U.S.S. TINOSA (SS-283) — war patrol report SS-283_TINOSA_Part1.pdf

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START OF REEL
JOB NO. [HANDWRITTEN: AR-5774-R#1]
OPERATOR [HANDWRITTEN: H]
DATE [HANDWRITTEN: 10-5-73]

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THIS MICROFILM IS
THE PROPERTY OF
THE UNITED STATES
GOVERNMENT

[SEAL: DEPARTMENT OF DEFENSE, UNITED STATES OF AMERICA]

MICROFILMED BY
NPPSO-NAVAL DISTRICT WASHINGTON
MICROFILM SECTION

REEL TARGET, START & END
NAVEXOS 3968

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FF12-10/A16-3(5)/(16)

Serial 0856

CONFIDENTIAL
[STAMP: DECLASSIFIED]
COMSUBSPAC PATROL REPORT NO P209
U.S.S. TINOSA - FIRST WAR PATROL.

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

Subject: U.S.S. TINOSA (SS283) - Report of First War Patrol.

Enclosure: (A) Copy of Subject War Patrol Report.
(B) Copy of Comsubdiv 101 Conf. ltr. FB5-101/A16-3,
 serial 048 of 20 June 1943.
(C) Copy of Comsubcomsubspac, Midway, Conf. ltr. A16-3,
 serial 08 of 21 June 1943.

1. This was the first war patrol of the U.S.S. TINOSA. Although
many contacts are listed, the majority were sampans.

2. It is noted that good use was made of the bathythermograph in
obtaining information regarding sound and also in establishing density layers.
Flooding in to go deep was necessary on several occasions and in each case a
large negative temperature gradient was noted.

3. The excellent performance of both SJ and SD radar is gratifying.

4. The apparent confusion existing in the fire control party during
the early part of the patrol seems to have been partially eliminated in the
latter attacks. It is hoped that the experience gained during this first patrol
will bear good results in the second.

5. The Commander Submarine Force, Pacific Fleet, congratulates the
Commanding Officer, officers, and crew for this patrol, during which the fol-
lowing damage was inflicted to the enemy:

DAMAGED
1 - Freighter (ONOE MARU Class) - 6,667 tons
1 - Passenger Freighter (HUSIMI
 MARU Class) - 10,936 tons
1 - Tanker (SHIRE TOKO Class) - 14,050 tons
 TOTAL: 31,653 tons

Distribution and authentication
on following page

[HANDWRITTEN: FILMED]
[HANDWRITTEN: 52067]

SUBMARINE FORCE, PACIFIC FLEET

Bz
[HANDWRITTEN: RECEIVED SC FILES]
Care of Fleet Post Office
San Francisco, California
5 July 1943.
[HANDWRITTEN: 28 JUL 1943]
ROUTE TO: [HANDWRITTEN: ---]
[STAMP: DECLASSIFIED ART. 0445, OPNAVINST 5510.1C] [HANDWRITTEN: 7/20/77]
Op File No. (SC) [HANDWRITTEN: ---]
Doc. No. [HANDWRITTEN: 88423]
Copy No. [HANDWRITTEN: 1] of [HANDWRITTEN: ---]

C. A. LOCKWOOD, Jr.

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[UNCLEAR: Filmed-Bureau-File]

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FF12-10/A16-3(5)/(16)
Serial 0856
CONFIDENTIAL

COMSUBSPAC PATROL REPORT NO. 209
U.S.S. TINOSA - FIRST WAR PATROL.

Subject: U.S.S. TINOSA (SS283) - Report of First War Patrol.

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U.S.S. TINOSA (SS 283)
B7

C O N F I D E N T I A L

U.S.S. TINOSA (SS283) - Report of First War
Patrol. Period from 3 May 1943 to 19 June 1943.
Operation Order 69-43 of May 1, 1943.

PROLOGUE
Arrived Pearl Harbor from San Francisco on April 16,
1943. Ten days training, one day sound survey, three days upkeep
by base. Ready for sea May 3, 1943.

I.
NARRATIVE

3 May 1943
1300(V) Departed Pearl under surface escort for assigned area
via Midway. Usual training dives and battle surface
drills enroute. Fired training rounds from all guns.

7 May 1943
0753(Y) Moored to dock and fueled to capacity. Received
16,400 gallons.

1620(Y) Departed with air escort.

8-14 May 1943 Uneventful. Daily dives and drills. Fired balance
training ammunition. Using SD radar during daylight
and SJ in periods of low visibility and at night.
Zigzagging during daylight periods of high visibility.
Running on surface. L/C of longitude 175E maintained
#1 periscope watch while on surface.

15 May 1943 Adjusted speed and made two hour dive so as to
approach SUMISU SHIMA after dark. Secured SD radar
100 miles from land. At

1852(I) Sighted white light. Sky was overcast, twilight in
progress, getting dark rapidly. Identified as small
sampan, light bobbing in heavy swells. No radar
contact. Passed 3000 yards abeam. At

1951(I) After passing out of visibility, changed course and
increased speed. At about

2100(I) Passed SUMISU SHIMA abeam to starboard, distance 16
miles. Not sighted and no SJ radar contact.

16 May 1943 At
0128(I) Sighted white light bearing 000° relative. Cut in
four main engines and at

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ENCLOSURE (A)

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CONFIDENTIAL
Subject: U.S.S. TINOSA (SS283) - Report of First War Patrol.
Bz
I
NARRATIVE (CONTINUED)

18 May 1943 At
0055(I) Ignored sound indications and time to periscope depth, then
         radar depth. Radar contact 6700 yards increasing. Moon be-
         hind clouds. At

0112(I) Surfaced. Moon obligingly came out from clouds, putting TINOSA
         in moon streak visible from convoy. Observed signals from rear
         escort. Opened out at best speed, charging batteries and began
         end around chase. Sent contact report on 750 KCS immediately.
         Did not transmit to Comsubpac as convoy appeared headed for
         KII SUIDO and only one chance to get it. Lost sight and radar
         contact at 15,000 yards, still in moon path. At
         reached area limit, ran north to head off convoy and at

0335(I)
0431(I) Submerged because of increasing light. Position twelve miles
         185° from ASHIZURI SAKI. Closing coast. It is believed con-
         voy may have headed into BUNGO SUIDO after their doubtful con-
         tact with us. However, the sudden stopping and milling around
         together with the deliberate constant zero angle on bow on one
         target when we were headed 90° to its track leaves no doubt in
         my mind that we had been sighted, probably when we first
         periscoped, and again when we had too much periscope exposed
         due to heavy swells. Lack of further ES measures makes it
         appear that we could have immediately returned to periscope
         depth and were misled by sound reports of incipient attacks.
         At

18 May 1943
0719(I) After having been closely followed by one sampan patrol
         (contact #4) and with a second approaching evaded at 120 feet.
         Closing coast again. At

1207(I) Sampan back on trail again. Despite all evasive maneuvers
         sampan would follow track of TINOSA about 1500 yards astern.
         Since any shipping would be warned went to 150 feet, began
         opening coast and at

1315(I) Lost sound contact. At

1405(I) Distant explosion. At

1955(I) Surfaced. Found fish line caught on port bow plane and
         streaming aft, length about 200 feet. Loose end frayed.
         Sampan may have been following float.

19-20 May 1943 Patrolling daylight submerged, night on surface along VAN
         DIEMAN - KII SUIDO route and off ARIAKE WAN.

21 May 1943 At
1256(I) Sighted target bearing 109°T. Target (contact #9) heavy
         cruiser similar to NACHI class.

                                   - 3 -
                                                           ENCLOSURE (A)

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CONFIDENTIAL                                                                Bz
Subject:         U.S.S. TINOSA (SS283) - Report of First War Patrol.

I                               NARRATIVE (CONTINUED)

21 May 1943 At    Maintained 7.5 knots on normal approach course for one hour
1256(I) (Con't)   except for intermittent observations. Closest range 9700
                  yards.

22 May 1943       Patrolling off OKINO SHIMA. At

0744(I)           Sighted masts two vessels. Closer approach indicated one
                  small merchantman acting as AS vessel. Came out of SUKIMO
                  KO east of BIRO SHIMA. Spent time lying to or patrolling
                  between OKINO and BIRO SHIMA. Too small to torpedo.

23-27 May 1943    Uneventful. Patrolling as indicated on track chart covering
                  coast and steamer routes. Spent 25 May reconnoitering
                  NOMEOA area for gun target but poor visibility hindered
                  observations.

28 May 1943 At    Had first false radar contact, range 21,950 yards. Others
2020(I)           up to 30,750 yards. Each investigated but nothing found.
                  Undoubtedly rain squalls which were prevalent.

29 May 1943       Patrolling off east coast KYUSHU, MIHITSU to TA ANAB.
                  Tentatively selected factory with six smoke stacks at Latitude
                  32-08N as gun target. At

2006(I)           Surfaced. At

2042(I)           Radar contact (contact #31) range 6500 yards, speed 7 knots,
                  and approaching entrance BUNGO SUIDO. Abandoned attack to
                  mediate sins of omission and commission.

30 May 1943       First aircraft patrols out today. Two small merchantmen
                  (patrol vessels) (contact #32) and one destroyer (contact #33)
                  searching, using echo ranging. Latitude 32-11N Longitude
                  132-43E.

31 May 1943       At Latitude 32-21N Longitude 132-26E.

0607(I)           Sighted target, range estimate 4000 yards, angle on bow
                  zero, began approach. (contact #34) Visibility very poor. At

0617(I)           Target identified as small P.C. too small for torpedo and
                  range much less than estimated. Passed nearly overhead.

1-2 June 1943     Uneventful. Patrolling as on track chart.

3 June 1943       Upon surfacing cheeked gun as preliminary to attack next day
                  on shore target when

4 June 1943       Using SD radar for first time since arriving in area At.

                                    - 4 -                               ENCLOSURE (A)

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Bz
CONFIDENTIAL
Subject: U.S.S. TINOSA (SS283) - Report of First War Patrol.

I. NARRATIVE (CONTINUED)

1001(I) Plane contact on radar, eight miles, closing. Dived.
1055(I) Surfaced. At
1643(I) Sighted plane, distance six miles, low. No radar
        indication but we were in middle of islands. Dived.
1745(I) Surfaced. At
1821(I) Sighted masts through #1 periscope. Identified as
        steam fishing sampan. Avoided. At
1840(I) Sighted tug with tow - dredge or target raft. A
        nice run target but twelve miles distant and on other
        side of TAKARA SHIMA Island. No time to lose.
5 June 1943 Sighted several lighted sampans during night, avoiding
        in each instance. At
5 June 1943 Sighted submarine bearing 257°T, distant 15000 yards,
0559(H) course 280°T. At
0603(H) Sighted smoke of convoy bearing 269°T, range 30000
        yards. Submarine (SEAWOLF?) dived. Reversed course
        and began running to gain position ahead and clear
        submarine. At
0646(H) Submerged, began approach. At
0916(H) Conducted attack and made two hits in largest ship,
        similar to HUSIMI MARU, page 83 ONI 208 J. After
        attack gunfire when periscope was up and moderates
        depth charging. At
0921(H) Went to 150 feet.
1052(H) With distant pinging came to periscope depth.
        Visibility spotty. Opening away from pinging.
1203(H) Sighted destroyer, source of pinging, on convoy track,
        range 10,000 yards.
1235(H) Two explosions.
1237(H) Two explosions.
1304(H) Two explosions.
1430(H) Destroyer last sighted. Visibility still spotty
        with rain squalls.

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CONFIDENTIAL                                                               Bz
Subject:        U.S.S. TINOSA (SS283) - Report of First War Patrol.

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Rs

CONFIDENTIAL
Subject: U.S.S. TINOSA - Report of First War Patrol.

II. WEATHER
1. Pearl to Midway -- Usual rough weather leaving the islands.
   Sky partially overcast. Moderate N and NE trades. Second
   day clear and warm with slight swell. Threatening weather
   then set in with occasional showers and moderate sea.

2. Midway to Nanpo Shoto -- Slight swell with variable winds and
   occasional showers. Generally clear and moderate.

3. Areas & -- Overcast about fifty percent of the time.
   Southwest and west winds and sea bring warm disagreeable
   weather. North and northeasterly winds produce detached
   clouds but unlimited visibility -- temperature 79° and caused
   sea to flatten. Southerly wind brings overcast, temperature
   83°, visibility limited. Ground haze existed generally over
   coastline making observations inshore extremely difficult.

4. East China Sea -- June 4-7 -- Overcast 100 percent, with rain
   about 70 percent. Mostly steady rain, but occasional squalls.
   Wind in a general easterly direction about force two. Sea
   calm with slight swells.

5. Areas to Midway -- Mild weather with excellent visibility
   occasionally interrupted by rain squalls. Seas from the
   east working around to the north and increasing from 1 to 4.

III. TIDAL INFORMATION (IF ABNORMAL)

1. Pearl to Midway -- Normal.

2. Midway to Nanpo Shoto -- Upon departing Midway on course to
   south of Kuro Is. experienced a current (tidal or otherwise)
   of 3 knots setting toward 085°. Generally normal charted
   currents found to exist.

3. Area & -- Pronounced current with wind and sea when in
   conformity with Kuro Shio - set 2.0 knots, drift 052°T (Av.
   25 days) Current in Osumi Kaikyo set 065° drift .75 knot
   rather light after a period of south westerly wind and sea.
   Normal currents in Osumi Kaikyo existed at other times.

4. East China Sea -- Current generally ENE about 1 knot.

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CONFIDENTIAL                                                              Rs
Subject: U.S.S. TINOSA - Report of First War Patrol.

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CONFIDENTIAL                                                              Bz

Subject:         U.S.S. TINOSA (SS283) - Report of First War Patrol.

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CONFIDENTIAL
Subject: U.S.S. TINOSA (SS283) - Report of First War Patrol.
Bz
V. ENEMY VESSELS SIGHTED (CONTINUED)

CONTACT | TIME | LAT | TYPE & DESCRIPTION | COURSE | SPEED | REMARKS
NO. | DATE | LONG | | | |
----|------|-----|||-------|
47 | 2109H | 31-40 | Four Patrol Boats | 240 | 5 | White running
    | 6/5/43 | 126-26 | | | | lights on
48 | 0050H | 32-32 | One Patrol Boat | 240 | 5 | White running
    | 6/6/43 | 127-36 | | | | lights on
49 | 0410H | 33-08 | Two Patrol Boats | 240 | 5 | See Sketch
    | 6/6/43 | 128-13 | | | |
50 | 0451H | 32-54 | One Patrol Boat | 240 | 5 | See Sketch
    | 6/6/43 | 127-52 | | | |
51 | 0810H | 33-02 | One Patrol Boat | 240 | 5 | See Sketch
    | 6/6/43 | 127-55 | | | |
52 | 1208H | 32-50 | Two Patrol Boats | 240 | 5 | See Sketch
    | 6/6/43 | 128-10 | | | |
53 | 2322I | 31-27 | One Sampan | --- | --- | Showing light
    | 6/7/43 | 129-55 | | | |
54 | 0255I | 31-02 | Small Patrol Boat | --- | --- | Showing light
    | 6/8/43 | 130-32 | | | |
55 | 1204I | 30-58 | Sail Boat | 030 | 5 | 150 ft.
    | 6/8/43 | 130-32.7 | | | |
56 | 1255I | 30-59.5 | Large Sampan | 220 | 7 | 100 ft.
    | 6/8/43 | 130-36.8 | | | |
57 | 1255I | 30-54 | Small Sampan | 240 | 6 | 50 ft.
    | 6/8/43 | 130-20 | | | |
58 | 1329I | 31-05 | One Sampan | 350 | 6 | 75 ft.
    | 6/8/43 | 130-30 | | | |
59 | 1340I | 30-58.5 | Inter Island Passenger | 210 | 9 | 200 ft.
    | 6/8/43 | 130-50.5 | Boat | | |
60 | 1343I | 31-00 | One Sampan | 010 | 5 | 100 ft.
    | 6/8/43 | 130-20 | | | |
61 | 1500I | 31-03.5 | One Fishing Sampan | 170 | 6 | 50 ft.
    | 6/8/43 | 130-33.0 | | | |
62 | 1504I | 31-05.2 | One Fishing Sampan | 220 | 5 | 40 ft.
    | 6/8/43 | 130-32 | | | |
63 | 2134I | 31-35.1 | Convoy of seven ships | 177 | 9 | Smoking
    | 6/9/43 | 132-43.6 | 2 large merchantmen | | | | heavily
    | | | | 2 small merchantmen | | | |
    | | | | 2 or 3 escorts | | | |
64 | 2259I | 31-14 | MITSUKI Class DD, P.C., | 316 | 5.5 | Pg. 120
    | 6/9/43 | 132-44.1 | 4,000 Freighter towing | | | | ONI 14
    | | | | SHIRETOKO Class Tanker | | | | Partially
    | | | | | | | loaded
    | | | | | | | 75 ft.
65 | 0315I | 31-30 | Small Patrol Vessel | | | |
    | 6/11/43 | 134-08 | | | |
66 | 0858I | 32-06 | Two Masted Patrol | 090 | 10 | 100 ft.
    | 6/11/43 | 136-22 | Vessel | | | | Sighted
    | | | | | | | through #1 pe-
    | | | | | | | riscope 1400 yds.
    | | | | | | | Reversed course
    | | | | | | | and headed for us.

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CONFIDENTIAL                                                              Bz

Subject:        U.S.S. TINOSA (SS283) - Report of First War Patrol.

— page 34 —
Okay, I will transcribe the text from the image you provided.

Here is the transcription:

rf

CONFIDENTIAL

Subject: U.S.S. TINOSA (SS283) - Report of First War Patrol,

— page 37 —
CONFIDENTIAL                                                              rf
Subject:           U.S.S. TINOSA (SS283) - Report on First War Patrol.

— page 38 —
rf

CONFIDENTIAL
Subject: U.S.S. TINOSA (SS283) - Report of First War Patrol.

XIV. MILES STEAMED TO AND FROM STATION
(a) Miles steamed, Pearl to station via Midway -- 3,925 Miles
(b) Miles steamed, on station -- 2,290 miles
(c) Miles steamed, station to Midway -- 2835 miles

XV. FUEL EXPENDED
(a) Fuel oil expended -- 96,500 gallons.

XVI. FACTORS OF ENDURANCE REMAINING
(a) Torpedoes -- 2
(b) Fuel -- 13,500 gallons.
(c) Provisions -- 25 days
(d) Personnel -- 7 days
(e) Fresh water -- Unlimited

XVII. Patrol terminated by orders of Commander Submarines,
Pacific Fleet.

XVIII. REMARKS

1. The performance of duty of the officers and men
during this first patrol was, on the whole, excellent. A
continuing improvement was noted as experience was gained. The
work of Lieutenant (junior grade) L. A. BECK, E-V(RS), USNR
and of W.A. WILSON, C24-25-59, RT1c, V-6, USNR, in maintaining
the radars was especially appreciated.

2. The S.J. radar is invaluable. Although small
patrol vessels were usually first sighted by their lights, the
range at which radar picks them up usually gives an immediate
indication of their size. No indication that the Japanese were
using radar was noted. The S.D. radar was usually secured when
within 100 miles of land. Several cases of interference were
noted but at least one was caused by operating a megger in the
Control Room.

3. The high altitude periscope is not satisfactory.
It has the appearance of fogging badly at times and requires too
long a time to clear. This fogging is almost certainly external
and due to the slowness of water in clearing the upper window.
At times a wedge of water seems to remain and cause a double
image.

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SUBMARINE DIVISION ONE HUNDRED ONE Bz
FB5-101/A16-3 Care of Fleet Post Office,
Serial 048 San Francisco, California,
20 June 1943.

C O N F I D E N T I A L

From: The Commander Submarine Division ONE HUNDRED ONE.
To : The Commander Submarine Force, PACIFIC FLEET.
Via : The Commander Submarine Force, PACIFIC FLEET,
Subordinate Command, Navy Number 1504.

Subject: U.S.S. TINOSA - First War Patrol.

1. TINOSA First War Patrol extended from May 3 to June
19, 1943. Twenty-six of the total of forty-seven days were spent
in the patrol area.

2. Attack Summary:-

Attempted night submerged attack on convoy, 17-18
May:
The attack on this well protected 4 ship convoy was
not completed due to various factors. The natural difficul-
ties, of an attack on a melee of ships, combined with the fact
that this was the first attack for the submarine and its con-
trol party, played prominent parts.

Attack No. 1(a):-
1 hit out of 4 torpedoes, with run about 2500 yards.
(Night surface attack on 6667 ton AK.)

Attack No. 1(b):-
Twenty-two minutes later fired 4 torpedoes on 170°
track, run 1200 yards at same target which had turned tail
after earlier hit. Two close misses and two wide ones which
were either erratic or, more probably, had had spindles en-
gaged while gyro setter read about 330°.

Attack No. 1(c):-
Twenty-nine minutes after previous attack, fired 4
torpedoes, run 2200 yards which missed ahead as target turned
away.

Attack No. 1(d):-
An hour later fired 2 more torpedoes, night surface,
run 1000 yards. One more hit, apparently magnetic, didn't
stop this target which went over the hill, still firing its
deck guns.

ENCLOSURE (B)

— page 41 —
SUBMARINE DIVISION ONE HUNDRED ONE Bz

FB5-101/A16-3
Serial 048
CONFIDENTIAL
Subject: U.S.S. TINOSA - First War Patrol.

Attack No. 2(a):-
Day periscope attack on a convoy of 12 merchantmen.
From position between the two starboard columns fired 2 stern
shots at 10800 ton ship, run 1000 yards: 2 observed hits.

Attack No. 2(b):-
Two bow shots at ship in third column from the
right, fired 1½ minutes after previous salvo. The first shot
went wide because the gyro setter switch had not been turned
on. The second, with 3° spread missed due to control errors,
large gyro angle, or maneuvers to avoid.

Attack No. 3:-
Fired 4 torpedoes at towed tanker, run 1550 yards,
morning twilight periscope attack. Spread used should and
did produce 2 hits (torpex). A third torpedo seemed to run
erratically and was observed to premature. A well conducted
attack.

3. The convoy encountered on June 12, with two torpe-
does remaining, appeared worth a chase.

4. The fogging of the High Altitude periscope in high
power is noted. This, reported to be external (slowness of water
in clearing upper window), has been noted by some other vessels.
Further reports on the performance of this type periscope should
be made in order that proper remedial action can be taken. The
pressure in subject periscope did not at any time drop below 7
pounds during the patrol.

5. SPERRY is refitting TINOSA at Midway.

ENCLOSURE (B)

— page 42 —
COMMANDER SUBMARINE FORCE,
PACIFIC FLEET, SUBORDINATE COMMAND, MIDWAY,

                                                Care of Fleet Post Office,
                                                San Francisco, California,
                                                21 June 1943.

A16-3

Serial 08

C O N F I D E N T I A L

From:      Commander Submarine Force, Pacific Fleet,
           Subordinate Command.
To :       Commander Submarine Force, Pacific Fleet.

Subject:   U.S.S. TINOSA - First War Patrol - Comments on.

           1. The first war patrol of the Tinosa extended over
a period of 47 days, of which 27 days were spent on station or
in contact with enemy vessels.

           2. This patrol was characterized by an apparent lack
of smoothness and coordination in the fire control party and by
a lack of tenacity in following up contacts and pushing home at-
tacks. A total of 27 merchantmen and one CA were contacted in 8
contacts.

           3. The first attempted attack was on a 4 ship, 7.3
knot convoy; May 17, targets were apparently shifted so frequently
that control party could not get a clear picture at the firing
point. No torpedoes were fired and no anti-submarine measures
were encountered.

           4. During the first attack on a 7.5 knot, 6700 ton
freighter a total of fourteen torpedoes were expended for two
hits. The target steamed away at 7.3 knots.

           5. It is recommended that Tinosa be credited with
following damage:
           AK (Once Maru Class)             6,667 tons.
           AP (Husimi Maru Class)          10,800 tons.
           AO (Shiretokoko Class)          14,050 tons.
                                   Total   31,517 tons.

                                                ENCLOSURE (C)

— page 43 —
DECLASSIFIED - DOD DIR. 5200.9
of 27 Sep 58
BY [HANDWRITTEN: 22C] DATE [HANDWRITTEN: 4/28/71]

DECLASSIFIED

U.S.S. TINOSA (SS283) - Report of Second War
Patrol. Period from 7 July 1943 to 4 August 1943.
Operation Order No. 126-43.

PROLOGUE

Arrived Midway on 19 June 1943 from first war
patrol for refit by SPERRY. Refit consisted of
minor repairs and routine items. Not depermed.
Degaussing not calibrated. Sound test was not
conducted. Two days training. Ready for sea
7 July 1943.

NARRATIVE

I.

7 July 1943
1300(Y) Departed Submarine Base, Midway, enroute area, air
escort.

9-13 July 1943
Crossed 180th Meridian. Omitted 8 July 1943. Short
daily trim dives. Fire control and gun drills con-
ducted on surface. Running at two and three engine
speeds to arrive as scheduled. Nothing sighted.

14 July 1943
0712(K) Arrived on station. Submerged. Calibrated magnetic
compasses. Patrolling station.

1953(K) Surfaced. Continued patrol.

15 July 1943
0441(K) Submerged. Maintaining periscope watch with short
frequent observations.

0653(K) Sound picked up fast screws bearing 315⁰T. Own
course 180⁰T. Battle stations. Nothing in sight.

0657(K) Sighted destroyer, bearing 350⁰T, angle on bow 10 port,
range 6000 yards. Visibility spotty. Six foot swells;
no chop or white caps. Tracked DD at 23 knots.
Changed course to close.

0712(K) Carrier appeared out of haze, bearing 280⁰T, angle on
bow 110 port. Course 210⁰T. Closing.

0714(K) One heavy cruiser leading two carriers in column,
range 9000 yards, now in sight. Speed checking 22
knots; zigzagging radically; never able to obtain

[STAMP: FILMED]
[HANDWRITTEN: 53759]

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CONFIDENTIAL
Subject: U.S. TINOSA (SS283) - Report of Second War Patrol.

I. NARRATIVE (CONTINUED)

24 July 1943 (Continued)
1011(K) Fired eighth torpedo. Hit. No apparent effect.

1014(K) Fired ninth torpedo. Hit. No apparent effect.
         Target firing at periscope, when exposed, and at wakes
         when torpedoes were running. Crossed track to observe
         for nets; none rigged.

1039(K) Fired tenth torpedo. Hit. No apparent effect.

1048(K) Fired eleventh torpedo. Hit. No effect. This torpedo
         hit well aft on the port side, made a splash at the
         side of the ship, and was then observed to have taken
         a right turn and to jump clear of the water about one
         hundred feet from the stern of the tanker. I find
         it hard to convince myself that I saw this.

1050(K) Fired twelfth torpedo. Hit. No effect.

1100(K) Fired thirteenth torpedo. Hit. No effect. Circled
         again to fire at other side.

1122(K) Picked up high speed screws.

1125(K) Sighted DD approaching from east. Angle on bow zero.

1131(K) Fired fourteenth torpedo. Hit. No effect.

1132½(K) Fired fifteenth torpedo. Started deep. DD range 1000
         yards. Torpedo heard to hit tanker and stop running
         by sound. Periscope had gone under by this time. No
         explosion. Had already decided to retain one torpedo
         for examination by base.

1142(K) After search, first pattern of three depth charges.
         Close but to port. Negative temperature gradient
         began at 190 feet.

1147(K) Destroyer passed directly overhead from starboard bow
         to port quarter. Screws could be heard clearly through
         hull at 310 feet.

1148(K) He didn't know it.

— page 51 —
CONFIDENTIAL
Subject: U.S.S. TINOSA (SS283) - Report of Second War Patrol.

II. WEATHER
1. Midway to Area -- Excellent, occasional rain squalls.
2. Area -- Frequent rain squalls. Seas generally calm. Little
wind. Air temperature averaged 91°F. Humidity generally
high.
3. Area to Pearl -- Frequent rain squalls west of Wake Island.
Seas increased as we approached the Hawaiian Islands.

— page 52 —
CONFIDENTIAL
Subject: U.S.S. TINOSA (SS283) - Report of Second War Patrol.

III. TIDAL INFORMATION (IF ABNORMAL)

     1. None observed.

     2. Hydrostatic density layers at which a submarine might have
        been balanced were observed in conjunction with rapid negatively
        changing temperature gradients in the following instances:

             July 21 -- 6°-31.5N, 150°-30.7E - 0046(K), at 180' the
             bathermograph commenced to drop off negatively and at 300'
             it was about 8° negative, where 3,000# had to be flooded
             in to maintain depth at creeping speed. Returning to 150'
             at 0300(K) discovered that the density layer had moved up
             to 260' where it decreased 8° rapidly up to 180'. Pumped
             out 3,000# to maintain 150' at creeping speed.

             July 24 -- 7°-00N, 148°E - 1133(K), at 175' the bathermo-
             graph commenced to drop off negatively indicating a layer
             from 170' to 260' about 6° negative, flooded in 5,000# at
             300' to hold depth. Returning to periscope depth about
             1400(K) noticed density layer was displaced up to 100'
             and was 2° more negative. Pumped out about 6,000# at 100'
             to maintain depth.

IV. NAVIGATIONAL AIDS

     None Sighted.

— page 53 —
CONFIDENTIAL
Subject: U.S.S. TINOSA (SS283) - Report of Second War Patrol.

V.
ENEMY VESSELS SIGHTED

CONTACT   TIME      LAT
NO.       DATE      LONG      TYPE & DESCRIPTION           COURSE SPEED REMARKS
-------
**CONFIDENTIAL**

Subject: U.S.S. TINOSA (SS283) - Report of Second War Patrol.

V.
ENEMY VESSELS SIGHTED

CONTACT | TIME    | LAT       | TYPE & DESCRIPTION           | COURSE | SPEED | REMARKS
NO.     | DATE    | LONG      |                              |        |       |
|||||-------|
The subject of this report is the U.S.S. TINOSA (SS283), and it details its Second War Patrol.

The report lists six enemy vessel sightings:

**1.**
*   **Time/Date:** 0700(K) on 7/15/43
*   **Location:** 10-20N, 151-25E
*   **Type & Description:** 2CV (Aircraft Carriers), 1ACV (Auxiliary Aircraft Carrier), 1AV (Seaplane Tender), 2CA (Heavy Cruisers), 1CL (Light Cruiser), Several DD (Destroyers)
*   **Course:** 180
*   **Speed:** 24
*   **Remarks:** Formation zigzagging ACV&AV astern

**2.**
*   **Time/Date:** 0713(K) on 7/20/43
*   **Location:** 5-10N, 147-15E
*   **Type & Description:** Tanker similar to NIPPON MARU No. 2
*   **Course:** 090
*   **Speed:** 13
*   **Remarks:** Loaded zigzagging pg263 ONI 208-J

**3.**
*   **Time/Date:** 0043(K) on 7/21/43
*   **Location:** 6-30N, 150-30E
*   **Type & Description:** DD (Destroyer), single gun fwd of bridge
*   **Course:** 050
*   **Speed:** 14
*   **Remarks:** Believed to be escorting tanker (cont #2) zigzagging Too dark to identify.

**4.**
*   **Time/Date:** 0555(K) on 7/24/43
*   **Location:** 6-55N, 147-10E
*   **Type & Description:** Tanker - TONAN MARU
*   **Course:** 073
*   **Speed:** 13
*   **Remarks:** Loaded

**5.**
*   **Time/Date:** 1120(K) on 7/24/43
*   **Location:** 6-57N, 148-00E
*   **Type & Description:** Destroyer
*   **Course:** 265
*   **Speed:** --
*   **Remarks:** High Speed

**6.**
*   **Time/Date:** 1737(K) on 7/25/43
*   **Location:** 11-44N, 148-12E
*   **Type & Description:** Hospital Ship
*   **Course:** 000
*   **Speed:** 13
*   **Remarks:** Similar to BAIKAL MARU. Changed course from 000°to330° to cross our stern

— page 56 —
CONFIDENTIAL

U.S.S. TINOSA (SS283)
SUMMARY OF SUBMARINE ATTACKS
(CONTINUED)

| | (6) | (7) | (8) | (9) | (10) |
|---|---|---|---|---|---|
| Attack | 3d | 3e | 3f | 3g | 3h |
| Time | 0011 | 0014 | 0039 | 0048 | 0050 |
| Date - Use CCT | 7/24/43 | 7/24/43 | 7/24/43 | 7/24/43 | 7/24/43 |
| Location - Lat. | 6-56N | same | same | same | same |
| Long. | 147-53E | | | | |
| No. & Type Torpedoes Fired on Each Attack | 1-TNT Mk 14-3A | 1-TNT Mk 14-3A | 1-TNT Mk 14-3A | 1-Torpex Mk 14-3A | 1-Torpex Mk 14-3A |
| Hits | 1 | 1 | 1 | 1 | 1 |
| Number Sunk (Tonnage) | 0 | 0 | 0 | 0 | 0 |
| Number Damaged or Probably Sunk(Tonnage) | same target -- same target | same target -- same target | same target -- same target | same target -- same target | same target -- same target |
| Type of Target | AO | AO | AO | AO | AO |
| Range | 1050 | 1300 | 900 | 1000 | 900 |
| Type of Attack: Periscope (P): | P | P | P | P | P |
| Estimated Draft of Target | 10'to 40' | 10'to 40' | 10'to 40' | 10'to 40' | 10'to 40' |
| Torpedo Depth Setting | 10' | 15' | 13' | 15' | 15' |
| Bow or Stern Shot | Stern | Stern | Stern | Bow | Bow |
| Track Angle | 75S | 75S | 90P | 70P | 75P |
| Gyro Angle | 3L | 3L | 1R | 3L | 2L |
| Estimated Target Speed | 0.5 | 0.5 | 0.5 | 0.5 | 0.5 |
| Firing Interval Spread - Amount & Kind | --- | --- | --- | --- | --- |
| Was Torpedo Perform. Satisfactory? | 0 | 0 | 0 | 0 | 0 |
| | No | No | No | No | No |

Remarks: See following pages.

— page 57 —
CONFIDENTIAL
U.S.S. TINOSA (SS283)
SUMMARY OF SUBMARINE ATTACKS
(CONTINUED)

| (11) | (12)
Attack | 3i | 3j
Time - Use GCT | 0100 | 0131
Date | 7/24/43 | 7/24/43
Location - Lat. | 6-56N |
Location - Long. | 147-53E | same
No. & Type Torpedoes | 1-Torpex | 2-*
Fired on Each Attack | Mk 14-3A | Mk 14-3A
Hits | 1 | 2
Number Sunk (Tonnage) | 0 | 0
Number Damaged or |
Probably Sunk (Tonnage) | same target |
Type of Target | AO | AO
Range | 1000 | 1200
Type of Attack: | P | P
Periscope (P) | 10'to | 10'to
Estimated Draft | 40' | 40'
of Target |
Torpedo Depth | 20' | 20'
Setting |
Bow or Stern Shot | Stern | Stern
Track Angle | 95P | 70S
Gyro Angle | 1R | 8L
Estimated Target |
Speed | 0.5 | 0.5
Firing Interval | --- | 63 sec.
Spread - |
Amount & Kind | 0 | 0
Was Torpedo Perform. |
Satisfactory? | No | No
| | *1-TNT
| | 1-Torpex
Remarks: See following pages.

— page 62 —
CONFIDENTIAL

Subject: U.S.S. TINOSA (SS283) - Report of Second War Patrol.

IX. DESCRIPTION OF ENEMY MINE SWEEPING OPERATIONS
    None observed.

X. MAJOR DEFECTS EXPERIENCED

    1. Cell #93 Forward did not respond to treatment during the
       refit period in Midway. It should be replaced at the first
       available opportunity. Both it and one cell aft, are now
       jumped from the batteries.

    2. Number Two periscope has a variable range error. When the
       range knob is returned to zero range at times a double
       image exists. The ranging scale does not coincide with the
       prescribed zero marks and the error is variable, sometimes
       amounting to as much as 100 yards at 1000 yards range.

    3. Number One periscope is too hard to train. Every effort to
       free it while at sea has been made. The SPERRY attempted
       to free it by reaming out the lower bearing. This was not
       successful.

    4. The ranging feature of Number One periscope is too stiff
       for satisfactory operation. Possibly as a result of this,
       when returned to zero range, a double image sometimes exists.

    5. Both shafts or reduction gears rumble severely as they pass
       through a speed range of 20 to 15 rpm while slowing down.
       The rumble was slightly reduced on the starboard side during
       the last refit by reducing the thrust clearance, which was
       found to be excessive.

    6. The vertical antenna mast bearings are out of line, distinct
       clicks being heard as the upper shoulder of the mast passes
       each successive bearing. There is no apparent ill effect.

    7. The Bendix Log is out of commission because of failure of a
       worm wheel in the main drive unit. No spare is provided and
       a new wheel must be obtained. A slow leak in the pressure
       system, when below ninety feet keel depth, has resulted in
       erratic speed indications. This leak should be eliminated.

— page 67 —
CONFIDENTIAL

Subject: U.S.S. TINOSA (SS283) - Report of Second War Patrol.

XIV. MILES STEAMED TO AND FROM STATION

     (a) Miles steamed, Midway to Station -- 2587 miles.
     (b) Miles steamed, on station -- 2104 miles.
     (c) Miles steamed, station to Pearl -- 3160 miles.

XV. FUEL EXPENDED.

     (a) Fuel oil expended -- 82,752 gallons.

XVI. FACTORS OF ENDURANCE REMAINING

     (a) Torpedoes -- 1
     (b) Fuel -- 9500 gallons.
     (c) Provisions -- 35 days.
     (d) Personnel -- 21 days.
     (e) Fresh water -- unlimited.

XVII. Patrol terminated by orders of Commander Submarines,
      Pacific Fleet.

— page 69 —
FB5-141/A16-3
Serial 0148

CONFIDENTIAL
FIRST ENDORSEMENT to
TINOSA report of second
war patrol dated
August 4, 1943.

From: The Commander, Submarine Division 141.
To : The Commander Submarine Force, U.S. Pacific Fleet.
Via : The Commander Submarine Squadron FOURTEEN.

Subject: U.S.S. TINOSA (SS283) - Report of Second War
Patrol.

1. Forwarded.

2. The second patrol of TINOSA is characterized by
disappointments. The first indication of the presence of the large
Carrier-Cruiser formation was a sound contact on a destroyer. A
favorable firing position was not obtained on any ship in the group.
The subsequent series of torpedo failures is incomprehensible. The
decision of the Commanding Officer to continue firing his torpedoes
at the stopped, damaged tanker was sound. He deliberately fired one
torpedo at a time on each side of the tanker and is confident that
the torpedoes hit, but, with probably only one exception, failed
to explode.

3. The one torpedo that TINOSA brought back was turned
over to the Torpedo Officer, Submarine Base, for examination and
report.

4. TINOSA proceeded to Navy Yard, PEARL, on August 6
for correction of air leaks, which involves renewal of all high
pressure air flask fittings. Accomplishment of this work will
probably require five weeks.

Copy to:
cc TINOSA

SUBMARINE DIVISION 141
Care of Fleet Post Office,
San Francisco, California,
6 August, 1943.

[SIGNATURE: J. L. Page]
LEO L. PAGE.

— page 70 —
FC5-14/A16-3
Serial 08

CONFIDENTIAL

SECOND ENDORSEMENT to
TINOSA report of second
war patrol dated
August 4, 1943.

From:
To :
Subject:

1.
Division 141 are concurred in.

2.
fifteen torpedoes at an unescorted tanker at good ranges, ob-
serving thirteen of them hit the target, and still fail to sink
her. It is hoped that some reason for this lack of destructive
effect can be discovered by a careful examination of the remain-
ing torpedo.

SUBMARINE SQUADRON FOURTEEN

Care of Fleet Post Office,
San Francisco, California,
6 August 1943.

The Commander Submarine Squadron Fourteen.
The Commander Submarine Force, Pacific Fleet.
U.S.S. TINOSA (SS283) - Report of Second War
Patrol.

Forwarded. The comments of Commander Submarine

[SIGNATURE: J. B. Longstaff]
J. B. LONGSTAFF.

ENCLOSURE (C).

— page 71 —
FF12-10/A16-3(5)/(16)
Serial 01071 [HANDWRITTEN: 3rd Cpy]
CONFIDENTIAL

THIRD ENDORSEMENT to
CO TINOSA Conf. ltr.
Serial 0012 of 8-4-43.

SUBMARINE FORCE, PACIFIC FLEET
Bz
Care of Fleet Post Office,
San Francisco, California.
10 August 1943.
[STAMP: RECEIVED S.C. FILES]
[STAMP: Room 2055]
[STAMP: 26 AUG 1943]
[STAMP: ROUTE TO:- 01-02]

COMSUBSPAC PATROL REPORT NO. 231
U.S.S. TINOSA - SECOND WAR PATROL.

[STAMP: Op File No. (SC) A16-3/SS283]
[STAMP: Doc. No]
From: | The Commander Submarine Force, Pacific Fleet. [HANDWRITTEN: Copy No. 5]
To : | The Commander-in-Chief, U. S. Fleet.
Via : | The Commander-in-Chief, U. S. Pacific Fleet. [HANDWRITTEN: 198]

Subject: | U.S.S. TINOSA (SS283) - Report of Second War Patrol.

Enclosure: | (A) Copy of subject war patrol report.
| (B) Copy of Comsubdiv 141 Conf. 1st. end. FB5-141/
| A16-3, Serial 0148 dated 6 August 1943.
| (C) Copy of Comsubron 14 Conf. 2nd. end. FC5-14/
| A16-3, Serial 08 dated 6 August 1943.

: 1 This is the second war patrol of the U.S.S. TINOSA.

2. All attacks were aggressively carried out. The
second attack and subsequent chase were well conducted. It is
regretted that gunfire by an enemy destroyer forced the TINOSA to
submerge and thus end a chance for a second attack.

3. The unusually poor torpedo performance in the third
ship attacked is being investigated and will be made the subject of
a separate report.

4. It is of note that the TINOSA used its bathythermo-
graph ably in locating density layers and subsequently evading the
enemy.

5. This patrol is considered successful for Combat
Insignia award.

6. The Commander Submarine Force, Pacific Fleet, con-
gratulates the Commanding Officer, officers, and crew for this ag-
gressive patrol. The TINOSA is credited with having inflicted the
following damage to the enemy:
DAMAGED
1 - Tanker (TONAN MARU class) - 19,425 Tons.

Distribution and authentication [HANDWRITTEN: Finished-X-File]
on following page.
- 1 - C. A. LOCKWOOD, Jr.
[HANDWRITTEN: (SC) A16-3(23)/SS283]

— page 72 —
SUBMARINE FORCE, PACIFIC FLEET
FF12-10/A16-3(5)/(16)                                                              Id
                                                                Care of Fleet Post Office,
Serial 01071                                                    San Francisco, California,
                                                                10 August 1943.
CONFIDENTIAL

THIRD ENDORSEMENT to
CO TINOSA Conf. ltr.
Serial 0012 of 8-4-43.

COMSUBSPAC PATROL REPORT NO. 231
U.S.S. TINOSA - SECOND WAR PATROL.

Subject:        U.S.S. TINOSA (SS283) - Report of Second War Patrol.

DISTRIBUTION:
Cominch, VCNO (5 ea), Cincpac (6);
Cinclant, S/M School NL, Comsopac,
Comsubsowespac, CTF 72, SUBAD MI,
ComsubspacSubordcom, All Squad. &
Div. Comdr. (2 ea); Serforpac (Adv.
Base Plan.Unit), Comsowespac CTF 16,
TINOSA (1 ea); Comsubslant (8);
Comsubspac (12);
All SS Subspac (less enclosures) (1).

[SIGNATURE: R. C. Lawver]
R. C. LAWVER,
Flag Secretary.

— page 73 —
[STAMP: DECLASSIFIED]
[HANDWRITTEN: CONFIDENTIAL]

DECLASSIFIED ART. 0445, OPNAV
BY [SIGNATURE: C. P. q988] DATE 8/20/72

U.S.S. TINOSA (SS283) - Report of Third War
Patrol. Period from 23 September 1943 to
12 October 1943. Operation Order No. 210-43.

PROLOGUE

Arrived Pearl on 4 August 1943 from second war
patrol for refit by BUSHNELL. Transferred to Navy
Yard, Pearl, governing job, change of H.P. air
flask fittings to stop external air leaks. During
this period following work accomplished:
(1) Altered air fittings on all air flasks,
(2) Installed ballistic protection around C.T. and
bridge, (3) Rerouted W.C. piping out of fuel
ballast tanks, (4) Placed #1 periscope in C.T.,
(5) Removed C.T. door, (6) Removed degaussing
coils and generators, (7) Placed "T" shaped
gaskets in all M.B.T. vents, (8) Doubler plates
over reduction gear lub. oil sumps, (9) Rewooded
and realigned shafts, (10) Realigned #2 periscope
bearings. Other minor repairs and alterations
made. Completion date 10 September. Left Yard
12 September 1943. Sound tested, depermed and
four days training. Two days firing Mark XIV
torpedoes at net. Readiness for sea 23 September
1943.

I. NARRATIVE

23 September 1943 Departed Pearl under surface escort until dark for
1119(VW) assigned area via Johnston. Escort's maximum
speed twelve knots. Trim dives and drills enroute.

25 September 1943 Moored to dock Johnston's Island and fueled to
0930(W) capacity. Received 11,000 gallons.

1852(W) Underway, having waited while new set of gears
for Bendix Log were manufactured. Departed with
air escort.

26-27 September 1943 Uneventful. Daily dives and drills. Using SD
radar during day and SJ radar at night. Zigzagging
during daylight periods. 28 September omitted
due crossing date line.

— page 74 —
CONFIDENTIAL
Subject: U.S.S. TINOSA (SS283) - Report of Third War Patrol.

I.
NARRATIVE (CONTINUED)

29 September 1943
1249(M) Radar contact, airplane 10 miles. Submerged.
Not sighted. Lat. 14-25N Long. 174-42W.

1445(M) Surfaced, after drills. Continued course and
speed.

30 September 1943
Uneventful. Drills.

1 October 1943
2200(L) Changed course to 252°T & pgc. Continued at two
engine speed. Long 162E

2 October 1943 Uneventful. Drills.

3 October 1943 On test dive discovered leak in supply ventilation
system outside hull. System had been tight on
previous dives. Unable to locate leak without
undue risk at this time.

4 October 1943
0330(K) Radar contact bearing 119°T. Range 8800 yards.
Own course 180°T. Tracked target on course
north and identified as probable patrol vessel.
Avoided. Lat. 08-01N Long. 150-19.5E

0420(K) Radar contact bearing 310°T, range 12300 yards.
Own course 000°T. Radar reported two targets of
comparable size nearly in line.

0449(K) Submerged to radar depth. One target, tanker
similar to HUZISAN MARU, 9527 tons, picked up
by periscope. Sound reported two sets of
reciprocating engine screws.

0455(K) Fired four torpedoes from bow tubes. Lat. 08-02N
Long. 150-19E. Submerged to periscope depth.

0456(K). Lost depth control. Poppet of first tube fired
stuck in open position. It was secured immediately
after firing all tubes. This water, plus the
flooding of the ventilation supply piping, made
ship too heavy to control.

— page 76 —
CONFIDENTIAL
Subject: U.S.S. TINOSA (SS283) - Report of Third War Patrol.

I.
NARRATIVE (CONTINUED)

5 October 1943
0200(K) Battery charge completed. Moon had set. Lay to
          and put air test on ventilation outboard piping.
          Glenn K. HICKMAN, CMOMM(AA), USN, volunteered to
          enter superstructure and search for leak; finally
          located in hand hole plate of outboard ventilation
          supply valve, which was loose. Trouble appeared
          caused by poor rubber gasket material which had
          compressed under load and had lost its resilience.
          Tightening plate made satisfactory repair.

0258(K) Resumed course and speed.

0608(K) Entered assigned area. Course 282°T & pgc.

2010(K) Slowed to 7½ knots.

2030(K) Reversed course to 102°T & pgc.

2300(K) Increased speed to 17 knots.

2313(K) Picked up radar interference bearing 020° relative.

2322(K) Radar target bearing 047° relative, range 6000
          yards. Tracked on opposite course. Target was
          using radar of same frequency, ranging on us.
          Maneuvered until satisfied it was friendly, then
          resumed course and speed.

6 October 1943
0422(K) Changed course to 310°T, slowed to 15 knots.

0524(K) Picked up target by sight, distance 15000 yards
          angle on bow about 45° starboard. Put target
          astern. We were in poor position, silhouetted
          by light horizon. Target was a tanker of at
          least 10,000 tons, loaded.

0539(K) Submerged. Angle on bow zero. Shortly thereafter
          target zigged away, giving 90° starboard angle on
          bow. After tracking a short time opened out to
          surface.

0622(K) Surfaced; began end run.

— page 77 —
CONFIDENTIAL
Subject: U.S.S. TINOSA (SS283) - Report of Third War Patrol.

I. NARRATIVE (CONTINUED)
6 October 1943 (Continued)
1110(K) Submerged to begin approach. During this end run
        target had averaged 14.7 knots over the ground
        from point of first sighting to her position when
        we submerged. She was zigzagging during this
        period. We had to run at full power to gain
        appreciably.
1155(K) Sound reported target slowing down. We had been
        tracking her at 16 knots.
1201(K) Fired six torpedoes from bow tubes.
1202(K) Momentarily ducked. Heard three loud explosions
        plus a metallic click as of a dud between first
        and second explosions. Explosions clearly heard
        through hull.
1204(K) Target began taking starboard list and was down
        by bow. We were turning to make stern tubes bear.
        Depth charges and gun fire from target.
1207(K) Target changed course to head for periscope.
        We were still turning to get stern tubes to bear.
1208(K) With target too close to shoot down the throat
        increased depth to 150 feet, rigged for depth
        charge and turned 90° to left at full speed.
1209(K) Four depth charges, all close. Bridge speaker
        diaphragms broken, various lockers opened, men
        knocked off feet in after torpedo room.
1210(K) Fire in motor room.
1212(K) Fire in port revolution counter under control.
1215(K) Periscope depth. Target had slowed, tracking
        about nine knots, and was headed southwest. Set
        course south and followed in hopes she would slow
        up or turn east and resume her course. Then
        began opening out to surface.
1430(K) Surfaced. Began end run.

— page 78 —
CONFIDENTIAL
Subject: U.S.S. TINOSA (SS283) - Report of Third War Patrol.

I. NARRATIVE (CONTINUED)

6 October 1943 (Continued)
1644(K) Submerged for approach. During this run the
target had averaged 6.5 knots from her position
when we fired to her position when we fired again.
She started off at about nine knots zigzagging and
decreased to about six knots, not zigzagging,
when we fired.

1818(K) Fired four torpedoes, stern tubes. Two hits.

1821(K) Target began dropping and throwing depth charges
and firing with both guns. Eight depth charges
in all were used. Target began turn to her right
as if to ram as she had done during morning attack.
We were swinging to bring bow tubes to bear.
Target swung past ramming course and was making
about five knots.

1825(K) Fired two bow tubes. No indication of hits or
explosions but shortly thereafter target stopped.
List had increased slightly but there was no
evidence of sinking. Gun fire continued.

1834(K) After maneuvering to obtain position desired fired
one stern tube using 180 gyro angle, spindle
disengaged and 180 periscope angle. Mark XIV
torpedo ran straight at target but no splash
was seen. Target opened fire as soon as wake of
torpedo was visible and explosions of shells were
numerous. Growing darker.

1859(K) Boats had been lowered by target and were heard in
water but occasional gun fire continued. After
maneuvering for position fired stern tube, using
180 gyro, spindle disengaged. Torpedo ran straight
to target and sound reported an explosion at
proper time interval. None seen or heard by
officer at periscope.

1910(K) With gun fire still occasionally occurring and no
evidence of sinking maneuvered and fired bow tube,
zero gyro, spindle disengaged. Sound tracked
torpedo running straight for target but heard
no explosion. None seen.

— page 79 —
CONFIDENTIAL
Subject: U.S.S. TINOSA (SS283) - Report of Third War Patrol.

I.
NARRATIVE (CONTINUED)
6 October 1943 (Continued)
1913(K) Fired second bow tube, same conditions. Heard
        to run straight for target but no explosion and
        none seen. These two torpedoes were not even
        heard to hit. Target still seemed to have lots
        of buoyancy.
1923(K) After maneuvering to obtain position prepared to
        fire stern tubes again. It was getting very dark
        and I had used speed to change position, not
        having observed target since 1918. Target now
        showed first evidence of sinking, the stern being
        down and settling fast.
1933(K) Target disappeared, sinking by the stern.
        STEELHEAD had made three hits on this target, ie.
        had at least six effective hits, ie. torpedoes
        which detonated.
1934(K) Surfaced. Set course north, speed 15 knots.
2048(K) Changed course to 155°T. Decided to bombard
        installation on Alet Island of Paluwat group at
        sunset next day.

7 October 1943.
0725(K) Sighted large airplane, headed at us, distance
        eight miles. Submerged. No radar contact. Plane
        elevation about five degrees. Heavy bomber, exact
        type not identified. Lat. 07-4N Long. 149-15E.
0903(K) Surfaced. Resumed course and speed.
1028(K) Sighted light on Alet Island.
1034(K) Submerged. Approached island, examined, took
        pictures, and showed targets to gun crew. Primary
        target radio station. Secondary barracks.
        Planned to surface just before sunset, so that
        enemy could be looking into setting sun and
        on bearing such that all targets would be in line.
1755(K) Sunset. Sun obscured by clouds. Decided to wait
        a little longer. Fishing canoe with sail distant
        about 5000 yards.

— page 80 —
CONFIDENTIAL
Subject: U.S.S. TINOSA (SS283) - Report of Third War Patrol.

I. NARRATIVE (CONTINUED)

7 October 1943 (Continued)
1803(K) Surfaced. Fired 41 rounds at target, range 3000
          yards. Dust clouds as evidence of hits visible.
          Estimate about two thirds of rounds hit target
          area. No opposition.

1810(K) Turned away, opened at 18 knots, 270°T. Fishing
          canoe apparently unconcerned. Jammed projectile,
          unable to clear quickly. Shell had cocked in bore.
          After extracting case, tried clearing bore with
          clearing charges; first two didn't fit but third
          charge did the trick.

1815(K) Cleared jam.

1953(K) Cleared message, changed course to 040°T & pgc.

2110(K) Crossed three streaks in water, resembling torpedo
          wakes.

8 October 1943
1200(K) Began patrolling route Truk to Saipan.

1528(K) Sighted airplane bearing 020° relative. No radar
          indication. Submerged. Lat. 09-42N Long 150-13E.

1700(K) Surfaced.

2135(K) Changed course to 073°T to patrol route Truk to
          Empire.

9 October 1943
0755(K) Began patrol of route.

1700(K) Changed course to 250°T to return to area.

2202(K) Received orders to return to Midway. Set course,
          speed three engines at 80/90.

— page 83 —
CONFIDENTIAL
Subject: U.S.S. TINOSA (SS283) - Report of Third War Patrol.

II. WEATHER
1. Johnston Island to Area -- Good, winds from NNE, average force 2.
2. Area -- Good, occasional rain squalls. General wind from
east and southeast, force 2. Sea generally calm. Average
temperature 87°F. Humidity generally high.
3. Area to Wake -- Sea increased as we approached Wake, with
winds from ENE, force 3 to 4.
4. Wake to Midway Island -- Moderate seas, winds from ENE, force 3.

III. TIDAL INFORMATION (IF ABNORMAL)
1. None observed.
2. Hydrostatic density layers were observed on every occasion of
going to deep submergence. Negative temperature gradients
were observed in the following instances:
3 October 1943 -- 9°-36'N, 152°-38'E - 1011(K), the bathy-
thermograph was observed to begin dropping off negatively
at 200', with a total drop of 4° at 300'.
3 October 1943 -- 9°-12'N, 151°-40'E - 1620(K), the bathy-
thermograph was observed to begin dropping off at 180',
with a sharp increase at 240' and reach a total drop of
6° at 310'. It was necessary to pump out about 3,000 lbs.
to maintain a trim at creeping speed when returning to 60'.
4 October 1943 -- 8°-01'N, 150°-21'E - 0458(K), the bathy-
thermograph was observed to begin dropping off at 200' and
reach a total drop of 6° at 340'. It was necessary to pump
out about 3,500 lbs. to maintain a trim at creeping speed
when returning to 60'.

IV. NAVIGATIONAL AIDS
1. Light tower on Alet Island in Pulauat Group is still erect
but was not seen at night.

— page 84 —
CONFIDENTIAL

Subject: U.S.S. TINOSA (SS283) - Report of Third War Patrol.

V. ENEMY VESSELS SIGHTED

CONTACT | TIME | LAT | TYPE & DESCRIPTION | COURSE | SPEED | REMARKS
NO. | DATE | LONG | | | |
------|------|------|||-------|
1 | 0310(K) | 08-01N | Radar Contact 119°T | N | 12K | Not
| 10/4/43 | 150-19.5E | 8800 yards | | | sighted.
| | | | | | From rad
| | | | | | contact
| | | | | | identi-
| | | | | | fied as
| | | | | | patrol
| | | | | | vessel
------|------|------|||-------|
2 | 0420(K) | 08-00-30N | Tanker similar to | 100 | 11.6K | Loaded
| 10/4/43 | 150-19E | HUZISAN MARU | | |
| | | | 9527 Tons. | | |
------|------|------|||-------|
3 | 0520(K) | 10-24N | Tanker, 10000(plus) | 85 | 16K | Loaded
| 10/6/43 | 146-52E | tons. | 1644(K) | 10-00N | same | | |
| 10/6/43 | 148-36E | | | |

— page 85 —
CONFIDENTIAL
Subject: U.S.S. TINOSA (SS283) - Report of Third War Patrol.

V. ENEMY VESSELS SIGHTED -- REMARKS

(1) Contact #3, the tanker, was of modern construction of at
least 10,000 tons. She had a raked bow and counter stern.
She had a short single pole mast forward, next a goal post
with a stick mast above it and then the bridge. On the
after part of the bridge structure was what looked like a
fire control tower. The next thing aft was a stick mast,
then a goal post, then a tripod mast with a stick mast
above it. This latter was just forward of the after deck-
house. The funnel was of the modern type located about
the middle of the deckhouse.

She was armed with two dual purpose guns in shields, one
forward and one aft, probably four or five inch. No salvo
fire was observed. She was equipped with depth charge
throwers amidships and aft, on both sides, and I believe
racks aft. She was well handled and was probably under
naval command.

(2) The radio station and barracks on Alet Island are well
described in ICPOA Bulletin No. 33-43, Vol. II, Page 123
under Puluwat Islands. From a low height of eye most of
the construction is hidden by heavy growth between the
buildings and the shore line but the roofs are clearly
visible. No opposition was encountered.

— page 86 —
CONFIDENTIAL
Subject: U.S.S. TINOSA (SS283) - Report of Third War Patrol.

VI. AIRCRAFT CONTACTS

CONTACT TIME     LAT       TYPE             COURSE ALTITUDE REMARKS
NO.     DATE     LONG

1       1249(M)  14-25N    --               --              Radar contact
        9/29/43  174-42E                                     10 miles
                                                             Not sighted.

2       0616(K)  8-01N     Single float     Dist.           Picked up by
        10/4/43  150-16E   Seaplane         Bearing 2 mi.   Captain on
                                            230°T           periscope

3       0725(K)  07-44N    Heavy            110°T           Sighted by
        10/7/43  149-15E   Bomber           6°              lookout
                                            Dist.
                                            6 mi.

4       1528(K)  09-42N    Single           142°T           Sighted by
        10-8-43  150-13.1E wing             4°              lookout
                               Monoplane    Dist.
                                            6 mi.

5       0729(L)  16-31.5N  MITSUBISHI 98    10°             Sighted by
        10/12/43 161-21.3E Reconnaissance                   lookout
                               Bomber       Bearing
                                            170°rel.

6       1721(L)  17-56.40N MITSUBISHI 98    6°              Sighted by
        10/12/43 161-03.45E Reconnaissance Dist.           lookout
                               Bomber       040°T
                                            4½ mi.

7       1705(L)  19-32.2N  Type 97          Bearing 4°      Sighted by
        10/13/43 165-31.2E Light            355°rel.Dist.   lookout
                               Bomber       4½ mi.

8       0600(L)  19-16.1N  Single           Bearing 4°      Sighted by
        10/14/43 167-52.4E wing             147°T           lookout
                               Monoplane    Dist.
                                            6 mi.

— page 87 —
CONFIDENTIAL
Subject: U.S.S. TINOSA (SS283) - Report of Third War Patrol.

VII. PARTICULARS OF ATTACKS - REMARKS

Attack No. 1.

4 October 1943.

     This target was one of a convoy of at least two ships,
accompanied by an escort. Radar consistently reported two
targets, approximately on the same bearing and of about the same
size. Experienced operators were convinced they were not ranging
on the two ends of one ship. When the range decreased sound
reported two sets of screws, both reciprocating engine type.

     Dawn was rapidly approaching and insufficient time was
available to fully develop the different targets. Only one
target could be seen with binoculars and only one later picked
up by periscope. No escort was seen. The targets horizon was
dark, that behind us light. The target zigged away just prior
to firing and the range was greater than desired. The size and
draft of the target were first underestimated.

     Two hits were heard at the proper time interval for the
inner torpedoes of the spread. The first was a metallic thud,
heard by sound, apparently a dud. The second was a loud
explosion clearly heard throughout the ship.

Attack No. 2.

6 October 1943.

     In spite of having been hit with three torpedoes by
the STEELHEAD the tanker was making 16 knots most of the morning.
About five minutes before firing she was heard to slow down and
tracked at 11.5 knots. Sound ranges were used freely and well
prior to firing gave us an accurate height for the periscope range
finder.

     The first four torpedoes fired, the inner ones of the
spread, were heard to hit, the second being a dud. Explosions
were clearly heard throughout the ship. The target was not
stopped and attempts to bring the stern tubes to bear were not
successful in time to fire them.

— page 88 —
CONFIDENTIAL
Subject: U.S.S. TINOSA (SS283) - Report of Third War Patrol.

VII. PARTICULARS OF ATTACKS - REMARKS (CONTINUED)
Attacks Nos. 3a, 3b, 3c, 3d, 3e, and 3f

6 October 1943

3(a) We obtained position well ahead of target, submerged,
and ran towards her. She was not zigzagging and had slowed to
six knots. The firing point would be reached shortly after sun-
set and it was planned to fire a port track with the stern tubes,
silhouetting the target against the western horizon. Just as the
time arrived to change course, the target changed base course to
her left forcing us to use a starboard track and a greater range
than we wished. Four torpedoes were fired and the left-hand two
were seen and heard to hit, the first just abaft amidships, the
second at the stern. With the spread used at least one other
torpedo should have hit forward. Ranges by periscope and sound
checked each other and the time of run.

The explosions of the torpedoes were not nearly so
loud in the conning tower as previous ones had been. In fact,
I did not hear them at all, but saw flames from the after hit
and a very large splash from the one about amidships.

3(b) The target turned as if to ram as she had done in the
morning. We swung to bring bow tubes to bear, meanwhile reloading
aft. We expected to shoot a down the throat shot. The target
swung by us but was still underway, making about 4.5 knots. We
fired two bow tubes as indicated in the table. The set up looked
good but no explosions resulted. The torpedoes were heard to run
on the correct course. The target's swing was undoubtedly due to
the previous hit aft disabling the starboard screw. I believe
these mark XVIII may have hit because shortly thereafter the
ship stopped dead in the water, whereas she ran for at least six
minutes after attack #3a.

3(c) Ship was dead in water but giving no evidence of
sinking. Rapidly growing darker. Obtained position and fired
one mark XIV which was seen and heard to run straight to target.
Used 180 gyro angle and periscope angle, spindle disengaged. No
evidence of explosion or hit.

3(d) Same as #3c except that sound and people in control
room reported an explosion. I saw torpedo wake but no evidence
of explosion.

— page 89 —
CONFIDENTIAL

Subject: U.S.S. TINOSA (SS283) - Report of Third War Patrol.

VII. PARTICULARS OF ATTACKS - REMARKS (CONTINUED)

Attacks Nos. 3a, 3b, 3c, 3d, 3e, and 3f (Continued)

3(e) Manoeuvered for bow shot. Fired zero gyro and periscope
angle, spindles disengaged. No evidence of hit, visual or aural.

3(f) Same as 3e. One of these last two torpedoes must have
been effective because shortly thereafter the ship began sinking
rapidly. This might possibly have been caused by the collapse
of bulkheads but there was no evidence of sinking prior to
attacks 3e and 3f.

— page 90 —
CONFIDENTIAL
Subject: U.S.S. TINOSA (SS283) - Report of Third War Patrol.

SUMMARY OF SUBMARINE ATTACKS

| | (1) | (2) | (3) | (4) |
| Attack | 1 | 2 | 3(a) | 3(b) |
| Time | 1855 | 0204 | 0818 | 0824 |
| Date - GCT | 10/3/43 | 10/6/43 | 10/6/43 | 10/6/43 |
| Location - Lat. | 08-02N | 10-35N | 10-01N | 10-01N |
|           Long. | 150-19E | 148-30E | 148-31E | 148-31E |
| No. & Type Torpedoes | 4-Torpex | 6-Torpex | 4-Torpex | 2-Torpex |
| Fired on Each Attack | Mk XVIII | Mk XVIII | Mk XIV | Mk XVIII |
| Hits | 2 | 4 | 2 | 0 |
| Number Sunk (Tonnage) | 0 | 0 | 0 | 0 |
| Number Damaged or | | | | |
| Probably Sunk (Tonnage) | 9525 | 10000 plus | Same as (2) | Same as (2) |
| Type of Target | AO | AO | AO | AO |
| Range | 1950 | 1540 | 1630 | 1350 |
| Type of Attack: | P | P | P | P |
| Periscope(P)-Radar(R) | R | | | |
| Estimated Draft | 20' | 20'-25' | 20'-30' | 20'-30' |
| of Target | | | | |
| Torpedo Depth | 10' | 20' | 20' | 20' |
| Setting | | | | |
| Bow or Stern Shot | Bow | Bow | Stern | Bow |
| Track Angle | 85S | 75S | 110P | 45P |
| Gyro Angle | 5L | 0 | 10L | 20L |
| Estimated Target | 11.5 | 11.5 | 6 | 4.5 |
| Speed | | | | |
| Firing Interval | 8 sec. | 9 sec. | 9 sec. | 10 sec. |
| Spread -- | 10.5° | 9° | 6° | 2° |
| Amount & Kind | Total | Total | Total | Total |
| Was Torpedo Performance | No | No | # | * |
| Satisfactory? | 1 dud | 1 dud | | |

REMARKS: #Should have been three hits.
         *See VII Particulars of Attacks - Remarks.

— page 92 —
CONFIDENTIAL
Subject: U.S.S. TINOSA (SS283) - Report of Third War Patrol.

VIII. ENEMY ANTI-SUBMARINE MEASURES

1. Five depth charges were received after the attack
on 4 October in a pattern of one, two, two. They were closer
each time but none were very near. We were running both trim and
drain pumps, making full speed, and reloading torpedoes at a
depth of 350 feet. There seemed to be only half-hearted efforts
to search. Torpedoes fired were wakeless torpedoes. Upon
regaining periscope depth an hour later found a plane searching
vicinity.

2. Within two minutes after being hit on 6 October,
the tanker began dropping and throwing depth charges. See
description of armament under section V. No salvo fire was used.
Gun fire was continuous.

After sighting the periscope she attempted to ram,
dropping depth charges as she passed close astern. These were
close. We had remained at 150 feet in order to come back to
periscope depth in order to get in a shot. Our change of course
to 90° from her course and increase of speed as we went deep
cleared us, the depth charges being aft.

3. After the second and succeeding attacks on this
tanker she threw depth charges at intervals until she was dead
in the water and fired guns whenever the periscope was visible.
Gun fire continued until about twenty minutes before she sank.

— page 94 —
CONFIDENTIAL
Subject: U.S.S. TINOSA (SS283) - Report of Third War Patrol.

X. MAJOR DEFECTS EXPERIENCED (CONTINUED)

4. Fresh Water Stills. On 25 September steam was found blowing
   from the bearing case vent at the drive end of No. 2 vapor
   still compressor. The compressor was disassembled and seals
   and bearings were renewed. The seals at the drive end were
   found to be worn out and were replaced. The same trouble
   later developed on No. 1 compressor. It is to be noted that
   any disassembly and inspection of the compressor requires
   renewal of the seals as it is impossible to remove the seals
   without destroying them. It is believed that if the shaft
   holes in the vapor compressor head plates, pieces 1 and 3,
   (Contractors Plan 2R-223 Alt 5, were made larger, the seals
   could be removed with a wooden block as contemplated in the
   instruction book, page 27, Disassembly. Because of having
   insufficient spare seals, the compressors could not be
   completely overhauled. It is believed that the seals in the
   gear end are nearly worn out and it is requested that both
   compressors be completely overhauled.

   In addition both units have given considerable trouble from
   grounds in the heater element wiring. Numerous leaks around
   the element joints in the still casing have been found.

5. No. 2 turbo blower has developed a rumble while accelerating
   and slowing down which is becoming progressively worse. The
   bearings should be checked.

6. Saltwater circulating piping. While still enroute to the area
   a pin hole leak developed in the salt water circulating water
   piping to the air conditioning condenser. It was stopped by
   use of an external strap patch.

   After being depth charged on 6 October numerous pin hole leaks
   developed in the main motor circulating water piping. These
   were repaired in the same manner.

7. A low resistance reading of one-half megohm has developed
   in the fathometer head. Soundings can still be obtained.

8. Torpedo Tubes. On 6 September 1943 in the first attack of that
   date a six tube salvo was fired from the bow tubes. After the
   attack it was ascertained that both tubes #2 and #5 had
   suffered casualties.

— page 96 —
CONFIDENTIAL

Subject: U.S.S. TINOSA (SS283) - Report of Third War Patrol.

XI. RADIO AND RADAR

1. Radio Reception: All consecutive serials were received.
Last serial received - 63 W - last serial sent -No. 3 -141650.
(a) Enroute from Pearl to the area reception was quite
good. While on station reception was satisfactory except for a
short period, usually around 1500(Z), when a slight fading
occurred. Several times during heavy rain and electrical storms
it became nearly impossible to copy the NPM Fox schedule during
the day. Reception during the Submarine Fox schedule, however,
was consistently good.
(b) The frequencies used were 4115 KC, 8230 KC, and 12345
KC. The four and eight thousand bands were used at night and
twelve thousand during the day.
(c) No effective interference was encountered while on
station.

2. Radio Transmissions: Four despatches were sent during the
patrol with no trouble encountered. On 5 October at 1725(Z)
intercepted a message on 450 KC. It was addressed to any and
all naval ships and was of immediate importance to us. On
6 October we sent our 060430 blind on 450 KC -- it was sent twice.
Our 070928 was sent on 8470 KC and addressed to NPM, VHM, Radio
Brisbane, answered up immediately so it was sent to them. A
receipt was later obtained from Comsubpac on the Fox Schedule.
On 9 October our 091310 was sent to NPM on 8470 KC. Reception
was very good with NPM being heard with a signal strength of three.
NPM receipted for this message and acknowledgement was obtained
later on the Fox Schedule. A slight delay was encountered in
transmission when two other ships came up on this frequency at
the moment we were ready to send. When our turn came the despatch
was cleared. Our last dispatch was 141650 sent again on 8470 KC.

3. SJ Radar:
(a) The SJ Radar operated satisfactorily throughout the
patrol. The initial contact was made at night at a range of
8800 yards. This was determined to be a patrol vessel and after
a short period of tracking was lost at 9000 yards. Later the
same night a 9000 ton tanker and escort were picked up at 12300
yards. The third contact was a large tanker of more than 10000
tons. This was first observed at 15200 yards. Three times radar
interference was encountered of a type that indicated a unit
operating on a frequency very close to ours, for the saturated
interference pips could be synchronized with our transmitter by
varying the pulse rate. This was done several times with first
our transmitter being synchronized to theirs and then having them
control their frequency when we set ours off beat. By synchron-
izing our transmitters the interference could be made stationary.

— page 97 —
CONFIDENTIAL
Subject: U.S.S. TINOSA (SS283) - Report of Third War Patrol.

XI. RADIO AND RADAR (CONTINUED)

3. SJ Radar (Continued)
(a) While this was not an absolute indication of a friendly submarine,
it did prove that the target's radar was of a type similar to
ours. In two instances the assumption that the target was a
friendly submarine was later proved to be true by an exchange of
recognition signals. In instances like this it would be very
useful to have a means of keying the radar so that positive
identification could be established without exposing the ship to
unnecessary danger.
(b) The SJ was inoperative for a period of about forty-five
minutes throughout the patrol. Several hours prior to an expected
contact the transmitter current meter reading began increasing,
indicating that the gas tube -722 A- was not firing properly.
To insure against a future breakdown, a new 722-A was installed
and normal operation restored. To increase sensitivity three
6AC7's were replaced in the I.F. circuit with the desired
improvement.

4. SD Radar:
(a) When leaving Johnston Island the SD gave clear indica-
tions of known airplanes at ranges varying from two to twenty-
four miles. While enroute one contact was made at a range of
twelve miles -- the plane was not seen by the lookouts. On
four other occasions the radar failed to pick up airplanes seen
by the lookouts. These planes varied in range from 6 to 10 miles
and in elevation from 2° to 10°. This is the first occasion on
which the radar has failed to indicate a plane flying at a
greater height than 1000 feet. Heavy interference was encountered
on several occasions and the continuous operation of the unit was
changed to intermittent periods of 15 to 30 seconds by varying
the high voltage. These short periods of operation still
permitted detection of any plane and the normal operation was
resumed when the interference disappeared.
(b) One night the SD was turned on when the lookouts
reported what they thought to be an airplane, but it failed to
operate normally. There was no transmitter pulse and the plate
current was exceedingly high. The 8014-A oscillator tubes were
replaced after having operated only 194 hours which was about
one-fourth the life of the previous pair. The unit was
inoperative for about forty minutes while the new tubes were
gradually brought up to the standard operating voltage.

— page 99 —
CONFIDENTIAL

Subject: U.S.S. TINOSA (SS283) - Report of Third War Patrol.

XIII. HEALTH AND HABITABILITY

1. Excellent. The operations of the ship while on
patrol were mainly surface; there was little need of any change
in daily routine. The performance of the air-conditioning and
refrigeration was excellent and their services were greatly
appreciated by all hands.

2. Multiple vitamin capsules were available to the
entire crew. Two capsules per day were compulsory for the
officers and look-outs. Sodium chloride tablets were available
for all hands and were used especially by those perspiring
profusely.

3. The diseases and injuries during the patrol were
as follows:

GORST, John H., FC3c(M), USNR, wrenched back, lumbar region,
while removing ammunition from ready boxes during battle
surface. Extreme tenderness and pain when moving. Camphor
and soap liniment massage and hot water bottle to area.
Sick days - 1. To duty well.

HOVANEC, Stephen J., MoMM2c, USN, lacerations, face, when
handle of engine inboard induction flapper snapped out of
catch, striking man below right eye causing injury. Suture
and sterile dressing and returned to duty.

— page 102 —
CONFIDENTIAL
Subject: U.S.S. TINOSA (SS283) - Report of Third War Patrol.

XVIII. REMARKS

1. Our crew christened the tanker sunk the OBSTINATE
MARU. The three hits by the STEELHEAD had no effect on her
speed during the morning of 6 October. The three effective hits
on our first attack slowed her to nine knots and finally to six.
During the succeeding attacks late that day it was very noticeable
that the torpedo explosions could not be heard as loudly through
the hull as they were during our first two attacks on this patrol.
Neither did depth charges at corresponding ranges sound as loud.
For this reason the Commanding Officer is unwilling to state that
these torpedoes definitely did not detonate. In fact, judging
from the effects, some of them did detonate and sink the ship,
even if the explosions were neither seen nor heard. The last
four shots were all aimed at a stopped target, fired deliberately
and at oblique track angles. The sound operator heard one explode;
this one gave no visual indication of doing damage. However,
after the last two torpedoes the target suddenly began sinking
rapidly. The target had been under attack for over sixteen hours
and was only about 250 miles from Truk when finally sunk. The
absence of any air protection at all made the final destruction
possible. There had been time for surface escorts to reach the
tanker even from Truk but none appeared. The raid on Wake Island
was probably responsible for this lack of interference.

2. The Mark XVIII torpedoes performed satisfactorily.
There were at least two duds. There was no evidence of prematures
or countermining, all explosions occurring at the proper time
intervals. Firing intervals of eight and nine seconds were used.

Sixteen Mark XVIII torpedoes were carried in the
forward torpedo room. These torpedoes were very carefully and
frequently checked and the new instructions on upkeep and routine
of these torpedoes were rigidly adhered to. This required an
average of fourteen hours a day until the last attack was made.
The running performance of these torpedoes was satisfactory
although a small percentage were duds.

The following minor deficiencies were found and
corrected by ship's force where possible:

(a) Torpedo #35448 -- the batteries were not secured
in the battery cases by means of the wing nuts.
(b) Two torpedoes (#53478 and #53509) had the
nichrome wires of the hydrogen eliminator circuit wound in a

— page 103 —
CONFIDENTIAL
Subject: U.S.S. TINOSA (SS283) - Report of Third War Patrol.

XVIII.                               REMARKS (CONTINUED)

                                On patrol one four tube salvo and one six tube
salvo were fired. Depth control on the first salvo was lost but
the difficulty was partly due to a sticking poppet and to flooded
supply ventilation piping. Depth control was momentarily lost
on the six tube salvo and the ship was at least four thousand
pounds heavy forward when the salvo was completed. It is not
believed that full advantage of the wakeless torpedo can be
obtained with the present system of air ejection and it is
recommended that an immediate study be begun to find some other
means of ejection.

          6.        Constant improvements are being made in the
illumination of the periscope azimuth dial. It is still
unsatisfactory. It is suggested that the azimuth scale itself
be made of a red light transmitting plastic, suitably engraved;
and that the light be introduced into the plastic in a manner
similar to that now used in attempting to illuminate a metal
scale by means of a plastic light ring.

          7.        On three occasions contacts were made with friendly
submarines, first indications being radar interference on the
SJ radar. Two of these contacts were incidental to attacks on
enemy shipping and the lack of a TBS was felt. No attempt was
made to verify the friendly nature of one contact; the night
was dark and it was thought unwise to use even a blinker gun.
On the other two occasions there was bright moonlight and exchange
of recognition signals was instituted by this command after
preparing for possible offensive action. It was thought best to
verify contacts to insure that the contact was not Japanese and
possessed of a radar of that frequency. In the future many more
opportunities will occur where coordinated attacks will be
possible and it is recommended that TBS equipment be reinstalled
on submarines.

          8.        The performance of officers and crew fully met
the high standards expected by the submarine service. The
Commanding Officer especially wishes to commend Glenn K. Hickman,
CMoMM(AA), USN, who volunteered to enter the superstructure to
locate and repair the leak in the ventilation supply system while
this ship was in enemy controlled waters.

— page 104 —
CONFIDENTIAL
Subject: U.S.S. TINOSA (SS283) - Report of Third War Patrol.

XVIII. REMARKS (CONTINUED)

9. The last two patrols of this command have been short
and the new men received have not had much experience on actual
patrol. The last refit was a long one with plenty of opportunity
for rest for all hands. For these reasons it is requested that
no changes be made in the crew during this short refit period.

— page 105 —
A16-3
Serial 0114

CONFIDENTIAL
SECOND ENDORSEMENT to
CO TINOSA Conf. ltr.
serial 0013 dated 16
October 1943.

From: The Commander Submarine Force, Pacific Fleet,
Subordinate Command.
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. TINOSA (SS283) - Report on Third War
Patrol.

1. The Third War Patrol of the TINOSA was hand-
icapped by questionable torpedo performance. It is noted that
sixteen torpedoes were necessary to sink a tanker that had al-
ready been damaged by the STEELHEAD. Although some misses
were undoubtedly due to control errors and spreads used, most
of the torpedoes were fired with accurate data and greater
damage should have been inflicted.

2. The Task Group Commander strongly concurs with
the Commanding Officer's remarks that a new type torpedo ejec-
tion is necessary. Observation of submarines firing training
torpedoes in the Midway area indicate that poppet valves are
not the answer to elimination of the impulse bubble. A pneu-
matic or hydraulic piston type ejection is suggested.

3. It is recommended that the TINOSA be credited
with inflicting the following damage on the enemy:

SUNK
1 AO (Type undetermined) 10,000 tons

DAMAGED
1 AO (HUZISAN MARU TYPE) 9,500 tons

[HANDWRITTEN: C. W. STYER.]

Copy to:
Comsubdiv 102
CO TINOSA
COMMANDER SUBMARINE FORCE, PACIFIC
FLEET, SUBORDINATE COMMAND, MIDWAY
Care of Fleet Post Office;
San Francisco, California,
19 October 1943.

— page 106 —
FB5-102/A16-3
Serial 081
CONFIDENTIAL

SUBMARINE DIVISION 102
Care of Fleet Post Office,
San Francisco, California,
19 October 1943.

From: Commander Submarine Division 102
To : Commander-in-Chief, United States Fleet.
Via : (1) Commander Submarine Force, Pacific Fleet.,
Subordinate Command, Navy No. 1504.
(2) Commander Submarine Force, Pacific Fleet,

Subject: U.S.S. TINOSA - Third War Patrol; Comment on.

1. This short patrol of only twenty three days
produced two worthwhile torpedo targets both of which were
attacked. In addition, a radio station on ALET ISLAND of the
Paluwat Group was bombarded from close range. The patrol was
terminated by dispatch orders from the Force Commander.

2. First Attack:- 9525 ton tanker under escort -
Four torpedoes - two probable hits - range 1950 yards - night
radar approach - periscope attack, submerged. This approach and
attack was well conducted. A faulty poppet valve and a leaky
main induction caused temporary loss of depth control after
firing but the evidence of two hits being obtained is very strong
and it is recommended that credit for damage be given.

Second Action: - Large tanker unescorted - Six-
teen torpedoes - six hits - sixteen hour running battle - night
radar tracking - daylight periscope attacks submerged. Evidence
indicates that this tanker already had been hit with three tor-
pedoes fired by STEELHEAD prior to TINOSA making contact. On
TINOSA's first attack with 6 torpedoes TINOSA again lost depth
control due to holding poppet valves open but the evidence is
very strong that three hits and explosions and one dud hit were
obtained. Another end run followed by five deliberate attacks
in which ten torpedoes were expended finally sank this well-
built ship. It is almost certain that the ship absorbed nine
torpedo hits before sinking. The entire engagement was conducted
with dogged determination by TINOSA and the large expenditure of
torpedoes was amply repaid by the final hard won result.

Bombardment: The plan for this attack was simple
and effective. Forty-one high capacity shells in a small radio
station must have done sufficient damage to pay for the time and
ammunition expended.

3. The performance of the Mark XVIII torpedoes
carried by TINOSA is gratifying. The exploders were not of the
modified type so a certain percentage of duds could be expected.
The remarks of the Commanding Officer concerning the inability
of the present size poppet valve to completely swallow the eject-
ion bubble is cause for serious thought. It is recommended that
further tests be conducted with-redesign in view if found neces-
sary.

4. The recommendation that TBS equipment be rein-
stalled on submarines is concurred in.

5. TINOSA is undergoing a five day refit period
with SPERRY undertaking all work.

6. No personnel changes are being made in TINOSA'S
crew in view of the request made in the last paragraph of the
Patrol Report.

7. The Commanding Officer, officers and crew of the
TINOSA are congratulated on an aggressive and successful patrol.

FRANK T. WATKINS.

— page 107 —
FF12-10/A16-3(8)/(16)
Serial 01533
CONFIDENTIAL
THIRD ENDORSEMENT to
TINOSA Report of
Third War Patrol.

ld
SUBMARINE FORCE, PACIFIC FLEET
Care of Fleet Post Office,
San Francisco, California,
24 October 1943.

COMSUBSPAC PATROL REPORT NO. 291
U.S.S. TINOSA - THIRD 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. TINOSA (SS283) - Report of Third War Patrol.
(23 September to 16 October 1943).

1. The third war patrol of the TINOSA was brief and extremely
aggressive.

2. The two contacts made were both large tankers. TINOSA succeeded
in damaging the first one, a modern tanker and apparently of a modern type
and had been previously hit by three torpedoes from the STEELHEAD (SS280) but
was still making sixteen knots. The TINOSA attacked and hit this tanker
repeatedly. Finally, after firing sixteen torpedoes and obtaining at least six
hits, the tanker was sunk. The tenacity and aggressiveness of the Commanding
Officer were outstanding in his desire to make the kill.

3. Intelligent use of the information obtained from the Bathy-
thermograph enabled the TINOSA to run at high speed under a density layer and
carry out a reload and noisy trim changes in the presence of enemy escorts.

4. In addition to the torpedo attacks the TINOSA conducted a well
planned daylight bombardment of Alet Island with apparently good results.

5. Keying of the SJ circuit, as suggested by the Commanding Officer,
is being investigated.

6. This patrol is considered successful for Combat Insignia Award.

7. The Commander Submarine Force, Pacific Fleet, congratulates the
Commanding Officer, officers, and crew for this aggressive and successful patrol.
The TINOSA is credited with inflicting the following damage to the enemy:

S U N K
1 - Tanker (class unknown) | - | 10,500 tons

- 1 -
[STAMP: RECEIVED
13 NOV 1943
[HANDWRITTEN: ROUTE TO:] A16-3(23)/SS283
[HANDWRITTEN: 551]
[HANDWRITTEN: 647]]
Finished-Ragan-File.

— page 109 —
[STAMP: DECLASSIFIED-ART. 0445, OPNAVINST 5510.1C]
[HANDWRITTEN: BY G9348] [HANDWRITTEN: DATE 6/21/72]

[STAMP: DECLASSIFIED] U.S.S. TINOSA
C-O-N-F-I-D-E-N-T-I-A-L

From: The Commanding Officer.
To : The Commander in Chief, U.S. Fleet.
Via : Official Channels.

Subject: U.S.S. TINOSA (SS283) - Report of War
Patrol Number Four.

Enclosure: (A) Report of Fourth War Patrol -
27 October 1943 to 16 December, 1943.

1. Enclosure (A) covering the Fourth War
Patrol of this vessel is forwarded herewith.

/ / /
[SIGNATURE: L. R. DASPIT.]

[STAMP: 63992 FILMED]

— page 110 —
CONFIDENTIAL
PROLOGUE

U.S.S. TINOSA (SS283) - Report of Fourth War
Patrol. Period from 27 October 1943 to
16 December 1943. Operation order No. 245-43.

Arrived Midway 16 October 1943 from third war
patrol for reload and short refit by SPERRY.
Not depermed. Painted black. Five days refit,
two days training, three days loading. Ready
for sea 27 October 1943.

NARRATIVE

I.

27 October 1943
1600(Y)         Departed Submarine Base, Midway, enroute area.

28 October 1943
                Omitted -- crossed 180th Meridian.

29-31 October 1943
                Daily dives and drills.

1 November 1943
1548(L)         SD radar, Contact #1. Submerged. No plane
                sighted. Lat. 19-13N Long. 161-23E.

1640(L)         Surfaced.

2 November 1943
1630(K)         SD radar, Contact #2. Submerged. No plane
                sighted. Lat. 16-46.2N Long. 156-34.4E.

1702(K)         Surfaced.

4 November 1943
0849(K)         Battle Surface drill. Used Japanese fishing
                barrel as target.

1235(K)         Sighted possible smoke bearing 276°t. Attempted
                to intercept but no further contact.

5 November 1943
1905(K)         Began patrol on probable convoy route --
                Palau to Truk.

6 November 1943
0603(K)         Set course 000°t to reach new position for patrol.

1037(K)         Sighted plane. Contact No. 3. Submerged.
                Lat. 7-35.6N Long. 145-21E.
                -1-

— page 111 —
CONFIDENTIAL
Subject: U.S.S. TINOSA (SS283) - Report of Fourth War
Patrol.

I.
NARRATIVE (CONTINUED)

6 November 1943 (Continued)
1108(K) Surfaced.

7 November 1943
0337(K) Began patrol of shipping lanes, Empire to Truk.

0721(K) Patrolling on surface; sighted masts of ship
          through periscope, bearing 265.5°t, estimated
          range 38,000 yards, angle on bow 5° starboard.
          Submerged.

0723(K) Changed course to 255°t. Believed base course of
          target to be 090°t and wished to close somewhat.

0741(K) Again sighted target from depth of 55 feet.
          Bearing 238°t, estimated range 24,000 yards,
          angle on bow 45° port. Changed course to 160°t,
          went ahead full speed. Target identified as a
          cruiser of Mogami type.

0804(K) Changed course to 140°t. Still attempting to
          close. One DD escort picked up ahead of cruiser,
          similar to Shigure class.

0830(K) Target passed; minimum range 8500 yards. This
          was a heart breaker. I had considered we were
          in excellent position when we submerged, about
          3000 yards north of the estimated base course and
          with the target on a course to the north of us.
          During the time between diving and again picking
          up the target, the plot indicates that she made
          good a right zig of about 50° to a course of
          140° and maintained this for about twenty minutes.
          After we sighted her again she made a series of
          smaller left zigs. After she had gone by and just
          before disappearing from sight she made a 50°
          left zig.

0922(K) Surfaced. Sent contact report. Set course for
          area.

8 November 1943
          Reached area.

— page 126 —
CONFIDENTIAL
Subject:
U.S.S. TINOSA (SS283) - Report of Fourth War
Patrol.
I.
NARRATIVE (CONTINUED)

3 December 1943 (Continued)
1820(I)        Began closing at maximum speed. Moon had risen
               over high cirrus giving bad conditions; too light
               for surface radar approach, hardly enough for
               effective periscope approach.

1847(I)        Picked up targets on radar and by sight. Base
               course of convoy about 055°t.

1922(I)        It became apparent that convoy had changed base
               course to about 105°t.

1928(I)        Submerged to radar depth. Range 4500 yards.

1938(I)        Submerged to periscope depth.

1944(I)        Unfortunate zig again spoiled chances for two
               ship shot. In too close to target and forced to
               swing for large track shot.

1947(I)        Target zigged again. Fired three bow tubes up
               stern, one hit set target afire aft and set ocean
               afire in general vicinity. Range 520 yards.
               Lat. 06-29N Long. 131-28E.

1948(I)        Swinging to get on another target but visibility
               intermittent and data too poor to warrant shot.
               Began reload forward.

1953(I)        First depth charge.

2002(I)        Escort passed close aboard ahead and sound reported
               one coming in aft on steady bearing and getting
               echoes off us so went deep. Much fire and smoke
               on ocean and visibility through periscope poor.

2016(I)        Back to periscope depth.

2017(I)        Depth charge. Distant. Target still burning
               and low in water aft. Heard high speed screws as
               from small boat.

-17-
[HANDWRITTEN: 18]

— page 129 —
- CONFIDENTIAL
Subject: U.S.S. TINOSA (SS283) - Report of Fourth War
Patrol.
I.
NARRATIVE (CONTINUED)

10 December 1943
0824(I) Arrived Darwin. 5800 gallons fuel remaining.
Received 39,000 gallons.

0238(I) Departed Darwin for Fremantle. Speed 80/90 on
three main engines.

13 December 1943
0615(I) Forced to slow to eleven knots because of heavy
head seas.

16 December 1943
Seas moderating.

1800(I) Arrived Fremantle.

-20-
[HANDWRITTEN: 21]

— page 131 —
CONFIDENTIAL

Subject: U.S.S. TINOSA (SS 283) - Report of Fourth War
           Patrol.

III. TIDAL INFORMATION (IF ABNORMAL)

     1. This patrol station was spent almost entirely in the counter
        equatorial current which seemed to exist between 3°N and 7°N
        with an average strength of 2 knots toward 090°T. North of
        7°N the equatorial current was encountered setting toward the
        SW averaging 1.5 knots. The current off Toagel Mlungui
        Passage is usually to the north and northeast, following the
        reefs. Off Malakal Passage the current is to the west and
        northwest.

     2. Hydrostatic density layers were observed on all dives, and
        large gradients were found at all times in the area. Around
        Palau an average negative gradient of 15° was found at deep
        submergence. The maximum obtained was 20° following the attack
        on 26 November 1943. In the open sea the normal gradient at
        300 feet was 8 to 10 degrees. The disadvantage of a large
        gradient is the great amount of water which has to be pumped
        out in order to get back to periscope depth. Following the
        attacks off Malakal Passage it was necessary to pump out
        6,000 - 8,000 lbs.

IV. NAVIGATIONAL AIDS

     1. West of Palau -- Off Toagel Mlungui Passage in good visibility
        the position could be easily fixed at all times. The
        prominent objects used were the tall tower on the northern end
        of Babelthuap near Aiyon; Hill 790 which does not seem very
        prominent because of its gradual slope, but which has a house
        or observation post on its crest; Hill 641, a thin needle
        like peak south of a higher rounder one; Toagel Mlungui light
        which is in front of Hill 641; and the tall white marker mast
        at the entrance to the pass. The latter can only be seen
        submerged within about 6,000 yards of the entrance. The
        black can buoy referred to in the GURN.RD's report was not
        seen, but the reefs at this point were well marked by high
        rocks and surf.

     2. East of Palau -- Malakal light is the most prominent object,
        sitting on a high hill about two miles south of the pass.
        Malakal Island to the right of the harbor is also prominent.
        Tangents and the eastern most peak on southern Babelthuap
        south of Goikul were also used.
[HANDWRITTEN: H]

                                  -22-
[HANDWRITTEN: 1 tho 23]

— page 135 —
CONFIDENTIAL
Subject: U.S.S. TINOSA (SS283) - Report of Fourth War
           Patrol.
V.         ENEMY VESSELS SIGHTED (CONTINUED)

CONTACT   TIME      LAT
NO.       DATE      LONG      TYPE & DESCRIPTION   COURSE   SPEED   REMARKS

10 -- Continued --            Chidori Torpedo Boat ---      ---     Escort for
                                                                    convoy

11        1630(I)   7-35N     Freighter            315      10      Similar
          11-17-43  134-20E                                         Kinisina
                                                                    Maru

12        0740(I)   7-07N     Convoy -- Freighter  315      10      Similar
          11-22-43  134-38E                                         Badoeng Maru
                                Freighter            315      10      Similar
                                                                    Kiso Maru
[HANDWRITTEN: I.]             Escort               ---      10      Minesweep
                                                                    AM-1 Class
                                Escort               ---      10      PC type

13        1930(I)   7-15N     Patrols              ---      ---     Two patrols
          11-22-43  134-58E                                         searching
                                                                    for us after
                                                                    attack

14        0223(I)   3-18N     Convoy -- Freighter  315      10      Similar
          11-25-43  136-50E                                         Akita Maru
                                Freighter            315      10      Nagano Maru
                                Freighter            315      10      Seiwa Maru
                                Two Escorts          ---      10      One PC
                                                                    One Trawler

15        1730(I)   6-04N     Convoy -- Freighter  105      14      Akagi Maru
          12-3-43   131-23E                                         Class
                                Tanker               105      14      Abt 10000
                                                                    tons
                                Tanker               105      14      Abt 10000
                                                                    tons
                                Escorts              ---      14      1-Chidori
                                                                    1 unidenti-
                                [HANDWRITTEN: 1.yha]                fied
                                                                    [HANDWRITTEN: 27]

— page 137 —
CONFIDENTIAL
Subject: U.S.S. TINOSA (SS263) - Report of Fourth War
Patrol.

V. ENEMY VESSELS SIGHTED -- REMARKS

The Toagel Mlungui Passage to Palau Harbor is well shown
on Chart No. 5423. Aiwokoko Passage is in use by ships of at
least seven foot draft. Navigational aids are described under
part IV. No current tables were available for this location and
the nearest tide tables were those for Yap. However, from
observations on 17 November 1943 it appears that the channel
can be used at any state of the current and not just within
one hour of slack water. No evidence of land radar was
noticed.

[HANDWRITTEN: #I]

-28-

[HANDWRITTEN: 1Xha]
[HANDWRITTEN: 29]

— page 140 —
CONFIDENTIAL

Subject: U.S.S. TINOSA (SS283) - Report of Fourth War
Patrol.

SUMMARY OF SUBMARINE ATTACKS

| | (1) | (2) | (3) | (4) |
|---|---|---|---|---|
| Attack | 1 | 2 | 3 | 4 |
| Time - GCT | 2338 | 2342 | 0633 | 0031 |
| Date | 11/22/43 | 11/22/43 | 11/25/43 | 11/26/43 |
| Location - Lat. | 07-09.8N | 07-09.8N | 05-09.0N | 06-56N |
| Location - Long. | 134-34.4E | 134-34.4E | 135-56.0E | 134-38E |
| No. & Type Torpedoes | 3-Torpex | 3-Torpex | 3-Torpex | 3-Torpex |
| Fired on each Attack | Mk 14-3A | Mk 14-3A | Mk 14-3A | Mk 14-3A |
| Hits | 3 | 2 | 0 | 2 |
| Number Sunk (Tonnage) | 3844 | 3800 | 0 | 4000 |
| Number Damaged or | 0 | 0 | 0 | 0 |
| Probably Sunk (Tonnage) | | | | |
| Type of Target | AK | AK | AK | AK |
| Range | 700 | 1100 | 900 | 1150 |
| Type of Attack: | P | P | P | P |
| Periscope (P)-Radar (R) | | | | |
| Estimated Draft | 12' | 12' | 14' | 14' |
| of Target | | | | |
| Torpedo Depth | 8' | 8' | 10' | 10' |
| Setting | | | | |
| Bow or Stern Shot | Stern | Bow | Stern | Bow |
| Track Angle | 110S | 95P | 135S | 108S |
| Gyro Angle | 182 | 004 | 185 | 359 |
| Estimated Target | 10 | 10 | 7.5 | 10 |
| Speed | | | | |
| Firing Interval | 10 sec. | 11 sec. | 9 sec. | 9 sec. |
| Spread | 80 | 80 | 11 sec. | 12 sec. |
| Amount & Kind | Total | Total | 80 | 80 |
| Was Torpedo Performance | Yes | Yes | Yes | Yes |
| Satisfactory? | | | | |

-31-
[HANDWRITTEN: 32]

— page 156 —
CONFIDENTIAL
Subject: U.S.S. TINOSA (SS283) - Report of Fourth War
Patrol.
XII. SOUND CONDITIONS AND DENSITY LAYERS

1. Sound conditions with one exception were quite
good.

2. Near Toagel Mlungui screws could be clearly heard
from 5000 to 7000 yards. The negative temperature gradients
averaged about 16° down to 300 feet and were very consistent.

3. On the first attack off Malakal Harbor conditions
were just fair with the first indications of screws at about
4000 yards. On going to deep submergence a 16° negative
temperature gradient was found from 140 feet to 380 feet.
Except for one close pattern which occurred considerably after
the initial attack no close depth charges were encountered which
would indicate that we were never clearly heard by the escorts.

4. Sound during the second attack was very poor.
Screws from the target were not heard until a range of 1000 yards
had been reached and then only intermittently.

5. During the second attack off Malakal sound condi-
tions were a repetition of the first with the temperature gradient
an exact reproduction.

6. The last attack occurred well at sea and screws
were heard at ranges around 6000 yards. The usual explosions
and crackings of the sinking ship were heard very clearly. A
negative temperature gradient of 8° was found between 180 feet
and 300 feet.

-47-
[HANDWRITTEN: 48]

— page 161 —
FC5-16/A16-3
Serial #01
C-O-N-F-I-D-E-N-T-I-A-L

SUBMARINE SQUADRON SIXTEEN
U.S.S. RASHER, Flagship,
2 January 1944.

FIRST ENDORSEMENT to
TINOSA 4th War Patrol
Report SS283/A16-3
dated 16 December 1943.

From: The Commander Submarine Squadron SIXTEEN.
To : The Commander in Chief, UNITED STATES FLEET.
Via : The Commander Submarines, SEVENTH FLEET.
The Commander SEVENTH FLEET.

Subject: U.S.S. TINOSA (SS283) - Fourth War Patrol -
Comment on.

1. The fourth war patrol of the U.S.S. TINOSA was
characterized by its dogged persistance in the face of an usually
long run of frustrated attack opportunities. That finally most
excellent results were obtained and heavy damage inflicted on the
enemy is cause for congratulation. The patrol covered a period
of fifty-one days of which thirty-three were spent in the areas
assigned.

2. Torpedo performance was most gratifying, no
erratic runs, prematures or duds having been noted and the
overall percentage of hits being 54.5. In this latter connect-
ion it is considered significant of this high percentage that
the average firing range was in the neighborhood of 840 yards,
well below that usually reported.

3. The material condition of the TINOSA is generally
most satisfactory and refit can be completed within the usual
time limitation. The remarks and recommendation concerning the
Bendix log are concurred in.

4. The Squadron Commander takes pleasure in wel-
coming the Commanding Officer, officers and crew of the TINOSA
and in extending his congratulations on a thoroughly workman-
like and effective patrol.

[SIGNATURE: J. M. Haines]
J. M. HAINES.

[HANDWRITTEN: 53]

— page 162 —
[HANDWRITTEN: 0427]

UNITED STATES NAVY
FE24-71/A16-3
12-roth
Serial 039
14 January, 1944.
C-O-N-F-I-D-E-N-T-I-A-L

SECOND ENDORSEMENT to
USS TINOSA Fourth War
Patrol Report SS283/A16-3
dated 16 December, 1943.

From: The Commander Task Force SEVENTY-ONE.
To: The Commander-in-Chief, UNITED STATES FLEET.

Via: The Commander SEVENTH FLEET.

Subject: U.S.S. TINOSA - Report of Fourth War Patrol -
           Comments on.

1. The remarks of the Commander Submarine Squadron
SIXTEEN are concurred in.

2. This patrol was conducted in a skilful manner.
Each attack opportunity was developed intelligently with a most
commendable display of aggressiveness and dogged determination.
Every ton of enemy shipping sunk and damaged was well deserved.

3. This patrol is considered successful for purposes
of award of the Submarine Combat Insignia.

4. The Force Commander takes pleasure in extending
his congratulations to the Commanding Officer, officers, and
crew of the TINOSA on this well conducted patrol and on inflict-
ing the following damage on the enemy:

SUNK
____

1 - AK (BADOENG MARU TYPE) .. 4,003 Tons
1 - AK (KISO MARU TYPE) .. 4,071 "
1 - AK (NAGANO MARU TYPE) .. 3,824 "
1 - AK (AKAGI CLASS) .. 6,546 "
                                     _______
TOTAL ..18,544 Tons

DAMAGED
_______

1 - AK (SEIWA MARU TYPE) .. 7,210 Tons
                                     _______
[STAMP: RECEIVED]
[STAMP: 21 JAN 1944]
[STAMP: COMMANDER SOUTHWEST]
[STAMP: PACIFIC FORCE]

- 1 -

[HANDWRITTEN: 54]

— page 164 —
[HANDWRITTEN: F4253]
[HANDWRITTEN: 381.....]
UNITED STATES FLEET
COMMANDER SEVENTH FLEET

A16-3(F-3/roj)
SERIAL: [HANDWRITTEN: 0161]

24 JAN 1944

C-O-N-F-I-D-E-N-T-I-A-L
THIRD ENDORSEMENT to
U.S.S. TINOSA Fourth War
Patrol Report SS283/A16-3
dated 16 December, 1943.

From: Commander SEVENTH FLEET.
To : Commander in Chief, UNITED STATES FLEET.

Subject: U.S.S. TINOSA - Report of Fourth War Patrol,

1. Forwarded.

[SIGNATURE: R. H. Cruzen]
R. H. CRUZEN
By direction.
[HANDWRITTEN: orig.
sent
1/24]

Copy to:
VCNO

[HANDWRITTEN: Forwarded]

[STAMP: FILMED]

[HANDWRITTEN: 56]

— page 165 —
DECLASSIFIED-ART 0445, OPNAVINST 5510.1C
[STAMP: CONFIDENTIAL]
[STAMP: DECLASSIFIED]
[HANDWRITTEN: C 93R] DATE [HANDWRITTEN: 6/10/77]
U.S.S. TINOSA (SS283) - Report of Fifth War Patrol.

PROLOGUE

Arrived Fremantle 16 December 1943. Commenced refit.
Drydocked, straightened Bendix log swordarm, inspected
tube outer doors and shutters, redesigned 2MC,
painted ship with new camouflage paint. Commander
D.F. WELSH, USN, relieved Commander L.R. DASPIT as
Commanding Officer. Five days training, four days
loading. Readiness for sea January 10, 1944.

I.
NARRATIVE

10 January 1944
1310(H) Underway for operating area.

1530(H) Conducting surface and submerged approaches on
U.S.S. CHANTICIEER.

2300(H) Departed area enroute EXMOUTH GULF.

11 January 1944
Enroute EXMOUTH GULF.

1200(H) Position: Lat. 28-26.4S, Long. 112-54.1
Miles: 298.7
Fuel used: 2,297 gallons

12 January 1944
Enroute EXMOUTH GULF. Training dives and fire control
drills.

1200(H) Position: Lat. 24-10.4S, Long. 112-25.1E
Miles: 371.0
Fuel used: 3,451 gallons

13 January 1944
0830(H) Moored alongside fuel barge EXMOUTH GULF and took on
8900 gallons of fuel oil.

1154(H) Underway from fuel barge, conducted training drill for
special mission.

1609(H) Departed EXMOUGH GULF, enroute patrol area.

1200(E) Position: EXMOUTH GULF
Miles: 234.9
Fuel used: 2,403 gallons

14 January 1944
1254(H) Sighted plane 6 miles A/C contact #1. Submerged.
Exercised fire control party and conducted drills.

[STAMP: FILMED]
[STAMP: 68693]
- 1 -
[HANDWRITTEN: 2]

— page 196 —
CONFIDENTIAL
Subject: U.S.S. TINOSA (SS283) - Report of Fifth War Patrol.

VI. AIRCRAFT CONTACTS (C(NTINUED)

| NO. | CONTACT DATE TIME | TYPE | COURSE | ALTITUDE | LAT LONG | REMARKS |
|---|---|---|---|---|---|---|
| 12. | 1-18-44 0905(H) | Single engine biplane. Fixed landing gear | 120T | 5° Dist. 4 miles | 01-41.9S 118-27.1E | Sighted by lookout |
| 13. | 1-24-44 0835(H) | Couldn't identify | 243T | 5° Dist. 7 miles | 07-14.0N 116-02.3 | Sighted by lookout |
| 14. | 1-24-44 1412(H) | Couldn't identify | 150T | 3° Dist. 6 miles | 07-21.5N 116-17.8E | Sighted by lookout |
| [HANDWRITTEN: Mark] 15. | 1-25-44 1406(H) | PETE | 055T | 4° Dist. 8 miles | 05-17.1N 113-49. E | Sighted by lookout |
| 16. | 1-25-44 1832(H) | --- | --- | --- | 05-19.9N 113-51.9E | Sighted, 5 miles |
| 17. | 1-29-44 1658(H) | RUFE | 100T | 6° Dist. 6 miles | 06-01.9N 112-21.4E | Sighted by lookout |
| 18. | 1-31-44 0923(H) | Two wing float PETE | 090T | 2° Dist. 5 miles | 07-17.2N 114-24.3E | Sighted by lookout |
| 19. | 2-2-44 1300(H) | RUFE | 065T | 1° Dist. 2 miles | 07-19. N 115-45. E | Sighted by lookout |
| 20. | 2-3-44 0710(H) | | 143T | 4° Dist. 5 miles | 06-07.8N 114-14.7E | Sighted by lookout |
| 21. | 2-3-44 1810(H) | RUFE | 100T | 2° Dist. 8 miles | 05-53.3N 114-39.9E | Sighted by lookout |
| [HANDWRITTEN: 1720] 22. | 2-4-44 0620(H) | RUFE | 200T | 4° Dist. 1 mile | 07-17.8N 115-44.9E | Sighted by lookout |

[HANDWRITTEN: (39)]
- 32 -
[HANDWRITTEN: 33]

— page 197 —
CONFIDENTIAL

Subject: U.S.S. TINOSA (SS283) - Report of Fifth War Patrol.

VI. AIRCRAFT CONTACTS (CONTINUED)

CONTACT DATE
NO. TIME TYPE      COURSE   ALTITUDE   LAT
                                     LONG       REMARKS

23 2-6-44          ----     ----       06-57.3N   Indication
   1255(H)                               114-29. E  on radar 6
                                                  miles

24. 2-6-44         ----     ----       06-39.8N   Indication
    1822(H)                              113-39.9E  on radar 8
                                                  miles

25. 2-8-44         ----     030T 1°    05-46.2N   Sighted by [HANDWRITTEN: I]
    0116(H)                   Dist.    116-28.5E  lookout
                              4 miles

26. 2-8-44         ----     ----       05-19.3N   SD radar
    0707(H)                              116-28.0E  10 miles

27.2-8-44          ----     ----       04-41.1N   Indication
    1136(H)                              110-38.1E  on radar 22
                                                  miles

28. 2-9-44         ----     ----       04-22.8N   Indication
    1425(H)                              112-19.5E  on radar 12
                                                  miles

29. 2-17-44        ----     ----       11-52.4N   Indication
    0837(I)                              131-32. E  on radar 8
                                                  miles

30. 2-17-44        ----     ----       05-19.3N   Indication on
    -9-5(I)                              116-28.0#  radar 10
                                                  miles

31. 2-21-44        MAVIS    270T 4°    19-16.5N   Sighted by
    1144(I)                   Dist.    144-26.1E  lookout
                              4 miles

32. 2-21-44        ----     ----       19-18. N   Indication on
    1419                                 144-55. E  radar 10
                                                  miles

33. 2-22-44        ----     ----       20-47. N   Indication on
    0954(K)                              148-13. E  radar 18
                                                  miles. Did
                                                  not dive

[HANDWRITTEN: (40)]
- 33 -
[HANDWRITTEN: 1x5]
[HANDWRITTEN: 34]

— page 202 —
This appears to be a page from a WWII submarine patrol report, specifically detailing "MAJOR DEFECTS EXPERIENCED". I will transcribe all the text, including the handwritten annotations.

CONFIDENTIAL
Subject: U.S.S. TINOSA (SS283) - Report of Fifth War Patrol.

— page 206 —
CONFIDENTIAL
Subject: U.S.S. TINOSA (SS283) - Report of Fifth War Patrol.

XII. SOUND CONDITIONS AND DENSITY LAYERS

1. Sound conditions were good with the usual fish and
bottom noises heard.

2. On one contact in the South China Sea screws were
first heard at 6500 yards on both the targets reciprocating engines
and the Destroyers high speed screws. On going to deep submergence
on 22 January at 07-25. E - 115-08.2N a 10 degree temperature
gradient was found. A sharp break of 4 degrees at 100 - 120 feet
required the flooding in of 1000 lbs of water. At 140 - 160 feet
1000 lbs were flooded in to break through a sharp 5 degree negative
gradient and 2000 lbs more were flooded in at 280 feet giving a
total of 5000 lbs for the 10 degree negative gradient.

3. East of Surigao on 15 February at 10-04. N - 126-52. E
at the deepest section of the ocean screws of one of the targets
were heard at approximately 15,000 yards. At test depth the B.T.
card showed absolutely no temperature change. Twice more at deep
submergence there was no temperature change indication, this at
18-03. N - 141-03. E and 19-28. N - 110-08. E. Suspecting the
bathermograph to be broken a test was made with warm water and its
operation appeared normal.

4. On all other surface and submerged attacks the initial
contact range of screws was from 4500 to 6000 yards. All enemy
pinging was on 18 K.C. and was first heard around 25,000 yards.
High seas made sound conditions on the last destroyer contact quite
poor for the screws were quite broad and increased and decreased
in intensity as they apparently broke the surface.

[HANDWRITTEN: (44)]
- 42 -
[HANDWRITTEN: 43]

— page 210 —
FB5-142/A16-3
Serial 011

CONFIDENTIAL
FIRST ENDORSEMENT to
USS TINOSA Report of
Fifth War Patrol.

From:
To :
Via :
Subject: SUBMARINE DIVISION 142

Care of Fleet Post Office,
San Francisco, California,
6 March 1944.

The Commander Submarine Division 142.
The Commander Submarine Force, Pacific Fleet.
The Commander Submarine Squadron Fourteen.

U.S.S. TINOSA (SS283) - Report of Fifth War
Patrol; Comments on.

1. The fifth war patrol of the TINOSA was the first for
the commanding officer as such. The patrol was conducted enroute
from West Australia to Pearl Harbor and lasted for a period of fifty-
five days of which thirty-three days were spent in assigned areas.
The TINOSA had many contacts with enemy planes but only three con-
tacts with surface targets worthy of torpedo fire. These contacts
were tenaciously developed and seven attacks were aggressively
pressed home with resultant severe losses to the enemy.

2. ATTACKS

Attack Number 1 - A day periscope attack on a four ship convoy
with two escorts. A zig made a stern tube shot most favorable, and
when the leading ships of the two columns over-lapped a spread of
three torpedoes were fired resulting in one hit on near target and
two hits on far target. The near target identified as similar to
HOEISAN MARU had its bow blown off and took a 30° dive angle. The
far target identified as similar to SAIHO MARU disappeared in a
cloud of smoke and flame.

Attack Number 2 - This was a night surface attack following a
chase of the remnant of the convoy. A good set-up was obtained on
the largest target, but the attack was frustrated by having two
prematures out of three torpedoes fired.

Attack Number 3 - In spite of gun fire from escort which had
re-joined the target the TINOSA tenaciously hung on and was finally
able to make an approach from astern. At range of 3,000 yards three
torpedoes fired on a track of 175° resulted in one hit on target
identified as similar to HOKUAN MARU.

Attack Number 4 - This attack was made on remaining ship of
convoy which by now had been thoroughly alerted. Three torpedoes
fired missed ahead due to target turning toward during firing.

- 1 -
[UNCLEAR: faint mark]

— page 211 —
FC5-14/A16-3
Serial 033.

CONFIDENTIAL
SECOND ENDORSEMENT to
USS TINOSA Report of
Fifth War Patrol.

From:
To :
Subject:

1.
Submarine Division One Hundred FORTY-TWO.

2.
Officer, the officers and crew are congratulated on the great dam-
age done the enemy.

Copy to:
Comsubdiv 142.
CO TINOSA.

SUBMARINE SQUADRON FOURTEEN

Care of Fleet Post Office,
San Francisco, California,
7 March 1944.

Hrw.

The Commander Submarine Squadron Fourteen.
The Commander Submarine Force, Pacific Fleet.

U.S.S. TINOSA (SS283) - Report of Fifth War
Patrol.

Forwarded, concurring in the remarks of Commander

This was an excellent patrol and the new Commanding

J. B. LONGSTAFF.

— page 213 —
SS283/A16-3
Serial #02
CONFIDENTIAL

U.S.S. TINOSA (SS283)
Care of Fleet Post Office
San Francisco, California

4 March 1944.

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

Subject: U.S.S. TINOSA (SS283) - Report of Fifth War
Patrol.

Reference: (a) ComSubForPac ltr. FF12-10/A16-3/(01)
Serial 906 dated 14 June 1943.

Enclosure: (A) U.S.S. TINOSA - Report of Fifth War Patrol
stencil and two copies.
(B) Fifth War Patrol Track Charts (3).

1. Enclosures (A) and (B) are submitted herewith.

D.F. WEISS.

Copy:
ComSubDiv 142 W/copy of Encl. (A)
ComSubRon 14 W/copy of Encl. (A)

[STAMP: FILMED]
68693

— page 214 —
F12-10/A16-3(15)/(12)
Serial 0465

CONFIDENTIAL

THIRD ENDORSEMENT to
TINOSA Report of
Fifth War Patrol.

COMSUBSPAC PATROL REPORT NO. 378
U.S.S. TINOSA - FIFTH 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. TINOSA (SS283) - Report of Fifth War Patrol.
(10 January to 4 March 1944).

1. The TINOSA's fifth war patrol was conducted northwest of Borneo and
in the southern Philippines while enroute Pearl Harbor.

2. Seven most aggressive attacks were made, being conducted in a cool,
businesslike, and daring manner resulting in severe damage upon the enemy. It is
unfortunate that Attack No. 2, after an excellent surface approach, was spoiled by
prematures.

3. It is again noted that new tactics were employed by the Japanese in
using distant escorts for their convoys which prevented the submarine from gaining
a favorable night surface attack position. It is also noted that escorts would
interpose themselves between submarine and convoy even when it was felt that
submarine could not possibly be seen.

4. It is evident that at least some of the Japanese destroyers are
equipped with radar and know how to use it. This is demonstrated by the very
accurate gun fire on TINOSA at ranges of 12,000 to 15,000 yards.

5. The cool daring of the Commanding Officer in electing to remain on
the surface during several attacks under heavy, accurate gun fire so as to retain
the initiative is noted with admiration and alarm. It must be borne in mind that
the Japanese are continually improving their gunnery against submarines, and the
risks involved in remaining on the surface in face of enemy gun fire must be very
carefully weighed with the value of the target being attacked.

6. This patrol is designated as successful for Combat Insignia Award.

7. The Commander Submarine Force, Pacific Fleet, congratulates the
Commanding Officer, officers and crew for this extremely aggressive and successful
war patrol. The TINOSA is credited with having inflicted the following damage upon
the enemy:

S U N K
1 - Freighter (Similar HOEISAU MARU) - 6,032 tons (Attack No. 1)
1 - Freighter (Similar SAIHO MARU) - 4,639 tons (Attack No. 1)
1 - Freighter (Class unknown) - 6,300 tons (Attack No. 6)

[STAMP: FILMED] TOTAL - 16,971 tons

- 1 -
SUBMARINE FORCE, PACIFIC FLEET

Care of Fleet Post Office,
San Francisco, California. [HANDWRITTEN: 3 44]
9 March 1944.

[HANDWRITTEN: hch F4253(2)]
3 02669
NOTE: THIS REPORT WILL BE
DESTROYED PRIOR TO
ENTERING PATROL AREA.

— page 215 —
```
FF12-10/A16-3(15)/(12) SUBMARINE FORCE, PACIFIC FLEET hch
Serial 0465
Care of Fleet Post Office,
CONFIDENTIAL San Francisco, California,
9 March 1944.

THIRD ENDORSEMENT to
TINOSA Report of NOTE: THIS REPORT WILL BE
Fifth War Patrol. DESTROYED PRIOR TO
ENTERING PATROL AREA.

COMSUBSPAC PATROL REPORT NO. 378
U.S.S. TINOSA - FIFTH WAR PATROL.

Subject: U.S.S. TINOSA (SS283) - Report of Fifth War Patrol.
(10 January to 4 March 1944).

— page 216 —
In reply refer to Initials
and No.

CONFIDENTIAL
NAVY DEPARTMENT 18 March 1946
OFFICE OF THE CHIEF OF NAVAL OPERATIONS
WASHINGTON
REASSESSMENT OF DAMAGE BY SUBMARINES

Reference: (a) ComSubPac ltr. FF12-10/L11(1) of
21 February 1946.

USS TINOSA (SS283) 5th War Patrol
Date of Attack: 15 February 1944
Position: Off SURIGAO STRAIT

TINOSA was credited with sinking 3
AK's and damaging 2 AK's as a result of her 5th War
Patrol. One of the AK's believed to have been only
damaged was thought to be of 5385 tons, similar to
the HOKKO MARU. This ship was attacked with three
torpedoes for two hits but positive results were not
observed.

DNI and Japanese verification lists
agree that as a result of this attack the ODATSUKI
MARU of 1988 was sunk. DNI credits TINOSA.

Credit assessment should be changed
accordingly. Commanding Officer, Captain D. F.
Weiss, U.S. Navy.

Copy to:
ComSubLant
SubSchool New London
CO SS283
Op-23E
Op-41C3

— page 217 —
SS283/A16-3
Serial 05

[CROSSED OUT: CONFIDENTIAL]
[STAMP: DECLASSIFIED]

U.S.S. TINOSA (SS 283)
Care of Fleet Post Office,
San Francisco, California.
15 May 1944
[STAMP: DECLASSIFIED ART. 0445, OPNAVINST. 5510.1C]
BY [HANDWRITTEN: C.M.B.] DATE [HANDWRITTEN: 6/21/77]

[STAMP: DECLASSIFIED]
From: The Commanding Officer.
To : The Commander Submarine Force, Pacific Fleet.
Via : (1) The Commander Submarine Division 142.
      (2) The Commander Submarine Squadron Fourteen.

Subject: U.S.S. TINOSA (SS283) - Report of Sixth War
         Patrol.

Enclosure: (A) U.S.S. TINOSA - Report of Sixth War Patrol.
           (B) Sixth War Patrol Track Charts.

1. Enclosures (A) and (B) are submitted herewith.
[SIGNATURE: D. F. WEISS]
D. F. WEISS.

Copy to:
ComTaskGroup 17.15 (with Enc. (A))

[STAMP: 76123] [STAMP: FILMED]
1

— page 218 —
CONFIDENTIAL
U.S.S. TINOSA (SS283) - Report of Sixth War Patrol.
Period from 29 March 1944 to 15 May 1944. Operation
Order No. 109-44.

PROLOGUE

Arrived Pearl Harbor on 4 March 1944 from fifth war
patrol for refit by U.S.S. BUSHNELL. Dry docked 15 -
19 March 1944. The following work was accomplished
during refit:
(1) Converted #4 MBT to a FBT.
(2) Cut down bridge (TRIGGER type).
(3) Overhauled #1 and #2 main engines.
(4) Installed SJ-A Radar.
(5) Installed JP sound receiver.
(6) Converted starboard head in crew's living space to
empty into #2 sanitary tank.
(7) Installed 4" gun.
(8) Removed DQ training gear and receiver.
(9) Installed RBE receiver in place of ANA receiver.
(10) Installed Mark 18 charging panel in after torpedo
room.
Sound tested and depermed. Light grey camouflage.
Two days training and one night convoy exercises in
company with U.S.S. PARCHE and U.S.S. BANG.
Readiness for sea 29 March 1944.

I. NARRATIVE

29 March 1944
1600 (VW) Departed Pearl in company with PARCHE and BANG (OTC,
Captain PETERSON, in PARCHE) under surface escort until
dark, enroute assigned area via MIDWAY. Trim dives and
drills enroute.

2 April 1944
0820 (Y) Moored to Submarine Pier, MIDWAY. Completed minor work
repairs. Received 14,000 gallons fuel.

3 April 1944
1210 (Y) Underway under air escort until dark in company with
PARCHE and BANG (OTC in PARCHE).

4 April 1944
Omitted - crossed 180th Meridian.

5 and 6
April 1944 Held battle surface drills. Fired all guns.

- 1 -
ENCLOSURE (A) 2

— page 236 —
CONFIDENTIAL
Subject: U.S.S. TINOSA (SS283) - Report of Sixth War Patrol.

I. NARRATIVE (CONTINUED)

9 May 1944 (Continued)
1534 (K) (Continued)
                 at about 12 knots, maneuvering to dodge. Checked fire
                 and closed to 3,000 yards. Trawler opened fire with
                 machine gun and rifle, not close. We opened fire,
                 still closing the range. Obtained several hits and
                 observed flying debris and Japs frantically abandoning
                 ship. One of these hits knocked out the machine gun.
                 At 1,400 yards we were hitting consistently. A water
                 line hit started a fuel fire. Two or three more hits
                 left her settling at the stern and burning like a bon-
                 fire.

1632 (K)         Ceased firing. Secured all guns except one 20mm and
                 sub-machine guns. Took pictures and maneuvered to
                 pick up survivors. The nearest one at first showed
                 disaffection, but changed his mind when the tommy guns
                 were brandished. We threw him a life ring and hauled
                 him aboard. Some of the crew wanted to turn him in on
                 a newer one, as he was definitely second hand. He had
                 numerous splinter wounds on his back and legs but we
                 kept him to give the pharmacist's mate something to do
                 on the way home. The others kept swimming away, so at

1656 (K)         departed scene on course 090°T, leaving the Trawler
                 burning and sinking by the stern. About 10 Japs
                 remained in the water clinging to various bits of
                 wreckage.

                 Ammunition expended was 71 rounds of 4" high capacity.
                 The high capacity hits seemed very effective. Total
                 of 12 hits. Two passed directly through target without
                 exploding, however. The shooting was bad even in light
                 of excessive range and considerable seas. If an in-
                 creasing number of gun actions are to be expected, it
                 is believed that additional firings should be scheduled
                 during training. We intend holding intensified point-
                 ing, training and loading drills while in port if load-
                 ing machine and dotter are available. Trawler (150
                 tons). Sunk: Lat. 22-20N Long. 146-40E.

                                      - 19 -

                                                               ENCLOSURE (A)

                                                               [HANDWRITTEN: 20]

— page 241 —
CONFIDENTIAL

Subject: U.S.S. TINOSA (SS283) - Report of Sixth War Patrol.

VII. SUMMARY OF SUBMARINE ATTACKS

Attack | 1 | 2 | 3 | 4 | 5
Time G.C.T. | 0137 | 0835 | 1952 | 2008 | 0048
Date | 4-30-44 | 5-3-44 | 5-3-44 | 5-3-44 | 5-4-44
Location - Lat. | 18-15.5N | 20-27N | 20-54.8N | 20-57.4N | 21-04N
Location - Long. | 120-18.4E | 118-55.5E | 118-14.9E | 118-06.3E | 118-10.1E
No. & Type of | 6 | 6 | 4 | 4 | 4
Torpedo Fired on | 14-3A | 14-3A | 14-3A | 14-3A | 14-3A
Each Attack | | | | |
Hits | 4 | 5 | 4 | Unknown | Unknown
| | | 2 Explosions | 2 Explosions | 2 Explosions
No. Sunk | 1-AK | 1-AO | 1-AK | -- | --
(Tonnage) | 5,500 | 10,000[HANDWRITTEN: x] | 9,467 | |
No. Damaged or | 1-AO | 1-AK | 0 | Unknown | Unknown
Probably Sunk | 7,500 | 6,000 | | |
(Tonnage) | 1-AK | 1-AO | | |
| 5,500 | 6,000 | | |
Type of Target | 1-AO | 1-AO | AK | AK | AK
| 2-AK | 2-AK | | |
Range | 3,000 | 1,600 | 3,200 | 3,520 | 3,350
Type of Attack | P | RP | RS | RS | P
Periscope (P) | | | | |
Radar (R) | | | | |
Surface (S) | | | | |
Night (N) | | | | |
Estimated Draft | 20' | 29' | 27' | 20' | 20'
| 18' | 18' | | |
| 18' | 18' | | |
Tor.Depth Setting | 8' | 8' | 8' | 8' | 6'
Bow or Stern Shot | Bow | Bow | Stern | Bow | Stern
Track Angle | 90S | 105S\n92S | 103S | 155S | 109P
Gyro Angle | 008.9 | 011\n333 | 006.5 | 0 | 17.3
Estimated Target | 10 | 8 | 10.5 | 6.5 | 7.5
Speed | | | | |
Firing Interval | 9 Sec. | 11 Sec. | 9 Sec. | 10 Sec. | 9 Sec.
Spread Amount | 10° Div. | 4° Div. | 4° Div. | 2° Long. | 3° Div.
and Kind | | | | |
Was torpedo per- | Yes | Yes | Yes | Yes | Yes
formance Sat.? | | | | |
Overhaul Activity | | U.S.S. BUSHNELL | | |

- 24 -

[HANDWRITTEN: ENCLOSURE (A) 25]

— page 251 —
SUBMARINE DIVISION 142

                                                                Care of
                                                                San Francisco, California,
                                                                16 May 1944.

FB5-142/A16-3.

Serial 024

CONFIDENTIAL
FIRST ENDORSEMENT to
USS TINOSA Report of
Sixth War Patrol.

From:         The Commander Submarine Division 142.
To   :        The Commander Submarine Force, Pacific Fleet.
Via  :        The Commander Submarine Squadron 14.

Subject:      U.S.S. TINOSA - Report of Sixth War Patrol; Comments
              on.

              1.      During the sixth war patrol the U.S.S. TINOSA oper-
              ated in the East China Sea as a unit of a coordinated attack group.
              The patrol was of forty-seven days duration of which nineteen days
              were spent in the assigned area. Patrol was terminated early due
              to the expenditure of all torpedoes. There were fourteen contacts
              with the enemy only three of which were torpedo targets. Five
              torpedo attacks were made and three of these were most successful.
              One trawler was attacked and sunk by gunfire while TINOSA was en-
              route home. Attacks were executed with aggressiveness and skill and
              resulted in severe losses to the enemy.

              2.      It is noted that the AK attacked on 4 May was making
              180 rpm for a speed of 6.5 knots. This is such a marked change from
              the usual speed - rpm characteristics of merchant vessels, that it
              may possibly indicate a shortage of standard marine engines and re-
              duction gears. It is believed that only a small reciprocating engine
              without reduction gears could give such an uneconomical combination.

              3.      The Commanding Officer reported that the night
              following the attack on the second convoy a radio broadcast from
              Tokyo was heard to state that U.S. submarines were operating in wolf
              packs. With the enemy aware of wolf pack operations our forces
              should be alert for new counter measures. It is believed we should
              intensify the study of our present doctrine and be ready to insti-
              tute changes which may be necessary to nullify new counter measures
              by the enemy.

              4.      Attacks.

                      Attack Number 1. assisted by a contact report from BANG,
              TINOSA made daylight smoke contact with an eleven ship convoy. A
              tracking and end around run placed both PARCHE and TINOSA ahead.
              PARCHE took position for attack on port flank and TINOSA for attack
              on starboard side. Following attack by PARCHE the ships zigged
              toward TINOSA and she found herself with a most beautiful set-up.

                                          - 1 -
                                                                                    [HANDWRITTEN: 35]

— page 252 —
- 2 - [HANDWRITTEN: 36]

SUBMARINE DIVISION 142

FB5-142/A16-3
Serial 024

CONFIDENTIAL
FIRST ENDORSEMENT to
USS TINOSA. Report of
Sixth War Patrol.

Subject: U.S.S. TINOSA - Report of Sixth War Patrol; Comments
on.

— page 253 —
- 3 -

SUBMARINE DIVISION 142

FB5-142/A16-3
Serial 024

CONFIDENTL.L
FIRST ENDORSEMENT to
USS TINOSA. Report of
Sixth War Patrol.

Subject: U.S.S. TINOSA - Report of Sixth War Patrol; Comments
on.

— page 254 —
SUBMARINE DIVISION 142
                                                                Care of Fleet Post Office,
                                                                San Francisco, California,
                                                                16 May 1944.

FB5-142/A16-3

Serial 024

CONFIDENTIAL
FIRST ENDORSEMENT to
USS TINOSA. Report of
Sixth War Patrol.

Subject:        U.S.S. TINOSA - Report of Sixth War Patrol; Comments
                on.

                                DAMAGED

1 AK (similar to ANZAN MARU)                                    5493 tons
1 AO (similar to SYOYO MARU)                                    7499 tons
1 AK (unidentified)                                             6000 tons
1 AK (unidentified)                                             6000 tons
                                TOTAL                           24,992 tons

                                GRAND TOTAL                     50,636 tons

7.      The Commanding Officer, officers and crew are most
heartily congratulated on this aggressive, outstanding and successful
patrol.

                                                                [SIGNATURE: W. D. Wilkin]
                                                                W. D. WILKIN.

Copy to:
CO TINOSA.

[HANDWRITTEN: 38]

— page 255 —
COMMANDER SUBMARINE SQUADRON FOURTEEN

FC5-14/A16-3                                                c/o Fleet Post Office;
Serial 054.                                                 San Francisco, Calif.,
                                                            17 May 1944.

CONFIDENTIAL
SECOND ENDORSEMENT to
USS TINOSA Report of
Sixth War Patrol.

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

Subject:     U.S.S. TINOSA - Report of Sixth War Patrol;
             Comments on.

             1.    Forwarded, concurring in the remarks of the
Commander Submarine Division One Hundred Forty-Two.

             2.    The Squadron Commander is not in agreement
with paragraph 3, under section XVIII, Remarks, submitted by the
Commanding Officer. Rather than being considered a penalty for
efficient operation, maintenance and repair of the ship, a defer-
ment of the overhaul is an expression of confidence in that pers-
onnel. No submarine is sent on patrol in doubtful material
condition. That Tinosa will be ready for her seventh patrol
without overhaul is a source of pride to the Squadron Commander.
It reflects the pride of the ship's company in their ship.

             3.    In view of the number of uncompleted alterations
outstanding, it is recommended that Tinosa be overhauled after
her next, the seventh, patrol.

             4.    The Commanding Officer, officers and crew of the
Tinosa are congratulated on an excellent patrol which has severely
hurt the enemy.

                                                            J. B. LONGSTAFF.

Copy to:
     Comsubdiv 142
     CO TINOSA

[HANDWRITTEN: 39]

— page 256 —
[HANDWRITTEN: F4253 mr]

FF12-10/A16-3(15)/(16) SUBMARINE FORCE, PACIFIC FLEET
Serial 01037 Care of Fleet Post Office,
San Francisco, California,
27 May 1944

CONFIDENTIAL NOTE: THIS REPORT WILL BE
DESTROYED PRIOR TO
THIRD ENDORSEMENT to ENTERING PATROL AREA.
TINOSA Report of
Sixth War Patrol.

6 01562

COMSUBSPAC PATROL REPORT NO. 427
U.S.S. TINOSA - 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. TINOSA (SS283) - Report of Sixth War Patrol.
(29 March to 15 May 1944).

1. The sixth war patrol of the TINOSA was conducted in the
Luzon Straits Area. The TINOSA was one of three submarines forming a
coordinated attack group.

2. The TINOSA made five aggressive and successful torpedo
attacks on the two large convoys contacted. In addition, a successful
gun attack was made on a damaged trawler. The series of attacks made
on the night of 3-4 May were particularly aggressive and successful.
Complete results of this series of attacks are unknown because the
TINOSA was forced deep by anti-submarine vessels.

3. It is noted that the TINOSA witnessed the sinking of a
freighter previously damaged by the U.S.S. PARCHE (SS384).

4. This patrol is designated as successful for Combat In-
signia Award.

5. The Commander Submarine Force, Pacific Fleet, congratu-
lates the Commanding Officer, officers, and crew for this aggressive
and successful war patrol. This is the sixth successive successful
war patrol for the TINOSA. The TINOSA is credited with having in-
flicted the following damage upon the enemy:

S U N K

1 - Freighter (KAZAN MARU class) - 5,500 tons (Attack No. 1)
1 - Tanker (NISYO MARU class) - 10,500 tons (Attack No. 2)
1 - Freighter (AFRICA MARU class) - 9,500 tons (Attack No. 3)
1 - Trawler - 150 tons (Gun Attack No. 1)

TOTAL 25,650 tons

[STAMP: FILMED] - 1 - [HANDWRITTEN: 40]
[HANDWRITTEN: Tra]
[HANDWRITTEN: Sory]

— page 257 —
FF12-10/A16-3(15)/(16)
Serial 01037

CONFIDENTIAL

THIRD ENDORSEMENT to
TINOSA Report of
Sixth War Patrol,

COMSUBSPAC PATROL REPORT NO. 427
U.S.S. TINOSA - SIXTH WAR PATROL.

Subject: U.S.S. TINOSA (SS283) - Report of Sixth War Patrol.
(29 March to 15 May 1944).

— page 258 —
DECLASSIFIED - DOD DIR 5200.9
of 27 Sep 58
BY [HANDWRITTEN: 9ZC] DATE [HANDWRITTEN: 4/28/71]

U.S.S. TINOSA (SS283)

SS283/A16-3
Fleet Post Office,
San Francisco, California,
Serial: 011
30 July 1944.

DECLASSIFIED [HANDWRITTEN: I-A-L]

From: The Commanding Officer.
To: The Commander-in-Chief, U.S. FLEET.
Via: (1) Commander Submarine Division FORTY-FOUR.
(2) Commander Submarine Squadron FOUR.
(3) Commander Submarine Force, PACIFIC FLEET.
(4) Commander-in-Chief, U.S. PACIFIC FLEET.

Subject: U.S.S. TINOSA (SS283) - Report of SEVENTH
War Patrol.

Enclosures: (A) Subject report.
(B) Track charts of patrol in area 9.

1. Enclosures (A) and (B), covering the SEVENTH
War Patrol of this vessel conducted in East China Sea (Area 9)
during the period 7 June 1944 to 30 July 1944, are forwarded
herewith.

/S/ D. F. WEISS.

[HANDWRITTEN: FILMED]
[HANDWRITTEN: 84975]

— page 259 —
CONFIDENTIAL
                                                                                                1
U.S.S. TINOSA (SS283) - Report of Seventh War Patrol
Period from 7 June 1944 to

(A) PROLOGUE:

Arrived Majuro on 15 May 1944 from sixth war patrol
for refit by U.S.S. BUSHNELL.
Installed:
(1) Blow and vent line from safety to control room.
(2) Mk. 108 demolition outfit.
(3) New 2MC.
Refit completed 29 May 1944. Conducted 3 day
training period. Did not fire torpedoes.
Readiness for sea 7 June 1944.
Camouflage No. 32/3SS-B

(B) NARRATIVE:

7 June 1944
1312(L) Departed Majuro with DE19 as escort.

1719(L) Made trim dive.

1726(L) Surfaced.

8 June 1944
0451(L) Escort departed.

9 - 12
June 1944 Enroute patrol area, holding daily dives and drills.

13 June 1944
0942(K) Sighted plane bearing 321°(T) distance 10 mi.
         Identified as "Emily". Aircraft Contact #1
         Lat. 29°-36' N
         Long. 151°-26' E.

1122(K) Sighted plane bearing 250°(T) coming in (unidenti-
         fied) Submerged. Aircraft contact #2
         Lat. 29°-34' N
         Long. 150°-57' E.

1245(K) Surfaced.

14 June 1944
1030(K) Sighted ship bearing 305°(T) distance 12,000
         (unidentified - believed to be submarine).

1035(K) Submerged on course 310°(T) and commenced approach.
         Did not sight target again. Ship contact #1.
         Lat. 29°-34' N
         Long. 145°-09' E

                                                                -1-
                                                                ENCLOSURE (A)

— page 273 —
CONFIDENTIAL
Subject: U.S.S. TINOSA (SS283) - Report of Seventh War Patrol.

3 July 1944
0040(I) Noted radar interference on SJ in direction of
        Kyobun To.

0150(I) Heard distant explosion to Northward.

0518(I) Dove 25 miles North of Danjo Gunto for submerged
        patrol.

1105(I) Sighted a convoy of eleven small trawlers bearing
        110°T, distance 8 miles. Ship contact #13
        Lat. 32°-24' N
        Long. 128°-34' E.
        Was tempted to attack them with gun fire but considered
        it best not to give away our location. Had a feeling
        something bigger should be on the way.

2003(I) Surfaced.

2051(I) Received SJ indication on 050°(T), distance 4 miles.
        The moon was high and bright but we could not see
        our contact. At

2100(I) Lost indication.

2111(I) Another indication on the SJ bearing 130°(T), distance
        9 miles. The FPI appeared to have several indications
        on this bearing. Ship contact #14
        Lat. 32°-10' N
        Long. 128°-50' E.
        Turned towards contact to investigate and when range
        decreased to 12,000 yards sighted several ships from
        the bridge in the bright moonlight. Commenced track-
        ing, using TBT bearings and radar ranges. One ship
        was smoking heavily making a good tracking target. At

2133(I) Could make out five ships of a convoy on base course
        approximately, 000°(T), speed 8.5 knots. Ships were
        in three column formation.

2135(I) Had an indication on radar at 5,000 yards in direction
        of convoy. Believed this was an escort running about
        6 to 8, thousand yards ahead of the convoy. At

2216(I) ith range at 12,000 yards went to radar depth and
        headed for convoy at 4 knots to close range rapidly.
        At 7200 yards convoy was clearly in sight so went to
        periscope depth. Still tracking leading ship which

-15- ENCLOSURE (A)

— page 274 —
The provided image is a page from a document. I will transcribe the text on this page, distinguishing between typed and handwritten text.

**CONFIDENTIAL**

Subject: U.S.S. TINOSA (SS283) - Report of Seventh War Patrol.