart and these points together with the more prominent peninsulas and rocks of Holtz Bay, Chignectv Harbor entrance and Saranza Bay constituted the landmarks from which navigational fixes were obtained. The details of the mesmeric of the Island's concurring furnished no aid in navigation.

Subdir Island was observed on two different occasions and the ship's position fixed by simultaneous bearing and Radar range, with very good results. The contour of the island appears as charted when viewed from the north. Apprehended to within five miles of the island the second time it was sighted. The two small islands on the northern west end of the main island were quite prominent at seven miles and the eastern tangent at 12 miles. The high peak on Buldir undoubtedly makes a very good distant landmark when the visibility permits and is excellently adapted to ranges by Radar.

The Trigger did not have a fathometer.

The following hydrographic information was furnished by Commander Task Group 8.5:

Chunisk Point on Arbu and Cillior Point on .gattu extend three to four miles less to seaward than charted on H.O. Chart 9.02 and to school with minimum depth of four feet was thought to exist at Latitude 52-30 N., Longitude 173-02 East. An experienced Alaskan Navigator was the source of these data.

The poleroid lense in the Bubble Octant was found to be very useful in filtering out the haze and thereby establishing the true horizon when taking sun sights. It is suggested that a polaroid glass be furnished as one of the horizon glasses in the endless tangent southeast for better results when shooting the sun on a hazy horizon and also on the very bright horizons that are encountered in the tropics.

- 11 -

ENCLOSURE (A)

— page 30 —
7/9/42: 1401 :20 miles bearing :095 : 10 :2 destroyers c.
: :040(T) from : : :SHIGURC class
: : :Sirius Point, : : :column form-
: : :Iiska Island : : :tion, 1000 year
: : : :distance botwe.
: : : :shivs. Eelicev
: : : :practolling.

2 : 7/10/42: 1553 :47 miles bearing :South- : :Fleet type sub-
: : :354(T) from Sir- oriy : :marine. Bc-
: : :ius Point. : : :licev to hwc
: : : :bccn GRUINON.Or.
: : : :cours6 toward
: : : :Iiska.

3 : 7/11/42: 0420 :22 miles bearing :225 : 12 :1 Medium size
: :020(T) from Chi- : :frichetter on
: : :richet Point, Attu: : :course toward
: : :Island. : : :Iatlu Island.

4 : 7/11/42: 0606 :Lat. 53-25N : 090 : :Two destroyers
: : :Long. 173-58 E : : :on course to-
: : : :ward Kiska.

5 : 7/14/42: 1200 :1: miles bearing :080 : 12 :1:rge froighter
: : :255(T) from Cape: : :on course to-
: : :Wrangell. : : :ward attu or
: : : :Kiska.

6 : 7/26/42: 1241 :6 miles bearing :280 :15-20:ladder subma-
: : :328(T) from : : :rino chaser
: : :Chall Point : : :with trim lines.

7 : 8/5/42: 2010 :13 miles bearing :270 : 12 :One medium size
: : :056(T) from Rad : : :frischter ser-
: : :ied. : : :ccend by two
: : : :destroyers
: : : :(flate #77 "Re-
: : : :cognition of
: : : :Japanese her-
: : : :chantman")

8 : 8/10/42: 1555 :Pat of Bogosif or :080 : 9 :2 Still-Olass
: : : :submarines on
: : : :heading for
: : : :Dutch farther.

- 12 - ENCLOSURE (A)

— page 32 —
7. There were no attacks made.

8. ENEMY A/S hit, SURRIS

The two destroyers observed patrolling north of Kiska on 9 July, 1942 (Contact No. 1) were in column formation, zigzagging at slow speed. Distance between ships was about 1000 yards.

The two screening destroyers observed on 5 August, 1942 (Contact No. 7) did not patrol their stations. They maintained constant speed and true bearing from the freighter. They screened well ahead and close to the track, so that an attack at favorable range would have been possible without passing through either screen.

No supersonic pinging was heard at any time.

It is believed that the submarine chaser observed off Holtz Bay on 26 July, 1942 (Contact No. 6) was there for the purpose of escorting traffic from the island. It is also believed that the destroyers are used for screening auxiliaries between Kiska and Attu and that they pass from 10 to 15 miles North or Attu Island.

The four-engine patrol bomber reported in Chicharof Harbor on 29 July, 1942, was probably there for the purpose of furnishing air coverage between Attu and the Empire Islands.

9. MAJOR DEFECTS ENUMERATED:

(..) Engineering:

1. Starboard Shaft - This shaft has an audible squeal which can be heard, in the after torpedo room, through a range of 130 to 200 RPM. Prior to departure on patrol a verbal report of the sound test indicated that this squeal could also be heard at slow speeds on sonic sound gear. On several occasions during the patrol with ideal conditions, flat echo and shallow water, the squeal could be distinguished at slow speeds of 43 RPM on the ship's supersonic sound gear.

2. #2 Vapor Compressor Still - It was necessary to renew the seal rings and garlock closures on the in-pipe shaft of this vapor compressor. Complete disassembly of the compressor unit was necessary. The still was out of commission about thirty hours.

- 14 -

ENCLOSURE (A)

— page 33 —
U.S.S. TRIGGER - Report of First War Patrol.

(B) Hull:

1. Periscopes - On about July 15 began to rotate fogging in number two periscope. Fogging became progressively worse with time. Observed same defect in number one periscope but to a lesser degree.

Fogging progressed to the extent in number two periscope that observations became extremely difficult. Continuous dipping of the periscope during observation cleared fogging for only a few seconds.

Working on the assumption that fogging was taking place within the periscope, out in static altitude on the theory that its rate might dry out the inside of the scope, I left stable azimuth out in too long causing it to over heat and smoke, completely clouding the inside of the periscope. Since there was no rigorous flaw or erasure reasonable about all it was impossible to develop.

Shifting number one periscope to the conning tower. This periscope was at first stiff in operation on fogging was in evidence. However, with operating most of the stiffness worked out and fogging gradually disappeared.

2. Bow Plane Shear Pins - On July 11 the bow plane shear pins in the horizontal rigging shaft sheared while attempting to rig the planes cut and in. Pins were replaced with new ones within one half hour, and no further difficulty was experienced.

Casualty is believed to have been caused by operating the rigging motor during the high voltage of a battery charge, about 300 volts at that time. Upon removal it was discovered that the shear pins had not been installed as a driven fit. This fact was undoubtedly a contributing factor to the failure.

(C) Communications:

1. Erratic Operation of Easy Cst Mike - Investigation disclosed that a spring loaded contactor in the basket had collapsed (i.e., internal spring had assumed a permanent set, and could no longer force the contactor firmly against the wheels on either side). Consequently the electrical circuit was poor at this point. Alight arcing occurred, and the resultant fouling of the contactor tips opened the circuit, thus disrupting the stepping sequence.

The apparatus was kept in operation by cleaning the contactor and wheels frequently, and by slow, full punching of the keys.

- 15 - ENCLOSURE (..)

— page 34 —
10. RADIO RECEPTION

Radio reception was excellent, NPM Fox being the primary medium. . . . split phse wet with maintained on 450 KGs. This vessel has no loud speaker in the radio room, and a split phone between NPM Fox and 450 KGs practically worthless, so frr as 450 is concerned, since the Fox schedules run continuously. The only alternative was to put two operators on wctch at a time, an inconvenience since these men sometimes stand sound watches while the ship is submerged, as well as receiving watches on the surface.

No difficulty was experienced with transmission, even when, at about 0900 Znd July 15th, suspected enemy jamming of the 4235 bend was noted. In this instance our message was sent to NPM through the interference. . . . source of annoyance and delay was the large number of shore station and commercial transmissions on norr this frequency. 4235 KGs was used exclusively for transmission. 8270 was tried several times unsuccessfully. 450 KGs was not used, although a few transmissions were heard from other vessels on this frequency. Messages were serviced through NPM, NPG, NFR and NFZ. Our authenticator was not satisfactory to NPG, although accepted by the other three stations. The last serial received was Contagicroup 8.5% D.L.RIDGE. His NPF serial was not received.

11. SOUND CONDITIONS AND DENSITY LAYERS

No sound contacts were made; consequently there is no information relative to sound conditions or density layers.

12. HE.LITH. JID. H.D.BIT.SLITY

The general health and habitability of the ship was excellent throughout the entire patrol. . . . few minor colds and the usual number of constipation cases were created. . . . all officers and personnel standing bridge watches were required to take vitamin pills daily, whereas other personnel were issued vitamins if they desired them.

To. sun lamps were used rather exclusively, and these, together with the vitamins, are believed to have contributed to the good health of the personnel.

In unusual course of consideration was present in the ship during the course of the patrol and as a result many personnel and crew were not able to be informed. The use of heaters and the use of conductive units did not allow the ship to adapt to the draught condition within the ship.

- 16 - ENCLOSURE (a)

— page 35 —
13. MILES ENROUTE TO AND FROM STATION

Enroute station: 2780 (From Port Harbor)
From station: 794 (To Dutch Harbor)

14. FUEL OIL EXPENDED

Enroute and from station: 36,328
On station: 23,215
Total: 59,543

15. PLATFORMS OF ENDURANCE REMAINING

Torpedoes: 24, 30,104
Fuel: 30
Provisions (days): 30
Fresh Water: 2000
Personnel (d.sys): 14

16. Cemtskagroup 8.5's secret dispatch 081043 (Yellow Hill) of August, 1942.

17. A hazc or fog hung over the Island of attu during practically the entire period of this patrol. Generally, the mountain peaks could be seen at these times. From own observations and those reported by aircraft, apparently the anchorage provided by Chichagof Harbor, Saran and Holtz Bays are not being used by enemy ships.

In future patrols, it is recommended that rather than make daily observations of anchorage at attu Island, submarines patrol 10 to 15 miles North of the island and off Cape Wrangell where ships must make a landfall before proceeding to Kiska.

— page 37 —
15 August. 2122 sent our 161303 to Contassfor 7 via 12A attack for an ack-ocq-ack of our 1A-1, 2,000 received "2" signal assting for a repeat of above message.

16 August. 0025 retransmitt'd our 1A-1 to TNT, till received Contassfor 7's 1618,7 assigned rendezvous point with Litchfield.

17 August. 0825 exchanged recognition signals with TPY plane on northerly course, 14,500 exchanged recognition signals with TPY plane on southerly course.

18 August. 0515 sighted Litchfield bearing 2500(T) distance about 4 miles, 0702 fired one tank of,50 caliber ammunition at balloon. Proceeded to Pearl Harbor, 1151 (plus 10) board steamer side to dock at Pearl Harbor, T.T.

2. Departure from Dutch Harbor was made with better than average visibility for that area and with a moderate sea running. The weather became very overcast and squally with the evening and this continued until the evening of 19th, at which time the ship's position was about 30° of Latitude 35° N. During this period almost continuous squalls of rain and mist were experienced with a heavy sea running. The barometer indicated that we were moving through a storm area from the southwest. Low haze and fog and thick haze were prevalent from just South of the Lituan Chain to Latitude 33° N.

Heavy squalls, rainily for the southeast, cloudy skies with exceptionally good visibility were encountered the rest of the trip.

Incidentally, the continuous twilight reported in the Lituanian Channel for the region around the Lituan Islands from April to August need not worry anyone burdened with the responsibility of charging batteries on the surface. Only one night's crash resulted when it was clear enough to even approach a twilight. The rest of the time the overcast skies and the fog made it as dark as the inside of a tunnel. This darkness occurred from 5 to 6 hours each night.

6. Aircraft Sighted.

| Date | Time (x) | Type | Position | Course | Time |
|------||------|||------|
| 8/12/42 | 1022 | Land Transport | Lat. 53-45N. | 300:2000 ft. | 165-37" |
| 8/17/42 | 0825 | U.S. Navy PAY | Lat. 27-02 N. | 000:1000 ft. | 125-44 N. |

- 2 -

MELODI (D)

— page 39 —
17. (Cont'd)
The following summary is submitted:
Days Pearl Harbor to station 9
Days on station 35
Days from station to Dutch Harbor 2
Days at Dutch Harbor 1 1/2
Days Dutch Harbor to Pearl Harbor 5 1/2
Total days 53
Total hours submerged 59 1/2

-4- NAVIGATION (3)

— page 41 —
05-10/-15-3
(TB5-102)
Serial 07

CONDITIONAL:
From: The Commander Submarine Squadron Ten.
To: The Commander Submarines, Pacific Fleet.

Subject: U.S.S. TIGER (SJ37) - First War Patrol - Comments on.

1. The TIGER's patrol covered a total of fifty-three days, of which thirty-five were spent on station.

2. The material performance of this vessel was excellent. The TIGER is deserving of credit for the excellent condition in which she returned from this patrol. A squeal in the starboard shaft at low speeds is a source of military weakness, particularly for silent running.

3. The health and endurance of personnel was excellent. No sickness other than minor ailments was ever-cancelled.

4. Of the eight contacts made, six were with the enemy. Contacts could not be developed sufficiently to detect due to unfavorable position and adverse weather conditions, namely, fog.

5. The Squadron Commander considers that this patrol would have been much more fruitful had it been conducted in a more frequented area and under more favorable weather conditions.

-1-

— page 42 —
1942
U.S.S. TRIGGER
U.S.S. TRIGGER. Report of 2nd War Patrol.
Period from September 23 to November 8, 1942.
Area 7 and 8. Operation Order No. 86-42.
PROLOGUE:
Arrived Pearl Harbor on August 18, 1942 from First War Patrol.
Commenced refit on August 19, 1942 by Navy Yard, Pearl Harbor,
Repair Department, U.S.S. SERRY, Relief Crew and Ship's Force.
Refit consisted of docking, reboiling of stern tubes to eliminate
snaff squeal; installation of 20 mm gun, removed propeller guards,
preliminary work for installation of S.J. radar, in addition to
normal refit items. Not depended, nor wiped. Sound test was conducted. Training consisted of three days and one night; ten torpedoes fired. Decided for sea December 23, 1942.

1. NARRATIVE:
September 23
0900 (VJ) Departed Pearl Harbor in company with USS FINBACK and
and CACHOLOT escorted by USS LITCHFIELD. During the
afternoon fired 8 rounds of 3" and several bursts of 20 mm, 50
calibre and 30 calibre at target streamed by LITCHFIELD. Later
LITCHFIELD dropped three depth charges for training. Made satisfactory
2000 (VJ) Escort departed, vessels proceeding independently.
Made usual training dives, etc., enroute.

September 27
0949 (Y) Arrived Midway in company with USS FINBACK and
moved to USS FULTON. Torped off fuel, fresh water,
etc. Repaired by tender to 3D radar and TBTS. Removed
softened white plastic from after trim tank.
1654 (Y) Departed Midway enroute assigned areas. Hile
enroute, in addition to normal training, made day and
night battle surface, and fired two rounds of 3" on each.

October 4
-5D radar has been giving difficulty for the past
few days.

October 5
0420 (K) (1st Contact) (1st attack)
Lat. 31-40 N, Long. 142-06 E
4000 ton Freighter - Damaged.
Sighted smoke on the starboard bow at a considerable
distance. It was the grey dawn, overcast sky, two hours before
sunrise.

FINALED
44323

— page 43 —
U.S.S. TRIGGER - Report of Second War Patrol.

October 5
0420 (K) Closed and then noticed that vessel was heading approximately for us. He looked small so manned the 20 MM, As his slightly greater size became apparent manned the 3" gun.

0439(K) Opened fire, range about 1500 yards. The target was sprayed with 20 MM. The 3" gun pointer said later he could see the target plainly and was right on. There were no splashes visible or other evidence as to where the 3" shells were going. The enemy returned the fire with a gun of about 3" calibre and machine guns. Shells and bullets could be heard whistling by, as result of his return fire and evidence of larger size than expected decided to torpedo him.

0445 (K) Ceased gunfire and changed course to bring the bow tubes to bear. Target, which was a freighter of approximately 4000 tons, now turned away and started zigging radically. Sent gun crews below. Commenced chasing the target.

0450 (K) Angle on the bow 180.

0453 (K) No, it isn't. The angle on the bow is zero and the relative speed is very fast. Too close to torpedo. He is attempting to ram. [Name] is going to avoid.

0455 (K) Target passed abeam to port distance about 50 feet opposite and parallel course. Target firing machine guns down on us. Unfortunately or perhaps fortunately our machine gun crews were below. Barely avoided him as we passed, target swinging left rapidly and so did we to keep him from striking our stern.

0500 (K) Fired torpedo tubes #7 and #8. One torpedo wake went under the target. The crew of the after torpedo room state that apparently the enemy had a range of 50 feet. They heard a rumble and a roar, and the torpedo was hit. They had made one hit.

0505 (K) Sound reported high speed screws and the Commanding Officer thought he heard a gun of larger caliber than fired thus far in the battle. Assumed that some support for the enemy had arrived, but visibility was not good and could see no other ship. Therefore, submerged. No screws heard by sound except our surface target. He was confidently lower in the water and his stack smoke greatly increased. Two torpedoes had been expended, he was damaged but would not sink. He was getting away.

0530 (K) (30 minutes before sunrise) Surface and classed him on four engines. Enemy opened up again with gunfire.

0550 (K) Saw a torpedo wake parallel to us and slightly on our port bow. The Commanding Officer crossed his fingers; of course, could not change course and therefore make the possibility of being hit a certainty. Then came the report that the T.D.C. operator had jumped the gun and caused one torpedo to be fired. Assumed that this was the wake seen. Afterwards found out that the torpedo was fired had been from a starboard tube, our course was steady, the

— page 44 —
0550 (K) wake s:en was on  thg port bow, torpedomen in the forward
(Cont'd)  rooah heard the enemy's torpedo sounding like a small reciprocating engine go down the port side. Our torpedo was well directed, however, for this TBT - TDC set-up was good and we had directed "standby".
0551 (K)  Fired #4 torpedo tube. Saw the wake go under the target. Reports from the forward room of a hit. By now planes could have reached the area as result of probable radio report, target was snarking tremendously, SD radar had been out of commisision repeatedly in the past few days, and the dawn was very light. Therefore, submerged with the enemy at a range of about 500 yards swinging toward us. The enemy passed our stern at a range of about 200 yards and dropped one depth charge. Advised at periscope depth. Target still not sinking but answering wildly and sinking.
0610 (K)  Fired one stern tube in desperation. Did not see torpedo wake. From this time tried to close him but could not.
0655 (K)  Abandoned the chase.
0750 (K)  The target's smoke did not seem to be drawing away fast enough so came to course 125 to close him again. Could see his smoke distinctly. Then there were several large puffs of smoke; then nothing. Continued in his direction until 1100 and nothing seen.
1100 (K)  Abandoned the search.
1418 (K)  Surfaced. The target was a three island freighter of about 4000 tons with a raked bow, counter stern, one stack, one mast from the forecastle and one from the poop, one pair of kingposts (geologists) from even of the forward and after well decks, gun on the forecastle. The speakers was not unlike that of the ship at which the USS CUDGEK fired five torpedoes on her second patrol without sinking her. The target had been definitely damaged and, at least, possibly sunk. This was the first action between the TNTGGER and the enemy. (See remarks).
October 8  (2nd Contact) (No Attack) Lat. 30-42 N. Long. 133-03 E.
0135 (K)  Sighted two objects, one large and one small, on the horizon dead astern at a great distance undoubtedly hull down. Change of bearing indicated that they were heading south. Connected tracking at full speed on all main engines and attempting to take position ahead. Tracking indicated that course 160, speed 15. Study of the chart indicated that they came from Bunzo Suide and were headed for the candidates; perhaps therefore of great value significance. The visibility was such that an undetected night surface attack was not considered possible, yet not light enough for night periscope attack. Decided to make periscope attack at dawn. 0409 (K)  Attained position ahead of the target(s); only one now in sight.
0600 (K)  Target not in sight. Slowed to allow target to close. Finally found the target broad on the port quarter angle

- 3 -  TECHNICAL (B)

— page 45 —
U.S.S. TRIGGER - Report of Second Far Patrol.
October 8
0600 (K) on the bow about forty-five starboard. Came to normal approach course at full speed. Could now see two ships.
0622 (K) Too light to continue on the surface. Submerged. Looking for the target.
0637 (K) Target located. Had zigged again, radical change to the right. Unable to close. Target passed at a distance of about four miles; no escort. It was a huge tanker fully loaded, bridge structure divided ship equally, stack was short and wide. Two masts, no kingposts. From study of available data, estimated 10,000 tons.
0745 (K) Surfaced when target was finally out of sight. Head full speed on all main engines to circle the target and make another attempt. Commenced to circle the A-frames with his masts just in sight. Attempted to clock his zigzag plan. It consisted of legs about five minutes long twenty and forty degrees to right and left of his base course.
1050 (K) (3rd Contact) (No Attack) Lat.28-44 N. Long.114-16 E. Plane sighted attern cutting in and out of the clouds. Continued the chase. Target now bearing normal to the base course.
1054 (K) Plane previously sighted headed for us. It was a small, high-speed plane.
Submerged, Abandoned the chase. The plane would undoubtedly advise the tanker that she was being stalked and the tanker would change course. Set course to return over the 200 miles covered during the chase. Everyone much disappointed at having lost this great chance to strike a telling blow. Set course directly toward BUNGO SUDO in the hope of catching some other ship coming this way. Decided not to radio information on tanker.
October 9 Entered assigned area having been slowed considerably 0530 (K) by the events of October 5th and 5th. Headed for OSUKI KAIKYO, "hot spot" of the area according to CUTTLEFISH. No sights for 48 hours.
October 10 Made a landfall. Turned out to be TANGA SHI'A. No 1030 (K) sights for over sixty hours. Commenced high periscope patrol close in to TOI TISAKI, patrolled track from TOI MISAKI TO ASHIGURI SAKI at night.
October 12 Commenced patrol off ARAKI 'AN. Sighted several small fishing vessels. Took picture of TOI MISAKI bearing 010 distant 3 miles. No ships in ARAKI 'AN these several days.
October 14 On surfacing headed for ASRIZURI SAKI and commenced patrol there.

ENCOURAGE (B)

— page 46 —
0000 (1) Passed through east-west line of survey buoys with colored flags. Depth of water 160 fathoms. Navy small gasoline driver. Hishig boat. Occupants typical Japanese with straw hats and 2ishish, with polices.

October 15
No ships are being sighted off JAPAN JAPAN. On surface: headed for east line to east south of SUNO BUDO entrance.

October 17 (14h contact) (2nd attack)
0511(K) Lat. 32-21 N., Long. 132-04 E.
5000 Ton. Pacific - 2km.

01h00 (1) Not sighted. No further contact.

0600 (1) Not sighted. No further contact.

0615 (1) Not sighted. No further contact.

0620 (1) Target took a deadened list to starboard, bow going down, stern coming up. Dew on, pebbles, life boats in the water.

0623 (1) Target sank for first. Another explosion. Could not locate familiar with the sound of a sinking ship.

0624 (1) Submerged and center port. Target was the coast toward 30N 50W. JAPAN

— page 47 —
1770 (C) (Cont'd)
close to the cockpit was out of the question. Recused pat-
rol up the coast.
(6th contact) (No attack, 3 in.
Lat. 32-29 N, Long 121-53 N.
sighted small plane up near 2,000 JUIDO.
Surfaced on course 045 to across the entrance of JUIDO
JUIDO with the hope of sighting a target coming out in
the afterglow.
2010 (7th contact) (7th attack)
Lat. 32-33 N, Long. 121-55 N.
Destroyer - issued, possibly damaged.
Our hours of sighting a target coming out of JUIDO
were fulfilled to a veritable, fantastic about 3 miles,
destroyer bearing 330 miles, a tremendous bow wave, sub-
merged to a deep depth, a destroyer captured a
the destroyer passed over our escort unmolested, close
and dropped a stern of depth charges to the
threat were no objects. He started several more but
turned away on about 2,000 yards, the enemy
hits. Strings of depth charges were being dropped quite
regularly but were very far away, none wasted. It was
succeedingly difficult to see through the noise. He
turned east, but he was not hit. The
angles on the bow position. The 6th contact officer
did not dare hold his fire longer, considering the
possibility of a carrier attack, fired three torpedoes
down his throat, range about 2500 yards. The first
torpedo had run about one minute three was a terrific
explosion which the Commander of the enemy was in the
direction of the nearest destroyer. The first, when
and broke over at least four times as high as the de-
sayer (no hidden) and was at the height of the
angle cleared near the Commander of the enemy. It was still
to see that the destroyer had disappeared. It was still
there but no longer on the surface. The first torpedo must
have exploded prematurely and the destroyer had
that passed through and the torpedo had
held tactical exercise, and the forward report
that a torpedo passed down the afterguard side. Finally
when he was at a range of about 1500 yards, angle on the
bow 90 point, fired one after about 15 minutes
to fire another at his stern. Could not see it due to
poor visibility. Sound reports were never heard. A few
boring. Could not see a ship any more. After a few
minutes of seeing an furious baring and nothing seen,
serves speeding up and getting closer, went to deep sub-
mergence thereby losing the initiative but probably saw-
ing the ship. Corroded cruiser tactics. He never
courses were limited to between 090 and 100 for the
based in on the 100 fathoms curve. Our battery was near-
ly exhausted for we have over an hour of full speed this
afternoon. We were continually getting heavy for we have

— page 49 —
1915 (N) 10th Contact (5th. attack) 10,000 ton loaded tanker - Ours. Lighted smoke bearing west. Jetcraft submerged approach until it was obvious that we could not close. Course was south-rlly. 1915 (N) 1915 (N) 2310 (K) 2310 (K) 2350 (

— page 50 —
2110(K) Slighted destroyer or other small fast ship coming at us from the west. Submerged. It was again either inaction or we had not been sighted for sound heard nothing was sighted through the periscope. However, we are back on the 160 line from BUNGO SUDO closing in an air patrol. Decided to remain submerged for a reasonable time.

2329(K) Surfaced.

October 24 (13th Contact) (No attack).

0824(K) Lat. 32-05 N. Long. 132-37 E.
Sighted freighter. Commenced approach, large angle on the bow. Could not close. Freighter had raked bow, counter stern; heavy pair of kinepots (goal most) forward, two masts, one stack, no walls, normal loading astime ted at 7000 tons. Course was northerly heading for BUNGO SUDO. Not far enough at sea to chase on surface.

1031(K) (14th Contact) (6th Attack).

Lat. 32-06 N. Long 132-31 E.
10,000 ton empty tanker very high in the water - damaged. Sighted large tanker zizzangerine base course about 340. "do not have any stern torpedoes left. Unable to ret a ping range.

1054(K) Fired lonitudinal spread of three torpedoes. Three hits, one seen right at his stern. Target turned away roin deep by the stern. Screws stopped. Heavy white smoke out of his after parts. Target opened up with munife from a forward gun. Range to target increasing. Afraid he may be able to get away.

1102(K) Fired our only remaining torpedo which had been saved for the "Cous de grace". The true bearing of the target was perfectly steady. No explosion at the proper time. Various small explosions being heard. Might be internal in addition to the quite regular sound of his shells landing. "Ith drew to range about 6000 yards to keep him in sight. Still well down by the stern and still afire aft; not sinking. His angle up by the bow had now increased to nearly ten degrees.

1405(K) Two light bombing planes are now circling the target and searching the area for us. "ent to 150 feet for the time being as we can do no road and will be able to look again later.

1450(K) Two depth charges or bombs at a considerable range. No screw. Probably from planes. Perhaps we have an air or oil leak; else they are being dropped to set us away. The latter is probably correct. "we can do no more road here. I'm sure that this empty tanker will not sink; too much reserve buoyancy. No use in inviting attack so remained at 150 feet clearing the area. Durine evening twilight surfaced and started home at high speed expecting to be ambushed as we are close in to BUNGO SUDO (See remarks)

2045(K) Left the area.

-9- ENCLOSURE (B)

— page 52 —
1. Weather
Weather in general was excellent. Encountered small storm just prior to 'entering' area and another storm covering a. large area when leaving.

2. Current Information.
The conditions re:ro:rted by the CUTTERWE were verified in nearly every instance. The currents ar:red vary closely with the charts and the description in the 'Japan Pilot (British) and the Translation of the Japanese Sailors' Directions. These publications were borrowed from the CUTTERWE prior to leaving Pearl Harbor and proved to be of the greatest aid in navigating the area.

Currents encountered inside the 100 fathom curve and close to the coast of KYUSHU were "inly tidal.

The strength of the KUROSHIO (Japan Stream) was found to average about 2 knots. The direction of set in the central portion of the stream averaged 0.65°curve, about 0.9°curve in south-western part, nearly due north in extreme eastern portion and almost due east when south of ASHIZUKI NMI.

4. Navigational Aids.
When close enough to the coast to observe them, the following Navigational lights were burning:

(1) TOI: ISAKI
Burning with normal characteristics but with reduced range on every occasion except one when it flashed at irregular intervals throughout the night.

(2) O SHIYA, UCHIYODA, TOKAI YAMA, NIIITSU, YOSORIYA and SHIMANOURA
Lights burning with listed characteristics and apparently with normal power.

ENCLOSURE (3)

— page 53 —
5. Vessels Sighted:

| Date | Time | Type                | Position | Course | Speed | Remarks                                                                 |
|------|------||||||
| Oct. 5 | 1042C | (K):Freighter | Lat. 31-40 N | 125    | 11     | Possibly sunk; In general similar to "Nimitz" 108.                      |
|      |      | (4000 tons)Long | 142-06 E |        |        |                                                                             |
| Oct. 8 | 0135  | (F):Tanker     | Lat. 30-42 N | 160    | 15     | Heavily loaded. Similar to "Nimitz".                                 |
|      |      | (Long)         | 133-03 E |        |        |                                                                             |
| Oct. 10 | Various | Fishing boats  | OFF TOR  |        |        |                                                                             |
|      |      | (MISAKI)        |        |        |        |                                                                             |
| Oct. 15 | Various | Fishing boats  | OFF ASTARID |        |        |                                                                             |
|      |      | (SAPID)         |        |        |        |                                                                             |
| Oct. 17 | 10541 | (K):Freighter | Lat. 32-21 N | 010    | 10     | Attack #2. Sunk. Similar to picture "Nimitz".                      |
|      |      | (5000 tons)Long | 132-04 E |        |        |                                                                             |
| Oct. 17 | 1335  | (K):Freighter | Lat. 32-28 N | 200    | 10     | Attack #3. Miss. Similar to picture "Nimitz".                      |
|      |      | (5000 tons)Long | 131-48 E |        |        |                                                                             |
| Oct. 17 | 2010  | (K):Destroyer | Lat. 32-33 N | 205    | 30     | Depth charge attack. Counter-attack by this vessel with torpedoes. |
|      |      | (Long)         | 131-55 E |        |        |                                                                             |
|      |      | (Long)         | 132-24 E |        |        |                                                                             |
| Oct. 18 | 1035  | (K):Tanker   | Lat. 31-38 N | 340    | 15     | Could not locate. Similar to our "Nimitz".                        |
|      |      | (Long)         | 132-38 E |        |        |                                                                             |
| Oct. 19 | 1302  | (K):Tanker   | Lat. 31-33 N | 340    | 15     | Could not locate. Similar to our "Nimitz".                        |
|      |      | (Long)         | 132-24 E |        |        |                                                                             |
| Oct. 20 | 1215  | (K):Tanker   | Lat. 32-00 N | 160    | 15     | Fully loaded. Enroute from BUNGO. SUIDC. Attack #5. Sunk. Similar to picture "Nimitz". |
|      |      | (Long)         | 132-35 E |        |        |                                                                             |
| Oct. 21 | 0033  | (K):Destroyer | Lat. 31-13 N | 315    | 25     | To attack by either followed.                                 |
|      |      | (Long)         | 132-50 E |        |        |                                                                             |
| Oct. 22 | 2110  | (K):Destroyer | Lat. 31-14 N | 090    | 25     |                                                                             |
|      |      | (Long)         | 132-58 E |        |        |                                                                             |
| Oct. 24 | 0824  | (K):Freighter | Lat. 32-05 N | 000    | 12     | Could not locate. Loading normal. Similar to picture "Nimitz". |
|      |      | (7000 tons)Long | 132-37 E |        |        |                                                                             |
| Oct. 24 | 1031  | (K):Tanker   | Lat. 32-06 N | 340    | 20     | Empty. Heated for BUNGO SUIDC. Three hits heard. Severly damaged. Torpedoes on board have now been expended. |
|      |      | (10000 tons)Long | 132-34 E |        |        | Similar to picture "Nimitz".                                 |
|      |      | (Long)         | 132-34 E |        |        |                                                                             |

— page 54 —
2000 ft: Plane was cutting in and out of clouds; finally headed for us. All that could be seen was that it was a small landplane like KAWASAKI 97.
: 2000 ft: Not seen sufficiently well to identify. Near BUNGO SUDO.
: 1000 ft: All crewmen for tanker damaged in Attack 46. KAWASAKI 97.
: 1000 ft: Excellent radar contact which won't from 12 to 5 miles in about 2 minutes. Plane not seen.

Date: 17:1730 (K): Small landplane
: 2000 ft: Not seen sufficiently well to identify. Near BUNGO SUDO.
: 2000 ft: Not seen sufficiently well to identify. Near BUNGO SUDO

— page 56 —
1(b)
The firing interval was excessive due to wild maneuvers of the target. The first torpedo was directed at the MOT and the second at his stern. The forward torpedo room personnel reported that the second one hit. The target was lower in the water after this attack but on an even keel.

Attack 1(c)
Again the firing interval was excessive due to wild maneuverings by the target. Both torpedoes were directed at the MOT. The wake of the second was seen to pass under the MOT and the forward room reported one hit. Two explosions were heard by the Commander-in-Chief, one of which sounded like a depth charge.

Attack 1(d)
This torpedo was wasted. However, two hits had been made and the target just would not sink and he was getting away. This torpedo was directed at the MOT but failed to hit.

Attack 2
Spread used in attack 2(a) was [NEGATIVE: text here] first torpedo at his bow, second at MOT; both hit. Attack 2(b) was made due to the inactivity of Commander Officer to get the target under. He was down by the bow but the angle was not increasing, the target's screws were still turning over and turning away. The first torpedo of Attack 2(b) was seen to miss at this point. The second went right under the MOT; no explosion.

The doctrine on this vessel is that, when we sound battle stations, two torpedoes in each and are ready and set at 6 feet, to run at 16 feet. Then we direct the number of torpedoes and the depth setting when we can. As no other instructions were given, the first two torpedoes ran at 16 feet, hit and finally sank the target. Before Attack 2(b) a better estimate of target draft was made and the depth setting increased to run at 25 feet. He was established the rule that torpedoes will still be set at 6 feet on Battle Stations but that the first will be reported as a hit to commander it.

— page 58 —
U.S.S. TRIGGER - Report of Second War Patrol.

SUMMARY OF SUBMARINE ATTACKS:

Remarks (Cont'd.)

Attack #4

This vessel was undergoing a severe depth charge attack while remaining at periscope depth with the target in view though not very distinctly. Finally the target went out and made its turn for another pass. We came around for a bow to bow shot and when the range was estimated at about 2500 yards (not possible to measure it) fired three torpedoes down his throat. The firing interval was undoubtedly less than 8 seconds for the torpedoen said that the first and second went out very close together, a personal error by torpedo firer. Approximately one minute after firing the Commanding Officer observed, and everyone heard, a terrific and long series of explosions. The water, flame and smoke were at least three times as large as the target had been. When the smoke cleared away the target was still there but broadside. Later, after more depth charging, the target was in a rather good position so fired one torpedo. Intended to fire a spread but could not see him. At that time sound reported another destroyer present. Could see nothing anywhere and, with screws reported on verious bearings, went deep.

Attack #5

Longitudinal spread; 1/4 ship's length ahead, 1/4 inside of bow, 1/4 inside of stern, 1/4 aft. therefore, 2 should have hit and two did. The target sank.

Attack #6(a)

The spread was MOT, bow and stern. Three hits reported by forwarder. Heard two myself and saw one at the stern. Attack #6(b) was the last torpedo "Coup du Grace" but missed though true bearing of target was steady and target stopped. Target was severely damaged aft.

ENCLOSURE (B)

— page 59 —
8. Enemy Anti-Submarine Measures:

The defensive measures employed by the enemy were much the same as experienced by other vessels on patrol.

The Japanese doctrine certainly appears to be that, as soon as the presence of a submarine is indicated, attempt is made to ram, depth charges are dropped and guns fired. On two occasions, once by a 1000 ton freighter (possibly Q-Ship) and once by a destroyer, the possibility exists that torpedoes were fired at us.

The enemy destroyer anti-submarine vessels near BUNGO SUDO, at least the forward well-deck destroyer there, have excellent sound equipment and are skilled depth chargers. Possession of radar by this destroyer is indicated by the speed and accuracy with which he was on us on October the 3rd. Apparently there is a shortage of anti-submarine vessels near BUNGO SUDO or our friend of the seventeenth would have had help and we would have been ambushed on surfacing on the twenty-fourth.

Tankers entering and leaving BUNGO SUDO are usually unescorted. Only once was an escort encountered on this run. However, the tankers do zigzag over at night.

The freighter encountered on October 5 may well be a Q-Ship. It was not unlike the vessel at which the GUNDEON fired five torpedoes on her second patrol. Details concerning this vessel, as encountered by us, are contained in the "Marative" and "Neikarks". Certainly the attitude of the opposing Commanding Officer was one of offense being the best defense. His ship was very manoeuvrable.

A blimp was possibly sighted on October 17 off BUNGO SUDO. It may have been a cloud.

9. Enemy Line-Sweeping Operations:

None encountered.

ENCLOSURE (5)

— page 60 —
10. Major Defects Experienced.

(A) Engineering:

(a) #2 main generator out of commission on account of a fire. At 1955, October 7, 1942, while running at 14 knots in a moderate sea (on the starboard quarter), received an unusually large amount of water into the main induction. #2 main generator connection block, directly beneath main induction inboard valve, was drenched, short circuited, and arced. Fire was immediately extinguished, and generator was stopped and placed out of commission. Generator leads and connection block were burned, two lugs wore fused and voltmeter leads were severed. Lead sheathing was melted off adjacent battery cables. Generator back in commission 0245, October 8th.

This casualty has been reported as U.S.S. TRIGGER, report of machinery derangement #7-42. It is stressed that the weather was moderate. Heavy spray, not grown on, entered the induction. The present location of the forward engines room main induction hull valve constitutes a serious military hazard. This is the second time this particular casualty has been experienced by this vessel.

In the future, the forward engine room induction will be closed and air for #1 and #2 main and #1 auxiliary engines will be received through the after engine room, whenever the condition of the weather is such that the entrance of spray into the main induction can be anticipated. This procedure is an expedient born of necessity, and is unsatisfactory for the following reasons:

1. Necessitates wiring open the following passages:
   - Engine rooms, thus decreasing compartmentation and as well constituting a hazard that the fastenings might carry away and the door close.

2. Insufficient air for all six engines. Necessitates taking air suction through control room at high speed.

3. Increased possibility of smoking.

Recruited action is not considered practicable in this (DRUM) class of submarines, since moving the forward main induction hull valve to the center of the forward engine room would involve extensive hull alterations. Mitigating action, involving more adequate drip protection for #2 generator connection block is requested.

In passing, attention is invited to the fact that the valves in question were placed in the immediately preceding class of submarines (TUNA) that this particular casualty could not have occurred.

(b) Pump room out of commission because power panel grounded out. At about 0700, October 31, while passing through a large low pressure area with moderate wind and high seas the ship encountered an unusually heavy sea. Green water poured over the top of the bridge, filled the covered section, and poured into the conning tower. About 200 gallons found its way into the control room, depth of water there being about six inches. Circuit breakers on the forward battery distribution board immediately went. All forward auxiliary power was temporarily lost; the following pieces of equipment being out; gyro follow-up, hyraulic plant, trim and drain pumps, turbo blow, both air compressors, #1 periscope hoist, radio

— page 61 —
10. Major Defects Experienced (Cont'd)
(A) Engineering:
(b) (Cont'd.) antenna mast hoist, refrigerating and air conditioning plants.
The hydraulic plant and trim pump were regained when the forward battery power circuit breaker was put back in, and bilges were pumped. Water was removed from gyro binnacle casing and follow-up system was put back in commission in 1/2 hours. The remaining equipment was out of commission for 1 1/2 hours, because the pump room power distribution panel (FB 205) had flooded and was grounded out.
This panel which feeds power to almost all pump room auxiliaries is located adjacent to #2 periscope well to port, just beneath the control room deck. The control room deck is pierced with a hole about 1/2 square foot in area just abaft #2 periscope well through which run numerous cables. There is a 1/2 inch coaming around this hole. When the water ran around the control room it slopped into the hole and fell directly upon panel FB 205, grounding it.
Work request has been submitted to build an 8 inch coaming around the hole, and to cover it with a sheet metal drip proof cover.
In order to prevent a recurrence of this casualty, the conning tower hatch was kept on the latch for the duration of the heavy weather. It is worthy of note that, although a large quantity of water entered the main induction with the same wave, the after conning room, which was in use, suffered no casualty.

(B) Hull:
(a) Trim System - Enroute to Midway it was necessary to pull the trim pump strainer every few minutes when pumping compensating water through the trim system. Upon arrival at Midway the variable ballast tanks were pumped dry and inspected. The variable tank coating had collected in a congealed clay like form in the bottom of after trim tank to a depth of about eighteen inches and in the other variable tanks to a much less degree. It was assumed that the "Barrier Kote", Mare Island paint formula #144, with which these tanks were internally coated, had come in contact with oil from Pearl Harbor when compensating there. The worst of it was bailed out with buckets, and we were not bothered with this difficulty during the remainder of the patrol.
While on patrol it was noted that pressure would build up on the trim system, and that the variable tanks gained about 1000 lbs. of water per hour. No leaks could be found, but upon completion of the patrol a careful investigation will be conducted to determine where the trim system is leaking.
(b) Negative tank vent gasket - On September 24th, during an emergency drill, negative tank was blown down to 4000 lbs. of water and the flood valve closed at 120 feet. When the tank was vented to release this pressure the vent gasket was blown. The gasket was reinstalled with rubber cement. On October 15th at a depth of 70 feet, negative tank was blown down to 4000 lbs. of water. When the gasket was opened to reflood the tank the pressure blew out the vent gasket.

— page 62 —
10. Major Defects Experienced (Cont'd).

(B) Hull

(b) (Cont'd.) As the negative flood valve was inoperative at this time, the stop valves in the negative vent lines were closed. The vent gasket was recovered and reinstalled with rubber cement. During the remainder of the patrol as an added precaution, the stop valves were kept closed.

(c) Negative tank flood valve - When the ship went to deep submerged during the depth charge attack on October 17th, negative tank was blown to about 10,000 lbs. of water and the flood valve closed at 200 feet. The pressure was not vented from the tank at this time due to the excessive noise that such action would create. When bringing the ship back to periscope depth, in order to release the pressure in the tank, the flood valve was opened at 190 feet. At the time of opening a very sharp crack was heard. After that a pressure could not be maintained in the tank, and for the remainder of the patrol negative tank was kept completely flooded both on the surface and submerged. Upon return from patrol an inspection will be made to determine whether the gasket was blown or whether the valve operating gear was damaged.

(d) Steering gear - Throughout the entire patrol a steady stream of water leaked through the conning tower steering control shaft bearing casting. It is believed that numerous sand holes in the casting are causing it to leak. The leaks are becoming progressively worse and are so extensive that no longer considered to be merely nuisance leaks.

(e) Bow plane rigging gear - When rigging in the bow planes on September 26, and again on October 27, the shore pins in the rigging shaft gave way. Pins were replaced by sending men down on deck.

(f) Radio antenna trunk - Enroute to area the antenna trunk completely flooded at periscope depth putting it out of commission for the remainder of the patrol. As the antenna trunk has been flooded out several times previously, it is strongly recommended that due consideration be given to using another type of gasket than the present rubber.

ENCLOSURE (B)

— page 64 —
12 Sound Conditions and Density Layers (Cont'd.):

Taperature readings to a depth of 250 feet were taken in the southern and northern part of the area. A definite density layer was found to exist at 190 feet. During the depth charging of October 17th, the destroyer was never successful in locating us after we had submerged to 250 feet, although his pinging on 24 KOS was still quite audible.

13 Health and Habitability:

The health of the officers and crew in general was excellent. Two men received from the relief crew of Squadron Ton had to be transferred to the Fulton at Midway on the way to station - one for chronic seasickness, and the other for reason of being temporarily unsuited for submarine duty. Replacements were furnished by the Fulton relief crew.

One case of "middle ear" infection, one case of granulated eye lid, and a reoccurrence of hemorrhoids following operation at Naval Hospital, Pearl Harbor were the only ailments other than the ordinary ones of constipation, etc.

Owing to the very efficient performance of the air en-criterion equipment the ship was very comfortable at all times except when running silent.

ENCLOSURE (B)

— page 65 —
14 and 15. Miles and Fuel:
Enroute Station
On Station
Return Trip

Fuel Expended
4259
1613
3983

Total
9855
97,906

Note: 1. U.S. torpedoes and fuel expended on route station were about 400 miles and 5500 gallons in excess of normal due to diver-sight of October 5 and 8; estimated that two days on station were lost due to these diversions. Increased fuel expendi-ture on return trip was due to heavy weather encountered.

16. Factors of Endurance Remaining:
TORPEDOES
FUEL
PROVISIONS (days)
FRESH WATER PERSONNEL (days)
None
18759
30
Unlimited
30

17. What Factor of Endurance, if any, caused ending of this patrol:
Torpedoes expended.

ENCLOSURE (B)

— page 66 —
18. Remarks.
1st Attack.
The Commanding Officer regrets having expended five torpedoes and yet not effected positive destruction of the target. The target was either damaged or could feign damage for its draft was increased by at least three feet during the action. He may have been a 3-Ship with some type of reverse compassing belt with which to preemptively detonate torpedoes. In that case his gun should have been larger. Perhaps our 20 1M wiped it out. The enemy Captain was not an ordinary tramp steamer man, but a proficient warrior. His ship was for some unencumberable than is expected of a freighter. The Commanding Officer cannot state definitively that the target did or did not fire a torpedo at us. The possibility exists. The Commanding Officer did not suspect any enemy in a second time raid. The chase because he was convinced at the time that a submarine trap had nearly been sprung. If we could report torpedo's attack would not rush in swinging with both arms, but could stow out, track and observe the target carefully and then go in for one attack, came or torpedoes, probably undetected and more careful and decisive. The Commanding Officer was too anxious to come to a prime with the enemy and due to being precipitous underexpected the target's size.

2d Attack.
The Commanding Officer is at a loss to assign a reason for this attack's failure to result in another sinking. The 3C sat-up was excellent though the range of 1000 yards was excessive. Could not, however, have gotten in further for full speed was necessary to just hold our own.

3th Attack.
This failure of the bow to bow shot was very disappointing for, if the explosion had not occurred prematurely, the destroyer could not have avoided destruction. The explosion must have been a severe shock to the destroyer's crew. It is certain that the initiative away from our opponent and, until we went out, he never again showed his initial dash. The destroyer perhaps sustained some damage. Improper operation of our negatives took flood the damaged it. Therefore, from now on, we have no operative tank.

5th Attack.
The attack to ran has been encountered twice now on this patrol. Had we fired bow tubes at this tanker he might have damaged us by ramming for we were just under 60 feet when he passed our track. Without negative we just ran at perilous depth.

Our estimate of the situation had been correct and this 160 line from BUNGO SUTDO is a boulevard.

The Commanding Officer knew that it was his duty to observe the actual sinking if possible. However, with the results of no negative tank fresh in his mind, and high speed screws reported by sound near the tanker close aboard, it was taking more than a calculated risk to return to periscope depth immediately. Moreover, it was a needless risk for we were maintaining sound contact. The target had been in clear view when we submerged.

-24-

— page 67 —
18. REARAGE.
5th attack (Cont'd)
Thirty minutes later we fired. Sound has not been able to hear the target until the range had closed to about 5000 yards. After firing the target's screws were hard distinctly and rerorted close aboard. The target was not in range. About five minutes after we fired, the target dropped a depth charge. From the time the target was in range, the target was in range. The target was

— page 68 —
6th Attack

Why was the traffic to BUNGO SUTTO not diverted after our attack on October 20th?
Can it be possible that the tanker did not even have time to report its disaster?
Expected on surfacing to be ambushed. CD reported the area at high speed charging batteries at the highest possible rate in anticipation of a bad night. Nothing is sighted. Can it be that they haven't enough anti-nubmarine vessels to do anything? Can it be our destroyer friend of the seventeenth required some refitting of material or nerves.
Considered seriously radiation the submarine in the adjacent area to come down to help get the tanker under. Decided against it for the submarine probably could not arrive in time (we would have had to wait until dark), he would find an impossible "hot spot" and our radiation would dislose our exact position.
It is reported that when we found the BUNGO SUTTO torpedo carrier only eight torpedoes remained on board, of which however, good use was made.
Tankers apparently make 12 turns per knot.

The Commanding Officer takes this opportunity, and the Patrol Report as a vehicle of expression, to commend and thank his officers, Lieutenant Schneider, Cmdr. Mann, Beach, Long and Garvey, and his entire crew, for their efforts and skill on this patrol. A submarine commanding officer on war patrol on the enemy's coast could not possibly ask for better assistance nor a sturdier ship. The efforts of the Navi-stor, Lieutenant W.C. Schneider, the Diving Officer and Engineer, Lieutenant S.H. Gilmer, and the T.D.C. operator, Lieutenant S.C. Mann were particularly appreciated.

ENCLOSURE (B)

— page 69 —
1. This was the first command patrol for the present commanding officer. Aside from damage inflicted, the assigned area was properly developed, all contacts pushed home and much valuable information obtained on the tanker route from Bungo. Nice hits were obtained out of the twenty-four torpedoes fired. This is considered good shooting and it is difficult to understand why more sinkings did not result.

2. ATTACKS.

First Attack.
On this attack two torpedoes with an interval of 30", two torpedoes with an interval of 20" and one single torpedo were fired. With such long firing intervals the results obtained are essentially the same as if five separate attacks were made and past experience has shown that it is a needless expenditure of torpedoes to fire single shots at a moving target in the war zone. Had TRIGGER waited for a favorable position and then fired a proper spread of three torpedoes the results would probably have been different. The one possible torpedo hit is in doubt as the ability of a 4000 ton freighter to maneuver as this one did after being hit is questionable.

Second Attack.
With screws of the target still turning over and little indication of sinking at the end of fifteen minutes, the decision to fire an additional torpedo was sound. Such a shot, however, should be fired in the most deliberate manner on a favorable track and at a proper range.

It is to be noted that Lieutenant Mann conducted this approach.

Third Attack.
With the Mark II or Mark III T.D.C., spreads using a speed variation or an angle offset is considered superior to a longitudinal spread.

-1- ENCLOSURE (A)

— page 70 —
5-43/A16-3
SUBMAFINE DIVISION FORTY-THREE
Serial (082)
Care of Fleet Post Office,
San Francisco, California,
November 13, 1942.

CONFIDENTIAL
Subject: U.S.S. TRIGGER - Second War Patrol,
Comment on:

Fourth Attack.
It is considered that this attack was coolly and
aggressively carried out and it is to be regretted that a pre-
mature explosion prevented a well deserved sinking.

Fifth attack.
A well executed attack with proper use of the sound
being made to obtain a correct range just prior to firing. It is
not believed that a heavily loaded tanker which has received two
torpedo hits on a 90 degree track at a range of 900 yards can
possibly turn and ram a submarine which is at periscope depth.
On the other hand, it is most difficult to size up the situation
correctly through a periscope at night, and the commanding officer
must be the sole judge of what maneuver he considers necessary.

Sixth Attack
An excellent attack. The ability of this tanker
to reach port after receiving three torpedo hits, one in the stern
where the large engine room compartment is located, is gravely
questioned.

3. The various major defects noted on patrol will be
properly investigated and remedied. It is estimated that an
overhaul of three weeks will be necessary and that TRIGGER will
be ready for next patrol in four weeks.

4. On this patrol a 5000 ton freighter was sunk and
two 10000 ton tankers either sunk or seriously damaged. An
aggressive spirit was evident throughout the patrol and the
commanding officer is to be commended on his well deserved
success.

-2-
ENCLOSURE (A)

— page 71 —
1/2-10/A16-3(5) SUBMARINE FORCE, PACIFIC FLEET
Serial 01331
Care of Fleet Post Office,
San Francisco, California,
November 24, 1942.

CONTRIBUTIAL
CONSULTANT
CO. SUBMARINE PATROL NO. 96.
U.S.S. TRIGGER - SECOND WAR PATROL.

From: The Commander Submarine Force, Pacific Fleet.
To: Submarine Force, Pacific Fleet.

Subject: U.S.S. TRIGGER (SS237) - Report of Second War Patrol.

Enclosures: (A) Comsubdiv 43 Conf 1tr F35-43/A16-3
    Serial 082 of November 13, 1942.
    (B) Copy of Subject War Patrol.

1. In this, the second war patrol of the U.S.S. TRIGGER and the first patrol of the present commanding officer, the area assigned was well covered and the commanding officer, particularly in the attack on the 4,000 ton freighter on 5 October, and the dual with the destroyer on 17 October, displayed a commendable spirit of aggressiveness. While some wild shooting was engaged in, the percentage of torpedo hits obtained, although disappointing, was on a par with average submarine patrol performance to date. With this aggressive spirit, plus additional training and the experience gained on this patrol, the TRIGGER should render a good account of herself on future missions.

2. The Commander Submarine Force, Pacific Fleet, concurs with the remarks of Commander Submarines Division Forty-Three regarding the various attacks.

3. The commanding officer and personnel of the TRIGGER are congratulated on the damage they inflicted upon the enemy which is credited as follows:

| SINK | 1 Freighter | 5,000 tons | 14 DEC 14 1942 |
|------||||
|      | DAUGHED     |              |                |
| 1    | Freighter   | 4,000 tons   |                |
| 1    | Tanker      | 10,000 tons  |                |
| 1    | Tanker      | 10,100 tons  |                |
|      | Total       | 24,100 tons  |                |

(Authorisation and distribution see following page)

R. H. ENGLISH.

— page 72 —
11/1/1942
Serial 01331
Care of Fleet Post Office,
San Francisco, California,
November 24, 1942

CONFIDENTIAL
CONSULAR PATROL REPORT NO. 96.
U.S.S. TRIGGER - SECOND AAR PATROL.

Subject: U.S.S. TRIGGER (SS237) - Report of Second
    War Patrol.

DISTRIBUTION
(350N-42)
List III: SS
Special:
21(5), ENS(5), ZL(5),
Consultant (2), XJ(1),
Consubosweepac (2).

E. R. S. INBURNE,
Flag Secretary.

— page 74 —
U.S.S. TRIGGER - Report of Third War Patrol.

December 11
Heavy seas. Making good only 8 knots.

December 12
Storms moderated. Making good 12 knots.

December 13
Rough again; 8 knots.

December 16
0410(K) (1st Contact) (No Attack)
Lat. 35-05 N. Long. 147-48 E.
(Preghior on Station Patrol)
Sighted ship bearing 010 on the horizon. As we are to make an undetected mine patrol it is essential that no warning be given of our approach to the Japanese Coast. Turned away to maintain contact undetected, and then develop the contact submerged during the day. The ship sighted appears from tracking not to be going consistently in any direction.

0454(K) (2nd Contact) (No Attack)
Approach it developed that the ship was a medium sized freighter engaged in station patrol. She was changing course frequently and in all directions so as to maintain station. She appeared to have some special apparatus high amidships. It is probably an aircraft warning vessel. Decided that it is destruction was not the immediate objective but that the undetected approach to INUBO SAKI and the successful laying of the mine plants so remain. Took scovral photographs of the ship and cleared the vicinity.

December 18
0558(K) (2nd Contact) (No Attack)
Mission is Reconnaissance.
Lat. 35-33 N. Long. 140-57 E.
Sighted freighter to the south of INUBO SAKI on nor.nor.south course. She passed INUBO SAKI close aboard on about the 20 fathom curve.

December 19
1510(K) (3rd Contact) (No Attack)
Mission is Reconnaissance.
Lat. 35-38 N. Long. 140-55 E.
Sighted freighter just to the south of INUBO SAKI on north. north. course. She also passed INUBO SAKI close aboard on about the 20 fathom curve.

- 2 -

ENCLOSURE (A)

— page 75 —
U.S.S. THUGG - Report of Third War Patrol.

December 20
0430(K) (4th Contact)(No Attack)
Mission is Reconnaissance.
Lat. 35-42 N. Long. 1440-58 E.
Sighted freighter abr.ast of INUBO SAKI on southerly course, again near the 20 fathom curve.
In site of the heavy seas and the full moon, decided to conclude the reconnaissance and to lay the mine plants this date. The proximity of INUBO SAKI to the preceptively positions of the mine fields precluded laying them in the daylight. It being only two days until full moon, laying them at night while on the surface was out of question. Therefore decided to lay them while submerged in the moonlight as soon after sunset as a reasonable chance would be in. Decided to lay the northern field first and then the southern field, each to be preponderant to the courses on which the ships passing INUBO SAKI appear red to be.
2058(K) Submerged preparatory to laying the mine fields.
2220(K) Commenced laying mine fields.
2243(K) Completed laying the first field.
2303(K) Commenced laying the second mine field.
2318(K) 1st. 35-45 N. Long. 1440-55 E.
2nd. 35-45 N. Long. 1440-55 E

— page 76 —
333(K) (Cont'd).
KIRKYU, HIROKAWA, KANSAI, KASII, CANBERRA, KYUSU, SADO, the average tonnage of which is 8400. She was making about 15 knots. The escort vessel appeared to be a motor torpedo boat. The presence of this escort, the first of the vessels sighted off INUBO SAKI with an escort, indicated the high value of the ship. Decided that there would probably be anti-submarine vessels in the vicinity at once so commenced retirement into deep water. We were in fifteen fathoms of water with a considerable distance to go before deep submergence would be possible.

2351(K) Another violent explosion. Nothing seen. Possibly another mine caught someone, perhaps the escort vessel.

December 21
COO5(K) Scrowe picked up by sound. Nothing seen. Went as deep as we could and rigged for silent running and depth charge attack. Evasion tactics successful. The enemy knows there was a submarine present and may not suspect the mine field yet.

0047(K) Surfaced and cleared the area at high speed.

0055(K) Sighted a huge cloud of smoke from the mine fields.

0615(K) On station on course line 312 to NOJIMA SAKI to intercept, traffic from the south.

1830(K) Surfaced and headed for NOJIMA SAKI at high speed to be off this point close in for the coming day's observation.

2300(K) Commenced patrol off NOJIMA SAKI.

December 22
1336(K) (6th Contact) (2nd Attack)
Lt. 34-52 N. Long. 139-49 E.
5000 ton freighter - sunk.
Sighted smoke up in IRAC SAIDO. As vessel approached, made it out to be a lighter zigzagging on about 60 degree legs. This vessel was in position to attack regardless of whether the destination of the target is north or southeast.

1333(K) Fired a spread of 7 torpedoes on 90 track just as she steadied on a loft zig, The spread used was speed spread using this diagram recently issued by ConsubPac; one torpedo at least to hit. One torpedo hit was made just forward of the bridge. She immediately started down by the bow, tooting her whistle and turning away. We were at that time in shallow water about two miles off-shore bearing 240 from NOJIMA SAKI with the current setting us on; therefore about to go around, so turned

— page 77 —
1333(K) (cont'd)
to seaward. Now approximately 6 seaplanes were sighted near NOJIM. SAKI, one of them right over the target. When the target had completed its turn to head back for port, her main deck forward was awash and her screws were nearly out of water, turning rapidly. It looked as if the one hit would suffice to sink the target. However, the position was nearly perfect for a stern shot and it was now or near the range was opening as the target was headed for port.

: 1342(K) Fire one stern shot at 2500 yards track 100'port. We were positive that the planes would see the wake and that there should be anti-submarine vessels here if anywhere in the Empire. The torpedo hit. The target was well under by now. The final plunge was not seen but her sinking was nevertheless certain even without the additional hit. The planes dropped several bombs but no anti-submarine vessels bothered us. Cleared the area to the southward. The freighter had had a crack bow, counter stern, two shallow wells, one tall slender stack, two combination masts and kingposts. She had dazzle camouflage. Her appearance was similar to that of the SYOTO MARI (Page 216) of 5139-5426 tons.

: 2102(K) (7th Contact) (No Attack)
Anti-Submarine Vessel. Sighted a small vessel on an unidentified type, apparently not with draft enough for torpedoing but probably outguinning us, bearing 060, distant about 5 miles. Having a low battery and being rather close to NOJIMA SAKI, turned away. The chances were on. Left one main on charges and rode full on three runs (18 knots). Our adversary was closing slowly and steadily. We changed course gradually to avoid the islands and yet make our purser see that the whole way while we were getting in a chrage. In the full moon and smooth sea the visibility was excellent. Expecta the arrival of seaplanes at any moment.

: 2152(K) Having a rather good battery charge in, put the fourth main on propulsion. Gradually pulled away. Had we not been able to get away would have assumed our enemy to have been big enough for torpedoing and would have taken a shot at him in the moonlight at periscope depth after diving. His appearance, however, had been that of small size. By midnight the chase was over. Turned to the eastward to cover the southwestern approaches to NOJIMA SAKI. The past few days had been full of action.

- 5 - ENCLOSURE (A)

— page 78 —
1532(K) Observation of IUBO 3 J1.
    Signed sleeve bearing 315. Commended approach but definitely such as to be south of our mine fields which now acted as defensive mine fields.
    (8th Contact) (3rd attack).
    Last: 35-45 N. Long. 140-55 E.
    5000 ton freighter - Damage or sunk by mines.
    The smoke has become four columns of smoke approaching IUBO SAI. We were approaching for an atlantic south of IUBO SAI. At this instant, however, the lead- ing ship, mine had reached the exact bearing of our mine planes, commenced smoking at least five times as great as before and the three other ships scattered to the northward. The smoke off our mine plants lasted only a few minutes while the other three columns of smoke disappeared to the northward. Consider that a freighter of at least 5000 tons was damaged if not sunk by this mine.
    Surfaced an patrolled off the east line through IUBO to catch the other three ships trying to get by outboard.
    Signed a searchlight on IUBO SAI searching the water in the vicinity of that point. Also sighted several other searchlights further down the coast searching the sky or engaged in exercises. This has become a usual practice.
    Having covered the area east of IUBO SAI for the other three frigates decided to proceed to observe for them off HULLA SAI during the coming day.

December 25.
Prior to patrol of the western approaches decided to observe off IUBO SAI while our mine plants were still new. Therefore, proceeded to the vicinity of IUBO SAI to seaward of the mine plant to intercept traffic being routed outside. This necessitated going a few miles outside of our area but considered that the situation warranted it.

December 26.
Observation of IUBO 3 J1.
Signed sleeve bearing 315. Commended approach but definitely such as to be south of our mine fields which now acted as defensive mine fields.
(8th Contact) (3rd attack).
Last: 35-45 N. Long. 140-55 E.
5000 ton freighter - Damage or sunk by mines.
The smoke has become four columns of smoke approaching IUBO SAI. We were approaching for an atlantic south of IUBO SAI. At this instant, however, the lead- ing ship, mine had reached the exact bearing of our mine planes, commenced smoking at least five times as great as before and the three other ships scattered to the northward. The smoke off our mine plants lasted only a few minutes while the other three columns of smoke disappeared to the northward. Consider that a freighter of at least 5000 tons was damaged if not sunk by this mine.
Surfaced an patrolled off the east line through IUBO to catch the other three ships trying to get by outboard.
Signed a searchlight on IUBO SAI searching the water in the vicinity of that point. Also sighted several other searchlights further down the coast searching the sky or engaged in exercises. This has become a usual practice.
Having covered the area east of IUBO SAI for the other three frigates decided to proceed to observe for them off HULLA SAI during the coming day.

December 26-31.
Station patrol covering southern and southeastern approaches to SAI J1. During this period, as during the entire period in the patrol area, the weather was a succession of storms, rather violent but usually of short duration. Within a period of a few hours the sea would change from moderate to mountainous and back to moderate again and with a visibility from excellent to noxt to nothing. Other incident of this

- 6 -

MILITARY (A)

— page 80 —
1735(K) An explosion similar to a depth charge at about 1000 yards. It was probably an internal explosion for, though the Japanese do not come ashore to attempt to frighten us, they do so at once and not 5 minutes later.

: 1749(K) Target no longer in sight through the periscope. Sur- faced to give chase and insure the target's destruc- tion. The target could then be seen broad on the starboard bow distant about 1000 yards. Her stern was high out of water and with about twothirths of her length under and still going down. Commenced ap. 1900. The full speed which, however, in the high seas was only about ten knots.

: 1752(K) Sighted a destroyer bearing exactly opposite from that of the target, distant about 4000 yards coming directly at us and fast. Submerge amm attemp to see her in order to get in an attack. In the high seas she could not be seen. She passed our stern amm con- tinued in the direction of the last target. Her pre- sence in the immediate vicinity must mean that she had been an escort vessel and had just turned back when we attacked.

: 1807(K) Sound could no longer hear the destroyer's screws. Surfaced. Nothing in sight. In the condition in which the target was last seen, her stern being the only part visible amm, at the time of diving, nearly all of her length under, it is extremely doubtful if the ship could have been surprised even in the calmest of seas. In the mountainous seas prevail- ing her survival is considered completely impossible. She was a large freighter with two combination masts and pairs of kingposts and two additional pails of kingposts, a composited superstructure, one squat stack, racked bow. She had a cargo of about ten planes on her stern. Her speed was fifteen knots, no smoke. The picture nearest to her appearance is that of the GOGYU HATU (page 49) of 8500 tons, possibly a sea- plane tender as reported. This was perhaps the last blow struck at the enemy during the old year.

- 1943 -

January 1:
Enroute the western approaches to SAGAMI NADA. Crossed the southern approaches during today.

- 8- ENGLISH (A)

— page 81 —
1. U.S.S. TRIGGER - Report of "Third War Patrol.
2. January 2.
   - On station off IRO SAKI to intercept traffic from two southwesterly aircraft. On surface, the IRO SAKI is in a position to intercept the convoy.
   - It is noted that the Japanese are using a new anti-submarine weapon, high powered searchlights from pro-minent points and along the shore to sweep over the adjacent waters.
3. January 3.
   - Station patrol off IRO SAKI. Have a persistent 120 volt battery ground in the after battery. On surfacing this date charged only the forward battery and sought deep and unconfined water to the east of IZU. On to clear up this battery trouble, we have had this difficulty repeatedly during this patrol.
4. January 4.
   - Patrol off the north-south line from NOCIMA SAKI. On surfacing heavy seas caused flooding difficulties, proceeding to the sea to the south of IRIWO SAKI. Enemy ground has been cleared.
5. January 6.
   - Numerous small vessels like TULA boats in sight headed toward IRIWO SAKI, possibly mine sweepers.
   - 1638 (K) Sighted a considerable amount of smoke near IRIWO SAKI. Commenced closing.
   - 1722 (K) (11th Contact) (no attack)
   - Lat. 35-34 N, long. 139-51 E.
   - Sighted smoke bearing 305 close in to the coast. Unable to close. In today's position it is next to impossible to see ships or smoke with the coast as a background. This ship goes so close in that they cannot be reached even if such an attempt is made. Apparently special marks have been built on the shoreline to assist in navigation extremely close in. Evidence of this.
6. January 7.
   - 1428 (K) (12th Contact) (no attack)
   - Lat. 34-50 N, long. 139-51 E.
   - Sighted smoke bearing 305 close in to the coast. Unable to close. In today's position it is next to impossible to see ships or smoke with the coast as a background. This ship goes so close in that they cannot be reached even if such an attempt is made. Apparently special marks have been built on the shoreline to assist in navigation extremely close in. Evidence of this.
7. January 8.
   - 9. ENCLOSURE (A)

— page 82 —
1830(K) Sighted a patrol vessel off the left tangent of NOJIMA. SIGHTED a patrol vessel off the left tangent of NOJ

— page 83 —
1337(K) One explosion like a depth charge rather close. No ships seen sufficiently close. It was possibly from an aircraft but one explosion indicate that more probably it was an internal explosion in the destroyer. In any event she sank r-r- rapidly now, still on an even keel.

1350(K) The destroyer sank, the last per se men being the bow which had been folded upward. The fishing vessels around the destroyer were still in sight. Her normal displacement was 13,15 tons. The position of h-ving 5 we are now in the unfortunate position of h-ving 5 torpedoes aft and only one forward.

January 11
1. Patrol off south-eastern approaches to S.&J.I. H.D.A. Depth control at periscope depth again nearly insoluble.

January 12
1. Reposition of yesteray with depth control, if possible, even worse.

January 13-14
1. Still very rough. Position uncertain. Working back, however, toward H.O.H.I.S. S.H.I.
1620(K) Sighted patrol plane on westerly course.

January 15
1. Storm has subsides. Ship is in a reasonably good patrol position south-east of H.O.H.I.S. S.H.I.
1130(K) Sighted patrol plane on southerly course.
1641(K) (List: Course) (No. attack)
Lat. 34-45 N. long. 159-59 E.
Frontal: Port or Destroyer.
Sighted most of a patrol boat or destroyer bearing west course northerly. Unable to close for attack. Upon surfacing this datastarted for !DIDLY, time on station completed.

January 17
1. Spent the forenoon searching the area in which the station patrol vessel was seen while enroute station; unsuccessful.

January 22
1. Arrived H.D.W.Y. for refit.

- 11 - ENCLOSURE (..)

— page 87 —
2000 tt: Just after firing torpedoes at a freighter six seaplanes were sighted in the immediate vicinity. They were single engine monoplanes.

: 1/14/43 : 1620(K) : Patrol plane : About 45 miles SE of Nojima Sakii : Westerly : 4000 ft : Ordinary 2 engine Navy Patrol plane.

: 1/15/43 : 1130(K) : ditto : About 15 miles ESE of Nojima Sakii : Southerly : 4000 ft : ditto

— page 88 —
8. Enemy Anti-Submarine Measures:

The anti-submarine measures reported by vessels which have previously had this area appeared still to be in effect. No echo ranging however was heard at any time. Extremely bad weather probably accounted for this vessel's failure to bring depth charges. On the few really good days there were many small boats all over the area, particularly within a radius of thirty miles of NUTIA SAIL and SMILE.

The traffic which can do so huge the coast so utterly closes that a sub-rigged submarine simply cannot get in. On December 22 off NUTIA SAIL was vessel, in order to attack a freighter, came close to running around. It is probable that there are sharks about a mile apart the entire coast line between NUTIA SAIL and IUNO SAIL to enable vessels to keep as close in as possible. At least lights so located were seen at night.

A now anti-submarine resource encountered was the use of searchlights. Almost nightly high powered searchlights swept the sky and the water. These searchlights were located at IUNO SAIL, numerous points from IUNO SAIL to NUTIA SAIL, at NUTIA SAIL (at least a 36°), on SMILE and at HOOK. Valuable targets are escorted. An escort vessel similar to a motor torpedo boat was seen on one occasion. There is an escort vessel in the area which has the general profile of a destroyer but which we ran away from at twenty knots.

9. Enemy Line-Sweeping Activities:

On January 6, while this vessel was to the south of IUNO SAIL numerous small vessels like tuna boats passed enroute IUNO SAIL. Later large quantities of smoke were seen near IUNO SAIL. These boats may have been magnetic mines swept working on the plants made by this vessel. Their activities, however, could not be seen.

10. Major Defects Experienced:

(A) Engineering:

The performance of all equipment was excellent throughout the patrol. Extremely heavy weather caused the only difficulties worthy of notice and pressed home a minor lesson in seamanship. Battery grounds were the greatest source of trouble and on five occasions grounds of 100 to 200 volts were experienced. This

— page 89 —
10. (Cont'd)

in spite of watering to a level of minus five. Hard work, as usual, eliminated or reduced the grounds to a safe limit. The worst cessation required complete removal of after battery ventilation ducts, however, the flexibility of the plant proved itself and the batteries were charged separately.

Being "pooped" once a petrol seems to be in order, and once again the poor design of main induction, coming tower, and control room were duly impressed upon us by loss of all pump room power.

The delays of six inches of water on the control room deck effectively ruined its way, as usual, down cables into the vital power panel so well easy set between the periscope wells. Four and one half hours later we were back to normal ready for the next one. In this regard it must be stated that this disastrous "pooping" occurred just after surfacing and on all other occasions the corning tower hatch was closed in time and the expedient of running with the forward certain room induction closed required only the after engine room throttleman to wear oil skins.

The minor flooding was so accidentally was a glissade on the return trip. It is heavy following sea we contactedly put two engines on and let her ride. The spacing of waves plus our speed was such that we continually wondered if the next one would lift our tail or keep coming at its threatening height. After a miserable day laboring at 12 knots and slicing back to 6 or 9 we, at a third engine on and our speed leaped to a phenomenal 15.5 knots accompanied by the pleasurable sensation of the flying trapeze. Note! By actual check the fuel consumption per engine per hour was reduced.

(B) Full: None

(C) Sd Radar:

(a) Found we were unable to use the radar in surfacing after running silent as the water circuit is energized from the ship's lighting circuit (D.C.). The circuit was revised so as to energize the heaters from the I.C. panel but found on operating that the Sd caused interference with other gear energized from the I.C. panel.

(b) Thwartion blower motor bearing burned out - no means of lubricating.

(c) An error of 110- yards in the range step was caused by the cover of the time delay circuit shorting out the con-! denser. Removed the cover and error disappeared.

- 17 - ENCLOSURE (A)

— page 90 —
10 Cont'd.

(C) 3J Radar (Cont'd.)

(d) Antenna feeder unit was not installed properly causing the bearing to wear excessively. Upon failure of the radar found that the cavity was filled with bearing filings and that the tuning plungers were black from arcing. After cleaning the radar functioned properly.

11. Radio Reception:

Excellent. No difficulties were experienced. Copying NFS submerged proved to be unsuccessful. The depth of the loop from the surface twenty feet. Last message received: GULP 16015 Last message sent: INSIPID 201002

Radar:

The performance of the 3D radar was excellent. Using it for night navigation proved invaluable. The general performance of the 3D radar was disappointing. Errors were small and extremely hard to identify from the grass. Maximum range obtained was thirty-five hundred yards; several tirs were within ten miles of land (height 2000 feet) and the radar failed to make contact. During our last training period and while on patrol, it was noted whenever the target was put astern contact was lost. It is believed that the beam is being deflected as it crosses over the periscope housing. For defects experienced see "Major Defects".

12. Sound conditions and Density Layers:

Fair to poor. Average range three thousand yards. No temperature gradients were noted. Usual prevalent noises such as cracking were heard.

13. Health and Habitability:

The health of the crew, except for a very few colds, was excellent. The habitability was also excellent. The food was adequate and well prepared.

- 18 -

ENCLOSURE (A)

— page 91 —
14 and 15. Miles and Fuel:
Enroute Station
On Station
Return from Station
Total
Miles Steamed
3582
3265
2279
9126
Fuel Expended
38,169
26,363
24,350
88,882

16. Factors of Endurance Remaining:
Torpedoes
Fuel
Provisions (days)
Fresh Water
Personnel (days)
6
15,516 gal
20
Unlimited
See below.

Remarks: With regard to Personnel Endurance Remaining it is considered that in view of the bad weather this patrol was just a bit too long. Too many considerations are involved to actually estimate. If the following refit period were to be rather long, more time could be spent on station but with reduced efficiency. This reduced efficiency, however, depends entirely on the amount of activity. A patrol in good weather, with a target to shoot at at least once a week, were successful in the attacks, and without the expected depth charging, can be far longer than one in which any of these features is missing.

17. What Factor of Endurance, if any, caused ending of this patrol:
Time on station completed.

Again the Commanding Officer desires to make known his command of the officers, Lieutenant Commander Schneider, Lieutenant Gimbler, Lann and Beach, Lieutenant (jg) Long and Garvey, and the entire crew of the TRIGGER for the way they have performed their duties on this patrol. Their spirit and ability are exactly the type we need in the submarine force in order to continue to sink and damage the ships of the enemy.

- 19 - ENCLOSURE (A)

— page 92 —
155-102/A16-3
SUBMARINE DIVISION 102
Serial 09
Care of Fleet Post Office,
San Francisco, California,
February 2, 1943.

From: The Commander Submarine Division ONE HUNDRED TWO.
To: The Commander Submarine Force, Pacific Fleet.

Subject: U.S.S. TRIGGER (SS237) - Third War Patrol;
Comments on.

1. The Third War Patrol of the TRIGGER was conducted in a most intelligent, determined and skillful manner. Six hits with ten torpedoes into three ships which resulted in three sinkings sets a new high standard for torpedo control and torpedo performance.

2. The commanding officer's decision to hold his torpedo fire against the large cargo vessel on the night December twentieth was recorded with this unusual experience of watching the vessel blow up in the main field just planted.

3. It is unfortunate that the 35 Radar performance was so erratic and poor. It is certain that, more corrects and sinkings would have resulted had it operated properly. The urgent need for specially-trained radar maintenance personnel in the complement of submarines is again indicated. The reported phenomena of the operation of 35 radar on targets set stern has not been noted by the originator on radar attacks conducted by many different submarines during training operations. Particular note of this feature will be made during training operations in the immediate future and, if found to exist, will be reported.

4. MATERIAL:
TRIGGER refit will be accomplished by the Submarine Repair Unit at Midway.

5. The Commanding Officer, Officers and Crew of TRIGGER are congratulated upon the remarkable success of this patrol.

— page 94 —
9/2/42-10/A16-3(5)/ SUBMARINE FORCE, PACIFIC FLEET A (12)
Serial 0138
COST/INITIAL
CONSUMPTION PATROL REPORT NO. 128
U.S.S. TRIGGER - THIRD WAR PATROL.
From: The Commander Submarine Force, Pacific Fleet.
To: Submarine Force, Pacific Fleet.
Subject: U.S.S. TRIGGER (SS237) - Report of Third War Patrol.
Enclosure: (A) Copy of subject report with comments thereon.
1. This third war patrol of the TRIGGER extended from December 3, 1942, to January 22, 1943. Twenty-nine of the total of fifty days were spent in the patrol area off the coast of Japan.
2. This was an aggressive, well conducted patrol. Six hits, out of ten torpedoes fired, were made, for the fine score of 60%. Each ship attacked was sunk.
3. Mention Mark 12 mines were laid, and one of those was observed to sink a freighter within the hour of its being laid.
4. The 3rd radar was inoperative for a large part of the patrol, and this, undoubtedly, reduced the number of contacts.
5. The use of inch powered searchlights from prominent points along the coast of Japan, to sweep the sea areas, is probably an anti-submarine measure designed to discourage submarines from closing the coast sufficiently to get at the very close-in traffic.

6. The Commanding Officer, officers and crew are congratulated on their fine performance. The TRIGGER is credited with having inflicted the following damage:

SUNK
1 - Freighter --- 5,426 tons
1 - Freighter --- 8,500 tons
1 - Destroyer, Minesweeper Class --- 1,345 tons
Total 15,271 tons

— page 95 —
1-10/A16-3(5)/ SUBMARINE FORCE, PACIFIC FLEET A (12) Caro of Fleet Post Office, San Francisco, California, February 1, 1943. CONFIRMATION Subject: U.S.S. TRIGGER (SS237) - Report of Third War Patrol. SUPPLY LINE LAID BY TRIGGER 1 - Freighter 8,400 tons Total Sunk 23,671 tons.

Insufficient evidence exists to credit any damage by mine field on December 26.

J. H. BROWN, JR., Acting.

DISTRIBUTION
[10-43]
List III, SS
Social:
Pl(5), EH(5), ZI(5),
Consubstant (2), X3(1),
Consubswospac (2),
Subschool, NL (2).

E. R. S. INBURNE,
Flag Secretary.

— page 96 —
12-10/A16-3(5)/(16) SUBMARINE FORCE, PACIFIC FLEET 1d

Serial 0486
PROCEEDING
C/O SUBPAC PATROL REPORT NO. 165
U.S.S. TRIGGER - FOURTH WAR PATROL.

From: The Commander Submarine Force, Pacific Fleet.
To: Submarine Force, Pacific Fleet.

Subject: U.S.S. TRIGGER (SS237) - Report of Fourth War Patrol.

Enclosure: (A) Copy of Subject War Patrol Report.
(B) Consubron 10 Conf. 1tr. FG5-10/All6-3(FB5-102)
Serial 050 of April 8, 1943.
(C) Consubdiv 102 Conf. 1tr. FB5-102/All6-3 Serial 040
of April 12, 1943.

1. The TRIGGER fourth war patrol was carried out aggressively but
   unfortunately was not too productive. The area was covered very effectively
   as the TRIGGER was able to patrol on the surface a good deal of the time.

2. The performance of the SB Radar was excellent and it is of in-
   terest to note that, on one occasion, a plane was picked up at a distance of
   23 miles. It is unfortunate that the performance of the SU Radar was so un-
   reliable. Every effort shall be taken to correct these deficiencies prior
   to departure for the next patrol.

3. Once again torpedo performance leaves a lot to be desired. Of
   six torpedoes, three that were fired from 700 yards range, apparently ran
   straight under the target, and of the other three, two sank at the start of
   the run while one ran circular right over the engine room of the TRIGGER.

4. The freighter hit on March 15, 1943, was probably sunk but
   because of insufficient evidence, only damage can be credited.

5. The Commander Submarine Force, Pacific Fleet, congratulates
   the Commanding Officer, officers and crew of the TRIGGER for its aggressive
   and efficient patrol, during which they inflicted the following damage to
   the enemy:

DAMAGED

1. Freighter (KORYU MARU class) - 7,072 tons.
2. Freighter (LONDON MARU class) - 7,191 tons.
3. Freighter (LSUKA MARU class) - 7,530 tons.

TOTAL: 21,793 tons.

Distribution and authentication:
on following page
J. H. BRONN, Jr.,
Acting.

— page 97 —
1d
FF12-10/116-3(5)/(16) SUBMARINE FORCE, PACIFIC FLEET
Serial 0486
CONFIDENTIAL
CONSUBPAC PATROL REPORT NO. 165
U.S.S. TRIGGER - FOURTH WAR PATROL
Subject: U.S.S. TRIGGER (SS237) - Report of Fourth War Patrol.
DISTRIBUTION:
(1M-43)
List III, SS
Special:
PI(5), EN3(5), Z1(5),
Consubjacent (2), X3(1),
Subschool, NL (2),
Comtaskfor 72 (2),
Consubron 50 (2),
Comscope (2),
Cinclent (2),
Comtaskfor 16 (1).

E. R. SWINBURNE,
Flag Secretary.

— page 98 —
1. NARRATIVE
February 13
Underway from Midway. While enroute area the usual training dive made for battle problems. Estilo surface and training in gunny was made.

February 19
Sloop to one engine opened to arrive on station for special assignment.

February 20
1805(K)
(1st contact) (no attack)
Lat, 15-12N, Long, 156-02 E.
Unknown type of ship.
Sighted masts of a ship dead ahead. Submerged. Keste not in sight. Made observations with increasing length of periscope cut. Nothing in sight.

1821 (K)
Surfaced. Target not in sight. In spite of all of our efforts for the next twenty hours the target was not again seen. Undoubtedly the Officer of the Deck dived too soon but the target came into view rapidly and he exercised his judgment. He found no found with this.

February 22
Station patrol, submerged during daylight, on the Truk to Empire Track.
Proceeding to alternate area authorized for use by this vessel for about one week.

February 23
2045 (K)
Sighted a flare and one lookout reported an object on the horizon bearing 150. Investigation revealed nothing there.

February 26
0430 (K)
Entered Area. As we were unable to reach PALU for today's operations took position on the PALU - 15N/AK course line, 140. From Midway: 11 days, 21 1/2 hours - 346 miles.

- 1 -

ENCLOSURE (i)

— page 100 —
0648 (K)
(Continued)
due to bad visibility and the rapidity with which the action developed but she had the general lines of a small destroyer.
Sighted mast of a ship. Commenced approach. Finally made it out to be two anti-submarine vessels like PC boats probably searching for us as they patrolled back and forth. Did not seek action with them. However, at 1253, when one of them turned in our direction, radio ready the tubes in order to take shots at them if they had detected us and were heading in for attack. They turned away again soon and at 1610 disappeared.

March 2
Off the channel between the islands at the southwestern part of YALAU.
Sighted three vessels sailing to PC boats on northwesterly course distant about 4 miles.

March 3
Off YALALALI Entrance.
During the day sighted several small fishing boats and patrol boats, when in question started approaches.
(4th contact) (no attack)
Oct. 7-12 M. Long. 134-24 E.
Three small frigates scoured by one small destroyer or other small escort vessel.
Sighted smoke on YALALALI Entrance. Observed it to note change in bearing. No change until 1730. Could now make out three columns of smoke, the bearing changing slowly to the left. Started approach.
Targets made out to be three frigates each of about 4000 tons, with one escort in the van, heading down the coast. Angle on the bow during the approach now less than 60 degrees, usually about 90 degrees. Unhitch to close. Kept in sight until about one-half hour before the time to surface.
Surfaced and started retiring search curve with best estimate of enemy's course 140, speed 8.
Secured from search and proceeded down 140 course line at 10 knot so as to be ahead of them for daylight. The targets were now again seen. Obviously the assumptions upon which the retiring search curve was based were erroneous. They probably went south or southwest after dark. The visibility was not, however, good during the search.

March 4
(5th contact) (2nd Attack)
Oct. 5-11 N. Long. 136-00 E.
Medium sized freighter - Missed.
Sighted smoke on the horizon bearing 131. Observed bearing to be nearly constant. Submerged and started approach. When the ship could be seen the angle on the bow was quite small. The change of bearing was however, in the opposite direction from that given by initial observations. Therefore the target was zigging but apparently not radically as we are accustomed to in observing Japanese ships close in to port.

- 3 -

ENCLOSURE (4)

— page 102 —
2030 (continued)
The search problem was successful for at this time the smoke was again picked up. Commenced tracking and circling the target to get into attack position. The visibility was definitely in the target's favor and our silhouette is too big.

2248 (K)
In the narrows small clouds on the horizon and locking into the low ocean, the target was lost to sight. Headed just ahead of its last bearing. We had by this time nearly reached the target's beam.

2257 (K)
Target noncentrically in sight. We were approaching at high speed. After a few moments the target was again lost. In spite of all of our efforts for the next two hours at high speed the target was never again seen. *ts type unknown. Course about 300 speed about 14 knots.

March 15
1035 (K)
(Eth contact) (3rd and 4th cttacks)
Lat. 0-00 N, Long. 145-00 E.
Convoy of 5 freighters with 2 escorts. One 7000 ton freighter probably sunk. One 7000 ton freighter damaged.
Picked up smoke on the horizon bearing 103. Commenced approach.
Turned out to be a convoy of two columns, 2 freighters in the right hand column and three in left. There was an escort, small destroyer or other type, on each outboard bow. The convoy was zigzagging with escorts patrolling station. We worked into position ahead in order to get to bottom the columns. Enemy ships were successful.

1215 (K)
Pired three stern tubes at the locking ship in the right hand column at 1600 yards 90 port track. Two hits. While these torpedoes were on the way got out on to the loading ship if the left hand column. The last zig had placed the columns in echelon so that the angle on the bow on our new target was 10 degrees starboard, relative bearing 300 and at a range of 2000 yards. The first firing, due to smooth sea, disclosed our position. Our new target headed for us. There was not time for us to turn.

1217 (K)
Pired three bow tubes at stern angle on the bow range 700 yards, gyro angles about 45 degrees. Used normal dispersion as the spread. Two hits. Went deep on firing to avoid the target. The escorts were after us with depth charges instantly, alternating listing and dropping. The sea was smooth and sound conditions excellent so could not at the time come up to take a lock. During the quiet periods the sounds associated with the breaking up and sinking of a ship were hot in the direction of our first target.

1420 (K)
Holding in sound. Came to periscope depth. Nothing in sight.
1437 (K)
Depth charges at a distance. Nothing in sight, assured they were from planes. Those distant explosions continued for the next hour.

1515 (K)
Sighted smoke on the horizon, Stcrted approach. Its bearing remains constant.

1705 (K)
Could now see a ship's masts. Continued the approach subarrogad. The now target was a ship which looked like our earlier second target the one at which we have fired and hit twice at 700 yards near angle on the bow. Alongside of her and on the far side and sticking out astern was the smaller ship resembling the freighter which had been third ship in the left hand column.

- 5 -

ENCLOSURE (A)

— page 103 —
1. U.S.S. TRIGGER - Report of Fourth War Petrol.
2. March 15 (continued)
3. 1705 (E)
4. 2142 (K)
5. 2201 (K)
6. March 17
7. 0127 (K)
8. 0207 (K)
9. 0622 (K)
10. 0820 (K)
11. 1227 (K)
12. 1316 (K)

---

**Subject:** U.S.S. TRIGGER - Report of Fourth War Petrol.

**March 15 (continued)**
1. This smaller ship was furnishing buoyancy and propulsion; spool about 2 knots, course 190. The pair was being protected by two small destroyer or corvettes. Continued the approach.
2. Fired 3 bow tubes at 700 yards 90 part track to run at 15 feet, apparently the torpedoes did not get up to the torpedo! loads in time, Scud tracked them straight on the torpedo! bearing. Irradiate secnets starting running around but apparently did not know where to look. It was bright moonlight. No reversed course and took position for stern shots. Possibly no look back too close but no turned and reversed course at one-third speed at striking was sufficient. The torpedo is believed that the range at firing was sufficient. The torpedoes, in any event, did not get up to the torpedo's local depth.
3. Fired three stern shots at 1100 yards 100 part track to run at 15 feet. The only one sound heard on circles; ran right over our engine room. The conning officer's confidence in himself and his weapons was so shaken that he considered further action by this vessel against this torpedo futile. After the secnets gave up, surfaced carried contact report. No wave not able to get any st.i.t.n to respond to our calls and therefore sought it blind on 2 frequencies.
4. The ship probably sank had the appearance of the HORNY MUR (page 162) of 6666-7072 tons. The ship damaged, the one at which 6 more torpedoes were fired, was similar to the LONDON MUR (page 20) of 7191 tons. Our reasons for believing that the first one sank is that we are not with two torpedoes, the usual crackling sounds associated with a ship sinking were heard very distinctly, she was not in sight when we got a look, both secnets stayed with the other ship. This latter fact, is rather impressive.

---

**March 17**
1. 0127 (K)
2. 0207 (K)
3. 0622 (K)
4. 0820 (K)
5. 1227 (K)
6. 1316 (K)

---

**Enclosure (L)**

— page 104 —
1316 (K) (Cont'd)
In spite of all of our tracking the targets' true bearing entered
immediately to decrease and continued to do so in spite of our
pulling full speed on normal approach between all absorbtions.
From the time the ships could be seen the angle on the bow was
never less than about 40 degrees. The convoy could now be seen
to consist of 6 frigicopters and one escort. Finally they started
zigging our way but not enough nor soon enough nearly tantalizing.
The last ship passed at about 3000 yards range 110 track. Having
already missed one of those three patrol, hold our fire, as such
as only the smoke of the convoy was visible, surfaced and started
circling again at high speed.
Position aimed again attained. Slowed to keep contact and
watch the change of true bearing. Suddenly it started to rain.
Contact was lost and in spite of all our efforts not regained.
Scanned all night. No contact report sent because we do not know
where they went.
We are now so low on fuel that, considering 105 reserve, we
can just reach Mayday en one cargo. Sont message that for that
reason we are leaving area on the 21st.

March 18 (2/3/46) (13th Attack)
Let, 3-44 N, 1.1g, 144-12 P. Convoy of 4 frigicopters. Made
one torpedo hit in the leader, 700 tonner. Sighted smoke. Con-
nected tracking and circling.
(13th Contact) (No Attack)
Lat. 3-44 N, 1.1g, 1.4-08 E. One large freighter. Avoided
as we are busy. Sighted, on our way out of rain squalls, a freighter
(about 8000 tons) came on the berth nearly 90, relative bearing nearly
abear, close enough for us to see nearly down to his main deck.
As we were already circling the convoy we ignored this vessel.
She challenged us, sending "NO!" with a light but we did nothing.
Submerged and commenced approach.
Fired a spread of three torpedoes at the leader (a 7000
tonner) 95 port track 1200 yards. One hit. She listed over to
port about 10 degrees, stopped and the other three ships commenced
circling her. All of them dropped depth charges and fired guns
at our periscope. Soon, and before we could get into position to
fire our two remaining torpedoes (stern tubes) they were all fur
again on the way at not much reduced speed. The one hit had been
a detonation of low order. The target listed, slowed, corrected
her list and was surprisingly seen back in formation. Our target
now occupied third place in the column. Did not give chase because
we could not even afford the fuel used on this chase. Also pur-
suit is rather futile with 2 stern torpedoes left and one of these
always flooded.

- 7 -

ENCLOSURE (A)

— page 105 —
20
1A10 (K) (Cont'd)
Sent contact report and resumed course for home. The enemy
of 4 freighters in one column unescorted. The leader was hit with
one torpedo. Her appearance was like the ASUKA MARU (page 184)
of 7530 tons.

March 21
1235 (K)
Left Area ---
arrived Midway twice days from Area --- 2903 miles.
Fueled sufficiently to proceed to Pearl.

April 1
Arrival Midway twice days from Area --- 2903 miles.
Fueled sufficiently to proceed to Pearl.

April 2
Deported Midway.

April 6
Arrived Pearl Harbor.

— page 107 —
5. Vessel: U.S.S. THUGGER - Report of Fourth War Patrol. Jk

| Date | Type | Unknown | Position | Course | Speed | Remarks |
|------|------||||||
| 2/27/43 | 1805(K) | Unknown | 15-12N | Unknown | Unknown | --- |
|      |      |         | 15-02N |          |        |         |
|      |      |         | 8500 ft | Entering | Malkani | 14 knots. --- |
| 3/7/43 | 0502(K) | 4/S vessel | 6-5/4N | 13-12N | 7-12N | We were sighted by this vessel at dawn, driven down depth charged. |
| 3/7/43 | 1700(K) | 3 firettores with one escort | 7-12N | Probably | 8 knots | Subsequent search, problem unsuccessful. |
| 3/7/43 | 1600(K) | 7000 ton freighter | 5-4/4N | 3-2N | 320 | 12 knots | Enroute Palao. |
| 3/7/43 | 0902(K) | Tanker | 13-12N | 360 | 100 | 17 knots. |
| 3/12/43 | 1850(K) | Unknown | 2 Cdr. | about 300 | 100 | 14 knots |
| 3/7/43 | 1035(K) | Convoy of 5 proj. | 13-12N | 300 | 10 knots | One prob. sunk. |
| 3/7/43 | 0127(K) | Convoy of 6 proj. | 13-12N | 120 | 10 knots | Lost contact |
| 3/7/43 | 0820(K) | Convoy of 5 proj. | 13-12N | Unknown | Unknown | Tracking contact #9 so excluded. |
| 3/7/43 | 1227(K) | Convoy of 5 proj. | 13-12N | Unknown | Unknown | |
| 3/29/43 | 0555(K) | Convoy of 4 proj. | 13-12N | 140 | 10 knots | One 7000 tonner damaged. |
| 3/29/43 | 1220(K) | One freighter | 13-12N | 140 | 10 knots | Tracking contact #12 as advised. |

6. Aircraft sighted:
   - None.

— page 108 —
1. CONFIDENTIAL
Subject: U.S.S. TRIGGER - Report of Fourth War Patrol.

SUBTARY OF SUBMARINE ATTACKS

Attack #1 #2 #3a
Date 2/27/43 3/14/43 3/15/43
Location (Lat.Long) 7-10N,134-32E 5-41N,136-00E 0-00, 145-00E
Torpedoes Fired 4' 3 3
on Each Attack
Hits 0 0 2
Number
Sunk (Tonnage) 0 0 --
Number Damaged 1 - 7072 ton
or Probably Sunk 0 0
Type of Target 8500 ton Frt. 7000 ton Frt. freighter
Range 1500
Yards 3000 1500 1600
Periscope Depth Yes Yes Yes
Surface Night --
Deep Submergence --
Estimated Draft
of Target 20 ft. 20 ft. 20 ft.
Torpedo Depth
Setting (to run at) 10 ft. 10 ft. 15 ft.
Bow or Stern Shot Bow Bow Stern
Track Angle 110 3 100 S 90P
Gyro Angle 0 0 0
Estimate Speed Target 14 12 10
Firing Interval 8 sec. 8 sec. 8 sec
Spread-Amount and KinSpeed=1 knot. Speed=2 knots. Speed - 2 knots
REMARKS: Attack #1: Shot became unfavorable to a zig zag way.
Considered still reasonable. Torpedoes were detected
enroute and avoided. Torpedo performance apparently
perfect except too visible. ENCLOSURE (A)

- 11 -

— page 110 —
U.S.S. TRIGGER - Report of Fourth War Patrol.

Summary of Submarine Attacks (Cont'd):

Attack #2:

Lack of perfection in set up due to rain squalls. Convinced that the set up was such that, with the speed spread used, the target was either hit or the torpedo, or more than one, which ran erratic was the one which should have hit. The commanding officer does not know for certain the cause of the "Block-buster" but is rather inclined to the opinion that it was our own circular run torpedo going off at the end of its run. Torpedo performance at least one circular run.

Attack #3(a):

Two hits. Torpedo performance apparently perfect. Target probably sunk.

Attack #3(b):

Two hits. Torpedo performance apparently perfect. Target damaged.

Attack #4(c):

Torpedo ran under the target. Could not possibly have been a miss in deflection; 2 knot target.

Attack #4(b):

Two torpedoes apparently did not run at all. One torpedo ran circular.

Attack #5:

One hit. Torpedo performance apparently perfect. Target damaged. Two stern torpedoes remaining, one of which always floods.

General Comments:

"Torpedo performance was definitely poor on this patrol. The detonations have a very clear echo-corrupted to those heard at the same ranges and tracks on a video playback.

During patrol, the routine check of torpedoes in tubes made ready and then not fired silenced at least one flooded torpedo on nearly every occasion.

-13- ENCLOSURE (a)

— page 111 —
8. Enemy Anti-Submarine Measures:

Unless the violent explosions experienced five to ten minutes after firing on two occasions near PALAU were our own circular run torpedoes detonating over the ship at the end of their run, the Japanese have some accurate method of placing heavy bombs or depth charges near the ship either by aircraft or throwers. Next to the detonation of a ship exploding, these were the most violent this vessel has experienced.

Anti-Submarine patrols are constantly on the job outside of Hickkel Entrance to PALAU. All sorts of small type were seen. The Japanese have in these areas an anti-submarine vessel, not only in use as patrol vessel and escort off PALAU, but as escort vessels for convoys which have the lines of a small destroyer or the TORCH class torpedo boat. They carry a gun of about 3" caliber, reach the same depth as a dozen depth charges. Apparently they have found gear because they stop to listen. Few of them did any pinging. Their depth charging patrolmen were not impressive but this is in comparison with these, not on previous patrols in the Empire from cruisers and destroyers. These escorts are difficult to see during torpedo approach, the only saving feature being their single man. During daylight the escorts patrol ahead and on the bows; in the column of merchant ships on the out-bored bows are if two escorts.

Area is not effectively patrolled by enemy planes. This vessel stayed on the surface during daylight and never sighted a plane. There was no evidence of air coverage for convoys in this area except in one doubtful instance.

Convoys use such zigzag plans that a base course indicated by tracking for two hours is not necessarily correct but may be considerably in error. This makes determination of the time to start the unescorted approach not at all easy. Our large silhouette does not make it any easier. At twelve thousand yards with 3d radar just keeping contact the enemy escorts could see us and yet be invisible to us, the escorts then being at about 6000 yds.

9. Enemy Mine-Sweeping Activities:

Have your encountered.

- 14 - ENCLOSURES (L)

— page 112 —
10. Major Defects Experienced:

(A) Engineering:

Just prior to departure on War Patrol while #2 auxiliary engine was being run during a battery charge, it was noticed that the water level of the fresh water cooling system was dropping, as evidence by the cyanarion tank sight glass. The charge was completed before the loss of water resumed serious proportions, and subsequent investigation disclosed a phthol in the exhaust nozzle of the engine. The nozzle was braced by the repair force and the ship left for patrol. After the nozzle cooled it was found that the leak had increased. The nozzle was subsequently braced four times and silver soldered once by the Ship's Force, each time unsuccessfully, the crack merely extending in each case. Finally lead solder was used, which stuck to the brass used in brazing, and the leak stopped. The rate of gyrotl and two coats of insulating varnish were applied on the water side of the nozzle, and the piece successfully withstood 25 lbs, pressure. Engine back in commission February 23, 1943.

(B) Hull:

Negative Tank Flood Valve. On February 17, 1943, while at a depth of 100 ft, and with the hydraulic plant running, negative tank flood valve failed to open by power. Flood valve was then opened and closed by hand, and another unsuccessful attempt was made at this depth to operate the flooded valve by power. Came to periscope depth and found operation of flood valve by power to be normal, down to a depth of seventy feet. Below seventy feet hydraulic pressure was not sufficient to operate flooded valve, March 15, 1943 while at periscope depth, operation of negative tank flooded valve by power again failed. No opportunity at this time to experiment with operation of valve, but some time later on returning to periscope depth found operation of the flooded valve to be normal.

— page 113 —
1. Radio Reception:

Reception in general was excellent. However, it was necessary, with few exceptions to carry NHM Focr Schedules on high frequency was exorcised on 26.1 KCS. Relocation on 8370 KCS was also guarded when possible. Having only one high frequency receiver (RLI-5) capable of receiving both Relocation and NHM, Relocation could only be guarded between NHM's first and second, and second and third submarine schedules, and at times when NHM was sending a long one not addressed to the trigger.

The following submerged radio reception data is obtained on return from area:

| Date | Time | Distance from | Depth (Kcal) | Frequency | Maxium Strength | Maximum Signal Strength | Effort not shown relative to carrier of Focr changed |
|------|------|||||||
| 3/28/43 | 0500 | GMT 2100 Mi. | 55-60° | Low | 0 | 090 | --- |
| 3/29/43 | 0300 | GMT 1900 Mi. | 55-60° | Low | 3 | 090 | --- |
| 3/30/43 | 0700 | GMT 1600 Mi. | 55° | Low | 1 | 185 | --- |
| 3/31/43 | 0430 | GMT 1440 Mi. | 53-55° | Low | 2 | 188 | --- |
| 3/31/43 | --- | --- | --- | --- | --- | --- | --- |
| 4/1/43 | 0430 | GMT 1200 Mi. | 52-53° | Low | 3 | 155 | --- |
| 4/3/43 | 0300 | GMT 810 Mi. | 53-55° | Low | 5 at 53° | 5 at 55° | Same effects as noted on 31st |
| 4/3/43 | 0300 | GMT 480 Mi. | 55-60° | Low | 5 at 55° | 5 at 60° | Same effects as noted on 31st |
| 4/5/43 | 0330 | GMT 160 Mi. | 60-66° | Low | 5 at 60° | 5 at 65° | Same as previously. |
| 4/5/43 | 0330 | GMT 160 Mi. | 60-66° | Low | 5 at 65° | 5 at 70° | Same as previously. |

Last (erial sent): No. 56, Date and time group 290800
Last (erial received): No. 56, Date and time group 060700

— page 114 —
11. Radio Reception (Cont'd):

SD Radar:

Excellent. On March 23, a plane was nocked up at a range of twenty-three miles and tracked in to seventeen miles. On March 29, a plane was picked up at twenty miles, closing in rapidly. A plane was sighted two minutes later by one of the lookouts; contact not verified.

SJ Radar:

During the TRIGGER's 550 hours of SJ operation, a constant lack of sensitivity or a limited maximum range has been experienced.

This lack of sensitivity was first noted when SJ was installed at Pearl Harbor, yet the Western Electric engineers were unable to increase the signal strength comparable to other units. The SJ radar's performance continues to be poor.

Upon our return to Midway, after our first patrol with the SJ radar, which, in regards to SJ operations was very disappointing, contact was made on Midway at a maximum range of 9,000 yards (average range at which other units make this contact is 20,000 Yards). During our refit at Midway all transmitter tubes were removed and the oscillator converter and antenna were returned.

During this patrol, SJ contact was made after sight contact on a convoy. The maximum range to which the targets could be tracked was 10,000 yards.

It is believed that in order to make this SJ installation effective, the transmitter receiver and the IF section of the range indicator should be removed.

12. Sound Conditions and Density Layers:

Sound conditions were excellent. Sounds were picked up at a maximum range of 12,000 yards.

There were no density layers noted.

13. Health and Habitability:

In general the health of the crew was excellent although more head colds than usual were experienced in the beginning of the patrol. Only two men were incapacitated for duty during the patrol, one for a crushed finger for 3 days and another for Tonsillitis Acute for 2 days. The usual number of cases of constipation were experienced.

Habitability was excellent. Even in the vicinity of the equator, the air conditioning plant was able to keep the ship reasonably cool. The only uncomfortable moments were experienced while running silent and, fortunately these were few.

- 17 -

ENCLOSURE (A)

— page 115 —
14. and 15. Miles and Fuel:

| Mileage | Fuel | Total |
||------|-------|
| 5,101  | 10   | 15,000 |

| Mileage | Fuel | Total |
||------|-------|
| 1,046  | 10   | 11,000 |

17. What Factor of Endurance, if any, caused ending of this patrol:
   - Expenditure of Fuel

18. Remarks:
   - This patrol has apparently established the fact that HALAKAL Entrance to PALAU is in use for convoys and has ended, if any was necessary, to the evidence of PALAU being an important terminal which must be covered constantly
   - Also that there is considerable traffic between PALAU and RABALU. Targets on that route prohibited much investigation of the quantity of traffic between PALAU and WENAK although our sc and target was on that track.

— page 118 —
1. The Commander Submarine Division ONE HUNDRED TWO.
To: The Commander Submarine Force, Iacifle-Fleet.

Subject: T.S.S. TRIGGER - Fourth War Patrol; Comments on.

1. The Fourth War Patrol of the Trigger covered a period of sixty two days which included two days at Midway enroute to and from the assigned area and twenty nine days in the area. Ten days were spent enroute at slow speed from the assigned area to Midway. Fuel expenditure necessitated the slow speed return from the area.

2. Comments on Attacks.

Attack No. 1. It appears that the enemy must have suspected the presence of Trigger, either by plane observation or by a flashing sight of the periscope wake, to have caused a 90° zigzag at a range of 4000 yards. It is not believed that the Japanese had any more radical than our own. The spread between first and fourth torpedoes (total coverage) was slightly in excess of 600 feet at each attack. This is considered to be reasonable and should have proved in the unner ordinary circumstances. The torpedo run, however, was slightly more than two minutes and carried detection no doubt, as it was only a few minutes after the attack. It was a bombardment which the commander officer recognized and no criticism can be made of his decision to fire.

Attack No. 2. Attack data was poor due to reduced visibility. The probable was in excess of that estimated in which case the spread at every track would be excessive. Spread in such cases should be applied by using different points of aim. For each torpedo and should cover at least 15 target lengths.

Attack No. 3 and 4. This was a well executed initial approach and attack. The firing position attained was perfect. It is unfortunate that the follow-up on the cripple was accompanied by sporadic torpedo performance. While there undoubtedly were many features of the situation which encouraged the commanding officer to abandon the attack, in retrospect it appears that the foresook a golden opportunity to sink two ships in one more attack.

Attack No. 5. It appears that the explosive force of the hit in this salvo left something to be desired. First reports on Torpex performance, however, is encouraging and there is promise that the type of failure experienced in this attack soon may be just an unpleasant memory. The spread employed in this attack (300 feet between torpedoes at enemy track) appears to be excessive in view of the seven-hour approach during which enemy speed must have been known within narrow limits.

-1- ENCLOSURE (C)

— page 119 —
PB5-102/A16-3
Serial (040)
COSTITUTIONAL
Subject: U.S.S. TRIGGER - Fourth Air Patrol; Comments on.

3. Although this patrol was aggressively conducted, the results were somewhat disappointing. Poor torpedo and explosive performance must bear their share of responsibility for the mediocre results of this patrol. Trigger had excellent torpedo performance with the same personnel on Second Patrol.

4. Material.
Trigger was in excellent material condition upon return from patrol. Normal refit, including a short docking period, will prepare her for the next patrol. Refit will be accomplished by Sperry.

5. The commanding officer, officers and crew of Trigger are congratulated upon the damage done to the enemy.

-2- INCLOSURE (C)

— page 120 —
U.S.S. TRIGGER - Report of Fifth War Patrol.

Period from April 30, 1943 to June 22, 1943.

Area: Operation Order No. 68-43.

PROLOGUE:
Arrived Pearl Harbor on April 6, 1943 from Fourth War Patrol. Commenced refit on April 7, 1943 by U.S.S. SPARRY and Division 102 Relief Crew. In addition to normal items, the refit included moving the three inch gun forward, cutting down the forward part of the bridge structure and installation of a second twenty millimeter gun forward of the bridge. Not deepened, degaussing not calibrated, sound test not made. Dry-docked to clean ship's bottom. Training consisted of three days and one night, deadliness for sea April 29, 1943.

1. NARRATIVE:
April 30, 1943
1300 (V) Departed Pearl Harbor on enemy mine speed.
Sample, Life Magazine 'Air Correspondent (Artist) was on board as a passenger to lndway.

May 4
Arrived lndway. Topped off fuel. submarine Base there made minor repairs; big job repairs to Hydraulic System. (See "Major Defects").

May 5
0900 (Y) Departed lndway at two enemy speed.

May 6
Omitted from the calendar due to crossing the International Date Line. Enroute assigned area the sea was rough, the weather a succession of storms.

May 8
Casualty to #4 main engine. See "Major Defects". The ultimate result was that from this time on #4 was only one-half of an engine.

May 12
(1st Contact) (No Attack)
Lat. 34-23 N. Long. 150-15E.
Fishing Vessel.
0620 (X) Sighted unidentified vessel's tops over the huge waves. Further study revealed it to be a fishing vessel of some type. Sea too rough for service of the three inch. Avoided contact.

May 13
The steering from the conning tower has been out for several days, difficulty suspected to be in the gear box forward of the conning tower, outside the pressure hull. He have

— page 121 —
13 (Cont'd.)
been forced to wait for a lull in the succession of storms to investigate; meanwhile storming from the control room, not very efficient control.

2100 (X)
The storms having abated for a few hours, effected repairs. Those repairs were made by Lieutenant A.S. Garvey, U.S.N.R. and Floyd C. Standloe, Nol. 20, U.S.N. In their location, while so engaged, it would have taken several minutes to have gotten the inside of the ship. Their intrepidity as well as skill are hereby cited. Their investigation revealed that, when storming from the bridge was removed during the last rush, two ball bearings, dropped into the bottom of the gear box and were not removed. These worked into the gears and caused jamming. Repairs were accordingly a success.

May 14
Entered the assigned area.
2345 (X)
(2nd Contact) (No attack)
Lat. 34-07 N. Long. 140-44 E.
Convoy of 3 cargo vessels with one escort.
Admiral contact. It developed into three objects.
Determined speed to be 13 knots base course about 120, zigzagging independently of one another with extreme changes of course and at irregular times. It was too light to get in on the surface in the quarter meeting, yet too dark to see anything through the periscope. Hoped they would settle down after noon and about 0200. After this time, however, we were sighted at 6000 yards, driven off and they continued their zigzag, maintained contact. Did not believe that we could cope with this situation in a "blind flying" run at 40 feet by S3rd radar. Dawn is at hand.

0450 (X)
Submerged and commenced the approach. Targets were soon in sight and we almost made it.
0616 (X)
The convoy got away. One escort vessel soon, in the van, as soon as we could, surfaced and commenced and around. The visibility was not good for our purposes. In the haze the targets were difficult to keep in sight, while our black color must have stood out clearly. In any event we were sighted about an hour after surfacing and the escort came after us. Only 3 min engines available.
1150 (X)
Driven down by the escort. Not considered large enough to detonate a torpedo. Depth charge attack did not follow. Considered that it would be futile to search again for these targets in the visibility prevailing. They had been difficult enough to see when we knew where they were.
Our lesson is that we should have tried the 40 foot S3rd radar "blind-flying" approach during the night.

May 15 - 16
Off NOMNA SAK; then decided to cover the coast close in north-east of that point, up where we sank a destroyer last winter.

- 2 -

ENCLOSURE (A)

— page 122 —
20
(3rd Contact) (No. Attack)
Lst. 34-53 T. Long. 139-57 S.
Two small cargo ships.

Sighted smoke to the north-eastward. Corroi-nced
approach though it lands into extremely shallow water.
1150 (K) Unable to close. This range aboon was equal to the
distance to land; so close in to thisy go.
1222 (X) (4th Contact) (No Attack)
Lst. 34-53 T. Long. 139-57 E.
Destroyer.
Sighted smoke to the north-eastward. Corroi-nced ap-
proach. Approached another freighter.
1250 (X) After one of several trains of ships, put up the usual
order to, keep the true bearing from changing, put up the usual
8 foot of periscope and, forttunately, took first a quick look
around in the bow, range about 2000 yards, all bow wave; prob-
ably about 25 knots. Sound had especially listened all around
during the slow down and nothing had been heard. Naturally no
tubes were ready. Made them ready at once but could not get
a reasonable set up for a shot. Did not go deep though should
have because all the had had to do was start dropping and we
would have been badly off. The destroyer passed us at about
200 yards range. She looked like the new Japanese type shown
in the January 13, 1943 issue of "O.N.I. "SALV", similar to
the USS AIDRISON.
1455 (K) Sighted the same, or similar, destroyer returning
still at high speed. Got all set but an unfortunate zig proven-
ted attaining a satisfactory firing position.

: 21
(Off O SHINA)
1005 (K) Sighted a 4-engine flying boat going to the southeast-
ward.
(5th Contact) (No Attack)
Lst. 34-42 K. Long. 139-34 Z.
Two destroyers, two sections of small planes and
possible two SIOXAU or RYUJO class carriers.
Sighted masts of a ship. Started approach. Unable
to close to firing position. They were two destroyers on
northerly course similar to the USS "LISSU". Two sections of
small frigate were sighted near O SHINA and, in that same
direction, two sets of stick masts like those on the SHOKAKU
or RYUJO class carriers, as shown on page 21 and 25 of O.N.I.
14 issued May, 1942. Unable to see whether or not these were
actually carriers; stick masts soon only once.

- 3 -
EXCLUSIVE (A)

— page 123 —
1555(K) 1655(K)
Sighted small pontoon bi-plane on southerly course.
(6th Contact) (No attack)
Lat. 34-40 N, Long. 139-31 E.
NATURI class light cruiser.
Sighted tops of a ship. Started approach. Unable to close. It was a NATURI class light cruiser on southerly course at high speed.
1818(K) (7th Contact) (No attack)
Lat. 34-37 N, Long. 139-32 E.
Convoy of 4 cargo ships with 2 destroyer escorts.
Sighted smoke. Started approach. Unable to close. Course northerly, speed 12 knots.

May 22 0717(K) Patrolling off O SHIMA. (8th Contact)(No attack) Lat. 34-38 N, Long. 139-30 E. Task force of three battleships, three or four heavy cruisers, one carrier and several destroyers. Sighted tops of a ship. Started approach. First sighted were the three battleships, then the carrier several miles astern of them. We did get inside the outer screen and could probably have fired at a heavy cruiser or one of two destroyers but at that time it looked as though we would be able to get into the carrier, certainly "HUDSON'S CHOICE". One of the destroyers passed practically right over us due to our carelessness of our own safety in trying to get to the carrier. The approach was not successful. The carrier zigged away and passed at 9000 yards, angle on the bow changing during the turn rapidly from 40 port to 110 port.
2033(K) Surfaced and headed out at high speed to send contact report. Sent it while only 45 miles from NORTH SHINA. SAIL with almost certainty of being DF4d and searched for by planes and destroyers. Upon completion of the transmission about 2300 headed for MICURA SHIMA to intercept north-south traffic.
2320(K) Dived on indication of a plane's radar on our SD radar. No attack followed. Probably a false alarm.
2355(K) Surfaced.
May 24 0010(K) (9th Contact) (No attack) Lat. 34-13 N, Long 139-58 E. One small cargo vessel and one escort. Sighted a dark object on the starboard bow. Then made SU radar contact with 9000 yards. Commenced tracking. It appeared to be two vessels, neither very large but one decidedly larger than the other, the smaller in the lead. They were zigzagging radically at 10 knots. Decided to make approach on SU radar at 40 feet; too dark to see through the periscope and took light for surface approach.
0045(K) Passed through some fishing boats. Those signalled to the target and escort. The escort started chasing us; target turned away. Nineteen knot chase followed, the escort closing slowly, our full speed still limited by #4 main's casualty. Tried to circle slowly to get between the escort and the target but the escort caught on and took position a bit on the inbound quarter.
0145(K) Escort turned on an extremely bright searchlight and commenced gunfire at 5300 yards. During the gunfire the escort apparently turned, for suddenly the radar lost contact. Attempted to regain contact and thereby be lead back to the target. Unsuccessful. Attempted then to search, regain contact and thereby attain favorable position for attack during the remainder of the night or at dawn. Attempts were unsuccessful.

-4- ENCLOSURE (A)

— page 124 —
5-5 ENCLOSURE (A)

| Subject | U.S.S. TRIGGER - Report of Fifth War Patrol |
|||
| May 25 | Off O SHIMA slightly inside SAGAMI NADA during a part of the day, further in than intended. Due to variable currents and poor visibility could easily have been aground if breakers had not been sighted in time. |
| May 26 | (10th Contact) (No Attack) Lat. 34-38 N. Long. 140-02 E. Small cargo vessel; about 3000 tons. Sighted smoke from just off KATSUURA VAN LIGHT; our position close in up the coast from NOUTMA SAKI. Commenced approach. The approach was fine except that we were practically surrounded by fishing vessels. Periscope exposures, therefore, were made especially short and fast. Finally we were in almost a perfect position dead ahead of the target on his apparent base course at a range of about 4000 yards. If he zigged reasonably or did not zig he was a goner. On the next periscope observation; however, he presented a 120 degree track. The nearest fishing boat had up a large red flag. The target circled us at just outside effective range. |
| 1728(K) | (11th Contact) (No Attack) Lat. 35-00 N. Long. 140-02 E. Unknown type of ship; possibly a small tanker. Sighted the masts of a ship way inshore, angle on the bow about 90 degrees. Unable to close. The estimated range was further than the distance to land, this as an example of how close in the traffic goes along this coast. |
| 1840(K) | (12th Contact) (No Attack) Lat. 34-55 N. Long. 140-08 E. Submarine; type not determined. Sighted top of a submarine at an unknown range, angle on the bow about 90 starboard. Unable to close. |
| May 27 | Off HICURE SHIMA to intercept north-south traffic to TOKTO; enroute the western approaches to SAGAMI NADA. |
| May 28 | (Off IRO SAKI) |
| 1430(K) | (13th Contact) (1st Attack) Lat. 34-33 N. Long. 138-50 E. One medium sized tanker followed by one much smaller. First one damaged. Sighted, suddenly, out of the mist, two ships. Commenced approach. The range was not over 4000 yards. Had to work fast. |
| 1440(K) | Fired 3 bow torpedoes at 1100 yards range 110 port track at the leader, a 7500 ton tanker; one hit aft, fired to get a set up on the ship following; unable to. Both turned away. Leader down by the stern. |
| 1446(K) | Loud explosion. Nothing in sight except the two targets. Assumed air coverage. Went deep. |
| 1450(K) | Sound reported one set of screws had stopped. Gave immediately back to periscope depth. Observed both ships heading away, the leader's stern, which before the attack had shown the counter stern clearly, was down to the main deck aft and the bow high. Headed in its direction to observe sinking or attack again. They both, however, soon disappeared from view. When last seen the vessel hit was undoubtedly still under her own power. She may eventually have sunk but due to the evidence not being conclusive a claim for damage alone is made. She was an old tanker similar to the STYRO MARU of 7499 gross tons (page 273). Her loading had been moderate; about half way between the two upper pictures on that page. |

— page 125 —
1524(K) Sighted: small plane circling around, apparently searching for us.
1805(K) (Ltth Contact) (No Attack) Let, 34-30 N, Long, 138-45 E, Submarine.
Sighted for just a few minutes in the distance the conning tower of a submarine.

May 29

1648(K) (Off IRO SAKI)
(15th Contact) (2nd Attack) Let, 34-35 N, Long, 138-40 E, Q-Ship
with the appearance of a small cargo vessel. Sighted ship with zero angle on the bow. At first the target looked like a large passenger liner; zero angle on the bow is, however, often confusing. The target doesn't seem to want to zig. Finally pulled off his track and came in on 70 port track for firing range of 1000 yards so as to be ready for a zig. The target could now be made out as a small cargo vessel but with large guns forward and aft. The target should never been on old bunker but there was no smoke and sound reported fast light screws. Could not find an escort vessel. Set torpedo depth 12 feet because of probable small draft. In order to be sure of the range, pinged. When almost at the firing point the target zigged away making larger track and range.

1726(K) Fired 3 bow torpedoes at 1900 yard range 110 port track. The first torpedo, which, if the problem was worked out correctly, should have hit, preentured in 15 seconds. The other two should have missed due to spread and did miss. The target turned toward us. Put up the periscope to give him a good point of aim and headed for him. Had only one torpedo ready forward because we try, normally, with only one old target, to save two dry torpedoes forward for the "coup de grace".

1729(K) Fired one torpedo dead ahead zero angle on the bow torpedo run 800 yards, depth 15 feet (to avoid another premature though the sea was not rough). No detonation. Went deep at full speed and as much rudder as depth, gaining could permit. As soon as we had gotten 60 degrees off the course shifted the rudder to pull the stern off the track. The first string of depth charges were bemtics. A severe depth charging was the price we paid for this attack. If we could do it over again would have had more torpedoes ready and on the down the throat shot would have given him two at 15 feet and the last at zero foot depth to deliberately preenture in his face. Might have blown his bow off. He had sound gear but did not ping. He was no amateur but made several runs and listened, just like a destroyer. He dropped about 20 charges in all.

1845(K) Last depth charge; not very close. Must be heavy ones because the usual swishing was more of a reverberation lasting nearly a minute. Our difficulty now is to get away. The current is equal to our one-third speed and setting us onto the islands of the IZU SHOTO. More speed means loss battery.

— page 127 —
1055 (K)
    June 1 (Cont'd.)
    First target had sunk. Second target was about 4 miles away making heavy smoke and heading for the harbor entrance.
    1130 (K) Patrol vessel sighted. From now until several hours later, patrol vessels and planes in sight almost continually. Obviously they know where we should be and in which direction we had to go due to the current. Later in the day two patrol craft or small destroyers hunted for us by pinging for about two hours.
    2110 (K) Surfaced and got away. Was really not very concerned about getting away this time for the current sets us to seaward, but the pingers were in the vicinity until almost dark. The ship that we had sunk was similar to the KOSEI NARU (partial wells and cruiser stern well seen) of 8223 gross tons; page 176. She was loaded just like the lowest picture of that page.

June 3
0950 (K) Sighted single ving landplane.
1450 (K) Sighted 4-encine Flying Boat.

June 6
1345 (K) Sighted single ving landplane.

June 9
0040 (K) (17th Contact) (No Attack)
    Two aircraft carriers with destroyer screening vessels, lade radar contact at twelve miles range. Immediately went to full power on all main engines on normal approach course. This course was, however, by plot parallel to enemy course and they have the edge on speed. Closed slowly still at full power at the expense of losing bearing in the hope of a zig towards. Cannot get full use of #4 main engine (See "Major Defects").
0230 (K) Contact is now in sight; two aircraft carriers with at least one other vessel. The minimum range was twelve thousand yards, angle on the bow 135 starboard. Our full power had not been sufficient.
1444 (K) (18th Contact) (No Attack)
    Lat. 32-32 N, Long. 140-46 E.
    Hospital Ship.
    Sighted smoke on the horizon. Made an easy approach, target making about 12 knots zigzagging. Finally made out proper Hospital Ship painting. Took pictures. This would have been an easy one. If this Hospital Ship can be considered a type of troop transport, we have now during this patrol seen all types of enemy vessels.

June 10
1924 (K) (19th Contact) (5th Attack)
    Lat. 34-13 N, Long. 139-50 E.
    Huge aircraft carrier with two destroyer A/S screens.

- 8 -

ENCLOSURE (A)

— page 128 —
U.S.S. TRIGGER - Report of Fifth War Patrol.

June 10 (Cont'd.)

Sighted what was reported as smoke on the horizon. On the next observation it showed itself as the island of a huge aircraft carrier. Sho was totally unlike any other Japanese carrier seen; looked most like the USS SARATOGA except no near structure, merely the island which was big. The destroyers were on her bows. Sho was zigzagging radically, TDC spood 21 knots.

1955(K) Fired 6 bow torpedoes at intitle range of 1200 yards near track 75 starboard using spood spread of 1 knot increments. At the time of firing we were inside the near screen, this vessel being at the center on our port beam distance about 2000 yards, angle on the bow 30 port. By the time the hits started coming in which was just as the 6th fish was fired the angle on the bow of the nearest DD was almost zero. No time to turn to fire the stern anywhere. Went deep and stood by heading for the carrier. The target's screen had slowed and then stopped. Continued to head toward the target in order to confuse the depth charges. We did not, however, have to wait long for their co-ordinated attacks, and they were excellent. As usual they alternated making runs and never wasted a charge.

2013(K) Cracking and popping sounds in the direction of the recent target. Those were clearly audible through the hull almost as loud as those of June the first. At this time the co-ordinated depth charge attacks ceased and one destroyer depth charged for a while and then the other. Probably taking off survivors. However, the attacks were sufficiently persistent to keep us down. The cracking and depth charging continued until 2105.

2145(K) Thought we were getting away so tried to get rid of some water. Screws and depth charges resulted. Then all quiet again.

2326(K) Started up to periscope depth to try to get a look before the quarter moon set. However, had little hope of seeing much because our experience out here is that a quarter moon does not afford sufficient illumination.

0012(K) (June 11th) Apparently could not see as well as we thought we could. Driven down again. No attack.

0244(K) Surface and got away. Nothing in sight. Fifty minutes of battery charge before dawn. During the day we had at least one patrol craft in sight nearly all the time. Due to low battery we were still very much on the defensive. Our time in the area was up so started home. Did not engage in shore bombardment for our welcome in the area was certainly worn out.

The carrier, which must have had a displacement of about 25,000 tons, received 4 hits distributed along her length and was stopped immediately. The ultimate result is that, if the target did not eventually sink, tens of millions of yen, months of work, vast quantities of material and equipment and the tie-up of a huge dry-dock will be necessary to convert this wreck into a man o'war. The psychological effect of towing her back to YOKOSUKA must have been tremendous.

The foregoing narrative, in the interests of brevity, has not included an account of all of the various small craft encountered. Particularly within a radius of 20 miles of NOUHA SAKI and near MITAKIE and MIGURE SHIMA, at least one patrol or fishing craft was in sight almost continually.

- 9 -

ENCLOSURE: (A)

— page 129 —
1708(Y) Departed Midway.

While armout Pearl conducted test discharge at 6 hour rate, percent armour hour capacity 120.

Mede dives for test of radio reception to the extent perattled by the necessity of meeting the time of the scheduled rendezvous.

June 22
Arrived Pearl Harbor for raft.

2. Weather:
Both to and from station storms of moderate intensity were encountered. However, while on station the weather was from good to excellent at all times. On one or two occasions there was haze and fog which made periscope observations difficult.

3. Tidal Information:
The currents were in general as indicated in the Asiatic pilot and on the H.O. charts of this area, but at times were subject to irregularities both as to direction and strength. The irregularities were chiefly noted around the numerous islands. To the east of them about fifteen miles and northward to the coast a rather consistent current of 1 1/2 knots on 0500hr was noted.

4. Navigational Aids:
The principle night aid to navigation in this area was the SD and SJ radar. When in the vicinity of two or more islands or approaching the coast the ship's position could be plotted with exactness in the worst sort of visibility. Mountain peaks and islands over 2500 feet high could be picked up on the SD from about 25 and sometimes 30 miles.

The need for an adequate telescope to be used with the sextant for night star sights was felt. The telescopes provided are completely inadequate both as to power and field. A telescope about the size of 1/2 of a pair of sovan fifty binoculars would be a great aid to the submarine navigator.

— page 130 —
5, V-1, U.S.S. TRIGGER - Report of Fifth "Ar" Patrol

Date: 5/12/43
Time: 08:20K
Type: Fishing Vessel
Position: 34-23N
Course: Unknown
Speed: Unknown
Remarks: 110 to 130

5/12/43: 2345H Convoy of three cargo vessels with one 20 lt escort
5/26/43: 1026H No small cargo ships
5/20/43: 1222D Destroyer similar to USS "MIMSON"
5/21/43: 1255H No destroyers similar to U.S.S. "MISSON"
5/21/43: 1605K N/RCII class cruiser
5/21/43: 1818K Convoy of 4 cargo sli ships with 2 destroyer escorts
5/22/43: 0747K T/Fst force of 3 EBs, 3 or 4 Cds, 1CV & several DDs
5/24/43: 0010K One small cargo vessel & one 20 kt escort
5/26/43: 1400K One small cargo vessel
5/26/43: 1728K Unknown type; only the masts seen
5/26/43: 1810K Submarine unknown type
5/28/43: 1430K Two tankers; one 7500 ton, one much smaller.
5/28/43: 1805K Submarine

34-23N
34

— page 131 —
5/29/43 16:48 (K) USS SHIP with 134-35 N: 280 10: Mids torpedo attack. Scour depth
: : appearance of a 1-38-40 E: 1: charge attack followed.
: : small cargo ship. 1:

— page 132 —
15

| ATTACK | II | II A | II B | III |
|-------|----|------|------|------|
| TIME  | 0440 | 0726 | 0729 | 0032 |
| DATE  | 1943 | May 28 | May 29 | June 1 |
| LOCATION | Let., Long. | 34-33N 138-50E | 34-35N 138-40E | 34-35N 140-40E | 34-35N 140-40E |
| NUMBER AND TYPE OF TORPEDOES FIRED | 3 - Mk XIV#3a | 3 - Mk XIV-3a | 1 - Mk XIV-3a | 3 Mk XIV-3a |
| HITS | 1 | 0 | 0 | 1 |
| NUMBER SINK (TONNAGE) | 0 | 0 | 0 | 1 - 1250 |
| NUMBER DAMAGED CR PROBABLY SURIKE (TONNAGE) | 1 - 7500 | 0 | 0 | 0 |
| TYPE OF TARGET | Tanker | Q-Ship | Q-Ship | Prototype |
| RANGE (1st ORDER) | 1100 | 1900 | 850 | 1400 |
| TYPE OF ATTACK | P | P | P | P |
| P.S., M. GR. R. | 18 | 7 | 7 | 20 |
| ESTIMATED DESTROY SPEED | 15 | 12 | 15 | 15 |
| BODY OF STERN SHOT | Boy | Boy | Boy | Boy |
| TRACK ANGLE (1ST) | 110 P | 110 P | 0 | 90 S |
| CYRO ANGLE | 25 L, 32 L | 5 L 10 L | 1 L | 0, 5 R |
| ESTIMATED TARGET SPEED | 10 | 10 | 11 | 11 |
| FIRING TIME | 8 sec. | 8 Sec. | 8 Sec. | 8 Sec. |
| STRAIGHT ALIGNMENT | 3 knot | 3 knot | 3 knot | 3 knot |
| KNOT | Incrementals | Incrementals | Incrementals | Incrementals |
| WAS TORPEDO TARGET RANGE SATISFACTORY | Yes | Yes | Yes | Yes |

- 13 -
- ENCLOSURE A

— page 136 —
8, Enemy Anti-Submarine Measures:

For one who has completed five war patrols during a bit over one year there was nothing new to the anti-submarine measures encountered. The Miss at not getting any worse, and not running out of depth charges. The Japs system of making depth charge attacks remains unchanged. During neither of the attacks sustained did they "ping", at least not on any frequency we could hear. However, they do a good job with listening if that is all they do. Their charges were mostly set too shallow. There is a possibility that they stray over a quantity of pieces of metal and listen for them as they hit the submarine; at least the two destroyers encountered on June 10 seemed to be doing something. I don't think.

The commanding officer has made two previous patrols in this area and was amazed by the increased activity. More contacts were made than the total of the previous two, perhaps familiarity has taught us where to look. Also the anti-submarine measures have been augmented. The nightly search of water and air by high powered searchlights was not noted but the crew was full of small craft, autos, and other craft. On two approaches, one day and one night, fishing boats disappeared during the patrols. They were in the way when they tried to get to a close in position. For next days hunt and three offed approaches by forcing us to be extremely careful with the periscope, observation.

Escorts were in use by targets in the area. One four-ship convoy had two destroyers, others had vessels like FOS and DDS. Air coverage was noted several times. The outstanding anti-submarine measure was the Q-ship encountered on May 29, a perfect small cargo vessel target but too shallow a draft. To detonate torpedoes, and with sound gear, at least 21 large depth charges, ability and nerve; made runs just like a destroyers. It was also noted that, on two occasions, when our presence had been disclosed, shortly thereafter a submarine was seen.

9. Enemy Hinge-Sweeping Activities:

None were encountered.

— page 137 —
10. Major Defects Experienced:

(A) Engineering:

No, I didn't engineer bearing failure. At 1400, May 8, 1943, #14 main engine was stopped by the throttlment because of an unusual noise. Then investigation it was found that, 1/6 lower main crank bearing had rusted. Then the bearing was removed the journal was found to be deeply scored, its diameter in area of -1.0 deepest scoring being 6.718 inches, compared to a damaged diameter of 6.718 inches. Both bearing dowell pins had sheared, and the bearing shaft had rotated inside its cap and body. The back of the shell was severely abraded, but there was no signs of any damage to the connecting rod body or the bearing cap.

It was realized that a new bearing could not be expected to hold, however, the exigencies of the situation, this vessel being on war patrol, were such that it was decided to try it. The journal was smoothed by stoning, a new bearing was installed, and the engine was run under 11.5 inch load. The new bearing ripped after two hours. A new upper bearing half was installed, and the decision was made to cut off the fuel from #6 cylinder, and operate the engine as an eight cylinder engine at reduced load. This was done, and the engine was back in commission at 1800, May 9th, 1943.

The soundness of this emergency procedure was demonstrated on May 15th and 24th, when this vessel was pursued on the surface by an enemy anti-submarine escort. #4 main engine developed 500 K.T., at 670 RPM for about twenty minutes at each of these times. Normally, however, the load had been limited to 500 K.T., at 550 RPM, and the engine has been used only when the other three are already in use.

(B) Hull:

1. Hydraulic Ram. Toward the latter portion of the previous patrol, excessive leakage developed in the main hydraulic plant accumulator. During the ensuing refit, the refitting activity was requested to investigate and eliminate the leak, repacking the ram if necessary, which was done. Upon departure for Midway, however, the leak was again noticed, and it rapidly became worse. The ram appeared scored. Submarine Base, Midway was asked to stem it down upon arrival. It developed that the plunger was badly scored throughout its length, and that the ring of packing had been cut before installation, Midway personnel worked all night, lifting the oil down, attending the ram, and installing a new unset ring of packing. The hydraulic system operated successfully during the patrol, and a major overhaul of the system is being requested for the next refit.

2. Steering Gear. On May 11th steering from the conning tower jammed, rudder could not be moved in either direction. Shifted steering to control room and from there steering was normal. May 13th the gear box forward of coming tower and outside the pressure hull was opened. Two ball bearings (balls had dropped in gear box when bridge steering was removed during last refit) were found to be jammed in lower jaw gear. Inspection of the gears showed both gears to be badly burned but still useable. Reassembled gear box, shifted steering to coming tower and found it to be normal again.

— page 139 —
1st Subj: U.S.S. TRIGGER - Report of Fifth War Patrol.
: SD Radar Casualties (Cont'd).

Only a half squawk was seen on the CRT screen with plate voltage at normal value. Cause of this defect was traced to an open contact on a pin on the in- vorter tube V212.

The squawk became erratic and arcing was noticed at the base of the r.f. input tube, V201. This was evidently an indication of faulty oscillitor tubes because soon afterwards the 801A-1s failed. Removing these tubes stopped the arcing and produced a steady squawk. A great difficulty was encountered in securing proper operation after changing the oscillator tubes. Three sets were installed before a steady squawk resulted. The 801A-1s had 350 hours operation before failure.

A la: of sensitivity was indicated by a decorose in grass amplitude. This was remedied by replacing two I.F. tubes.

Operation: While on station the SD was a great aid to navigation. The maximum range was 26 miles. This was probably an airplane since no land was close. Since the range did not close the echo could not be verified. Maximum land echo observed was 26 miles.

Total hours of operation on this patrol 24.1
Total man hours spent on maintenance 15

SJ Radar

Casualties: The range tank leaked. This was first detected by the disapcoperance of the range stop before the nexium range was cranked on the range dial. The leaking was partially stopped by removing all range tank gaskets. One leak occurred at the range crank rod bearing and since it was impracticable to remedy this fault the range unit was pulled over three days and the tank filled. No operating hours were lost due to this casualty but 90% of the man hours required for SJ maintenance were used to keep the range unit in proper oper time condition.

Arcing occurred in the TR unit from the junction of R49, R50 and R27 to ground. Simultaneously the squawk became unsteady, the sensitivity decreased and an excessive amount of current was drawn from the H.V. rectifier resulting in the burning out of the H.V. rectifier ammeter. This trouble disappeared after replacing the thyristor tube, V2.

The labor motor operates slowly producing a noticeable flicker of the trace. This is probably due to the lobing mechanism gears binding or to improper lobing motor packing.

Operation: Results obtained from the SJ wore very (critifying. Below is shown a table of maximum ranges for various targets:

| Target | Range |
||-------|
|        | 20    |
|        | 22    |

— page 140 —
11. Radio Reception (Cont'd.)

SJ RADAR (Cont'd.)

| Type of Target | Maximum Range |
|||
| Land           | 31,000 Yards |
| Aircraft Carrier | 26,000 " |
| Destroyer       | 10,000 " |
| 800 ton patrol vessel | 8,000 " |
| Jap fishing vessel | 5,000 " |
| Rain squall     | 3,500 " |
| Wave echoes     | 2,500 " |

The aircraft carrier echo was first noticed at the extreme right end of the expanded sweep. On switching to the main sweep a near saturation echo was observed. The sea was extremely calm and the sky overcast.

The rain squall pip was not clearly defined, showing considerable variation in range and bearing.

For a period of 15 to 30 minutes after the high voltage is turned on the receiver tuning varies considerably. The "echo box" was used very effectively in keeping the receiver always at a maximum tuned condition.

Total hours operation this patrol: 327
Total man hours spent on maintenance: 25

Negative results were obtained with the ARC-1 radar detector. The operation of this device was tested upon arriving at Midway on route to the area and again on route from the area.

12. Sound Conditions and Density Layers:

Variable sound conditions were observed, ranging from poor to very good. A great deal of unusual fish noises sounding like propellor screws were heard on both the JK and QB. Maximum listening range was approximately 10,000 yards on a calm clear day. Echo ranging was good considering only single ping ranges were ever used. Fathometer soundings were used whenever close into shore and visibility was poor. Horo too single ping soundings were employed to good advantage.

While in Pearl Harbor during last of the war, a bathythomograph was installed and used successfully. Careful observation and indications showed varying density layers from 60 feet on down to 250 feet. In all cases negative temperature gradients were experienced. During normal soundings during the 60 feet, temperature changes had a marked influence on the overall trim varying the trim approximately 800 lbs. per degree change in temperature. In all cases, however, this figure did not hold true, due perhaps to various changes in the density of sea water caused by other factors. At 300 feet, on night of June 11, a negative gradient of 16°F. was encountered.

- 21 -

ENCLOSURE (A)

23

— page 141 —
13. Health and Healthiness:

As usual the health of the crew during this patrol was good. The number of cases of constipation, colds and headaches were average.

Man days lost because of sickness were as follows:

Lymphangitis
- One case = 3 man days.
- One case = 3 man days.
- One case = 10 man days.

The cause of the case of Seismic Neuritis is unknown. Two or three painful attacks occurred and morphine was administered. The patient during these attacks was hardly able to move his leg at all due to the severe pain. Sun lamp treatments seemed to help more than anything else. There were no recurrent attacks after ten days inaccptation. Upon return to port a complete physical check up will be made of the man concerned.

Habitability was excellent. However, the ship was forced to remain submerged on two occasions for over 19 hours after which time the CO 2 percentage reached about 3.5%. CO 2 absorbent was spread and oxygen bled into the boat. No ill effects of any kind were noted.

The food as to quantity and quality left little to be desired.

14. 14. Miles and Fuel:

| Item | Miles Stored | Fuel Exp. |
|------|||
| Enroute Midway | 1250 | 12,568 |
| Enroute Station | 2310 | 24,675 |
| On Station | 3200 | 26,020 |
| Enroute Midway | 2200 | 26,785 |
| Total | 8960 | 90,048 |

Received 10,400 gallons fuel at Midway.

Enroute Pearl | 1280 | 15,080 |

Grand Total | 10240 | 105,128

16. Factors of Endurance Reraining:

| Torpedoes | Fuel | Provisions (days) | Fresh Water | Personnel (days) |
||------||||
| 14,000 gals. (1st Midway) | 10 | Unlimited | 10 |
| 4,080 gals. (1st Pearl) | | | |
| 17. That Factor of Endurance, if any, caused ending of this patrol:

Tine on station completed.

- 22 - | ENCLOSURE (A)

— page 142 —
01019
SUBMARINE DIVISION 102
Care of Fleet Post Office,
San Francisco, California,
21 June 1943.

From: The Commander Submarine Division OPE HUNDRED TTO.
To: The Commander Submarine Force, PACIFIC FLEET.
Via: The Commander Submarine Squadron TEN.

Subject: U.S. TIGGER - Fifth War Patrol; Comments on.

1. The Fifth War Patrol of the TIGGER occurred a period of fifty days from December 1st until arrival at Midway. Of this period twenty eight days were spent in the assigned area. While in the area there were seventeen contacts with worthwhile targets, five of which were brought under attack. The TIGGER was somewhat hampered by the numerous small vessels encountered, which on two occasions were unable to get through the submarine's presence and proved to be a serious threat. There were four contacts with valuable ships of which the submarine was unable to close due to extreme ranges or high enemy speed. It is regretted that on 2nd of February 22nd, the submarine was attacked by the enemy. The submarine was attacked by the enemy.

— page 143 —
5. Attack No. 5 June 10: This was a brilliantly executed attack on a large new aircraft carrier with two destroyer escorts. The ship was placed in a perfect firing position and choice of track and spread was excellent. Six torpedoes were fired from the bow tubes and four well distributed hits were made. It is not known whether the carrier sank following this attack but if she did survive the enemy will be deprived of a valuable unit for many months to come.

6. Torpedo Performance.

Twenty torpedoes were fired and 6 hits obtained for a percentage of 30%. One precautious was observed.

7. Material.

The bearing casualty on No. 4 Main engine while on route to the patrol area was unfortunate but the intelligent manner in which emergency repairs were made permitted this engine to be used at reduced power for the remainder of the patrol.

8. The TRIGGER returned from patrol in excellent material condition. She will be profited at Pearl Harbor and it should be accomplished in the normal period.

9. The Commanding Officer, officers and crew of the TRIGGER are congratulated on an excellent patrol and upon the damage inflicted on the enemy.

— page 144 —
7 01019
SUBMARINE SQUADRON TEN
Care of Fleet Post Office,
San Francisco, California,
20 June 1943.

From: The Commander Submarine Squadron Ten.
To: The Commander Submarine Force, Pacific Fleet.

Subject: U.S. TRIGGER - Fifth War Patrol - Report on.

1. The fifth war patrol of the U.S. TRIGGER was outstanding for the numerous contacts on combatant ships and for the successful attack on a large aircraft carrier. Probably never before has a United States submarine contacted so many enemy warships of all types as has the TRIGGER on this single patrol.

2. The many times the TRIGGER was in unfavorable positions for attacks on various targets must have been a source of keen disappointment to the Commanding Officer and personnel. It is unfortunate that more attacks could not be carried home, for such opportunities seldom present themselves to our submarines.

3. This is the second engagement the TRIGGER has had with Q ships. This engagement, like the one of the "TRIGGER" as second patrol, was packed with action and excitement, but again proved that such vessels are of too shallow a draft to show any concern for our torpedoes with respect to our submarines. The TRIGGER has not been able to get much enough to avoid movements, and the TR

— page 145 —
1-10/416-2(5)/16) SUBMARINE FORCE, PACIFIC FLEET
Serial 0825
Care of Fleet Post Office,
San Francisco, California,
June 28, 1943.

CONFIDENTIAL
COMMSUSPAC PATROL REPORT NO. 203
U.S.S. TRIGGER - PITTS WAR PATROL.

From: The Commander Submarine Force, Pacific Fleet.
To: Submarine Force, Pacific Fleet.

Subject: U.S.S. TRIGGER (SS237) - Report of Fifth War Patrol.

Enclosure: (a) Copy of Subject War Patrol Report.
    (b) Copy of Consubdiv 102 Conf. 1st. PS-102/416-3 Serial 060
    of June 21, 1943.
    (c) Copy of Consubdiv 10 Conf. 1st. PS-10/416-3 (FPS-102),
    Serial 0101 of June 20, 1943.

1. The fifth war patrol of the TRIGGER was the fourth consecutive patrol for its present commanding officer. This patrol, like the previous three, was aggressively and successfully carried out.

2. The patrol was most unique in that it is believed that the TRIGGER made zero combatant ship contacts than any other U.S. submarine has done during the war. The TRIGGER was successful in obtaining a good tactical position in an attack on a large aircraft carrier which resulted in a successful full attack causing severe damage to this very important target.

3. Although many contacts were made in the area, several possible attacks were frustrated because of the increased enemy anti-submarine activity that has apparently recently developed in many of the Empire areas. It is noted that the enemy has closed in to the Empire area by using offensive tactics and the enemy has been successful in destroying several of the enemy's submarines.

4. The Commander Submarine Force, Pacific Fleet, concentrates the Commanding Officer, officers, and crew for this aggressive and well-conducted fifth war patrol. Particularly gratifying was the attack and damage inflicted on the Japanese aircraft carrier. TRIGGER is credited with having inflicted the following damage on the enemy:

| Damage | Tons |
||------|
| 1 - Tanker (SKOTE MARU Class) | 8,223 |
| 1 - Aircraft Carrier (new type) | 27,500 |

Total: 34,999 tons

Distribution and authentication on following page
- 1 - C. LOCKWOOD, Jt.
- 1 - FILMED
- 51660

— page 146 —
12-10-16-3(5)/(16) SUBMARINE FORCE, PACIFIC FLEET 1d

Serial 0825

CONFIDENTIAL

CONSUBSHIP P.TROL REPORT NO. 202
U.S.S. TRIGGER - FIFTH WAR PATROL.

Subject: U.S.S. TRIGGER (SS237) - Report of Fifth War Patrol.

DISTRIBUTION:
(Complete Reports)
Cominch (5)
VONO (5)
Cinipac (5)
Cinelant (2)
Comsubsblant (2)
S/M School, HL (2)
Comsopac (2)
Comsoospec (1)
Comsubsovspec (2)
CTF 72 (2)
CTF 16 (1)
Comsubspec (10)
SUEAD, HL (2)
Comsubconstubspec (2)
Midway (2)
All Squadron and Div.
Commanders, Subspec (2)
U.S.S. SULION (1)
(COMSUBSP.C. Endorsement only)
All Submarines, Subspec (1)

R. L. LAVNER,
Flag Secretary.

— page 147 —
35237/A16-3
Serial (354)
Care of Fleet Post Office
San Francisco, California
September 30, 1943

DECLASSIFIED
DECLASSIFIED, 0443, CPAN/WINST 5510.C
DATE 7/20/43

From: The Commanding Officer.
To: The Commander in Chief, United States Fleet.
Via: The Commander Submarine Division ONE HUNDRED TWO.
The Commander Submarine Squadron TEN.
The Commander Submarine Force, Pacific Fleet.

Subject: U.S.S. TRIGGER - Report of War Patrol Number SIX.

ENCLOSURE:
(A) Subject Report.
(B) Track Chart (For the Commander Submarine Force, Pacific Fleet)
(C) "Summary of Submarine Attacks" forms with carbon copies.
(D) One roll of film with exposure data.
(For the Commander Submarine Force, Pacific Fleet)

1. Enclosure (A) covering the sixth war patrol of this vessel conducted off the coast of China, north of Formosa, during the period from September 1, 1943 to September 30, 1943, is forwarded herewith.

FILMED
57647

— page 148 —
1. U.S.S. TRIGGER - Report of Sixth War Patrol.

(A) PROLOGUE:

Arrived Pearl Harbor at conclusion of fifth war patrol on June 22, 1943. Commenced normal refit by submarine base and Relief Crew, Submarine Division 142. On June 28, 1943 it was decided that the progressively poorer condition of the main motors made necessary a Navy Yard overhaul. On June 29, 1943, the ship was moved to the Navy Yard, Pearl Harbor. Overhaul commenced on June 30, 1943, and was completed August 14, 1943. On July 28, 1943, Commander P. S. Benson, U.S.N., on leave at the time, was relieved as Commanding Officer by Lieutenant Commander F. E. Dornin, U.S.N.

During overhaul the following major alterations were completed:

Installation of topside ballistic protection; removal of conning tower door; installation of P.P.I. unit; relocation of A1 periscope in the conning tower; installation of skewed-slot main motor armatures; installation of leantrated rubber battery jars; installation of all necessary equipment to handle 1K. 18 torpedoes, including MK. 3, 50T, 5 TDC; shock-mounting A1 trim and drain pumps; installation of 110 pump and new by-pass valve in hydraulic plant; installation of inside shear pins on bow plane rigging gear; installation of modified propellers; removal of degaussing coils.

Post-overhaul refit accomplished alongside USS BUSHBELL. Had eight days training exercises, including a two-day joint exercise with an out-bound convoy. Ship was Deperred at Beacons Point, and sound tested in West L. Ready for sea September 1, 1943.

(B) NARRATIVE:

Departed Pearl Harbor at 1100 W September 1, 1943, on sixth war patrol, in company with USS UUDGEON and USS ALLEN (escort).

September 3, 1943

1035 W | Moored starboard side to USS GUNDERSON at Johnston Island, Topped off with fuel and water. Transferred JOHNSON, N.W., KOMI 1c, USN to dispensary, case diagnosed as pneumonia. Received GORDON, R. K., M2 oz, USN from Johnston Island.

1630 W | Departed Johnston Island. Set course for Area.

September 5, 1943

Received instructions to proceed directly via great circle course to area. New course passes 230 miles north of Wake and 70 miles north of Marcus.

September 11, 1943

0720 L | Radar contact, 6 miles. Dived. Plane not sighted. Eighty miles from Marcus. Took this opportunity to check torpedoes.

- 1. - Enclosure (A)

— page 149 —
1943 (Cont'd.)
September 11, 1943 (Cont'd.)
1816 K Surfaced.
1447 K Plane sighted low on port quarter (direction of Karius) coming in fast. Simultaneous radar contact, 6 miles. Div'd, received two small bombs at moderate range.

September 12, 1943
Unventful. Changed course slightly to pass between HAHA JINA and KITA INA JINA.

September 13, 1943
1020 K Sighted patrol plane through high periscope. Div'd. Plane did not sight us.

1159 K Surfaced.
2215 K Sighted KITA INA JINA distance 34 miles in bright moonlight.
2345 K Sighted patrol vessel about 6 miles away, bearing 20 degrees forward of the starboard beam, on southerly course. Avoided.

September 15, 1943
2030 I Entered Area.
September 16, 1943
0523 I First all day dive. Passed between YORON JINA and OKINOYERABU JINA, entered East China Sea.

1902 I Surfaced.

September 17, 1943
0543 I Div'd.
0705 I Surfac'd. Intended to patrol this part of the area on the surface while passing through enroute to the northern end of the Straits of Formosa, where targets appear most likely.

0925 I Simultaneous sight and radar contact on two planes dead astern, distance 6 miles. Div'd, not sighted.

CONTACT # 1 - 5 SHIP COINVOY WITH AIR COVERAGE
No attack.
Lat. 27 - 10 N. Long. 126 - 15 E.

-2- Enclosure (A)

— page 150 —
1530 I
Sighted five ship convoy consisting of two tankers, two freighters, and one unidentified ship, with a land based bomber as escort. Convoy is headed for HOKO SHO LIGHT, course 250, speed eleven.

1700 I
It is apparent that we will be unable to close. Convoy is already past, in spite of our running at full speed since sighting it. Decided to surface before sunset as soon as a reasonable possibility exists of making an undetected end around run. The plane certainly cramps our style.

1745 I
Lost sight contact with convoy.

CONTACT # 2 - 2 SHIPS IN COMPANY - NO ESCORT.

ATTACK NO. 1 - 8500 TON FREIGHTER - TWO DUSKS.

Lat. 27 - 10 N. Long. 126 - 15 E.

1800 I
As we were about to surface sighted two ships on opposite course, bearing 208°T. Commenced approach on those two, consisting of a 5000 ton 5 islanded ship torpedo, and a large new type 3 deck passenger-freighter. Held huddle to decide which convoy to go after. Decided this one, inasmuch as it was in sight, making only eight knots, and unescorted.

1911 I
Convoy got by at 1Bng range. Have two hours of darkness in which to make a night surface attack.

1941 I
Surfaced. Very dark. Commenced surface approach. It developed that the two ships were making eight knots, zigzagging on base course 070°T. Unfortunately the ships were too far apart to attain a firing position on both of them at the same time.

2045 I
Attained firing position for large ship.

2055 I
Fired four torpedoes, 80 starboard track, 1100 yards, 3A 15 L. At time of firing had 7T bearing, periscope bearings, 3D bearings and ranges, all checking. Two hits soon from the bridge, both duds. Nothing heard below decks. No doubt about the hits - the first was aft of the midship superstructure, and the second was on the bow. Immediately afterward, flashlights were seen on deck and over the side at the points where the torpedoes hit. The target swung towards to ram and we went to full speed and swung away. Lights all over his decks by this time.

- 3 -
Enclosure (A)

— page 151 —
2067 I
Target commenced firing deck guns. Obtained set-up to fire
after tubes, but withheld fire because of poor firing data.
Range now 700 yards, and with the visibility improving with
approaching moonrise and the shells coming too close for com-
fort, at

2056 I
dived. Nade reloaded. Watched target through periscope, still
firing.

2100 I
Received three depth charges, not close.

2107 I
Moonrise.

2136 I
Roload completed. Surfaced, full speed on all main engines.

2142 I
Radar contact. Commenced end around on dark side of the moon.
The two ships had separated, so went after the big one, hoping
to be able to return for the other later.

2347 I
In position ahead, very bright moonlight, dived to radar depth.

September 15, 1943

ATTACK # 2 - SAME TARGET - SUNK

Lat. 27 - 31 N.  Long. 126 - 67 E.

COO6 I
Target in sight through periscope. He was zigzagging radially
at about one minute intervals from 050° to 150°. Went to 55
feet at 4000 yards. At 2000 yards commenced getting continuous
echo ranges on him, and at

0023 I
fired 4 torpedoes, 150 port trawl, 1000 yards, GA 0. 45 seconds
later saw and heard one hit on storm. Eight seconds later sound
reported another hit, but not seen through pariscoop (maybe nonth-
or dud). However, the effect of the single hit was remarkable.
Target sank in two minutes, by the storm. All hands in conning
tower got a look.

0026 I
Target completely under.

0026 I
Boilers blew up. A tremendous explosion.

0029 I
Nade battle surface. Nothing in sight. No wreckage, no Japs.
They never knew what had happened.

Save heard of targets sinking fast, but this is the first time
this ship or the Commanding Officer has ever experienced such a
thing. It seemed very unreal. The ship was similar to the
JOSYO KARU, or 8500 tons, page 49, ONI 208-J.

- 4 -

Enclosure (A)

— page 153 —
1955 I
Radar contact. Commenced working around an starboard side of convoy. It is still fairly light, and lookouts picked up the convoy at about 8000 yards range.

2030 I
On starboard beam of the convoy, range 8000. Plot indicates course 080° T, speed 3, not zigzagging. Disposition from PPI - Two columns of three ships each, 1000 yards apart. From the size and location of the pipes, decided the tankers are on our side, hence will attack this side. "Waited till it became a little darker.

2045 I
Commenced surface approach, planning to fire three torpedoes at the first ship, three at the second, then swing and fire four at the third ship.

2048 I
Rearst column of ships in plain sight - TANKER, with the big one leading. It is still fairly light. They should see us - but they don't.

ATTAOK # 3 - TANKER, 10,000 TONS - SUNK

2056 I
Fired three torpedoes at TANKER # 1, 60 S track, GA 10 L, 1800 yards.

ATTAOK # 4 - TANKER, 7500 TONS AND FREIGHTER, 6700 TONS - SUNK

2057 I
Pired three torpedoes at TANKER # 2, 60 S track, GA C, 1200 yards. Came left with full rudder and full speed. During the firing, had TNT bearings, radar bearings, radar ranges, sound bearings, and. periscope bearings, all checking.

2057-10 I
One hit seen on after part of the TANKER # 1. Flame shot five hundred feet into the air, lighting up the whole area as bright as day. All six ships could plainly be seen. Eight seconds later the second torpedo hit her amidships; but nothing could have added to the furious holocaust already taking place. Kembers of her crew in various stages of dress (most in white uniforms) could be seen running forward ahead of the rapidly spreading flames. She was still driving ahead, a brilliant blazing funeral pyre. The men in the bow manned the bow gun and fired three or four times, but she was soon burning throughout her length. The flames were yellow-red, evidently a gasoline fire.

Enclosure (A)

— page 154 —
5 - TANKER, 7300 TONS - MISSED

2100 I fired three torpedoes aft at this tanker, 50 S track, GA 0, 100° yards. All missed, probably because we had not steadied enough, and he was swinging toward us, as we realized in a moment.

ATTAOK # 6 - SAME TARGET - HIT

2101 I Fired one torpedo aft down the throat, angle on the bow zero, GA 10 R, 800 yards. Hit on the starboard bow, observed from the bridge, he were making full speed by this time, and pulling away. However, he continued firing, and was getting a little better, as was evidenced by shells whistling overhead.

2102 I Divod. Slight confusion in the conning tower. The Commanding Officer fell into the periscope well and the quartermaster began to lower the periscope. Fortunately the Commanding Officer, supporting himself on his elbows, was able to make himself heard in time.

— page 156 —
2105 I
One-violent explosion.
Another violent explosion. Both sounded like ships sinking.
No depth charges were dropped at any time during these attacks.

2120 I
Periscope depth. Burning ship still very bright, but nothing
else could be seen. Hade reload, two torpedoes left forward,
four aft. Took periscope pictures and allowed crow to view burning tanker through both periscopes.

2140 I
Reload completed.

2141 I
. Surfaced. Took more pictures of burning ship. Radar and PPI
reported five contacts, three in the vicinity of the burning
tanker, and two others. The situation as clarified by plot and
PPI was as follows: TANKER # 1, stopped, burning. TANKER # 2,
burning, course east. TANKER # 3, down by bow. FREIGHTER # 1,
undamaged, stopped near burning ship. PREIGHTER # 2, sunk.
PREIGHTER # 3, undamaged, course north.

2142 I
Took off after ship moving north. As we passed the burning
NIPPON 'ARU' steam, the stern of a ship, pointing vertically into
the air, drifted between us and was distinctly silhouetted. It
is believed that this was the stern of TANKER # 3, but it is
possible it was the stern of PREIGHTER # 2. However, this
freighter already had been seen to sink at about 2058.

2147 I
The stern went under. At this time the whole hull of TANKER
# 1 could be seen, red hot.

2210 I
Attained surface firing position on FREIGHTER # 3. So bright
we nearly dived, but decided to ride our luck.

ATTOR: # 7 - FREIGHTER, 7000 TONS - DAMAGED.

2212 I
Fired last two bow torpedoes, SO 3 track, GA 0, 1400 yards.
Two hits in the bow, target immediately went down by the bow, and
we left him in an apparently sinking condition. As we swung left
he opened fire. A light came on on his bridge and he commenced
scrambling. With this, PREIGHTER # 1 opened fire also. While
we circled, it seemed there were flashes of gunfire all around us.
Shooting still pretty wild.

2220 I
FREIGHTER # 3 down to his main deck forward, dead in the water,
but still not under. Decided to polish him off, and made surface
approach. He was still firing but evidently to wrong side, because we could see no flashes. PREIGHTER # 1, several thousand
yards beyond him, was shooting back. Score zero for both, as
far as we could see.

- 9 -
Enclosure (A)

— page 157 —
2235 I
Swung to bring stern tubes to bear, range 1500 yards. At this moment he discovered us, and commenced shooting in our direction. Went to full speed, and at:

ATTACK # 5 - SALT TARGET - MISSED (OR DUD)

2235 I fired two stern tubes, 110 port track; GA O, 2200 yards. Should have got a hit, but nothing happened. Although no definite proof, from firing data feel sure we must have hit, and hence at least one dud.

Pulled out again and thought it over. We have only two torpedoes left, both aft, and he is getting pretty handy with his gun.

2242 I Divred for radar approach. Target in meantime had got underway, and we had to go to full speed submerged. Had almost reached favorable position when he reversed course, :

2232 I Surfaced. Found ourselves silhouetted against burning TANKER # 1. Went to full speed, pulled around FRIGHTER # 3 on the dark side.

Passed too close (2500 yards). Target saw us and opened fire.

September 22, 1943

0010 I Dived. Attained firing position for radar depth approach. Used radar, periscope, and continuous echo ranges.

ATTACK # 9 - SALT TARGET - DUD

0022 I Pired last two torpedoes, 90 port track, GA O, 1000 yards. One hit, one missed, according to sound. To detonation, but target evidently felt the hit, for he opened fire immediately. The feel-ings of the Commanding Officer and the control party by this time can be imagined. Held huddle over a battle surface, decided against it, because our three inch deck gun has never in its history fired five consecutive shots without jamming. We felt, under the circumstances, that our chances in a gun fight against a fully aroused enemy were not of the best, and that the probability of the target's sinking eventually was still good.

0036 I Surfaced. Three radar contacts. Turning TANKER # 1, damaged FRIGHTER # 3, and undamaged PERISHER # 1. The latter was slowly steaming back and forth near the fire; like a moth drawn to a flame. PERISHER # 3 was still firing aimlessly, forecastle awash, but able to make 4 knots.

Enclosure (A)

— page 158 —
0220 I

U.S.S. TRIGGER - Report of Sixth War Patrol (Dont'd.)

September 22, 1943 (Cont'd.)

The whole action covered a period of 3 1/2 hours, and took place within a circle of 8000 yards of the burning NIPPOI MARU. The light cast by t.ais fire was intense; the flames being, most of the time, a hundred feet over the tops of his mast. Continuous minor explosions took place, throwing up globules of fire even higher. The smoke emitted toward a third of the sky, and was blown by the wind into a plume twenty miles long.

It must be admitted that the light of the fire was probably of more benefit to us than to the enemy, however, since we were always able to get around to the dark side and use it to our advantage.

0045 I Set course for edge of area, full speed on all engines.

0050 I Sighted a glow over the horizon, beyond the burning tanker.

0055 I The glow flared up, and burst into brilliant flame, identical to that of the burning tanker. It was TANKER # 2, as she blew up. By 0100 I, two huge fires could be seen. The bow, bridge, and stern of the distant tanker were incandescent. Nothing more could be seen of the hull of the NIPPOI MARU, but the place where she had been was still burning fiercely, with flames 50 to 100 feet high.

Allowed numbers of the crew, one at a time, to come up on the bridge to see the two burning ships.

0220 I Lost sight of fires, distance 26 miles astern.

Receptitulation of results of attacks 3, 4, 5, 6, 7, 8, 9 on six ship convoy:

FRIGGINGER # 1 (Rohaku Karu type) escaped, undamaged.
FROGTER # 2 (Argun Karu type) sunk. Broken in half.
FREIGHTER # 3 (Lima Karu type) damaged, two hits in bow.

TANKER # 1 (Nippon Karu type) sunk. Slow up immediately.
TANKER # 2 (Suyoyo Karu type) sunk. Slow up after burning for several hours.

TANKER # 3 (San Pedro Karu type) sunk. The Commanding Officer realizes that proof of this sinking of this vessel is not completely conclusive. However, by reason of the evidence put forward in the narrative, it is felt that the storm which sank at 2147 belonged to this ship.

- 11 - Enclosure (A)

— page 159 —
4 - 4 SHIP CONVOY WITH ESCORT

No attack.

Lat. 27 - 23 N.  Long. 127 - 40 E.

0520 I  Sighted smoke dead ahead bearing 090° T, distance 15 miles.

0530 I  Dived, avoided.

0542 I  Smoke identified as a small convoy of one old type tanker and three old type freighters, escorted by a PC or small DD. Course 250, speed 5, zigzagging.

0555 I  Sighted IHEY JINA bearing 139° T, distance 15 miles.

1915 I  Surflood, full speed on all engines.

September 24, 1945

0400  Departed area. Set course for Midway.

September 25, 1945

0850  Sighted plane, dived.

1050  Surflooded.

September 27, 1945

0345 K  Sighted patrol vessel. Avoided.

September 30, 1945

Arrived Midway.

- 12 - Enclosure (A)

— page 160 —
11 0122

U.S.S. TRIGGER - Report of Sixth War Patrol (Cont'd)

(C) FEATHER:

Weather was uniformly excellent. Experienced heavy seas and high winds, 1st: 26-30 N., 123-30 E. on September 19-20, 1943. From wind force and directions, deduced that a typhoon was passing to eastward of our position, general course northeast.

(D) TIDAL INFORMATION:

Tidal information obtained was very meager. For two nights in succession, in general vicinity 1st: 27-30 N., 127-00 E. we experienced a set of 028°T, drift 2 xmots. During the day, submerged, no set was noticed. A northerly set was experienced on both passages between YOROI JIM and OXYMORROW JIM, about 1 kmot.

(E) NAVIGATIONAL AIDS:

No navigational aids were sighted.

-15- Enclosure (A)

— page 161 —
21

U.S.S. TRIGGER - Report of Sixth War Patrol. (Cont'd.)

(F) SHIP CONTACTS:

| NO. | DATE  | LAT. LONG. | TYPE(S) | INITIAL RANGE | ESTIMATED COURSE & SPEED | HOW CONTACTED | REMARKS |
|-----|-------|||||||
| 1   | 1530  | 27-10 N  | 2-tankers (old) | 20000 yds | 250 11 kts | Periscope | Sighted by #1 periscope with 15 feet extended above the surface. This illustrates the value of a large aperture periscope for day use as well as night. #2 periscope did not pick up target till range 15000 yards, in any one of these three sightings. Contact #2 - one ship sunk. Contact #3 - 4 sunk, 1 damaged. Contact #4 - avoided by diving. (All torpedoes expended). |
| 2   | 1715  | 27-10 N  | 2-freighters (1 new, 1 old) | 20000 yds | 070 8 kts | Periscope |        |
| 3   | 1510  | 26-27 N  | 3-tankers (1 new, 2 old) | 20000 yds | 080 8 kts | Periscope |        |
|     | 9/21/43 | 122-40 E | 3-freighters (old) |        |        |          |        |
|     |       |           | Land based bomber escort. |        |        |          |        |
| 4   | 0529  | 27-20 N  | 1-tanker (old) | 30000 yds | 250 8 kts | Sighted by bridge |        |
|     | 9/23/43 | 127-44 E | 3-freighters (old) |        |        |          |        |
|     |       |           | 1 PC type escort |        |        |          |        |
| 5   | 0645  | 29-34 N  | Small ship resem | 30000 yds | 130 8 kts | High periscope | Avoided. |
|     | 9/27/43 | 155-40 E | 3-freighters (old) |        |        |          |        |
|     |       |           | boat. |        |        |          |        |

— page 162 —
6. U.S.S. THIGGER - Report of Sixth War Patrol (Cont'd.)

(G) AIRCRAFT CONTACTS:

| NO. | TIME    | LAT. LONG. | TYPE(S)    | INITIAL RANGE | EST. COURSE SPEED | HOW COMPACTED | REMARKS |
|-----||||||||
| 1   | 0720 L  | 25-25 N   | Not seen, probably large. | 6 mi.        | Unknown        | Radar         | Dived. Plane did not sight us. |
| 2   | 1147 K  | 25-35 N   | Land-based 2 engine bomber | 5 mi.        | 290° T 200 kts | Sight        | Divded. Received 2 bombs. This plane saw us first. |
| 3   | 1020 K  | 25-55 N   | 4 eng. high wing flying boat. | 10 mi.       | 180° T 150 kts | High peziscope | Dived. Plane did not sight us. |
| 4   | 0925 I  | 27-12 N   | Single enc. low wing fighter and 2 eng. bomber | 6 mi.        | 000° T 200 kts | Simultaneous sight and radar | Dived. Planes did not sight us. |
| 5   | 1530 I  | 27-10 N   | 2 engine land based bomber | 7 mi.        | 250° T 11 kts (escorting convoy) | Periscope | Plane was escorting a convoy, circling above it. |
| 6   | 1545 I  | 26-27 N   | 2 engine land based bomber | 7 mi.        | 080° T 8 kts (escorting convoy) | Periscope | Plane was escorting a convoy, circling above it. |
| 7   | 0950 I  | 28-40 N   | 2 engine land based bomber | 6 mi.        | 270° T 200 kts | Sight        | Dived. Plane did not sight us. |

— page 163 —
U.S.S. TRIGGER - Report of Sixth War Patrol (Cont'd.)

CONFIDENTIAL

TORPEDO ATTACK REPORT

U.S.S. TRIGGER
Torpedo Attack No. One
Patrol No. Six

Time: 1145 Z
Date: Sept. 17, 1943
Lat. 27-10 N.
Long. 125-15 E.

TARGET DATA -- DAMAGE INFLICTED

Description: Second ship in two ship unescorted convoy. Similar GOSYO
NARTU, page 49, CHI 2P8 J, 8500 tons. Radar contact.
Visibility poor.

Ship(s) Sunk: None.

Ship(s) Damaged or
probably Sunk: None.

Damage Determined by: Saw two torpedoes hit, both duds.

Target draft: 20 Course: 070 Speed: 8 Range 1100 (at firing)

ON SHIP DATA

Speed: 5 Course: 345 Depth: Surface Angle: 15 L (at firing)

FIRE CONTROL AND TORPEDO DATA

Type Attack: Night surface, with radar, periscope, sound and TPT
bearings and ranges.

- 16 -
Enclosure (A)

— page 164 —
U.S.S. TRIGGER - Report of Sixth Year Patrol (Cont'd.)

CONFIDENTIAL

Tubes fired: #1 #2 #3 #4

Track Angle: --- Averaged 80 starboard ---

Gyro Angle: --- Averaged 15 left ---

Depth: --- Twelve feet ---

Power: --- H I G H ---

Hit or Miss: --- Two hits - Two misses ---

Erratic: --- None ---

Mark Torpedo: --- Mk. 14-S-A ---

Serial No.: 25451 25544 24286 20065

Mark Explorer: --- Mk. 6 - 1 ---

Serial No.: 17575 6153 6577 17451

Actuation Set: --- Contact ---

Actuation Actual: --- None ---

Mark Warhead: --- Mk. 16 ---

Serial No.: 10582 2125 1642 1927

Explosive: Torpex Torpex Torpex Torpex

Firing Interval: --- Eight Seconds ---

Type Spread: --- 0 - 0 - 4H - 4L ---

Sea Conditions: --- S H O O T H ---

Overnaut Activity: --- U.S.S. EISHNELL ---

Remarks: Both hits were duds.

* - Estimates only.
  It is impossible to get those data during action.

- 17 - Enclosure (A)

— page 165 —
25
L

U.S.S. TRIGGER

CONFIDENTIAL

TORPEDO ATTACK DATA

U.S.S. TRIGGER
TORPEDO ATTACK NO. TWO
PATROL NO. SIX
Time: 1523 Z
Date: Sept. 17, 1943
Lat. 27-31 N.
Long. 126-57 E.

TARGET DATA -- DAMAGE INFLICTED

Description: Unescorted new type freighter. Same target as attack #1. Radar contact. Visibility good - bright moon.

Ship(s) Sunk: The target. GOSIO MARU type - 3500 tons.

Ship(s) Damaged or probably sunk: None.

Damage determined by: Saw torpedo hit. Saw ship sink.

Target draft: 20 Course: 150 Speed: 8 Range: 1000 (at firing)

CONT. SHIP DATA

Speed: 4 Course: 010 Depth: 65 ft. Angle: 10 L (at firing)

FIRE CONTROL AND TORPEDO DATA

Type Attack: Night radar at 40 feet, radar end sound ranges, periscope bearings. Periscope bearings and periscope depth at time of firing.

- 16 - Enclosure (A)

— page 166 —
U.S.S. TRIGGER
TORPEDO ATTACK NO. TWO

Tubes Fired: #6 #5 #4 #3

Track Angle: --- Average 130 Port ---

Gyro Angle: --- Average 10 left ---

Depth: --- Twelve feet ---

Power: --- HIGH ---

Hit or Miss: --- Two hits - two misses ---

Erection: No No No No *

Mark Torpedo: --- Mk. 14-5-A ---

Serial No.: 23149 23161 24255 23608

Mark Exploder: --- Mk. 6 - 1 ---

Serial No.: 11846 10771 17667 17971

Actuation Set: --- Contact ---

Actuation Actual: --- One Contact ---

Mark Warhead: --- Mk. 16 ---

Serial No.: 15327 9279 1970 10455

Explosive: Torpex Torpex Torpex Torpex

Firing Interval: --- Eight Seconds ---

Type Spread: --- Middle - Middle - Bow - Stern ---

Sea Condition: --- S M O O T H ---

Overhaul Activity: --- U.S.S. BUSHNELL ---

Remarks: One hit was a dud.

* - Estimates only.
  It is impossible to get these data during action.

- 19 - Enclosure (A)

— page 170 —
1 0122
CONFIDENTIAL
TORPEDO ATTACK NO. FOUR
Tubes Fired: #4 #5 #6
Track Angle: Average 60 starboard
Gyro Angle: Average 0
Depth Set: Twelve feet
Power: HIGH
Hit or Miss: Two hits
Efficacy: No
Mark Torpedo: Mk. 14-5-A
Serial No.: 25547 24588 26552
Mark Explorer: Mk. 6 - 1
Serial No.: 6560 3426 6545
Actuation Set: Contact
Actuation Actual: Two contact
Mark Warhead: Mk. 16
Serial No.: 10420 2144 1041
Explosive: Torpex Torpex Torpex
Firing Interval: Eight Seconds
Type Spread: 0 - 3R - 3L
Sea Condition: SMOOTH
Overhaul Activity: U.S.S. BUSHWELL
Remarks: None.

* Estimates only.
It is impossible to get these data during action.

- 23 - Enclosure (A)

— page 171 —
1943
TORPEDO ATTACK REPORT
U.S.S. TRIGGER
TORPEDO ATTACK NO. FIVE
PATROL NO. SIX
Time: 1200 Z
Date: September 21, 1943
Lat. 26-27 N.
Long. 122-40 E.

TARGET DATA -- DAMAGE INFLICTED
Description: Old type tanker, third ship right hand column of six ship convoy.
Ship(s) Sunk: None.
Ship(s) Damaged or Probably Sunk: None.
Damage Determined by: ---
Target Depth: 20 Course: 100 Speed: 8 Range: 1000 (at firing)

OWN SHIP DATA
Speed: 10 Course: 150 Depth: Surface Angle: 0 (at firing)

FIRE CONTROL AND TORPEDO DATA
Type Attack: Night surface, with radar, periscope, and TBT bearings and ranges.

- 24 -
Enclosure (A)
31

— page 172 —
7
# 8
# 9
Average 50 starboard
Average 0
HIGH
No hits
No
Mk, 14-3-A
Serial No.
24884
24229
24235
Serial No.
11890
10320
6571
Excitation Set:
Contact
Excitation Actual:
None
Mark Threads:
Mk, 16
Serial No.
5729
4728
1897
Explosive:
Torpex
Torpex
Torpex
Firing interval:
EIGHT SECONDS
Type Spread:
0 - 3R - 3L
Sea Condition:
SMOOTH
Overall activity:
USS, DUSKNELL
Remarks:
None.

* - Estimates only.
  It is impossible to get these data during action.

- 25 -
Enclosure (A)

32

— page 174 —
0122

CONFIDENTIAL

Tube Fired:
# 10

Track Angle:
16 starboard

Gyro Angle:
10 right

Depth Set:
12 feet

Power:
High

Hit or Miss:
Hit

Erratic:
No

Mark Torpedo:
14-3-a

Serial No.:
24153

Mark Exploder:
No. 6-1

Serial No.:
10837

Actuation Set:
Contact
One contact

Actuation Actual:
16

Mark Warhead:
Serial No.:
1008

Explosive:
Torpex

Firing Interval:
--

Type Spread:
--

Sea Condition:
Smooth

Overhaul Activity:
USS BUSHNELL

Remarks:
None.

- 27 -

Enclosure (A)

34

— page 176 —
1  # 2
Tubes Fiord; Average 90 starboard
Gyro angle; Average 0
Depth Set; Twelve feet
Power; H I G H
Hit or Miss; Two hits
Error; No
Mark Torpedo; Mk. 14-3-1
Serial No.; 39506 3554
Mark Explorer; Mk. 6-1
Serial No.; 6437 6586
Actuation Set; Contact
Actuation Actual; Two Contact
Mark Warhead; Mk. 16
Serial No.; 3619 1989
Explosive; Torpex Torpex
Firing Interval; Eight Seconds
Type Spread; Two degrees
Sea Condition; S M O T H
Overhaul Activity; U.S.S. BUSHNELL
Remarks; None.

* Estimates only.
It is impossible to get these data during action.

- 29 - Enclosure (A)

— page 177 —
1
TORPEDO ATTACK REPORT

U.S.S. TRIGGER
TORPEDO ATTACK NO. EIGHT
PATROL NO. SIX
Time: 1336 Z
Date: Sept. 21, 1943
Lat: 26-27 N.
Long: 122-40 E.

TARGET DATA -- DANGER INFLICTED

Description: Same target was attacked # 7, damaged.

Ship(s) Sunk: None.

Ship(s) Damaged or Probably Sunk: None.

Damage Determined by: No results. One dud.

Target Draft: 30 Course: 345 Speed: 0 Range: 2200 (at firing)

OWN. SHIP DATA

Speed: 10 Course: 236 Depth: Surface Angle: 0 (at firing)

FIRE CONTROL AND TORPEDO DATA

Type Attack: Night surface, with radar, periscope, sound, and TBT bearings and ranges.

- 30 - Enclosure (A)

37

— page 178 —
U.S.S. TRIGGER
TORPEDO ATTACK NO. EIGHT.

CONFIDENTIAL

Tubes Fired: #10 #7
Track Angle: --- Average 110 port ---
Gyro Angle: --- Average 0 ---
Depth Set: --- Twelve feet
Power: --- H I G H
Hit or Miss: --- One miss, one dud ---
Erratic: --- No ---
Mark Torpedo: --- Mk. 14-3-A 23462
Serial No.: 23195
Mark Exploder: --- Mk. 6-1
Serial No.: 6608 6379
Actuation Set: --- Contact ---
Actuation Actual: --- Mk. 16
Mark Turned: --- Mk. 16
Serial No.: 6960 2086
Explosive: Torpex Torpex
Firing Interval: --- Eight seconds ---
Type Spread: --- Two degrees ---
Sea Condition: --- S M O O T H
Overnight Activity: --- U.S.S. BUSHNELL
Remarks: The single hit was a dud.

* Estimates only.
It is impossible to get these data during action.

- 31 - Enclosure (A)

— page 179 —
TORPEDO ATTACK REPORT
U.S.S. TRIGGER
TORPEDO ATTACK NO. NINE
PATROL NO. SIX
Time: 1522 Z
Date: Sept. 21, 1945.
Lat: 26-27 N.
Long: 122-40 E.

TARGET DATA -- DAMAGE INFLICTED

Description: Same target as attack #7, damaged.

Ship(s) Sunk: None.

Ship(s) Damaged or Probably Sunk: None.

Damage Determined by: No results. One dud.

Target Draft: 30 Course: 340 Speed: 4 Ranges: 1000 (at firing)

GUN SHIP DATA

Speed: 4 Course: 260 Depth: 40 ft. Angle: 0 (at firing)

FIRE CONTROL AND TORPEDO DATA

Type Attack: Submerged, night radar attack, using periscope bearings, sound bearings and ranges, and radar ranges.

- 32 -
Enclosure (A)

39

— page 180 —
U.S.S. THIAGER
TORPEDO ATTACK NO. NINE.

Tubos Fiord:
    # 8    # 9
Track Angle:
    - Average 90 port
Gyro Angle:
    - Average 0
Depth Set:
    - Twelve Foot
Power:
    - HIGH
Hit or Miss:
    - One miss, one dud
Erratic:
    - No
Mark Torpedo:
    - Mk. 16-3-A
Serial No.:
    24243    23459
Mark Explorer:
    - Mk. 6 - 1
Serial No.:
    3781    14250
Latution Set:
    - Contact
Latution Actual
    - Mk. 16
Serial No.:
    1877    6260
Explosive:
    Torpex    Torpex
Firing Interval:
    - Eight seconds
Type Spread:
    1/4 inside bow    1/4 inside stern
Sea condition:
    - SMOKE
Oversalt Activity:
    - U.S.S. BUSHNELL
Remarks:
    The hit was a dud.

* Estimates only.
It is impossible to get these data during action.

- 33. - Enclosure (A)

40

— page 183 —
5.3. TRIGGER - Report of Sixth War Patrol (Cont'd.)

(K) RADAR (Cont'd.)

SJ RADAR

The SJ radar operated very satisfactorily during the time on station. Maximum land range was 40,000 yards and maximum range on a convoy was 16,000 yards. A rain squall was picked up at 3,000 yards (See PPI notes).

SD RADAR

No trouble was experienced with the SD radar during the entire patrol. Maximum land echo was 30 miles, while on patrol the radar detected three planes. In each case the range was about 6 miles. There was no indication of any irregularity in antenna radiation pattern.

REMOTE PLAN POSITION INDICATOR

This was one of the three PPI units installed at Pearl Harbor for experimental purposes. The operation was very satisfactory and extremely helpful during the night approach on the convoy September 21. It is believed that, as operational experience is gained, the PPI will prove invaluable for night attacks.

The disadvantages of the present unit are:

(1) The large size. By reducing the unused space in the cabinet, this same unit could be made one-fourth its present size.
(2) Range scale too great. A shorter range scale (about 8000 yards) should be provided instead of the present 15,000 yard scale. The short range scale could be best used when closing convoys.
(3) The present one-way antenna rotation control should be replaced by a two-way antenna rotation control with a variation in antenna speed from zero to ten rpms (similar to the "Sail Onset" antenna control).

An unusually severe and concentrated rain squall was encountered during this patrol. Below are shown diagrams of its appearance at various ranges on the PPI:

- 7000 Yds.
-

— page 187 —
U.S.S. TRIGGER - Report of Sixth War Patrol (Cont'd.)

(U) REEARMS (Cont'd.)

It is strongly recommended that submarines be equipped with a PPI as soon as practicable.

During the night surface approaches the Commanding Officer remained in the conning tower and conning the ship. The Executive Officer manned the PPI and acted as safety officer. In this type ship, with the TDC, SJ radar, PPI, sound, Plot, etc. all in the conning tower, the Commanding Officer feels that the approach should be made from the conning tower. The approach officer then has positive control of all the fire control equipment at his disposal. The night submerged approaches were made in a similar manner with the Executive Officer manning the periscope and the Commanding Officer coming the ship.

With such a system, the Commanding Officer must have the utmost confidence in his Executive Officer or Co-approach officer. In the case of the Trigger, this confidence was more than well placed. Lieutenant E. L. Beal, Jr., USN, is a most outstanding naval officer. His desire to come to grips with the enemy and coolness under fire was an inspiration to the entire ship.

- 40 - Enclosure (A)

— page 188 —
1. Commander Submarine Division One Hundred Two.
To: Commander-in-Chief, United States Fleet.
Via: (1) Commander Submarine Force, Pacific Fleet,
    (2) Commander Submarine Force, Pacific Fleet.

Subject: U.S.S. THIEGER-Sixth War Patrol; Comment on.

1. The Sixth War Patrol of the THIEGER was conducted in the East China sea. It covered a period of twenty nine days, eight of which were spent in the area. It was terminated due to expenditure of all torpedoes. It was Lt. Commander Dornin's first patrol in command.

2. Nine attacks were delivered against vessels in two separate contacts. All attacks were delivered at night, seven on the surface and two submerged. Unmistaken evidence of excluder failure was observed in one attack and evidence of probable failure was noted in two other attacks. Despise these failures, however an impressive amount of enemy tonnage was sunk.

First Battle - Two attacks - Gosyo Iaru - sunk.

Excellent position was attained for a night surface attack at 1100 yard range. Two of the four torpedoes fired on an 80" starboard track were observed to hit and fail to explode. A reload and an end-around run preceded the next attack. In every bright moonlight a radar-depth approach and a skillful periscope-depth attack upon the now wary target produced one very effective hit out of a four torpedo salvo which caused the ship to sink in two minutes.

Second Battle - Seven attacks - six ship Convoy - Four ships sunk, One damaged.

A three and one-half hour aggressive night surface battle in which all fire-control instruments were skillfully employed, including a recently installed P.P.I., resulted in the sinking of four vessels, three of which were tankers, and the damaging of one other cargo vessel which probably sank. Each attack was pressed home in a cool and deliberate manner despite heavy, but fortunately erratic, enemy gun fire. All attacks were hampered by the lack of the bridge - conning tower communication system which unfortunately had been demolished early in the patrol when Gosyo Iaru boilers exploded. One of the attacks failed due to this lack of communications. Two other follow-up attacks on a damaged ship failed probably due to dual exploders.

— page 189 —
3. Instruments:
    Particular attention is invited to the Commanding Officer's remarks under paragraph (V) "general." If our submarines are properly equipped with an efficient night periscope, a reliable bridge-conning tower communication system and a large scale P.P.I., it is certain that this attack will become far more popular with commanding officers. Procurement and installation of this large head light-traced periscope and the large scale PPI at earliest practicable date is urged. Every effort also should be made to speed-up delivery of material for shore proof bridge speakers and the 25 MCD bridge to coming tower talkback system.

4. Material:
    TARGET RATI will be conducted by SPARRY in the normal period. A complete overall of the hydrographic and air containing systems appears to be necessary. An attempt will be made to rebuild the bridge-conning tower communication system with such material as SPARRY has on hand.

5. The Commanding Officer, Officers and crew of TAI-GER are confident upon a highly successful and well conducted patrol which initiated severe damage upon this enemy.

— page 190 —
1. The Commander Submarine Squadron Ten.
To: The Commander in Chief, United States Fleet.
Via: (1) The Commander in Chief, United States, Fleet.
(2) The Commander in Chief, United States, Pacific Fleet.

Subject: U.S.S. TAIGGER - Report of Sixth War Patrol.

1. This, the Sixth War Patrol of the U.S.S. TAIGGER was an outstanding patrol, of short duration, but highly destructive from the standpoint of the enemy.

2. This patrol was terminated when the TAIGGER found a six ship convoy to work on. In three and one half hours, four of the six ships had been sunk and another was badly damaged. Only one vessel escaped unharmed and that one only because the TAIGGER had expended all its torpedoes. Sixteen torpedoes were fired during this short period and seven hits made.

3. It is gratifying to note that three of the five enemy vessels sunk by the TAIGGER during this patrol were tankers. This is an effective blow to the enemy for he apparently already suffers from a serious shortage in that category of ships.

4. Attention is invited to the valuable performance of the Plan Position Indicator. The remarks of the Commander Officer concerning this radar are concurred in.

5. The Commander Submarine Squadron Ten congratulates the Commanding Officer, officers, and men of the U.S.S. TAIGGER for this outstanding war patrol. It is recommended that the TAIGGER be credited with inflicting the following damage on the enemy:

| SSN | Tonnage | Damage |
|-----|||
| 1   | 3,592   | 8,592  |
| 1   | 6,662   | 6,662  |
| 1   | 9,974   | 9,974  |
| 1   | 7,499   | 7,499  |
| 1   | 7,269   | 7,269  |
| 1   | 7,269

— page 192 —
1d
FF12-10/A16-3(8)/(16) SUBMARINE FORCE, PACIFIC FLEET
Serial 01.69
CONFIDENTIAL
THIRD ENDORSEMENT to
TRIGGER Report of
Sixth War Patrol.
COMMUNICATOR PATROL REPORT NO. 279
U.S.S. TRIGGER - SIXTH WAR PATROL.
From: The Commander Submarine Force, Pacific Fleet.
To: The Commander-in-Chief, United States Fleet.
Via: The Commander-in-Chief, U. S. Pacific Fleet.
Subject: U.S.S. TRIGGER (SS237) - Report of Sixth War Patrol.
(1 September to 30 September 1943).

1. The sixth war patrol of the TRIGGER was the first for the new
   Commanding Officer, as such.

2. The patrol was extremely successful, aggressive, and brisk. The
   TRIGGER fired all of its torpedoes at two convoys after being in area but nine
   days.

3. Particularly outstanding was the night radar attack on the six
   ship convoy. Using the experimental PFI accidentally, the TRIGGER made an
   excellent estimate of the situation, conducted all attacks efficiently and
   aggressively, and in three and one-half hours sank three enemy tankers, one
   freighter, and probably sank a second freighter.

4. The decided advantage of PFI in quickly working out the fire-
   control problems and also keeping the entire convoy picture present during the
   attack was most evident. This instrument will greatly improve the efficiency
   of night attacks.

5. This patrol is considered successful for the purpose of Combat
   Insignia Award.

6. The Commander Submarine Force, Pacific Fleet, congratulates the
   Commanding Officer, officers, and crew for this outstanding sixth war patrol.
   The TRIGGER is credited with inflicting the following damage to the enemy:

SUNK
1 - Tanker (NIFTON MARU class) - 9,974 tons
1 - Tanker (SYOYO MARU class) - 7,429 tons
1 - Tanker (SAN PEDRO MARU class) - 7,265 tons
1 - Freighter (GOSYO MARU class) - 8,592 tons
1 - Freighter (ARGUN MARU class) - 6,662 tons

TOTAL: 39,996 tons

57647 FILMED

— page 193 —
1-10/116-3(8)/(16) SUBMARINE FORCE, PACIFIC FLEET 1d

Serial 01469

CONFIDENTIAL

THIRD ENDORSEMENT to
TRIGGER Report of
Sixth War Patrol.

COMBUSPAC PATROL REPORT NO. 279
U.S.S. TRIGGER - SIXTH WAR PATROL.

Subject: U.S.S. TRIGGER (SS237) - Report of Sixth War Patrol.
(1 September to 30 September 1943).

D A M A G E D

1 - Freighter (LIMA MUR class) - 6,989 tons

DISTRIBUTION:
(Complete Reports) (5)
Cominch (5)
CINCO (6)
CINCE (1)
Intcl. Con. Fac. (1)
Ocean Aircos (1)
Comscrvpac (1)
(Adv.Baso Plan.Unit) (1)
Cincident (2)
Comsubelant (8)
S/M School, NL (2)
Comscope (2)
Comsoscscope (1)
Comsubscopescope (2)
CTF 72 (2)
CTF 16 (1)
Comsubpsce (18)
SHEILD, MT (2)
ComsubpsceSubordcom (2)
All Squadron and Div.
Commcndors, Subspace (2)
U.S.S. TRIGGER (1)
(Endorsements only) (1)
All Subcarriers, Subspace (1).

d. W. WOODRUFF, J.R., Flag Secretary.

— page 194 —
1 0176
SS237/A16-3
Serial ( 038 )
Care of Fleet Post Office
San Francisco, California

DECLASSIFIED
From: The Commanding Officer.
To: The Commander in Chief, United States Fleet.
Via: The Commander Submarine Division ONE HUNDRED TWO.
The Commander Submarine Squadron TEN.
The Commander Submarine Force, Pacific Fleet.

Subject: U.S.S. TRIGGER - Report of War Patrol No. SEVEN.

ENCLOSURE: (A) Subject Report.
(B) Track Chart (for ComSubPac)

1. Enclosure (A) covering the SEVENTH war patrol of this vessel conducted in the East China and Yellow Seas during the period October 22, 1943 to December 8, 1943, is forwarded herewith.

R. E. DORNIN
FILMED
CA 1257

— page 195 —
1 0176
U.S.S. TRIGGER - Report of Seventh War Patrol.

(A) PROLOGUE:
Arrived Midway after 6th patrol on September 30, 1943. Normal two week refit accomplished by USS SPERRY. New bridge speakers and communication system designed and installed by the tender, experimental cut down bridge, and a complete overhaul of the hydraulic plant were the major items accomplished. Three days training, including one night, and the ship was ready for sea on October 22.

(B) NARRATIVE:
October 22
1500 Y Departed Midway on 7th War Patrol.
October 22 - 30
Conducted training exercises enroute.
October 30
0900 K Dived for a plane. Took this opportunity to check torpedoes.
1244 K Surfaced.
November 1
0735 I Sighted formation of 5 unidentified planes, heading south at high altitude. They passed out of sight almost immediately, and we did not dive.

FIRST CONTACT - LARGE ESCORTED CONVOY.
Lat. 29-35 N. Long. 134-51 E.

2025 I Radar contact, several ships, range 10,000 yards. Commenced tracking on port side of the convoy, which consisted of 12 or more ships, zigzagging from 140°T to 180°T, speed 8. There were at least one escort ahead and one astern, persistently patrolling the port side of the convoy. Therefore increased speed and crossed ahead, repeating tracking procedure on the right flank. The convoy disposition appeared to be an attempt at two columns, but the zigzagging made for poor station keeping, to say the least. It was so dark that the escorts at 1800 yards and the ships of the convoy at 3000 yards could not be made out.

2130 I Started in for an attack on the starboard beam. Broke off when the convoy zigged away, and two more escorts suddenly showed up on this side, making an estimated total of four escorts. During

— page 196 —
2130 I (Cont'd.)
the next half hour made several false starts and balked each time because of convoy 3igs, the unusual perspicacity of the escorts, and the uncertainty as to convoy disposition.

FIRST ATTACK
#1 FRIGATE, 7000 TONS (CLASS UNKNOW), SUNK.
#2 FRIGATE, 7000 TONS (CLASS UNKNOW), TROGABLY SUNK.

Lat. 29-12 N. Long. 134-37 E.

2200 I Started in for attack, distance to patrolling escorts having increased to approximately 3000 yards. Original idea was to fire ten torpedoes at the three nearest ships. However, at about 2210, PPI got the leading escort closing in, and at the same time the two leading ships, sighted, presenting a 0° or 180° angle on the bow. Two frigates, one in the near column and one in the far column, were overlapping and still presented their broadsides, so at

2217 I fired three torpedoes forward, range 1400 yards, 110 starboard track, GA O, at the near (#1) FRIGHTER, figuring we had a good chance of hitting the far (#2) FRIGHTER also. Both were 3 island type freighters of about 7000 tons.

2218 I One hit in the bow of #1 FRIGHTER, 60 seconds after firing. A large column of spray and smoke enveloped his forward part. He was last seen down by the bow, definitely sinking.

2218 1/2 I One hit andships in #2 FRIGHTER, 90 seconds after firing. This was a terrific explosion. Smoke and debris rose over the tops of his masts, and continued to rise and spread until not only the remains of this ship, but also several other ships, were obscured. Smoke and poor visibility prevented seeing this one sink.

2219 I Swing left to reverse course and went ahead full on four engines. In the meantime the convoy scattered in all directions.

2221 I PPI reported a pip on the starboard bow and one astern, range about 1800 yards to each, and bridge then saw two escorts coming out of the smoke with zero angles on their bows and boncs in their teeth.

2222 I Made quick dive to 300 feet.

2223 I Heard somebody's boilers explode.

— page 197 —
1 0176
U.S.S. STRIKER - Report of Seventh Far Patrol (Cont'd.)
November 1 (Cont'd.)
2232 I Commenced receiving 20 depth charges from two escorts, pinging and making runs alternately.
November 2
0015 I Escorts still echo ranging, but had apparently lost contact.
0025 I Radar depth, all clear.
0028 I Commenced reload.
0043 I Two distant explosions.
0048 I Reload completed.
0050 I Surfaced, full speed on four engines. Course 160°T, attempting to regain contact.
SECOND ATTACK
FRIGHTER, HEDIUM 3 ISLAND TYPE, 7000 TONS, DAYAGED
Lat. 28-55 N. Long. 134-43 E.
0145 I Radar contact. Target tracked on course 310° T, speed 8, not zigzagging.
0203 I Fired three torpedoes forward, range 1200 yards, 105 starboard track, GA 0. One hit. Target covered with smoke and steam.
THIRD ATTACK
SAME TARGET, SUNK.
0208 I Target not sinking. Commenced another approach. Tracked target on course 010, speed 5.
0210 I The FRIGHTER opened fire with bow and stern guns, but no shells landed even dangerously close.
0216 I Fired three torpedoes forward, range 1700 yards, 90 starboard track, GA 0. Two hits in forward part of the target.
0220 I FRIGHTER sank, bow first in a vertical plunge. Headed in that direction in hopes of picking up survivors. No luck. They would have been hard to see, in any event.
0228 I Changed course to 160°T, at full speed.

-3- Enclosure (A). 10

— page 198 —
U.S.S. TRIGGER - Report of Seventh War Patrol (Cont'd.)

November 2 (Cont'd.)

POURTH ATTACK
TANKER, 8000 TONS (CLASS UNKNOWN) SINK

Lat. 28-49 N.  Long. 134-50 E.

0245 I  Radar contact. Commenced approach and tracking.

0310 I  Target in sight.

0315 I  Target identified as a TANKER of about 8000 tons, course 130° T, speed 8.

0321 I  Fired three torpedoes forward, range 1200 yards, 90 starboard track, GA 0.

0322 I  Three hits. Target appeared to disintegrate. When the smoke cleared away she was awash aft, and her bow was broken off and projected straight up in the air. The bow sank at once, but the after two thirds remained awash for two minutes, finally going under in a flat dive.

0327 I  Ran through a large diesel oil slick. Heard indescribable screaming and yelling from ahead, and saw a group of two or three life boats and about five life rafts.

0330 I  Reversed course and searched for survivors, but could find only one shattered empty life boat. Finally departed, course 160° T, at full speed.

0545 I  No further contacts; dived. Rough weather and poor visibility throughout day (from 500 to 5000 yards) precluded any surface search.

0855 I  Heard four distant explosions.

1732 I  Surfaced, transmitted message on course 090° T, then came to 290° T at 16 knots.

2315 I  Heard yells and moans on the port beam, and passed 25 yards from a life raft. Reversed course, stopped abreast the raft, about 20 feet away. There were three men in all, but they made no effort to swim over to the ship. During maneuvers to bring them closer alongside, the raft drifted into the darkness, and all efforts to regain contact proved unavailing. In the heavy seas and high wind, which grew progressively worse during the night and next day, it is doubtful that those men survived.

- 4 -

Enclosure (A).

— page 199 —
1 0176
U.S.S. TRIGGER - Report of Seventh War Patrol (Cont'd.)
November 3

SECOND CONTACT - NO ATTACK
TWO DESTROYERS
Lat. 29-24 N. Long. 132-57 E.

0540 I In the dawn, saw two destroyers on the horizon. No radar contact. Very heavy seas, distance to the track too great for a submerged approach. They were apparently on course 130° T, speed 15.

0630 I Lost contact.

November 4

Uncomfortable. Surface patrol.

November 5

THIRD CONTACT
CONVOY WITH SURFACE AND AIR COVERAGE
Lat. 29-08 N. Long. 129-37 E.

0625 I Divcd 20 miles southward of AKUSEMI JIMA. Went deep for density layer information, then commenced submerged patrol.

0708 I Sighted smoke bearing 223° T, commenced approach. Smoke developed into a 3 ship convoy, with a destroyer of the NOMI class escorting, consisting of one large 9000 ton FREIGHTER, and two medium 3 island type of about 6000 tons. There was air coverage consisting of two small landplanes.

0745 I The convoy took an unfortunate zig away, which took us out of position for the largest ship, but left us in good position for the other two.

0800 I Another zig away, leaving a long range shot on the second ship and a good shot at the third. Unfortunately had but four torpedoes left forward.

FIFTH ATTACK
TWO MEDIUM 3 ISLAND FREIGHTERS, MISSED
Lat. 29-08 N. Long. 129-37 E.

0814 I Fired three bow torpedoes at the second FREIGHTER, range 24°0 yards, 110 starboard track, GA O.

- 5 -
Enclosure (A).

— page 200 —
0815 I Fired the last bow torpedo at the third FREIGHTER, range 1200, 90 starboard track, GA 10 L. Went deep to avoid depth bombs.

0820 I Heard two explosions. Time too great for hits.

0830 I Commenced receiving about 20 depth charges. The destroyer seemed to have us well located, but his runs were only fair.

0926 I Thinking we were well clear, came to periscope depth. For- iscope had hardly been raised, when at

0926.1 I received 5 depth charges or bombs very close aboard. Scared hell out of us. No screws were heard, and the echo ranging was still off in the distance. Concluded those were aircraft bombs and went deep again. The destroyer regained contact, guided by the planes, no doubt, and dropped a few more depth charges.

1215 I Periscope depth. DD still in sight, evidently patrolling a retiring search curve, still echo ranging, but distant about 10,000 yards.

1400 I Sighted a plane bearing 190° T, heading north.

1836 I Surfaced heading cast at 13 knots.

November 6

0602 I Div'd for trim and density layer.

0633 I Surfaced, on course 270° T, intending to patrol on surface.

0636 I Sighted two planes astern. They turned and headed toward us.

0636 I Div'd.

November 7

Conducting submerged patrol, near NANSEI SHOTO Islands.

1206 I Sighted periscope bearing 155° T, distance about 1500 yards. Watchd it lowered. (4th Contact).

November 8

0430 I Passed through NANSEI SHOTO Islands.

- 6 - Enclosure (A).

— page 201 —
1 0176
U.S.S. TRIGGER - Report of Seventh War Patrol (Cont'd.)
November 9
0200 I Entered Area.
November 9 - 13
FIFTH CONTACT
9 SHIP CONVOY WITH 4 ESCORTS
Lat. 33-05 N. Long. 125-13 E.
0300 I Slighted smoke of several ships. Because of extraordinarily bright moonlight, could not close to radar range.
0415 I Tracking by TBT boring and estimates of range and angle on the bow, determined the convoy to be on base course 250° T, zigzagging from 210 to 290, speed 8. Either three or four escorts, a total of about twelve ships.
0459 I In position ahead of convoy, estimated range 11,000 yards. Divd. Still unable to get radar ranges. Target in sight through periscope, wont to 60 feet.
SIXTH ATTACK
10,000 TON TRANSPORT, SINK
Lat. 32-57 N. Long. 125-06 E.
0515 I Commenced moonlight periscope approach heading for center of the convoy.
0535 I Passed bottom on the patrolling destroyer screen (MOMI class DD's), distance 1000 yards to each of the three. The destroyers were echo-ranging and patrolling on station. One made a knuckle at 700 yards right around us, and he apparently had us with his echo-ranging. However, he kept on going.
0545 I The convoy zigged towards, placing us directly between two columns of ships. Three ships, overlapping and presenting a perfect bow tube shot, passed 700 yards ahead, and the last and largest ship presented a zero angle on the bow, range 2000 yards. Selected the latter for the target, and swung left at full speed, lining up for a stern tube shot. Had there been any torpedoes left forward, we would have had a field day in this convoy.

— page 202 —
0555 I  Fired four torpedoes aft, range 600 yards, 100 starboard track, GA O. Two hits seen, one under the stack and one aft. "Sent to 200 feet (depth of water 240) with the rear escort heading for us at about 800 yards range.

0602 I  Received 5 very excellent depth charges. Pound density layer and the escort lost contact, but remained in the near vicinity, altarmotly listening and echo-ranging.

0840 I  Periscope depth. Saw the destroyer and another ship picking up survivors, and an unidentified plane patrolling at the scene of the sinking. Headed toward the spot. The rescue ship had booms rigged out and boats in the water, and was making continual wild and sudden manouvers. The patrolling destroyer was slowly circling the area. About an hour before we arrived there, rescue ship, destroyer and plane departed.

1520 I  Reached scene of sinking and found a huge mass of debris, consisting of a great streak of coal dust, many barrels and oil drums, five life boats, several rafts, shattered hatch covers, life belts, and what appeared to be a section of the bridge of the sunken ship. Took pictures.

1620 I  Sighted and photographed a red flag on the end of a bamboo pole, lashed to a can and floating vertically.

The sunken ship was a large new type passenger-cargo ship, not illustrated in ONI 208-J. She is believed to have been a troop transport because of the fact that it took approximately 5 hours to pick up the survivors and that she was carrying a large deck cargo.

November 14 - 16

Patrolling submerged in the vicinity of QUELPART Island.

November 16

Encountered a total of 7 patrol boats (possibly some ropcats), 5 while submerged, 2 while surfaced at night. (6th Contact). Suspecting presonoe of radar on MARA TO, near QUELPART Island, headed southwest at high speed, then doubled back to northward, proceeding to Yellow Sea.

November 17 - 18

These days entirely wasted, because of a storm.

- 8 -

Enclosure (A).

— page 203 —
1 0176
U.S.S. TRIGGER - Report of Seventh War Patrol (Cont'd.)

November 19

0640 I Div'd for trim and density layer information.

0800 I Surfaced, intonding to patrol on the surface in order to increase visibility. This is the first day weather conditions made this possible.

0801 I SD radar contact at two miles. Div'd. No plane seen either before or after diving. Considered it probable that the pip was due to electrical disturbances in the boat; so at

0900 I surfaced.

0934 I Plane sighted about two miles away. Div'd. Stayed down. Evidently a fairly close air patrol is maintained over the Yellow Sea - or else we have been unusually unlucky.

November 20

0640 I Div'd 5 miles off CHOSAN KAN.

1145 I Sighted smoke between CHOSAN KAN and HAKURIE TO. Commenced approach. (7th Contact).

1208 I Lost sight of smoke. Believe the ship slipped down the coast close inshore, doubled CHOSAN KAN and then ran between HAKURIE TO and the KOREMN mainland.

1232 I Surfaced for a better look, about four miles off shore. The smoke was seen again, passing out of sight behind HAKURIE TO.

1239 I Sighted a plane distant about four miles. Div'd.

1430 I Sighted patrol boat. Avoided. (8th Contact).

1914 I Surfaced and started south because of lack of worthwhile contacts. During three days in the Yellow Sea; rain, snow, sleet, heavy seas, intense cold, and low visibility gave only six hours of what might be termed effective patrol. Will run down the 20 fathom curve close off the west coast of CHOSEN, in hopes of picking up coastal traffic.

November 21

0638 I Div'd in 20 fathoms of water off MOKUTOKU TO.

1239 I Sighted smoke, proved to be a very small coastal FREIGHTER, passing close inshore. Too small for torpedoes and too close to MOKUTOKU TO (five miles) to use 3" gun. (9th Contact).

- 9 -
Enclosure (A).

— page 204 —
1340 I Headed closer inshore.
1707 I Sighted patrol boat resembling a converted yacht. Depth of
    wntor 12 to 15 fathoms at tho time, not a comfortable situation.
    He passed close aboard, but evidently did not suspect our presence.
    (10th Contact).
1832 I Surfaced, full speed on all engines.
2027 I Rounded WEST CLIFFORD Island, distance 5 miles.
ELEVENTH CONTACT
SEVENTH ATTACK
5000 TON FREIGHTER, SUNK
Lat. 36-40 N. Long. 125-31 E.
2130 I Radar contact. Very dark night and target could not be seen
    until range decreased to 3500 yards. Commenced approach. Bo-
    cause of tho necessity of firing stern tubes, tracked from
    directly ahead, settling as nearly as possible upon the same
    course and speed as the target. The target course and speed
    were determined as 300° T, 7 knots.
2215 I When the range had decreased to 2000 yards, pulled off the
    track a distance of 300 yards and stopped, swinging slowly to
    the right and kicking ahead occasionally to keep stern toward
    him, and opening out so as to be 1000 yards from the track at
    the firing point.
2237 I Firod four torpedoes aft, range 1000 yards, 90 starboard track,
    GA O. Two hits. Target started down by the bow.
2238 I Started around to head for deep water, and observo sinking.
2240 I The target is straight up and down, his bow on bottom (sound-
    ing 24 fathoms). His stern slowly sagged, and finally sank with
    a rush, at 2247 I. He was a new typo medium size freighter, with
    cruiser stern, composite superstructure, Japanese clipper bow,
    similar to KIMISIMA MARU, page 118 ONI 208-J.

November 22
0322 I Radar contact. Avoided. Vessel not seen. (12th Contact).
November 24
0406 I Left area.

- 10 - Enclosure (A).

— page 206 —
0176

U.S.S. TRIGGER - Report of Seventh War Patrol (Cont'd.)

November 27

0841 I Div'd for plane. Radar contact. Not soon.

1013 I Surfaced.

December 3

Arrived midway.

December 8

Arrived Pearl.

(C) WEATHER:

No unusual conditions were encountered. Weather in the Yellow Sea was uniformly bad, with high winds, heavy seas, and freezing temperatures. Much rain and sleet, and a very light touch of snow were experienced.

(D) TIDAL INFORMATION:

In the vicinity of the NANSEN SHOTO Islands, a 2 - 3 knot current setting 055° T was experienced. In the Yellow Sea off CHOSAN KAN, a 3 knot variable current, as indicated on H.O. Chart # 5397, was experienced.

(E) NAVIGATIONAL AIDS:

The following lights were observed to be exhibiting the correct characteristics:

KOKUZAN TO; MARA TO; OSEI TO; NOKUTOKU TO; KAKUREPPI RETTO and SHOSEI TO.

- 11 -

Enclosure (A).

— page 207 —
1. 2300 Z: 30-11 N :B:plane
: 2. 0239 Z: 29-39 N :Unidentified
: 3. 2330 Z: 29-08 N :2 land planes;4 miles: 250 K
: 4. 1500 Z: 29-02 N :1 land plane;4 miles: 000P T
: 5. 2136 Z: 29-04 N :2 land planes;6 miles:000P T
: 6. 2340 Z: 32-57 N :Seaplane
: 7. 2301 Z: 36-11 N :Unknown
: 8. 0034 Z: 36-12 N :Seaplane
: 9. 0339 Z: 38-12 N :Seaplane
: 10. 2301 Z: 30-34 N :Unknown
: 11. 2301 Z: 14-31 E :

— page 208 —
14 - Enclosure (A).

U.S.S. TRIGGER - Report of Seventh War Patrol (Cont'd.)

(H) ATTACK DATA:
TORPEDO ATTACK REPORT FORM
U.S.S. TRIGGER
Time: 2217 I
Torpedo Attack No. ONE. Patrol No. SEVEN.
Date: November 1
Lat. 29-12 N. Long. 134-37 E.

TARGET DATA - DAMAGE INFLICTED
Description: Two 3 island freighters. (Glass unknown) 7000 tons each.
Ship(s) sunk: One of the above.
Ship(s) damaged or
probably sunk: One of the above, probably sunk.
Damage determined by: Saw torpedoes hit. Saw one ship sinking, saw other damaged, probably sunk.
Target draft: 20 ft.
Course: 160. Speed: 8. Range: 1400 (at 2400 firing)

OWN SHIP DATA
Speed: 10. Course: 100. Depth: Surface. Angle: 0 (at firing)

FIRE CONTROL AND TORPEDO DATA
Type Attack: Night surface, using Radar and TBT.
Tubes fired: #1 #2 #3
Track angles: 110 S 10 ft High High High
Gyro Angle: 0
Depth set: 10 ft High High High
Power: Two hits
Hit or miss: No No No
Erratic: No 14-3-A 14-3-A 14-3-A
Mark Torpedo: 23762 24604 23355
Serial No.: 6-1 6-1 6-1
Mark Exploder: 6403 5927 6748
Serial No.: Contact Contact Contact
Actuation Set: Contact Contact Contact
Actuation Actual: 16 16 16
Mark Warhead: 2509 1744 1149
Serial No.: Torpex Torpex Torpex
Explosive: 8 Sec 8 Sec 8 Sec
Firing Interval: 8 Sec 4" ahead 4" astern
Type Spread: MOT
Sea Condition: State four
Overhaul activity: U.S.S. SPERRY
Remarks: Hot, straight and normal. One ship sunk, one probably sunk.

— page 209 —
U.S.S. TRIGGER - Report of Seventh War Patrol (Cont'd.)

(H) ATTACK DATA (Cont'd.) TORPEDO ATTACK REPORT FORM

U.S.S. TRIGGER Torpedo Attack No. THREE. Patrol No. SEVEN. Time: 0216 I Date: November 2 Lat. 28-55 N. Long. 134-43 E.

TARGET DATA - DAMAGE INFLICTED

Description: Same target as attack #2. 3 island froighter, class unknown, about 7000 tons.

Ship(s) sunk: The target.

Ship(s) damaged or probably sunk: ---

Damage determined by: Saw two torpedoes hit. Saw ship sink.

Target draft: 20 ft. Course: 010. Speed: 5. Range: 1700 (at firing)

OWN SHIP DATA

Speed: 8. Course: 280. Depth: Surface. Angle: 0-10 R (at firing)

FIRE CONTROL AND TORPEDO DATA

Type Attack: Night surface, with Radar and TBT.

Tubes fired: #4 #5 #6

Track Angles: 90 S 14-3-A 14-3-A

Gyro Angles: 0-10 R 6-1 6-1

Depth Set: 6139 5940 3890

Power: High High Contact Contact

Hit or miss: --- Two hits ---

Erratic: --- One erratic run ---

Mark Torpedo: 14-3-A 14-3-A 14-3-A

Serial No: 25265 23513 23260

Mark Exploder: 6-1 6-1 6-1

Serial No: 6139 5940 3890

Actuation Set: Contact Contact Contact

Actuation Actual: Contact Contact Contact

Mark Varthoad: 16 16 16

Serial No: 6048 1175 11175

Explosive: Torpax Torpax Torpax

Firing Interval: 8 Sec 8 Sec 8 Sec

Type Spread: VOT 3" ahead 3" astern

Sea Condition: --- State Pour ---

Overhaul Activity: U.S.S. SPERRY

Remarks: One erratic run, two hits. Target sank.

- 16 -

Enclosure (A).

— page 210 —
1 0176
U.S.S. TRIGGER - Report of Seventh War Patrol (Cont'd.)
(H) ATTACK DATA (Cont'd) TORPEDO ATTACK REPORT FORM
U.S.S. TRIGGER Torpedo Attack No. TWO. Patrol No. SEVEN.
Time: 0203 I Date: November 2 Lat. 28-55 N. Long.134-43 E.

TARGET DATA - DAMAGE INFLICTED
Description: 3 Island freighter, (class unknown) about 7000 tons.
Ship(s) sunk: ---
Ship(s) damaged or probably sunk: The above ship was damaged, one hit.
Damage determined by: Saw torpedo hit. Saw ship damaged.
Target draft: 20 ft. Course: 310. Speed: 8. Range: 1200 (at firing)

OWN SHIP DATA
Speed: 7. Course: 205. Depth: Surface. Angle: 0 (at firing)

FIRE CONTROL AND TORPEDO DATA
Type Attack: Night surface, using Radar and TBT.
Tubes fired: #1 #2 #3
Track Angle: 105 S
Gyro Angle: 0
Depth Set: 10 ft 10 ft 10 ft
Height: High High High
Hit or miss: --- One hit ---
Erratic: No No No
Mark Torpedo: 14-3-a 14-3-a 14-3-a
Serial No: 23476 24163 23985
Mark Explorer: 6-1 6-1 6-1
Serial No: 6397 11121 17962
Actuation Set: Contact Contact Contact
Actuation Actual: Contact Contact Contact
Mark Warhead: 16 16 16
Serial No: 3942 1253 1164
Explosive: Torpex Torpex Torpex
Firing Interval: 8 Sec 8 Sec 8 Sec
Type Spread: MOT 1/4 ahead 1/4 astern
Sea Condition: --- State four ---
Overhaul Activity: U.S.S. SPERRY
Remarks: Hot, straight, and normal. Target damaged.

- 15 - Enclosure (A).

— page 211 —
0176
U.S.S. TRIGGER - Report of Seventh War Patrol (Cont'd.)
(H) ATTACK DATA (Cont'd.) TORPEDO ATTACK REPORT FORM
U.S.S. TRIGGER Torpedo Attack No. FOUR. Patrol No. SEVEN.
Time: 0321 I Date: November 2 Lat. 28-49 N. Long. 134-50 E.

TARGET DATA - DAMAGE INFLICTED
Description: Tanker, class unknown, about 8000 tons.
Ship(s) sunk: The target.
Ship(s) damaged or probably sunk: ---
Damage determined by: Saw three torpedo hit, saw target sink.
Target draft: 20 ft. Course: 130. Speed: 8. Range: 1200 (at firing)

OWN SHIP DATA
Speed: 8. Course: 050. Depth: Surface. Angle: 0 (at firing)

FIRE CONTROL AND TORPEDO DATA
Type Attack: Night surface, using Radar and TFT.
Tubes fired: # 4 # 5 # 6
Track Angles: 90 S High High High
Gyro Angle: 0
Depth Set: 10 ft 10 ft 10 ft
Hit or miss: --- Three hits ---
Erratic: No No No
Mark Torpedo: 14-3-A 14-3-A 14-3-A
Serial No: 24407 24560 24560
Mark Explorer: 6-1 6-1 6-1
Serial No: 6010 11172 10083
Actuation Set: Contact Contact Contact
Actuation Actual: Contact Contact Contact
Mark Warhead: 16 16 16
Serial No: 9535 9545 9795
Explosive: Torpex Torpex Torpex
Firing Interval: 8 Sec 8 Sec 8 Sec
Type Spread: MOT 4" astern
Sea Condition: --- State Four ---
Overhaul Activity: U.S.S. SPERRY
Remarks: Not, strut.g:t and normal. Target disintegrated.

- 17 - Enclosure (A).

— page 212 —
U.S.S. TRIGGER - Report of Seventh War Patrol (Cont'd.)

(H) ATTACK DATA (Cont'd.) TORPEDO ATTACK REPORT FORM

U.S.S. TRIGGER Torpedo Attack No. FIVE. Patrol No. SEVEN.
Time: 0814 I Date: November 5. Lat. 29-08 N. Long. 129-37 E.

TARGET DATA - DAMAGE INFLICTED

Description: Two medium 3 island freighters, 6000 tons each.

Ship(s) sunk: ---
Ship(s) damaged or probably sunk: ---
Damage determined by: No explosions. Missed.

Target draft: 20 ft. Course: 010. Speed: 10. Range: 2400 (at 1200 firing)

OWN SHIP DATA

Speed: 4. Course: 310. Depth: 64. Angle: 0 - 10 L (at firing)

FIRE CONTROL AND TORPEDO DATA

Type Attack: Submerged. Daylight. Periscope. Ship in convoy.
* Fired first 3 torpedoes at 2nd ship in convoy.
** Fired 4th torpedo at last ship in convoy.

Tubes Fired: # 1 to # 3* # 4*
Track Angles: 110 S 110 S 90 S
Gyro Angle: 0 8 ft 8 ft 8 ft
Depth Set: 8 ft High High High
Power: High Miss Miss Miss
Hit or miss: No No No
Erratic: No 14-3-A 14-3-A 14-3-A
Mark Torpedo: 23304 24385 24141 23052
Serial No: 6-1 6-1 6-1 6-1
Mark Explorer: 6803 11905 5902 6408
Serial No: Contact Contact Contact Contact
Actuation Set:
Actuation Actual: 16 16 16 16
Mark Warhead: 3927 9602 3833 9203
Serial No: Torpex Torpex Torpex Torpex
Explosive: 8 Sec 8 Sec 8 Sec 8 Sec
Firing Interval: 1½" ahead 1½" ahead 1½" ahead 1½" ahead
Type Spread: MOT State two
Sea condition:
Overhaul Activity: U.S.S. SPERRY.
Remarks: Hot, straight, and normal. Missed.

- 18 -

Enclosure (A).

— page 213 —
1 0176
U.S.S. TRIGGER - Report of Seventh War Patrol (Cont'd.)

(H) ATTACK DATA (Cont'd.) TORPEDO ATTACK REPORT FORM
U.S.S. TRIGGER. Torpedo Attack No. SIX. Patrol No. SEVEN.
Time: 0555 I Date: November 13 Lat. 32-57 N. Long. 125-06 E.

TARGET DATA - DAMAGE INFLICTED
Description: 10,000 ton transport, coal burner, composite 3 deck superstructure, about 1/4 length of ship. Single raked stack, raked bow, cruiser stern. Lightly loaded, much deck cargo, two shallow wells, four pairs of goal posts, two forward, two aft. AIKOKU MARU, page 43 of ONI 208-J most nearly approximates this ship in appearance.

Ship(s) sunk: The target.
Ship(s) damaged or probably sunk: ---
Damage determined by: Saw two torpedoes hit. Saw ships picking up survivors. Passed through debris consisting of lifeboats, rafts, section of bridge, and shattered hatch covers, etc.

Target draft: 20 ft. Course: 230. Speed: 7.5 Range: 600(at firing)

OWN SHIP DATA
Speed: 4. Course: 330. Depth: 60 ft. Angle: 0 (at firing)

FIRE CONTROL AND TORPEDO DATA
Type Attack: Submerged, periscope. Light moonlight night. Stern tube shot.

Tubes fired: # 7 # 8 # 9 # 10
Track Angle: 100 S
Gyro Angle: 0
Depth Set: 8 ft 8 ft 8 ft 8 ft High High High High
Hit or miss: --- Two hits ---
Erratic: No No No No
Mark Torpedo: 14-3-A 14-3-A 14-3-A 14-3-A
Serial No: 23364 24569 24526 24067
Mark Exploder: 6-1 6-1 6-1 6-1
Serial No: 10808 11170 10230 11079
Actuation Set: Contact Contact Contact Contact Contact
Actuation Actual: Contact Contact Contact Contact
Mark Warhead: 16 16 16 16
Serial No: 5638 6239 4784 991
Explosive: Torpex Torpex Torpex Torpex
Firing Interval: 8 Sec 8 Sec 8 Sec 8 Sec
Type Spread: 1 inside bow 1 inside stern 1 ahead 1 astern
Sea Condition: --- State Two ---
Overhaul Activity: U.S.S. SPERRY
Remarks: Two hits. Target sank.

- 19 -

Enclosure (A).

— page 214 —
U.S.S. TRIGGER - Report of Seventh War Patrol (Cont'd.)

(H) ATTACK DATA (Cont'd.)  TORPEDO ATTACK REPORT FORM

U.S.S. TRIGGER  Torpedo Attack No.  SEVEN.  Patrol No.  SEVEN.
Time:  2237 I  Date:  November 21.  Lat. 35-40 N.  Long. 125-31 E.

TARGET DATA - DAMAGES INFLICTED

Description:  New type 5000 ton freighter.  Single stack, one deck, composite superstructure.  Similar to KIMISIMA MARU, page 116 ONI 208-J.

Ship(s) sunk:  The target.
Ship(s) damaged or probably sunk:  ---
Damage determined by:  Saw two torpedoes hit.  Saw target sink.
Target draft:  18 ft.  Course:  300.  Speed:  7.  Range:  1000 (at firing)

OWN SHIP DATA

Speed:  6.  Course:  035.  Depth:  Surface.  Angle:  0 (at firing)

FIRE CONTROL AND TORPEDO DATA

Type Attack:  Night, surface radar.

Tubes fired:  # 7  # 8  # 9  # 10
Track Angle:  90 S
Gyro Angle:  0
Depth Set:  10 ft 10 ft 10 ft 10 ft
Power:  High High High High
Hit or miss:  -
Erratic:  No  No  No  No
Mark Torpedo:  14-3-A  14-3-A  14-3-A  14-3-A
Serial No:  39733  24062  24060  39658
Mark Exploder:  6-1  6-1  6-1  6-1
Serial No:  12337  10214  107  7373
Actuation Set:  Contact  Contact  Contact  Contact
Actuation Actual:  Contact  Contact  Contact  Contact
Mark Warhead:  16  16  16  16
Serial No:  9510  9511  3926  1482
Explosive:  Torpex  Torpex  Torpex  Torpex
Firing Interval:  8 Sec  8 Sec  8 Sec  8 Sec
Type Spread:  1" R  1" L  4" R  4" L
Sea Condition:  -
Overhaul Activity:  -
Remarks:  Hot, straight, and normal.  Target sank.

- 20 -

Enclosure (A).

— page 215 —
1 0176
U.S.S. TRIGGER - Report of Seventh War Patrol (Cont'd.)

(1) MINES: Not Applicable.

(2) ANTI-SUBMARINE MEASURES AND EVASION TACTICS:

Anti-submarine measures, while lacking in effectiveness, suggested that the enemy is giving the problem considerable attention. Out of three convoys contacted, two consisted of twelve or more ships, with at least four escorts. Two convoys had daylight air coverage. On the occasion of an attack on one of these, five well directed air-raft bombs were dropped upon us, as we attempted to return to periscope depth after going deep. The unusual alertness of the escorts of one convoy attacked on the surface at night brings up the possibility that they were radar equipped. It is believed that there is a radar installation on MARA TO, where radio towers were seen. During the nights in the vicinity of MARA TO we were continually bothered by PC boats, some echo ranging. Their concentration was certainly above normal, and substantiated our belief in the existence of the MARA TO radar.

Air coverage over the East China and Yellow Seas was very good. On the three occasions we attempted surface patrol, we were driven down by planes within an hour.

The periscope of a submarine was sighted while this vessel was conducting a submerged patrol off AKUSEKI JIMA, in the vicinity of the unsuccessful attack of two days before. In two instances during a previous patrol, enemy submarines were sighted in the vicinity of and shortly after an attack.

Evasion tactics consisted of diving deep every morning for density layer information, and, during enemy counter measures, of hiding below the layer. Once in the density layer, apparently we were safe from both sonic and super sonic detection.

The freighter attacked on the night of November 1 tried to use gunfire to drive us down. It was very ineffective and the shooting wild, to say the least.

(K) MAJOR DEFECTS AND DAMAGE:

(1) # 2 Main Motor - loose commutator segment.

After a particularly close and heavy depth charge, received on November 13, noise and vibration were noticed in # 2 Main Motor. Investigation disclosed that one of the commutator segments had loosened and raised up, presumably as a result of the depth charge. Operation of the motor continues to be satisfactory, but the brushes jump with each revolution of the armature, as the raised segment comes under them, and the motor continues to vibrate.

(2) Port Reduction Gear - knock, damage to Thrust Bearing.

On November 1, during a deep dive, an intermittent throb was noticed at slow speed, which disappeared when shaft turns were varied.

Enclosure (A).

— page 217 —
1 0176
U.S.S. TRIGGER - Report of Seventh War Patrol (Cont'd.)

(N) SOUND CONDITIONS:
Sound conditions varied from poor to good, depending on existence or non-existence of density layers. Morning deep dives for density layer information were made while in the area, and, when a layer was established, sound conditions were found to be very bad in or beneath it, although good to very good above the layer. In instances when no layer was found, sound conditions were good. On the occasion of the unnecesseful attack of November 5, there was a two knot current or better, fairly rough sea, and no layer. The enemy destroyer seemed to have little difficulty in maintaining contact.

(O) DENSITY LAYERS:
Throughout the area, radical density layers were found. In general, in shallow water, the depths of the layers averaged three quarters of the depth of water. All layers experienced, except two, were of the negative gradient type. No layers of any kind were found in localities where strong local currents were prevalent. Following is a tabulation of layers and localities:

| DATE | LAT  | TYPE | DEPTH | DEPTH | DEBRES | AMOUNT |
|------|------|------|-------|-------|||
|      | LONG | GRADIENT | WATER | LAYER | LAYER | CURRENT | Oct 24:28-49 N | :    | :    | :    | :    | :    | :    |
| :    | :    | :    | :    | :    | :    | :    |
| :    | :    | :    | :    | :    | :    | :    |
| Oct 25:29-52 N | :    | :    | :    | :    | :    | :    |
| :    | :    | :    | :    | :    | :    | :    |
| Oct 25:30-29 N | :    | :    | :    | :    | :    | :    |
| :    | :    | :    | :    | :    | :    | :    |
| Oct 26:30-36 N | :    | :    | :    | :    | :    | :    |
| :    | :    | :    | :    | :    | :    | :    |
| Oct 26:30-36 N | :    | :    | :    | :    | :    | :    |
| :    | :    | :    | :    | :    | :    | :    |
| Oct 27:30-42 N | :    | :    | :    | :    | :    | :    |
| :    | :    | :    | :    | :    | :    | :    |
| :    | :    | :    | :    | :    | :    | :    |
| Oct 27:31-47 N | :    | :    | :    | :    | :    | :    |
| :    | :    | :    | :    | :    | :    | :    |
| Oct 28:30-44 N | :    | :    | :    | :    | :    | :    |
| :    | :    | :    | :    | :    | :    | :    |
| Oct 29:30-32 N | :    | :    | :    | :    | :    | :    |
| :    | :    | :    | :    | :    | :    | :    |
| Oct 29:30-32 N | :    | :    | :    | :    | :    | :    |
| :    | :    | :    | :    | :    | :    | :    |
| Nov 1:29-10 N | :    | :    | :    | :    | :    | :    |
| :    | :    | :    | :    | :    | :    | :    |
| :    | :    | :    | :    | :    | :    | :    |
| Nov 1:29-10 N | :    | :    | :    | :    | :    | :    |
| :    | :    | :    | :    | :    | :    | :    |
| :    | :    | :    | :    | :    | :    | :    |
| Nov 2:29-31 N | :    | :    | :    | :    | :    | :    |
| :    | :    | :    | :    | :    | :    | :    |
| :    | :    | :    | :    | :    | :    | :    |
| Nov 2:29-31 N | :    | :    | :    | :    | :    | :    |
| :    | :    | :    | :    | :    | :    | :    |
| :    | :    | :    | :    | :    | :    | :    |
| Nov 4:29-40 N | :    | :    | :    | :    | :    | :    |
| :    | :    | :

— page 218 —
U.S.S. TRIGGER - Report of Seventh War Patrol (Cont'd.)

(O) DENSITY LAYERS (Cont'd.)

Following is a tabulation of layers and localities (Cont'd.)

DATE  |  LAYER  |  TYPE  |  DEPTH  |  DEPTH  |  DEGREES  |  AMOUNT
:---  |

— page 219 —
1 017

U.S.S. TRIGGER - Report of Seventh War Patrol (Cont'd.)

(P) HEALTH AND HABITABILITY:

No comment.

(Q) PERSONNEL:

No comment.

(R) MILES STEAMED - FUEL USED:

Midway to area 2912 Mi. 32,890 Gals.
In area 2275 Mi. 17,430 "
Area to Midway 2920 Mi. 33,470 "
Fuel received at Midway 34,595 Gals.
Midway to Pearl 1268 Mi. 18,300 "

Totals 9,375 Mi. 112,090 "

(S) DURATION:

Days enroute to area 17 (Including time spent in special area)
Days in area 16
Days enroute to Pearl 16
Days submerged 24
Total days underway 48

(T) FACTORS OF ENDURANCE REMAINING:

Torpedoes Fuel Provisions Personnel Factor
None 4,000 Gals 20 days 15 days
(at Midway)

Limiting factor this patrol - expenditure of torpedoes.

- 25 - Enclosure (A).

32

3/2

32

— page 220 —
U.S.S. TRIGGER - Report of Seventh War Patrol (Cont'd.)

(U) REMARKS:
The communication problem between the bridge and conning tower was solved by the USS SPERRY. A new type bridge speaker designed and installed by the tender has successfully stood 50 good close depth charges, one heavy enough to do minor damage to one main motor and one main thrust bearing. It may be considered to have passed its service test successfully, and to be virtually depth charge proof.

The experimental cut down bridge, designed and built by the USS SPERRY, is incomparably better, in every way, than the previous high bridge of this vessel. Its adoption for all ships of this type is urged.

It is desired to emphasize here the remarks made in paragraph (M) in regard to submarine radar. It is considered that immediate installation of a new aircraft detector radar is of utmost importance. There is not the slightest doubt that the intensification of Japanese air patrols will begin to bear fruit in increased losses of our submarines, just as the intensification of our air patrols over the Atlantic resulted in the destruction of more German submarines. The faults of the SD Radar are well known; it cannot be depended upon to detect planes, and it is of such low frequency that it may easily be "D-Ped". Rumors have been extant for longer than eighteen months that a new SD radar was in process of development. The imperative need for this new radar cannot be exaggerated, and its installation should be accomplished immediately.

The PPI cannot be used to its best advantage in its present location. Plans and sketches are being submitted by separate correspondence to improve this situation. It is believed that a slight change in the switching arrangement will make an 8000 yard dial possible with the present PPI equipment. This change is also being submitted separately.

With regard to the SJ, the performance of the low-powered transmitter, with which this vessel is still equipped, was not satisfactory. It is felt that this patrol should have been terminated on November 1, with the contact on the large convoy. Undoubtedly, several ships, which escaped by getting outside our 8000 yard effective radar range, would have been tracked down had the radar been effective out to 30,000 yards. Installation of the improved high powered transmitter will solve this difficulty; it is considered that procurement and installation of this transmitter is priority number one for the current refit.

- 26 - Enclosure (A).

— page 222 —
3. The above described attacks leave nothing to be desired in aggressiveness or tactics. The entire patrol was conducted with superb skill and judgment.

4. Material - TRIGGER will be refitted by SEAFY in the normal period. A new high power radar transmitter will be installed and the original API will be replaced with a PPI modified to operate with the 5J.

5. The Commander submarine Division 102 takes great pleasure in again congratulating the commanding officer, officers and crew of TRIGGER upon completion of another highly successful patrol.

Copy to:
CO US TRIGGER

— page 223 —
1 0176
FC5-10/A16-3(102)  SUBMARINE SQUADRON TEN  dn
Serial 0208  Care of Fleet Post Office,
  San Francisco, California,
CONFIDENTIAL  10 December 1943.

SECOND HIDDENS TENT to
CO TIGGER SS237/A16-3
Ser 038 of 12-8-43.

From: The Commander Submarine Squadron Ten.
To: The Commander in Chief, United States Fleet.
Via: (1) The Commander Submarine Force, Pacific Fleet.
    (2) The Commander in Chief, U. S. Pacific Fleet.

Subject: U.S.S. TIGGER - Seventh Star Patrol - Comments on.

1. The seventh war patrol of the TIGGER was conducted in the East China and Yellow Seas; the patrol lasted 48 days, 15 of which were in the patrol area.

2. This was an extremely aggressive and successful patrol; within five hours firing time the TIGGER had fired twelve torpedoes and had sunk three ships and probably sunk one more; in the total of 23,000 tons, her first contact with the enemy. In three more attacks, two of which were successful, she sank two more ships totalling 15,000 tons. All attacks were exceptionally well conducted.

3. Every effort should be made to improve the present unsatisfactory SD radar. Surface patrols are becoming more and more necessary, and there must be a greater safeguard against surprise by aircraft. A new frequency should be used that will not permit the submarine to be D.F.'d.

4. Attention is invited to the very satisfactory bridge communication system which was recently developed and installed by the U.S.S. SPARR (S12). The Commanding Officer's recommendations for the experimental cut-down bridge are concurred in.

5. The Commander Submarine Squadron Ten takes pleasure in extending a "ell Done" to the Commanding Officer, officers and crew of the TIGGER for conducting this highly successful patrol.

6. It is recommended that the TIGGER be credited with inflicting the following damage to the enemy:

SUNK
AK (Class unknown) 7,000 tons
AK (Class unknown) 7,000 tons
-1-

— page 224 —
10 December 1943.
Serial 0208
CONFIDENTIAL
SECOND ENDORSEMENT to
CO TRIGGER SS237/A16-3
Ser 038 of 12-8-43.
Subject: U.S.S. TRIGGER - Seventh Air Patrol - Comments on.
SUNK (Continued)
AO (Class unknown) 8,000 tons
AP (Class unknown) 10,000 tons
AK (Similar KIMISHA MATU) 5,000 tons
TOTAL 37,000 tons
DAMAGED
AK (Class unknown) 7,000 tons
Copy to: Comsubdiv 102, CO TRIGGER.

— page 225 —
1-016/3(8)(/), SUBMARINE FORCE, PACIFIC FLEET, 1 0176 m
Serial 01904
CONFIDENTIAL
NOTE: THIS REPORT WILL BE DESTROYED PRIOR TO ENTERING PATROL AREA.

THIRD ENDORSEMENT to
TRIGGER Report of
Seventh War Patrol.

CONSUSFAC PATROL REPORT NO. 322
U.S.S. TRIGGER - SEVENTH WAR PATROL.

From: The Commander Submarine Force, Pacific Fleet.
To: The Commander-in-Chief, United States Fleet.
Via: The Commander-in-Chief, U. S. Pacific Fleet.

Subject: U.S.S. TRIGGER (SS237) - Report of Seventh War Patrol.
(22 October to 8 December 1943).

1. The TRIGGER's seventh war patrol was conducted in the East China and Yellow Seas.

2. The patrol, the second for the present commanding officer, was extremely aggressive and successful. The TRIGGER made seven attacks, six of which were night radar attacks, resulting in successful sinkings of enemy ships. This was the first successful night attack by the use of FRI. All attacks were extremely well planned and conducted. Such results indicate the high state of efficiency of the TRIGGER's fire control party.

3. Improved aircraft radar and the installation of search receivers in our submarines in the near future is expected to better the detection of enemy aircraft.

4. This patrol is considered successful for Combat Insignia Award.

5. The Commander Submarine Force, Pacific Fleet, congratulates the Commanding Officer, officers, and crew of the U.S.S. TRIGGER for this second successful attacking war patrol and for the unusual record of having sunk eleven ships for a total tonnage of 84,689 tons in two war patrols. The TRIGGER is credited with having inflicted the following damage upon the enemy:

| Damage | Description |
|||
| 1 - Freighter (class unknown) | 7,000 tons |
| 1 - Freighter (class unknown) | 7,000 tons |
| 1 - Freighter (class unknown) | 7,000 tons |
| 1 - Tanker (class unknown) | 8,000 tons |
| 1 - Transport (LINKUMAU class) | 10,500 tons |
| 1 - Freighter (KAHISIMA MARU class) | 5,192 tons |

TOTAL 44,693

62127 FILMED
Distribution and authentication on following page.
J. H. BROWN, Jr., Acting.

— page 228 —
U.S.S. TRIGGER - Report of EIGHTH WAR Patrol.

(A)  PROLOGUE:
Arrived Pearl Harbor from Seventh Patrol December 8, 1943.
Normal refit by USS SPERRY was accomplished in two weeks. The experimental
PTI was replaced with the standard submarine type, and the new high powered
SJ transmitter was installed; ship was deepened and sound tested. Three days
and one rights training and ship was ready for sea on 1 January 1944.

(B)  NARRATIVE:
January 1, 1944

1100 W  Departed Pearl Harbor for EIGHTH WAR PATROL.

January 5

0630 Y  Arrived Midway.

January 6

1100 Y  Departed Midway.

January 10

1020 L  Dived for a plane.
1235 L  Surfaced.
1030 L  Div'd for a plane.
1730 L  Surfaced.

January 11

0820 L  Dived for a plane.
1030 L  Surfaced.
1350 L  Div'd for a plane.
1730 L  Surfaced.

January 14

0927 K  SD radar contact, 13 miles. Div'd. Utilized this opportunity
to check torpedoes.
1245 K  Surfaced. Commenced day and night surface patrol at slow speed.
1400 K  Entered area.
1505 K  SD radar contact. Pip seen at 25 miles, closed to 22 miles,
then went out to 30 miles. Did not dive.

January 16

0615 K  Sighted the mast of a ship. Div'd dead ahead. The contact de-
veloped into a Corvette with lines of a small AY, about 500 tons.
She carried a heavy gun on the foremast and mast-lights carried, very
chalky drafte. Traced on course 100° I, 5 knots, met zigzagging.
(COMMAT # 1). Too shallow draft for torpedoes and her gun was
too large for our three lines.

-1-  Enclosure (A).

— page 229 —
1. TRIGGER - Report of EIGHTH War Patrol (Cont'd.)
January 16 (Cont'd.)
0812 K Sighted a fleet of ten sampans proceeding in company with the Corvette.
1245 K Surfaced. Continued surface patrol.
January 17
0925 K SD radar contact at 30 miles. Dived when range closed to 16 miles.
1246 K Surfaced.
1735 K Sighted a twin engine land based bomber heading directly at us. Range about 6 miles. Dived. Consider our presence known to the enemy. Decided to stay down till dark, make a radical change of location for next day's patrol.
1902 K Surfaced.
January 18 to 21
Uncertainly submerged patrol in vicinity YOGAMI and GRAY FEATHER BAYS.
January 22
Recommended daylight surface patrolling.
1127 K Dived for a plane.
1300 K Surfaced.
January 27
SECOND CONTACT - NO ATTACK
"RCM CLASS JAP SUBMARINE - APPROACH UNSTOODESSUL
Lat. 10 - 55 N. Long. 147 - 14 E.
1224 K Sighted coming tower of a submarine dead ahead with zero angle on the bow. Dived, commenced approach.
1235 K Sub identified as Jap "MO" type, painted black, with a large Jap ensign painted on the side of the bridge. Tracked on base course 120° T, at 13 knots, zigzagging radically.
1255 K With the Jap perfectly set up for bow tubes at a range of 800 yards, put up the periscope for the firing bearings, only to find he had zigged directly towards us, was crossing our bow at a range of less than one hundred yards, and was swinging to put his stern toward us.

-2-
Enclosure (A).

— page 230 —
1256 K
Went to 150 feet expecting a torpedo. None was heard; so at

1300 K
Returned to periscope depth.

1330 K
Surfaced. Commenced an end around. Possibly we surfaced too soon; the Jap had his periscope up too.

1430 K
End around proceeding satisfactorily, except that our top speed seems to be only 17 knots (with foul bottom and high injection temperatures), while the enemy is making about 15.

1435 K
Target put his stern toward us, and disappeared. Headed for his last bearing, hoping he had gone "over the hill" instead of diving.

1455 K
Sub not seen again, though with our speed we should have overheated him. Concluded he must have dived.

1456 K
Reversed course, broke off the chase.

January 28

0950 K
Radar contact, twelve miles. Div'd.

1235 K
Surfaced.

January 31

THIRD CONTACT - FIRST ATTACK
FUBUKI CLASS DESTROYER - 1700 TONS, SINK
Lat. 9 - 50 N. Long. 147 - 06.5 E.

0131 K
Radar contact, 22,000 yards. Commenced approach. The contact proved to be a convoy of three large ships and two escorts, base course 160°, speed 14, zigzagging about 30° at irregular intervals. The large ships were in column, with one escort on each quarter.

0200 K
Ships identified as three large, new type AK or AP, not smoking. Escorts were two FUBUKI class destroyers. The night was clear, with good visibility, no moon, but plenty of starshine. Ships seen from the bridge at 11,000 yards.

0225 K
Approaching the firing point, when the convoy zigged away, forming a line of bearing, ships overlapping. Determined to accept the situation and fire three at the last AP and three at the near DD.

0227 K
Preparing to fire. kept TNT on the nearest escort. SJ got set up on a target at perfect firing bearing, 40.5.

0228 K
Pilot drove torpedoes across the bar at the rear. FUBUKI at this rate: target (irradiated to be the last AP at 1600 yards range), gyro angle 120, 120 port track (ATTACK 1-1). Bridge, however, reported the target to be the far escort, at about 2500 yards range.

-5- Enclosure (A).

— page 231 —
0228 K (Cont'd.)
Range to the near DD at this time was 900 yards, and he began to swing toward us. Immediately shifted targets, and at
0229 K
Fired three torpedoes at the DD, range 700 yards, 90 port
track, gyro angle zero. Total divergent spread 10°. (ATTACK 1-5).
Owing right with full rudder and full speed.

The quickness with which this situation developed was such that there was no time to do anything but shoot, shift targets, and shoot again. The six torpedoes were fired practically as one.

-4- Enclosure (a).
-5-

— page 232 —
1. U.S.S. TRIGGER - Report of EIGHTH War Patrol (Cont'd.)
January 31 (Cont'd.)
continuous salvo. Although it had been intended to shoot first at the last AP, the radar got on the far DD instead.

0230 K Heard and saw two hits in the direction of the convoy. The fer escort disappeared in a cloud of smoke and debris.

0230 K Saw one torpedo track cross just in front of the near DD. Did not see the other two. No hits. Sound reported a torpedo had been fired at us. Believe, of the three torpedoes fired at the DD, one at least, possibly two, were erratic, and that this was one of them.

0230 1/2 K The DD came to life, fired a green Very star from the bridge, and dropped a pattern of six depth charges. Range about 500 yards; they jarred past and corked from the bulkheads.

0232 K The range to the DD, which had opened to 2200 yards, commenced to close rapidly, with this angle on the bow decreasing, and it appeared that he had sighted us.

SECOND ATTACK
FURMIK CLASS DD - NTGSD

0233 K Stoodid with our stern toward the DD, and fired four torpedoes at it at a range of 1500, 40 port track, gyro angle 10 L. All missed.

0234 K The DD seemed to go wild, turning this way and that, dropping numerous depth charges and firing his guns.

0235 K Fith the DD methodically depth charging the area, completed ro-load and set out after the convoy. Tracked it on course 210° at 16 knots. with the conditions prevailing and our fuel bottom, 17 1/2 knots was our top.

0235 K 'c are losing the race to get back to the convoy. The DD passed us at about 10,000 yards, going hell bent for election.

THIRD ATTACK
10,000 TON AP OR 2YVAL AMILJARY - SUNK
Lat. 9 - 21 N. Long. 147 - 02 E.

0441 K Rejoined the formation. Four ships in column, the pestiferous DD leading. Speed now 14 knots again. All zigzagging radically. On account of the proximity of drydock, and the fact that a three knot speed differential gives little chance to pick and choose, resolved to fire at any remotely favorable situation.

— page 233 —
0340 K
The convoy zigged away again, converting a favorable situation into a poor one. The 1st and largest ship was slowed to 2ig, and the escort reversed course and headed toward us. Possibly he saw us in the growing light.

: 0457 K
First five torpedoes forward at the 1st AP, range 3000 yards, 130 port track, gyro angle zero. Came right with full speed, readying the stern tubes in case the DD had seen us.

: 0459 K
Two hits on the last ship in column. Yellow flame leaped about masthead height, followed by several lesser explosions and flames.

: 0500 K
The DD commenced dropping more earth charges from a seemingly inexhaustible stack, and headed over toward the stricken ship, blinking the numeral '45' repeatedly from 'for' and 'main' masthead bilincars.

: 0510 K
The AP sank. The DD stopped depth charging, and how to, in the midst of a group of lights on the water.

: 0510 K
Commenced an approach on the remaining two APs, speed now 16 knots, but it was obviously impossible to close before dawn. One-manned and around.

Gave up the end around as hopeless, with only a 1.5 knot speed differential.

In retrospect, four hits out of fifteen torpedoes fired is not an outstanding performance. The commanding officer is at a loss to explain the failure to hit the nearest target at a range of 700 yards on the first attack. On the 1st of it, a miss was impossible. Possible explanations are: (1) The firing range was so short that the torpedoes, though fired on the surface, ran under. (2) Two torpedoes had erratic runs. This is substantiated by the facts that only one wake was seen (a miss) and that sound reported a torpedo fired at us. Both these torpedoes were fired from the upper bow tubes, and, although spaced had been reduced to one third, the ship still had 10 knots way on when firing.

Attack number two was entirely a defensive measure. It appeared that the destroyer had finally seen us, and was heading in pursuit, zigzagging radically. Hiving would have ruined all chances for another attack; so the after tubes were fired in order to disassemble, apparently successfully, for he acted badly scared, and made no further order to come up.

Attack number three was a case of making the best of a bad situation. The convoy zigged away, but there was nothing the firing bearing. With the destroyer bearing down on us at 2000 yards range, it was clear or near, because we could not have regained firing position before daylight. Fortunately, luck was with us, and the target was sunk when two hits out of five fired.

— page 234 —
2156 K
Sighted ships on the horizon. Commenced approach. (FOURTH COMTACT).

2140 K
Convoy developed into 6 very small vessels. Tracked on course 130° T, 7 knots, not zigzagging. Maximum radar range, 7000 yards.

2200 K
Closed to 4500 yards. Vessels identified as sampans, escorted by a Corvette. Discontinued approach.

February 8
0800 K
Headed south at two engine speed to make reconnaissance of atolls.

1230 T
Divied for a plane.

1314 X
Surfaced.

February 9
Spent most of day submerged recommoitoring LIGHTER and ETALO Islands.

1600 X
Surfaced, headed for TOLETAI.

February 10
0130 K
Completed moonlight reconnaissance of TOLETAI lagoon. Headed north to get back into traffic lanes.

February 12
0640 K
Radar contact, 25 miles, did not dive.

1000 K
Departed area.

February 13
1200 K
Radar contact, 23 miles. Did not dive.

February 14
0610 K
Radar contact, 9 miles, closing fast. Dived.

0730 K
Surfaced.

Enclosure (A).

— page 235 —
U.S.S. THIGGER - Report of EIGHTH War Patrol (Cont'd.)
February 19 (West Longitude)
Arrived Midway.
February 23
Arrived Pearl Harbor.

(C) WEATHER:
Uniformly excellent. No comment.

(D) TIDAL INFORMATION:
Average set 270° T, drift 0.6 knots.

(E) NAVIGATIONAL AIDS:
None.

-8- Enclosure (A). 9

— page 238 —
U.S.S. TRIGGER - Report of EIGHTH War Patrol (Cont'd.)

(H) ATTACK DATA
TORPEDO ATTACK REPORT FORM

U.S.S. TRIGGER
Torpedo Attack No. ONE - A. Patrol No. EIGHT.
Time: 0228 Date: 31 January 1944. Lat. 9-50 N. Long. 147-06.5 E.

TARGET DATA - DAMAGE INFLICTED

Description: DD, FUBUKI Class, patrolling the far quarter of the convoy.
Ship(s) sunk: The target.
Ship(s) damaged or probably sunk: None.
Damage determined by: Saw two torpedoes hit. DD disappeared in smoke of the explosion, not seen again.
Target draft: 10. Course: 140°. Speed: 14. Range: 2800 (at firing)

GUN SHIP DATA

Speed: 10. Course: 200. Depth Surface. Angle: 0° (at firing)

FIRE CONTROL AND TORPEDO DATA

Type attack: Surface radar.

Tubes Fired: # 3 # 4 # 5
Track Angle: 120° P
Gyro Angle: 0
Depth Set: 8 ft 6 ft 6 ft
Power: High High High
Hit or Miss:

— page 239 —
U.S.S. TRIGGER - Report of EIGHTH War Patrol (Cont'd.)

(H) ATTACK DATA

TORPEDO ATTACK REPORT FORM

U.S.S. TRIGGER
Time: 0230
Torpedo Attack No. ONE - B. Patrol No. EIGHT.
Date: 31 January 1944. Lat. 9-50 N. Long. 147-05.5 E.

TARGET DATA - DAMAGE INFLICTED

Description: FUBUKI Class DD.
Ship(s) sunk: None.
Ship(s) damaged or probably sunk: None.
Damage determined by: ---.
Target draft: 10. Course: 110. Speed: 14. Range: 700 (at firing).

OWN SHIP DATA

Speed: 10. Course: 200. Depth: Surface. Angle: 0° (at firing).

FIRE CONTROL AND TORPEDO DATA

Type Attack: Surface radar.

Tubes Fired: # 6
Truck Angle: 90°
Gyro Angle: 8 ft
Depth Set: 8 ft
Power: High
Hit or Miss: Miss
Depth: 8 ft
Hit or Miss: High
Depth: Miss
Fire: 14-3-A
Fire: 14

— page 240 —
13 - Enclosure (A).

14 - Page number.

19 - Page number.

U.S.S. TRIGGER - Report of EIGHTH War Patrol (Cont'd.)

(E) ATTACK DATA

TORPEDO ATTACK REPORT FORM

U.S.S. TRIGGER
Time: 0233
Torpedo Attack No. TTO.
Date: 31 January 1944
Lat. 9-50 N.
Long. 147-06.5 E.

TARGET DATA - DAMAGE INFLICTED

Description: Same target as #1-S.
Ship(s) sunk: None.
Ship(s) damaged or probably sunk: None.
Damage determined by: ---.
Target draft: 10.
Course: 010.
Speed: 14.
Range: 1500 (at firing).

CYN SHIP DATA

Speed: 17.
Course: 340.
Depth: Surface.
Angle: 10° - 15° L (at firing).

FIRE CONTROL AND TORPEDO DATA

Type Attack: Surface radar, with stern tubes. Defensive shot. Target appeared to move sighted us, was zigzagging wildly in pursuit.

| Type | Attack | # | # | # | # |
|------||----|----|----|----|
| Track Angle | 40° | 3 | 9 | 10 |
| Gyro Angle | 10° - 15° L | 6 ft | 6 ft | 6 ft |
| Depth Set | 6 ft | High | High | High |
| Power | High | Miss | Miss | Miss |
| Hit or Miss | No | No | No | No |
| Erect | No | 14-5A | 14-5A | 14-5A |
| Mark Torpedo | 35581 | 4 | 25510 | 25535 |
| Mark Exploder | 6-4 | 6-4 | 6-4 | 6-4 |
| Serial No | 24 | 10763 | 59 | 100 |
| Attrition Set | Contact | Contact | Contact | Contact |
| Attrition Actual | Contact | Contact | Contact | Contact |
| Mark Tarnished | 16 | 1 | 16 | 16 |
| Serial No | 3110 | 3121 | 10316 | 3055 |
| Explosive | Torpex | Torpex | Torpex | Torpex |
| Firing Interval | 6 Sec | 6 Sec | 6 Sec | 6 Sec |
| Type Spread | 1 L | 1 R | 3 L | 3 R |
| Sea Condition | --- | --- | --- | --- |
| Overall Activity | --- | --- | --- | --- |
| Remarks | --- | --- | --- | --- |

- 13 -
- 14 -

— page 241 —
U.S.S. TRIGGER. - Report of EIGHTH YAR Patrol (Cont'd.)

(H) ATTACK DATA
Torpedo Attack No. THREE. Patrol No. EIGHT.
Time: 0456 Date: 31 January 1944. Lat. 9-21 N. Long. 147-02 E.

TARGET DATA - DAMAGE INFLICTED

Description: Large high speed oil fuelled AP. 16 knots and no smoke. 10,000 tons. Standard new type dap passenger-freighter design.

Ship(s) sunk: The target.
Ship(s) damaged or probably sunk: None.
Damage determined by: Saw torpedoes hit. Saw several heavy explosions and flames. Saw target sink.
Target draft: 25. Course: 130. Speed: 14. Range: 3000 (at firing)

CUT SHIP DATA

Speed: 9. Course: 190. Depth: Surface. Angle: 0 (at firing)

FIRE CONTROL AND TORPEDO DATA

Type Attack: Surface radar.
Tubes fired: #1 #2 #3 #4 #5
Torpedo: 130 P
Depth: 8 ft 6 ft 8 ft 6 ft 6 ft
Depth Set: High High High High High
Power: 16
Hit or Miss: No No No No No
Error: 14-3-A. 14-3-A. 14-3-A. 14-3-A. 14-3-A.
Mark Torpedo: 22770 25871 25875 22993 24156
Serial No: 6-4 6-4 6-4 6-4 6-4
Mark Exploder: 128 5920 66 7041 17462
Serial No: 6-4 6-4 6-4 6-4 6-4
Actuation Set: Contact Contact Contact Contact Contact Contact
Actuation Actual: Contact Contact Contact Contact Contact
Mark Warhead: 16 16 16 16 16
Serial No: 3114 3078 11312 11188 11364
Explosive: Torpex Torpex Torpex Torpex Torpex
Firing Interval: 8 Sec 8 Sec 8 Sec 8 Sec 8 Sec
Type Spread: 0 1/2 L 1/2R 2 1/2 L 2 1/2 R
Sea Condition: U.S.S. SPEEDY
Overhaul Activity: Torpedo # 24155 by Sub Base, Midway.

Remarks: ---

- 14 - Enclosure (A).

15

— page 242 —
15 - Enclosure (A).

U.S.S. TRIGGER - Report of EIGHTH War Patrol (Cont'd.)

(I) NIMS:
Not applicable.

(2) ANTI-SUBMARINE MEASURES AND EVASION TACTICS:

The performance of the enemy during our single opportunity to observe anti-submarine measures during this patrol was not good. Possibly the ardor of the surviving PUERTO WAS coolie by the fate of the other. At any rate, he patrolled well but never slowed to listen, did not echo range, dropped 62 depth charges on nothing, and gave evidence of confusion throughout the engagement. During the final attack on the convoy, it appeared he had sighted us, and was heading toward us. After the torpedoes hit, however, he gave up the pursuit, dropped a few depth charges, and commenced picking up survivors, leaving the remaining two vessels of the convoy to proceed by themselves.

There was no evidence of radar or radar detectors in transparencies or destroyers. We sighted transparencies at 11,000 yards, destroyers at 7000 yards, were not sighted at 700 yards.

Although there was moderate air activity in the area, several contacts were by radar at extreme CD range, indicating large planes at high altitude, and therefore probably not on anti-submarine patrol. For the amount of time spent in the area of the surface, enemy air coverage was not impressive. JAPOA statements with regard to Jap. seaplane bases in the atolls were not substantiated by our reconnaissance.

(2) MAJOR DEFECTS:

Number one periscope out of conception with zero ground on hoisting motor armature. It is believed this cause in order to return to the periscope during surface patrolling with high voltage due to battery charge. In areas as a periscope watch is imperative, this casualty is evidence of a design defect which should be corrected.

There planes hydraulic plant out of commission with zero ground on motor armature and commutator bars fused together. Cause believed to be the same as to number one periscope. The star planes have a tendency to creep, and the motor has been in fairly frequent use in order to return them to zero after they have rowed off. After the casualty this storm planes were operated in need power during the remainder of the patrol.

As a result of these two casualties, the equipment affected was out of commission for the latter part of the patrol, luckily only two weeks. Corvette measures involving alterations, if necessary, to the motors concerned, and to all others in the same category, is considered of major importance. In the meantime, the following measures are being instituted to prevent occurrence: (1) Charge batteries at such times that high voltage is reached only at night. (2) Eliminate as much of creep in storm planes as possible, and always use hand power for bringing them back to zero after they have swept off.

— page 243 —
22

---

### Transcript:

U.S.S. TRIGGER - Report of EIGHTH War Patrol (Cont'd.)

(L) RADIO:
No comments.

(M) RADAR:
No comments.

(N) SOUND GEAR AND SOUND CONDITIONS:
Good sound conditions. No comment.

(O) DENSITY LAYERS:
None encountered.

(P) HEALTH, FOOD, AND HABITABILITY:
No comments.

(Q) PERSONNEL:
No comments.

(R) MILES STEAMED - FUEL USED:
Pearl to area (via Midway) 3400 M.H. 33,250 gals.
In area 4418 M.H. 33,780 gals.
Area to Pearl (via Midway) 3622 M.H. 42,500 gals.
TOTAL 11438 M.H. 114,530 gals.

(S) DURATION:
Days enroute area 13 days
Days in area 30 days
Days enroute to base 12 days
Days submerged 5 days
TOTAL 55 days

(T) FACTORS OF ENDURANCE REMAINING:
Torpedoes Fuel (at Midway) 9 3500 gals. Provisions 20 days Personnel Factor 15 days

Patrol terminated by provisions of operations order.

- 16 -

Enclosure (A).

---

### Page Number:
17

— page 245 —
15-101/AL6-3SULTRATN DIVISION ON:
Serial 015
C.S. of Fleet Post Office,
San Francisco, California,
24 February 1944.

FIRST ADDRESS TO:
CO TRIGGER CONF. 1tr.
SS237/AL6-3 serial 042
dated 23 Feb. 1944.

FROM: The Commander Squadron Division 101.
TO: The Commander-in-Chief, U. S. Fleet.
VIA: (1) The Commander Submarine Squadron Ten.
(2) The Commander Submarine Force, Pacific Fleet.
(3) The Commander-in-Chief, U. S. Pacific Fleet.

S.S.SS. TRIGGER - Report of War Patrol Number Eight.

1. TRIGGER Eight, War Patrol was conducted in
TAUK - GUAM areas from 1 January to 23 February 1944. Twenty-nine of the 54 days were spent in the patrol areas, and nearly all daily hit patroling was done on the surface.

2. The attacked attack on the Jap submarine was
unfortunately thwarted by a last minute zig-toward the TRIGGER and by the fact that it was a lucky day for the Jap.

3. The attack on the convoy was at night on the
surf. The attacks 1. and 1B it would have been better to use the bridge TNT for both tar. ats, as had been planned, instead of only one. In the quick setup that was used, radar firing, bearing, were used for the JBT but actually the radar was on a destroyer about 100 to the right of the J. This was a quick attack (attack no. 1a). In attack no. 1B no definite indication of error, torpedo performance exists other than that one or two torpedoes probably ran under. The 1D was rather definitely identified as 'Rubik' class, supposedly drawing in 9 feet. It appears probable that this class draws more than this. The torpedo run was about 600-650 yds. and the 8 foot depth, used, open-ers to have been too much. attack no. 2 was a defensive shot on the same DD maneuver. Radar call, and missed. attack no. 3 was made possible by determined chasing and finally overhauling the convoy just before daylight. It resulted in sinking a modern naval auxiliary. The initial attacks were conducted in bright starlight, in which the JBTs were seen thru binoculars at 11000 yards and the DD's were visible at 7000 yards. How the TRIGGER could, under these conditions, close a destroyer unobserved to 700 yards is no bequest for the Jap lookouts, for any sort of camouflage or non-conflagration paint should have been plainly visible long before this. Conflagration spray was employed.

— page 246 —
10/1/45-3 SUBMARINE DIVISION ONE TURKISH ONES
Serial 015
C.O.-N.-F.-I.-D.-Z.-N.-T.-I.-J.-L.
Subject: U.S.S. TIGRE - Report of War Patrol Number 1.
4. It is noted that scarpan convox's were twice encountered. No suitable weapon was available to counter them.
5. T.T.A.L.I.:
   (a) The niht hit, hitting installed on TIGRE's TDC, which was so satisfactory, is Sylvia's type.
   (b) It is not believed that a design defect is at indicated in erissoje and stern pl.ine motor armatures.
   (c) L.test try.e easily removable blank flanges will be installed on TIGRE's fuel ballast tank vents. It is believed that TIGRE's slow surface speed was due to:
      (1) Hot converting F.B.T.'s to L.T.'s when fuel was used up. Co.vision is recommended.
      (2) 7. months out of dock.
      (d) Normal raft will be accomplished along side STRAIT.
6. Commander Submarine Division One T.ordered One con.retulates a splendid ship and crew for another production patrol.

F. C. HANSL.

— page 247 —
1/AL6-3(102)  SUBMARINE SQUADRON TEN
Serial 043
Care of Fleet Post Office,
San Francisco, California,
25 February 1944.

CONFIDENTIAL
SECOND ENDORSEMENT to
TRIGGER 8th War Patrol.

From:
To:
Via:

Subject:
U.S.S. TRIGGER, Report of Eighth War Patrol -
Comments on.

1. Forwarded concurring in the remarks of the Commander Submarine Division One hundred One.

2. Contacts with convoys of sampans escorted by shallow-draft heavily-armed vessels may become more frequent as the enemy's lines of communications are shortened and his shipping lessened. Consequently the need for a suitable weapon to combat this type of escort is becoming more and more important.

3. The Commander Submarine Squadron Ten wishes to extend a "Well Done" to all hands of the TRIGGER for the completion of another successful patrol, and recommends the following damage be credited:

SUNK
1 Destroyer (FUBURI Class)
1 Naval Auxiliary (type unknown).

Copy to:
Consubdiv 101,
CO TRIGGER.

— page 248 —
1 - Naval Auxiliary (class unknown) - 10,000 tons (Attack at)
1 - Destroyer (FURUKI class) - 11,500 tons (Attack at)
TOTAL: 11,500 tons

DISTRIBUTION:
(a) United States (1)
C. Smith (5)
C. Smith

— page 249 —
75124 FILMED

Care of Fleet Post Office, San Francisco, California.
U.S.S. TRIGGER
BY ORDER OF THE COMMANDING OFFICER
The Commander in Chief, United States Fleet.
The Commander Submarine Division ONE I NDRED TWO.
The Commander Submarine Squadron TEN.

Subject: U.S.S. TRIGGER - Report of War Patrol N. 1. Number Nine.

Enclosures: (A) Subject Report.
(B) Track Chart for Consubpac.

1. Enclosures (A) and (B) covering the NINTH War Patrol of this vessel conducted off PALAU during the period 23 March to 20 May 1944, is forwarded herewith.

F. HARLFIGER, II.

— page 251 —
U.S.S. TRIGGER - Report of MINTH War Patrol (Cont'd.)

April 1
Having continual air compressor and air condi.oning trouble. Held sweepstakes on how long #2 air compressor w old run between repairs. "Inning time, 21 minutes. This compresor was out of commission virtually all this patrol.

April 3
0934 L Much interference on SD. Dived.

1045 L Surfaced.

April 7
1118 K Dived for a plane.

1235 K Surfaced.

2200 K SJ radar interference. Localized in three distinct bearings, evidently three friendly submarines moving in same direction as we. This interference continued intermit. tly for two hours. Perhaps sure they knew of our presence th.igh our radar, kept distance to the west in order to extend whe was in effect a scouting line.

April 8
0037 K Radar contact (and interference) 3350 yard: broad on port bow. OOD saw the target in bright moonlight, ident ied it as a sub practically in attack position with small ang. on the bow. Avoided at full speed, and gave the recognition: signal. Exec and several lookouts also saw the vessel, and all ar. sure it was a friendly submarine. (CONTACT #1).

0045 K Reversed course, went to battle stations, atten ted to approach the sub for exchange of information.

0048 K Radar contact disappeared.

0055 K Reversed course again. If this bird has dived, don't want to stick around.

0115 K Noticed occasional radar interference bearing 320° T.

SECOND CONTACT - FIRST ATTACK
LARGES LADDER TANKER similar to Whale factory probably sunk. One or two freighters damaged. Lat. 19 - 06 N. Long. 142 - 31 E.

0137 K Radar contact bearing 330° T, 16,100 yar s. Another at 240° T, 9000 yards. Commenced tracking.

0140 K Sighted ship on 240° T. -2- Enclosure (A).

— page 252 —
0200 K
"Believe the ship on 240° T is the escort of a convoy bearing 330° T. Several pipes and radar interference there.

0235 K
Radar contact 6000 yards bearing 630° T with radar interference. Realized this was another escort. Both escorts began to close in; so, contrary to previous intentions, went to radar depth at this time to avoid detection. Convoy still 13,000 yards away, as yet not tracked. Contact report not cleared, because of being forced down. Heard "pinging" from direction of the convoy upon diving.

0500 K
Much echo ranging and radar interference from direction of the convoy. Many small pipes closer than the convoy. "Sent to 60 feet to pass through the inner anti-submar. to screen. Began to hope our friends were also attacking - the: were an awful lot of pinners. "Whatever we had stumbled on", it was big.

0320 K
Many hectic moments. Several escort. became suspicious, and two in particular stayed right on us, I, |lowing us in with steady bearing, range decreasing. Through the |riscope saw one of the "on" boys signaling with flashing light |ward the convoy. Some escorts were destroyers, some apparently I's. "To counted 12 in our immediate vicinity.

0325 K
Convoy in sight, four columns of large chis with 2 DMs leading each column, and two or more flanking each side, close in. This would have been a submariner's dream, except for the terrific escort force.

FIRST ATTACK
LOADED TANKER - Silhouette similar to 'Thale Factory - 16,764 Tons
Two hits - probably sunk
One or two freighters - 5000 tons - two hits - damaged
Lat. 15° - 08 N. Long. 142° - 31 E.

0335 K
Visibility, which had been fair, decreased somewhat because of clouds in front of the moon. The le.ding ship in the middle column gave a good set up, and was the biggest ship in sight, a large tanker, low in the water. Two ships astern in his column and the three loading the far column all overlapped. Another column was heading up to pass astern. Came to 47 feet for a quick radar range and got 200 yards, |hicl we decided was a wave pip, and 2000 yards to the tanker. |it back down, got all tubes ready. Planned to fire 10 torpedoes, 5 at the column ahead and 4 at the column shaping up to pass astern. Delayed a moment and swung left, trying to get perpend. |ular between the columns. This was our mistake, and the followl. is what happened to us for being too greedy.

0338 K
Put up the periscope for firing beari. 5 and could not see. Finally made out the shape of a DD, about 50 yards away, boiling

-3- Enclosure (A).

— page 254 —
1900 K
For the period between 0350 K and 1900 K, see Anti-Submarine Measures. In order to avoid describing this christianizing experience more than once, will merely state here that TRIGGER ran silent at 300 feet or more for 17 hours, that most of the time we were silently dogged by 6 anti-submarine vessels, and that it was the most nerve-wracking experience in the history of this vessel. One item is worthy of note; the DD attempting to ram was apparently unable to free his depth charges. Men were soon on his stern working frantically. This undoubtedly was our salvation on this attack.

1900 K
Believe we have finally shaken our pursuers.

2010 K
Surfaced, with the forward torpedo room flooded to the floor-plates, all other compartments except battery compartments and after torpedo room flooded to lower flats, hull induction flooded. Bow planes, trim pump, sound gear, both radars out of commission, most auxiliary machinery out of alignment. Unable to transmit because radio antenna trunk was grounded.

April 12
Hull induction, starboard sound hub, both sound training motors, and SD antenna mast still out of commission. All other damage repaired by use of spares and baling, fire, and the exercise of considerable ingenuity by the ship's crew.

1752 K
Sighted the tops of a ship; dived. Commenced approach. (CONTACT # 3).

1830 K
Ship identified as fishing sampan.

1856 K
Battle Surfaced. Pired small arms and a few rounds of 4" ammunition at 2100 yards range. Broken a pin on 4" prevented accurate fire, as it was necessary to hold the firing pin back by means of a lanyard, fire by releasing l-yard. Sea moderately rough. Sampan returned fire with rifle, 20 yards short.

1943 K
Censored fire at dark. Sampan hit by 20 mm and 50 cal. bullets. Proceeding to area, charged at our failure to do more than score the Jap, and disappointed in our newly installed four inch gun.

April 13
0930 K
Entered area. Surface patrolling.

1615 K
Divid for a plane.

1940 K
Surfaced.

-5- Enclosure (A).

— page 255 —
U.S.S. TRIGGER - Report of NINTH MAR Patrol (Cont'd.)

April 14

0405 K Contacted U.S.S. TANG. (CONTACT # 4) Mad. arrangements for rendezvous and exchange of information.

0640 K Dived for submerged patrol off Toagel Mungui pass.

1558 K Heavy rain squall - land out of sight. Surface d.

2345 K Rendezvoused U.S.S. TANG. Exchanged information via line throwing gun.

April 15

1153 K Sighted patrol plane through periscope.

2155 K Radar contact - no interference. Commenced tracking, suspecting U.S.S. TANG, at rendezvous.

2255 K Contact identified as TANG, SJ out of cc mission.

2330 K Executive Officer went aboard TANG in ru ber boat to make plans for coordinated search and attack, and to rrow air compressor and SD parts.

April 16

0150 K Pubber boat returned.

0638 K Surfaced after trim dive, commenced surface patrol on 60 mile circle from Toagel Mungui.

0645 K Divod for a plane.

0905 K Surfaced. Conducted surface patrol lying to, ith sound gear manned.

April 17

Submerged patrol off Toagel Mungui.

April 18

1110 K Sighted patrol plane.

1905 H Rendezvoused TANG.

2115 H Executive Officer of TANG came aboard vi rubber boat with more air compressor spares, and bad SJ modulator for exchange.

-6- [NAVY] [NA

— page 256 —
2154 H
Rubber boat returned to TANG.
Our # 2 H.P. Air Compressor from now on is fit for emergency use only. In fact, this air compresso. was out of commission at the termination of the previous patrol, and apparently the refit had had little beneficial effect upon it.

: April 19
Surface patrol on 60 mile circle in southern part of area.
0523 H
Dived for a plane. (Radar)
0644 H
Surfaced.
0652 H
Sighted fishing sampan. Avoided. (CONTACT 5)
April 20
Submerged patrol off Anguar Island, investigating possibility of bombardment. Took picutres. Saw gun emplacements.
1323 H
Sighted plane type "Zorro", with loading wheels down.
1458 H
Sighted large medium bomber, appro.ching for landing.
1649 H
Sighted large medium bomber, appro.ching for landing.
1755 H
Surfaced, proceeding up east coast of Palau.
1820 H
Sighted light on land. This light remained in sight until 2240.
2025 H
Reversed course.

: April 21-3
Surfaco patrol west of Palau on estimat. i track of a convoy. Sighted many oil drums but no ships.

: April 22
0700 E
Dived for a plane.
0935 H
Surfaced.
1643 H
Dived for a plane.
1755 E
Surfaced.

: April 24-6
Submerged patrol off Taegel Mlungui.

— page 257 —
2255 H.  Radar contact. Convoy of six ships seen from the bridge at 14,000 yards. One ship smaller than the others, believed to be an escort. Ships were flashing red and white masthead lights at each other. Tracked on base course about 000° T, zigzagging frequently and radically.

Spent the next hour determining course, speed, zigzag plan, and convoy disposition.

The convoy consisted of five freighters, 1 about identical in silhouette, with one large escort, about 400 yards ahead. Four smaller escorts, not seen at first, were piled up by radar and sight just before the initial attack. The last of four A/K's maintained a very closely bunched bow formation 400 yards astern of the large escort, 3 small escort were deployed around this group of 4 ships, one just ahead, one just astern, on, on their near (port) flank. About 2000 yards astern of this group followed the 6th A/K, with another large escort sticking close to him.

SECOND ATTACK
Two New Type A/K - 7000 tons - Sunk
Two New Type A/K - 7000 tons - Damaged
Lat. 8 - 20 N. Long. 134 - 55 E.

'ith the convoy settled momentarily on course 350° T, came in for attack on their port side. Decided to fire at 2600 yards range, in order to avoid detection and allow time to get off the stern tubes. As we came in, the freighters presented a perfect target; Four ships, closely bunched, overlapping so that a solid mass of ships stretched about 20° across our bow.

April 27
0002 H.  Fired 6 torpedoes forward at all four sh/os, range 2400 yards, 90 port track, gyro angle zero. Torpedoes 'are spread by offset, firing bearings set in by TBT. Reversed c arse to right at full speed, readying stern tubes.

0004 H.  Four hits, seen and heard. One terrific explosion on each of the two near ships, two others farther away, apparently on the two far ships.

-8-  Enclosure (A).

— page 258 —
0005 H
A. torrifie explosion on the after o' the near ships. Ship blew up. One of the far flank ships seen a right up and down, sank immediately.

The group of ships and escorts began a lling around, in hopeless confusion, presumably dropping depth cha- os, etc., although as yet no depth charges had been heard. The leading escort took off at high speed on a wilo sweep to the North.

0005 H Steadied on stern tube firing bearing, and stopped.

THIRD ATTACK
One AK - 7000 tons - Sunk (Damaged in Attack #2)
Lat. 8 - 20 N. Long. 134 - 55 E.

0006 H Fired four 1k 18 torpedoes aft at the group of ships, including the near escort now in the line of fire. Range 1800 yards to escort, 2800 yards to frigtherers. 105 port track, gyro angle 10 L. The point of aim was the DD. Torpedoes missed the DD, wont out on a course headed for the massed 1' rus, in line of fire beyond.

0009 H One hit heard. There may have be a more hits, but by now there were so many depth charges going off and explosions from the sinking ships that nothing is definite.

0010 H Escorts charging around, sowing da th charges. Several passed within 1500 yards, but apparently ft lad to see us in our light grey paint. Pulled clear to reload ad await developments. #9 tube out of commission, with blown o' der door gasket.

Of the four frigtherers in the load: group, one only got underway, down by the bow, making 7 knots, across he had been making 12. The 5th A' came up into the mclc stopped, and commenced signaling. Escorts put on red masthead lights, also commenced signaling. The large escort sent "2" and over. /mother was altrnately making the numerals "5" and "A". About

0020 H the 5th frigther and the damaged frigther formed column and, accompanied by three of the escorts, steadcd on course 330° T. The last escort remained at the scene with the other damaged frigther, which had evidently been hit again in attack # THREE, and which was slowly sinking.

0030 H Reload completed. Being by this time certain of the destruction of the ship hit in attack # THREE, there being lights in the water and an escort vessel evidently picking up survivors, took off after the last two frigtherers, the undamaged one leading, tracked on course 330° T at 7 knots.

— page 259 —
0330 H to 0330 H
During this period made in all four false starts for an attack. Each attempt was foiled by unexpected radical zigzags of the targets, by the untimely approach of one of the three escorts, or by the close proximity of the erstwhile leading escort, which was all this time charging around at about 20 knots and which several times came uncomfortably near to spotting us. Several casualties to the 8th during this period also. The maneuvered for a while on the targets' port flank, then went around astern to the starboard flank, finally attacked from that side.

0050 H
The sinking freighter disappeared from the radar screen at a range of 8000 yards, evidently sunk. The escort picking up survivors was still clearly seen on the radar. Boats and many lights in water.

0140 H
The damaged ship stopped, and the leading ship moved to close aboard. Continued our approach, not sure which ship was which or which was nearest to us, preparing to fire at both.

FOURTH ATTACK
One AK - 9794 tons - Sunk (damaged in Attack # 2)
Lat. 8 - 29 N. Long. 134 - 55 E.

0157 H
Fired 6 torpedoes forward, 90 track, rang 3300 yards, gyro angle zero: Four aimed at the damaged AK, two at the escort vessel.

0159 H
Two hits, in the AK. A small fire burst out, but the ship did not sink immediately. However, felt sure he would, with three torpedoes in him, and a fire.

Reversed course at full speed, and stopped. The three escorts were closed together in a group, overlapping, signs ing back and forth, all showing red mashed lights.

FIFTH ATTACK
One escort probably "akatake class ODD.
820 tons - Sunk
Lat. 8 - 29 N. Long. 134 - 55 E.

0202 H
Fired 3 torpedoes aft, 90 port track, range 1800 yards, gyro angle 40 L at the group of three escorts.

0203 H
A cloud of smoke suddenly blossomed in the place where the middle escort had been, and it disappeared. One hit was heard below, followed by the rapid-fire concussion of a load of depth charges exploding almost at once.

-10- Enclosure (A).

— page 260 —
0210 H Pulled clear, loaded our one remaining torpedo aft, in pursuit of the remaining freighter, tracked on course 240° T, speed 14, with two escorts. Radar picked up the ex-leading escort again, closing at high speed. Avoided him and kept on after the last freighter. Eventually this escort closed the burning ship and began rescuing survivors.

: 0230 H The damaged freighter flared into br>lliant flame, greatly increasing the visibility. Had to pull around him to get into position on the target.

: 0245 H End around proceeding satisfactorily. "TIGGER slowly gaining position, although much too close to Vela. o Reef for comfort (8 miles dead ahead), when the target suddenl made a radical course change to the left, and increased speed. I w target course 200° T, speed 17.

: 0320 H No hope of attacking with our one remaining torpedo. The three ships have not slackened speed, nor changed course. Plot of their position shows them 12 miles bearing 020° T from Ngarungal Reef, probably intending to go between it and Kayangol Island in order to hamper pursuit. One of the escorts periodically emitted a blinding flash, like an explosion of flashlight powder, probably some type of anti-submarine measure.

: Gave up the chase. Sincerely hope the Jap doesn't find his mistake in navigation in the next for>y minutes, because if he keeps on his present course, he will o aground on Ngarungal Reef at about 0400.

: From the maneuvers of the remaining vessels of this convoy, it appears that the repeated attacks and perhaps occasional sighting of TIGGER must have completely confuse d they coming as they did fr all directions. Evidently the enemy be ived he was under attack by more than one submarine, else we she d have been bothered more by escorts which instead remained close o their convoy.

: The necessity of being in position for feguard duty next morning prevented our closing the reef sub>rgad during the day. Decided to retire via the burning ship to so if he might need another torpedo.

: 0345 H Divcd, inspected burning ship through the poriscope.

-11- Enclosure (A).

— page 261 —
0426 H
Ship identified as Awazisan Maru Class, 9794 tons. One escort, a Yakatake class old destroyer, was prowling about, echo-ranging. The freighter was listed well to starboard, down by the bow, and was ablaze from stem to stern. No doubt at all he was done for. Flames shot hundreds of feet into the air. Frequent explosions on board blew great masses of red hot debris into the air.

The DD was a difficult target for one torpedo, presenting a different angle on the bow at every observation, circling the target and dropping occasional depth charges all day. Several times he appeared to have made sound contact upon us, would close (not very close) drop a few charges, then drift away.

We gave up finally. The Maru was sure to sir without any further persuasion, and the strain of keeping us with the escort was too great for a tired crew. Set course for North. Heard echo-ranging and periodic depth charging until 15:00.

1755 H
Surfaced. Light of burning ship still visible, 20 miles away, still shooting huge flames into the sky. Total search for the day, 4 Maru 1 escort sunk, 1 Maru 2 escorts chased aground or back to Palau, 115 depth charges received!

April 28 to May 3, 1944

Surface patrol northwest of Palau, air strike delayed, awaiting another sampan, an unescorted freighter with rusty sides, or orders to come home. The latter received on May 3.

May 1

2000 H
Radar interference; suspected U.S.S. BLACKFISH, knowing of her presence.

2150 H
Radar contact, 6300 yards. (CONTACT # 7)

2203 H
Established contact with BLACKFISH, exchanged information via blinker, made plans for coordinated search. At range of 2000 yards, bright moonlight (1/2 moon), BLACKFISH could not be seen from TRIGGER. Under certain conditions of a neophere and angles of lighting the grey camouflage amounts to ir visibility.

May 2

0515 K
Sighted U.S.S. BLACKFISH 194" T, distant 15 miles (through high periscope).

May 5

1125 K
Divided for a plane.

1413 K
Surfaced.

-12- Emolosure (A).

— page 262 —
0558 K
Sighted submarine on starboard quarter bearing 250° T, distance 8000 yards, 30° starboard angle on the bow. Dived, commenced submerged approach. (CONTACT # 8).

Evidently the submarine dived also. Contact by sound was made at 0616 K, 110 RPM, and lost at 0644 K, last count 80 RPM. Not seen at any time.

The submarine was painted black and had a large bow wave. Enemy identity not certain.

1523 K
Surfaced. Have been bucking wind and sea since leaving station, beginning to worry about fuel.

May 7
Surfaced and submerged all day ducking planes. One flight of B-24's soon.

May 8 to May 15, 1944
Enroute Midway. Sighted U.S.S. BLITZISH several times during May 5. Dived for several planes - see section "G".

May 16, West Longitude Date.
Arrived Midway.

May 20
0115 K
Radar contact 9000 yards. Commenced tracking on four engines, cleared message to ComSubPac.

0307 K
Target apparently sighted us, turned toward, and we became the pursued.

0331 K
Answer "Friendly". Gave recognition signal, and received immediate reply. Broke off contact.

1300
Arrived Pearl.

— page 267 —
U.S.S. TRIGGER - Report of NINTH War Patrol (Cont'd.)

(H) ATTACK DATA
TORPEDO ATTACK REPORT FORM
U.S.S. TRIGGER Torpedo Attack No. ONE. Patrol No. NINE.
Time: 0343 K. Date: 8 April 1944. Lat. 19-06 N. Long. 142-31 E.

TARGET DATA - DAMAGE INFLICTED
Description: Large AO, very low in the water. Silhouette similar to Whale Factory. Three medium freighters in line of fire beyond the tanker.
Ship(s) damaged or probably sunk: The target (AO), and two of the AK in the line of fire beyond. Damage determined by: Heard 4 torpedoes hit; time of run and firing interval of first two checked with range to AO. The others hit two of the ships beyond. Times of second two hits checked with range to the second column, the 3rd torpedo having been spread ahead, and the last astern of the AO.
Target draft: 30. Course: 150°. Speed: 10. Range: 2000 (at firing).

OWN SHIP DATA
Speed: 3. Course: 240°. Depth: 60. Angle: 15° L (at firing).

FIRE CONTROL AND TORPEDO DATA
Type attack: Submerged moonlight periscope attack after radar (surface and submerged) approach. Bow tubes.

Tubes Fired: # 1 # 2 # 3 # 4
Track Angle: 90 P
Gyro Angle: 15° L
Depth set: 6 ft 10 ft 10 ft 6 ft
Power: High High High High High
Hit or Miss: Hit Hit Hit Hit
Erratic: No No No No
Mark Torpedo: 23 23 23 14-3-A
Serial No: 41448 41024 41001 39934
Merk Exclod: 6-1-A 6-1-A 6-1-A 6-1-A
Serial No: 11572 11561 8590 8054
Actuation Set: Contact Contact Contact Contact Contact
Actuation Actual: Contact Contact Contact Contact
Mark Mark: 16-1 16-1 16-1 16-1
Serial No: 2818 11153 11415 3703
Explosive: Torpex Torpex Torpex Torpex
Firing Interval: 5 Sec 7 Sec 3 Sec
Type Spread: Average 2°.

Sea Condition: CALM
Overhaul Activity: Submarine Base, Pearl Harbor, T.H.
Remarks: All H.S.N. Four hits; two in the target at 2000 yards (large AO); time of run and hit interval checked ex.ctly with first two fired. Number 3 spread ahead, hit a ship in the far column. Number 4, spread astern, hit another ship in the far column.

Enc: sure (^).

— page 268 —
U.S.S. TRIGGER - Report of NINTH War Patrol (Cont'd.)

(H) ATTACK DATA
TORPEDO ATTACK REPORT FORM

U.S.S. TRIGGER Torpedo Attack No. TWO. Patrol No. NINE.
Time: 0002 H Date: 27 April 1944. Lat. 8-20 N. Long. 134-53 E.

TARGET DATA - DAMAGE INFLICTED

Description: 4 leading freighters of a 5 freighter convoy with 5 escorts.
First four overlapping. All 7-8000 ton class passenger
freighters with composite 2-deck superstructure. Speed 12
knots, no smoke.

Ship(s) sunk: Two of the above.
Ship(s) damaged or
probably sunk: The other two.
Damage determined by: Saw torpedoes hit. Saw o.o ship explode, saw another
go down by the storm and sink immediately. Saw another
hit, stopped, well down b: the stern. Saw fourth pull
out at reduced speed, down by the bow.

Target draft: 25. Course: 350°. Speed: 12. Range: 2400 (at firing).

OWN SHIP DATA

Speed: 6. Course: 090°. Depth: Surface. Angle: 15 L to O (at firing)

FIRE CONTROL AND TORPEDO DATA

Type Attack: Night surface attack. TBT bearings and radar ranges. Bow tube:

Tubes Fired: #1 #2 #3 #4 #5 #6
Track Angle: 90 P - 80 P
Gyro Angle: 15 L to O 6 ft 6 ft 6 ft 6 ft 6 ft
Depth Set: 6 ft High High High High High
Power: High High High High High
Hit or Miss: * Hit Hit No No No No No
Erratic: No 23 14-3-A 14-3-A 14-3-A 14-3-A 14-3-A
Mark Torpedo: 52967 23880 24609 22588 40583 8599
Serial No: 6-4 6-4 6-4 6-4 6-4 6-4
Mark Exploder: 8588 11605 13098 11565 14849 8599
Serial No: Contact Contact Contact Contact Contact Contact
Actuation Set: Contact Contact Contact Contact Contact
Actuation Actual: Contact Contact Contact Contact Contact
Mark Warhead: 16 16 16 16 16 16
Serial No: 1626 8021 3137 10268 2741 11342
Explosive: Torpex Torpex Torpex Torpex Torpex Torpex
Firing Interval: 12 Sec 10 Sec 11 Sec 11 Sec 11 Sec
Type Spread: 1° Div CALM

Sea Condition: Submarine Base, Pearl Harbor, T.H.
Overhaul Activity: Estimated hits by plot, and gyro angle.

Remarks:

-19- Enclosure (A).

— page 270 —
U.S.S. TRIGGER - Report of NINTH War Patrol (Cont'd.)

(H) ATTACK DATA
TORPEDO ATTACK REPORT FORM
U.S.S. TRIGGER
Torpedo Attack No. FOUR.
Patrol No. NINE.
Time: 0057 H. Date: 27 April 1944. Lct. 8-29 N. Long. 134-55 E.

TARGET DATA - DAMAGE INFLICTED
Description: AK, damaged by attack # 2; in light of early dawn and her own fire as result of hits during this attack ship identified as large 9000 ton passenger freighter. (AMAZISAN MARU Class, 9794 tons.)

Ship(s) sunk: The damaged AK.
Ship(s) damaged or probably sunk: None.
Damage determined by: Saw two torpedoes hit. Saw ship burst into flame.
Ship burned for 24 hours, with many explosions.
Target draft: 30. Course: 045°. Speed: 0. Range: 3300 (at firing).

OWN SHIP DATA
Speed: 6. Course: 315°. Depth: Surface. Angle: 0° (at firing).

FIRE CONTROL AND TORPEDO DATA
Type attack: Night surface, with TFT bearings and radar ranges. Bow tubes.

| Type | Range | Target | Depth | Course | Speed | Angle | Firing | Type |
|------|||||-------|-------||------|
| AK   | 14-3-A | 22313  | 52796 | 6-4   | 6-4   | 6-4   | 6-4   | 6-4  |
| AK   | 14-3-A | 22315  | 52854 | 6-4   | 6-4   | 6-4   | 6-4   | 6-4  |
| AK   | 14-3-A | 22316  | 52855 | 6-4   | 6-4   | 6-4   | 6-4   | 6-4  |
| AK   | 14-3-A | 22317  | 52856 | 6-4   | 6-4   | 6-4   | 6-4   | 6-4  |
| AK   | 14-3-A | 22318  | 52857 | 6-4   | 6-4   | 6-4   | 6-4   | 6-4  |
| AK   | 14-3-A | 22319  | 52858 | 6-4   | 6-4   | 6-4   | 6-4   | 6-4  |
| AK   | 14-3-A | 22320  | 52859 | 6-4   | 6-4   | 6-4   | 6-4   | 6-4  |
| AK   | 14-3-A | 22321  | 52860 | 6-4   | 6-4   | 6-4   | 6-4   | 6-4  |
| AK   | 14-3-A | 22322  | 52861 | 6-4   | 6-4   | 6-4   | 6-4   | 6-4  |
| AK   | 14-3-A | 22323  | 52862 | 6-4   | 6-4   | 6-4   | 6-4   | 6-4  |
| AK   | 14-3-A | 22324  | 52863 | 6-4   | 6-4   | 6-4   | 6-4   | 6-4  |
| AK   | 14-3-A | 22325  | 52864 | 6-4   | 6-4   | 6-4   | 6-4   | 6-4  |
| AK   | 14-3-A | 22326  | 52865 | 6-4   | 6-4   | 6-4   | 6-4   | 6-4  |
| AK   | 14-3-A | 22327  | 52866 | 6-4   | 6-4   | 6-4   | 6-4   | 6-4  |
| AK   | 14-3-A | 22328  | 52867 | 6-4   | 6-4   | 6-4   | 6-4   | 6-4  |
| AK   | 14-3-A | 22329  | 52868 | 6-4   | 6-4   | 6-4   | 6-4   | 6-4  |
| AK   | 14-3-A | 22330  | 52869 | 6-4   | 6-4   | 6-4   | 6-4   | 6-4  |
| AK   | 14-3-A | 22331  | 52870 | 6-4   | 6-4   | 6-4   | 6-4   | 6-4  |
| AK   | 14-3-A | 22332  | 52871 | 6-4   | 6-4   | 6-4   | 6-4   | 6-4  |
| AK   | 14-3-A | 22333  | 52872 | 6-4   | 6-4   | 6-4   | 6-4   | 6-4  |
| AK   | 14-3-A | 22334  | 52873 | 6-4   | 6-4   | 6-4   | 6-4   | 6-4  |
| AK   | 14-3-A | 22335  | 52874 | 6-4   | 6-4   | 6-4   | 6-4   | 6-4  |
| AK   | 14-3-A | 22336  | 52875 | 6-4   | 6-4   | 6-4   | 6-4   | 6-4  |
| AK   | 14-3-A | 22337  | 52876 | 6-4   | 6-4   | 6-4   | 6-4   | 6-4  |
| AK   | 14-3-A | 22338  | 52877 | 6-4   | 6-4   | 6-4   | 6-4   | 6-4  |
| AK   | 14-3-A | 22339  | 52878 | 6-4   | 6-4   | 6-4   | 6-4   | 6-4  |
| AK   | 14-3-A | 22340  | 52879 | 6-4   | 6-4   | 6-4   | 6-4   | 6-4  |
| AK   | 14-3-A | 22341  | 52880 | 6-4   | 6-4   | 6-4   | 6-4   | 6-4  |
| AK   | 14-3-A | 22342  | 52881 | 6-4   | 6-4   | 6-4   | 6-4   | 6-4  |
| AK   | 14-3-A | 22343  | 52882 | 6-4   | 6-4   | 6-4   | 6-4   | 6-4  |
| AK   | 14-3-A | 22344  | 52883 | 6-4   | 6-4   | 6-4   | 6-4   | 6-4  |
| AK   | 14-3-A | 22345  | 52884 | 6-4   | 6-4   | 6-4   | 6-4   | 6-4  |
| AK   | 14-3-A | 22346  | 52885 | 6-4   | 6-4   | 6-4   | 6-4   | 6-4  |
| AK   | 14-3-A | 22347  | 52886 | 6-4   | 6-4   | 6-4   | 6-4   | 6-4  |
| AK   | 14-3-A | 22348  | 52887 | 6-4   | 6-4   | 6-4   | 6-4   | 6-4  |
| AK   | 14-3-A | 22349  | 52888 | 6-4   | 6-4   | 6-4   | 6-4   | 6-4  |
| AK   | 14-3-A | 22350  | 52889 | 6-4   | 6-4   | 6-4   | 6-4   | 6-4  |
| AK   | 14-3-A | 22351  | 52890 | 6-4   | 6-4   | 6-4   | 6-4   | 6-4  |
| AK   | 14-3-A | 22352  | 52891 | 6-4   | 6-4   | 6-4   | 6-4   | 6-4  |
| AK   | 14-3-A | 22353  | 52892 | 6-4   | 6-4   | 6-4   | 6-4   | 6-4  |
| AK   | 14-3-A | 22354  | 52893 | 6-4   | 6-4   | 6-4   | 6-4   | 6-4  |
| AK   | 14-3-A | 22355  | 52894 | 6-4   | 6-4   | 6-4   | 6-4   | 6-4  |
| AK   | 14-3-A | 22356  | 52895 | 6-4   | 6-4   | 6-4   | 6-4   | 6-4  |
| AK   | 14-3-A | 22357  | 52896 | 6-4   | 6-4   | 6-4   | 6-4   | 6-4  |
| AK   | 14-3-A | 22358  | 52897 | 6-4   | 6-4   | 6-4   | 6-4   | 6-4  |
| AK   | 14-3-A | 22359  | 52898 | 6-4   | 6-4   | 6-4   | 6-4   | 6-4  |
| AK   | 14-3-A | 22360  | 52899 | 6-4   | 6-4   | 6-4   | 6-4   | 6-4  |
| AK   | 14-3-A | 22361  | 52900 | 6-4   | 6-4   | 6-4   | 6-4   | 6-4  |
| AK   | 14-3-A | 22362  | 52901 | 6-4   | 6-4   | 6-4   | 6-4   | 6-4  |
| AK   | 14-3-A | 22363  | 52902 | 6-4   | 6-4   | 6-4   | 6-4   | 6-4  |
| AK   | 14-3-A | 22364  | 52903 | 6-4   | 6-4   | 6-4   | 6-4   | 6-4  |
| AK   | 14-3-A | 22365  | 52904 | 6-4   | 6-4   | 6-4   | 6-4   | 6-4  |
| AK   | 14-3-A | 22366  | 52905 | 6-4   | 6-4   | 6-4   | 6-4   | 6-4  |
| AK   | 14-3-A | 22367  | 52906 | 6-4   | 6-4   | 6-4   | 6-4   | 6-4  |
| AK   | 14-3-A | 22368  | 52907 | 6-4   | 6-4   | 6-4   | 6-4   | 6-4  |
| AK   | 14-3-A | 22369  | 52908 | 6-4   | 6-4   | 6-4   | 6-4   | 6-4  |
| AK   | 14-3-A | 22370  | 52909 | 6-4   | 6-4   | 6-4   | 6-4   | 6-4  |
| AK   | 14-3-A | 22371  | 52910 | 6-4   | 6-4   | 6-4   | 6-4   | 6-4  |
| AK   | 14-3-A | 22372  | 52911 | 6-4   | 6-4   | 6-4   | 6-4   | 6-4  |
| AK   | 14-3-A | 22373  | 52912 | 6-4   | 6-4   | 6-4   | 6-4   | 6-4  |
| AK   | 14-3-A | 22374  | 52913 | 6-4   | 6-4   | 6-4   | 6-4   | 6-4  |
| AK   | 14-3-A | 22375  | 52914 | 6-4   | 6-4   | 6-4   | 6-4   | 6-4  |
| AK   | 14-3-A | 22376  | 52915 | 6-4   | 6-4   | 6-4   | 6-4   | 6-4  |
| AK   | 14-3-A | 22377  | 52916 | 6-4   | 6-4   | 6-4   | 6-4   | 6-4  |
| AK   | 14-3-A | 22378  | 52917 | 6-4   | 6-4   | 6-4   | 6-4   | 6-4  |
| AK   | 14-3-A | 22379  | 52918 | 6-4   | 6-4   | 6-4   | 6-4   | 6-4  |
| AK   | 14-3-A | 22380  | 52919 | 6-4   | 6-4   | 6-4   | 6-4   | 6-4  |
| AK   | 14-3-A | 22381  | 52920 | 6-4   | 6-4   | 6-4   | 6-4   | 6-4  |
| AK   | 14-3-A | 22382  | 52921 | 6-4   | 6-4   | 6-4   | 6-4   | 6-4  |
| AK   | 14-3-A | 22383  | 52922 | 6-4   | 6-4   | 6-4   | 6-4   | 6-4  |
| AK   | 14-3-A | 22384  | 52923 | 6-4   | 6-4   | 6-4   | 6-4   | 6-4  |
| AK   | 14-3-A | 22385  | 52924 | 6-4   | 6-4   | 6-4   | 6-4   | 6-4  |
| AK   | 14-3-A | 22386  | 52925 | 6-4   | 6-4   | 6-4   | 6-4   | 6-4  |
| AK   | 14-3-A | 22387  | 52926 | 6-4   | 6-4   | 6-4   | 6-4   | 6-4  |
| AK   | 14-3-A | 22388  | 52927 | 6-4   | 6-4   | 6-4   | 6-4   | 6-4  |
| AK   | 14-3-A | 22389  | 52928 | 6-4   | 6-4   | 6-4   | 6-4   | 6-4  |
| AK   | 14-3-A | 22390  | 52929 | 6-4   | 6-4   | 6-4   | 6-4   | 6-4  |
| AK

— page 272 —
U.S.S. TRIGGER - Report of NINTH War Patrol (Cont'd.)

(H) ATTACK DATA (Cont'd.)

U.S.S. TRIGGER: Gun Attack No. ONE, Patrol Report No. NINE.
Time: 1858 I. Date: 12 April 1944 Lat. 10-26 N. Long. 134-29 E.

TARGET DATA - DAMAGE INFLICTED

Damaged: Sampan - 50 tons.
Damage determined by: Saw .50 cal and 20 mm bul.ots hit.

DETAILS OF ACTION

The shot sampan at 1752 K, April 12, 1944. Dived; at 1858 made battle
cruiser. Torpedo gun would not fire because of "roken sear pin (discovered
by the sea-boring breech after the action). Fire .50 cal and 20 mm. Fired
at 5 o'clock, holding back the firing pin until it command "Fire", then
released it. No hits with 4". Sampan returned fire with rifle. Broke off
accursed disk. Sends moderate.

Expended: .50 cal - 400 rds
20 mm - 1200 rds
4" - - - - 25 rds

(I) ATTACK:

Hit applicable.

(2) ATTACK VARIATIONS AND EV/SION TACTICS:

The convoy entered on April 8th was composed of about 20 large ships
at a rate of 75 knots. Complete disposition was not seen, but it appeared
that the enemy's concentration circles were on or near the convoy. Next
circular, about 10,000 yards from convoy c.ter. Next circle, 10 to 15
minutes, and the next 10 to 15 minutes. The last circle, 10 or more
seconds,

— page 277 —
1 AUXILIARY GENERAL/TOR - just prior to the blower can. a. lube oil was discovered leaking from the generator outer bearing pad. the seal ring into the generator housing. This lube oil was sprayed over the armature, brushes and commutator. The ground readings taken at this time are: Armature, 4 megohms; Field, 8 megohms. The Armature was washed down: thoroughly and dried out with hot air. Immediately after the engine was started the lube trouble developed and prevented further drying of the generator. The grounds then read: Armature, 150,000 ohms; Field, 8 megohm. At the end of the patrol the ground readings were: Armature, 300,000 ohm; Field, 400,000 ohms. It is believed that this casualty was caused by worn seal rings and a leaky fitting in the lube oil line from the generator bearing to the pump suction.

TFT - Much trouble was had keeping TFTs operative. The depth charging received resulted in flooding and broken connections. Moreover, as more and more reliance is being placed in this instrument for night firing, it is time that improvement were made in it. Its faults are:

(1) Easily put out of order, by shock or flooding.
(2) Minimum error averages 1°. (1-1 sel.syns.).
(3) Pincocular device excellent, but non-ster. standard, not adjustable, not precision-built.

The following measures are recommended:

(1) Eliminate topside TFT sel.syns. Install a vo-tical shaft through the overhead of the conning tower, mounting a me. an.

— page 278 —
1. RADIO (Cont'd.)
On the morning of April 9th an unsuccessful attempt was made to call NPM. The trouble was found to be caused by grounds in the antenna trunk, caused by moisture and seepage resulting from de- charging. After wash- ing no difficulty was encountered in transmittin. next night.

(1) RADIO
The depth charging of April 8, the SD was out of commission with the engines in the antenna mast and broken tubes. The tubes were replaced, but the insulation readings of the mast continued to drop until the SD radar was no longer operative. Suspecting a flooded mast, the base plug was removed, and several gallons of water fell out. In order to wash out the mast, the top of the mast was scraped and the top, and fresh water was added. The mast by means of a hose. After flushing, compressed air was used to the upper hole, and then a hot air blower to the open base. The radio installations of this treatment were necessary before the insulation readings had become high enough for operation. The whole procedure had to be repeated about once every two weeks, since the mast head was cracked and could not be made tight.

See comments anent "SD" in paragraph (L), "Anti-Submarine Measures and Evasion Tactics". While the statement of the Commanding Officer, U.S.S. SADIRSE, that the "SD is a menace" is certainly true if it is used as heretofore, the following discussion may throw a different light on the subject.

It is true that all but one of the plane contacts made while TRIGGER was suffered during this patrol were by sight. It is also true that we were not bothered by planes for the period durin which the SD was out of operation. However, all but a few plane contacts were prefaced with inter- ference. This interference would be an on for a few minutes and the next. Half an hour later it would be seen again for a few minutes. Later time usually brought the plane in shortly afterward. The next day, likewise interference was seen continuously when the Japs shore stations.

It is believed demonstrated that:

(1) The airship planes have a radar of frequency similar to that of the ship.
(2) The airship interferes with the ship's radar.
(3) The ship can see the same way as the ship.
(4) The ship can detect the interference indirectly: the presence of a ship in the vicinity of the ship's radar, plotting the bearings of the ship's interference; then he rides in with his radar off.
(5) All Japs shore stations have a similar radar, of much greater range.

-29- Enclosure (A).

— page 287 —
4. In the third attack four minutes later four Mk 18 torpedoes were fired from the stern tubes on the surface at the remaining ships of the original target group with one DD in line of fire, range 2800 yards to AK's 1800 yards to escort, 105 port track, 10 degrees left gyro angle, depth setting 6 feet. One hit was heard in one of the AK's. Other hits could not be definitely distinguished from the random depth charges of covering escorts.

5. The fourth attack was executed at 0145 after four attempts to gain attack position on the fifth AK of the convoy accompanied by a large damaged AK which was the only one of the four AK's left after the second and third attacks. Four torpedoes were fired on the surface at the large damaged AK, range 3300 yards, 90 starboard track, depth setting 6 feet. Two torpedoes fired at one of the three escorts in this attack missed, two hits were seen in the large damaged AK which commenced burning. This ship was later seen burning fiercely from end to end and continued to burn for at least 24 hours.

6. On the fifth attack three Mk 18 torpedoes were fired at a group of three escorts at 0202, range 1800 yards, 90 port track, 40 left gyro, depth setting six feet. The middle escort, a Wakatake of 820 tons, was hit and disappeared in a cloud of smoke amid the explosions of his remaining load of depth charges.

7. With only one Mk 18 torpedo left pursuit was immediately commenced of the remaining AK of the convoy protected by two escorts. The chase was given up when it became evident the AK would reach Ngrauangl Reef long before attack position could be attained.

8. The aggressiveness, the retention of initiative, and the skill exhibited by the Trigger in action with this convoy are outstanding. The comments in this well written patrol report on the first convoy action, radar, and coordinated attacks, are particularly worthy of note.

9. On the evening of 12 April Trigger battle surfaced for gun attack on a 50 ton Sampan at 2100 yards range. Several 50 cal. and 20mm hits were obtained. Accuracy of 4" gunfire was hampered by a casualty necessitating firing by lanyard in a rough sea. The attack was broken off at dusk.

— page 288 —
10. In view of the material condition of the Trigger upon return from patrol and low insulation readings on main generators Trigger will be given an overhaul on the West Coast.

11. The Commanding Officer, Officers and crew of the Trigger are heartily congratulated on this aggressive and outstanding patrol during which great damage was inflicted upon the enemy.

K. C. HURD.

— page 289 —
11/jak
F5-4/16-3
Serial: 0215
Fleet Test Office,
San Francisco, Calif.,
1 June, 1944.

SSCC 2. D.C. to:
U.S.S. TRIGGER report
of 7th War Patrol.

From: The Commander Submarine Squadron CUC.
To: The Commander-in-Chief, U.S.S. TRIGGER.
Via: (1) The Commander Submarine Force, U.S.S. TRIGGER.
(2) The Commander-in-Chief, U.S.S. TRIGGER.

Subject: U.S.S. TRIGGER - Report of War Patrol number M.I.

1. Forwarded, concurring in the remarks of the Commander Submarine Division LMT-1.

2. The Commander Submarine Squadron U.S. considers this patrol outstanding and congratulates the Commander Submarine Officers and crew on the completion of a most aggressive and successful performance against extremely determined enemy anti-submarine measures.

C. E. LARSON.

— page 290 —
6. 02404
FF12-10/A16-3(15)/(16)
Serial 0116
CONFIDENTIAL
THIRD ENDORSEMENT to
TRIGGER Report of
Ninth War Patrol.
CONSUBSAPAC PATROL REPORT NO. 428.
U.S.S. TRIGGER - NINTH WAR PATROL.
From: The Commander Submarine Force, Pacific Fleet.
To: The Commander-in-Chief, United States Fleet.
Via: The Commander-in-Chief, U. S. Pacific Fleet.
Subject: U.S.S. TRIGGER (SS237) - Report of Ninth War Patrol.
(23 March to 15 May 1944).

1. The ninth war patrol of the TRIGGER was the first for the new Commanding Officer as commanding officer of a fleet type submarine. The patrol was conducted in the Palau Area.

2. Co-tinuing a long line of successful war patrols, the TRIGGER conducted another extremely aggressive and successful patrol. Two convoys were contacted and aggressively attacked. Observation of results in the attack on the first convoy was thwarted by extremely efficient anti-submarine activity. The series of night radar attacks made on the second convoy of five ships and five escorts were exceptionally well carried out and resulted in the sinking of four of the ships and one of the escorts.

3. This patrol is designated as successful for Combat Insignia Award.

4. The Commander Submarine Force, Pacific Fleet, congratulates the Commanding Officer, officers, and crew for this aggressive and successful war patrol. In addition, the TRIGGER is congratulated for completing its eighth successive successful war patrol, during which she has sunk 24 ships totalling 166,633 tons, and damaged 12 ships totalling 105,931 tons. The TRIGGER is credited with having inflicted the following damage upon the enemy:

| Damage | Type | Tonnage | Date | Location |
||------||------||
| 1 - Passenger Freighter | class unknown | 7,500 tons | Attack No. 2 |
| 1 - Passenger Freighter | class unknown | 7,500 tons | Attack No. 2 |
| 1 - Passenger Freighter | class unknown | 7,500 tons | Attack No. 3 |
| 1 - Passenger Freighter | AWAZISAN MARU | 9,800 tons | Attack No. 4 |
| 1 - Destroyer (WAKATAKE class) | - | 900 tons | Attack No. 5 |

TOTAL 33,200 tons

FILMED -1-

— page 291 —
1-10/A16-3(15)/(.6)  FF12-10/A16-3(15)/(.6)  Serial 01116  Confidential  THIRD ENDORSEMENT to  THRIGGER Report of  Ninth War Patrol.  CONSUBSPAC PATROL REPORT NO. 428.  U.S.S. TRIGGER - NINTH WAR PATROL.  Subject:  U.S.S. TRIGGER (SS237) - Report of Ninth War Patrol.  (23 March to 15 May 1944).  D A M A G E D 1. Tanker (class unknown)  - 10,000 tons (Attack No. 1)  - Freighter (class unknown)  - 4,000 tons (Attack No. 1)  - Freighter (class unknown)  - 4,000 tons (Attack No. 1)  - Sampan  - 50 tons (Gun Attack No. 1).  TOTAL 18,050 tons  GRAND TOTAL 51,250 tons  DISTRIBUTION:  [Complete Reports]  (7)  C. A. LOCKWOOD, Jr.  COINCH  (5)  CINCPac  (6)  Intel.Cen.Pac.Ocean Areas  (1)  ComServPac  (Adv. Base Plan. Unit)  (1)  CinClant  (2)  ComSubsLast  (8)  S/M School, NL  (2)  ComSoPac  (2)  ComSolves2ac  (1)  ComSubsoWesPac  (2)  CTF 72  (2)  ComNorPac  (1)  ComSubsPac  (40)  SUBAJ, NL  (2)  ComSubsPacSubordCom  (3)  All Squadron and Division  Commanders, SubPac  (2)  ComSubsTrainPac  (2)  All Submarines, SubPac  (1)  E. V. TITTLE,  Flag Secretary.