Balao-class submarine

TheBalaoclasswas a design ofUnited States Navysubmarineused duringWorld War II, and with 120boats completed, the largest class of submarines in the United States Navy. An improvement on the earlierGatoclass, the boats had slight internal differences. The most significant improvement was the use of thicker, higheryield strengthsteel in thepressure hullskins and frames,which increased theirtest depthto 400 feet (120 m).Tangactually achieved a depth of 612 ft (187 m) during a test dive,and exceeded that test depth when taking on water in the forward torpedo room while evading a destroyer.
TheBalaos were similar to theGatos, except they were modified to increase test depth from 300 ft (90 m) to 400 ft (120 m). In late 1941, two of the Navy's leading submarine designers, CaptainAndrew McKeeand Commander Armand Morgan, met to explore increasing diving depth in a redesignedGato. A switch to a newHigh-TensileSteel (HTS) alloy, combined with an increase in hull thickness from9⁄16inch (14.3 mm) to7⁄8inch (22.2 mm), would result in a test depth of 450 ft (140 m) and a collapse depth of 900 ft (270 m). However, the limited capacity of the trim pump at deep depths, and lack of time to design a new pump, caused Rear Admiral E. L. Cochrane, Chief of theBureau of Ships, to limit test depth to 400 ft (120 m). Fortunately, in 1944 a redesigned Gould centrifugal pump replaced the noisy early-war pump, and effective diving depth was increased.
TheBalaos incorporated thefairwater,conning towerand periscope shears reduction efforts that were being retrofitted to theGatos and the preceding classes in the original design, refining the reductions and reducing the sail to the smallest practical size. By the time the boats began to be launched, lessons learned from patrol reports had been worked into the design and the bridge and sail proved to be efficiently laid out, well equipped, and well liked by the crews.
For the masts and periscope shears, the original arrangement for both the Government and Electric Boat designs had (forward to aft) the two tapered cone shaped periscope support shears, followed by a thin mast for the SJ surface search radar, and then by a thin mast for the SD air search radar. There were minor differences in how the periscopes were braced against vibration, but both designs were nearly identical. About halfway through their production run, Electric Boat altered their design, moving the SJ radar mast forward of the periscopes, then altered it again a few boats later by enlarging the SD radar mast. Late in the war, manyBalaos built with the original design had the SD air search radar moved slightly aft onto a thickened and taller mast. These mast arrangements, along with the tremendous variation in the gun layout as the war progressed account for the numerous exterior detail differences among the boats, to the point that at any given time no twoBalaos looked exactly alike.
The propulsion of theBalao-class submarines was generally similar to that of the precedingGato-class. Like their predecessors, they were truediesel-electricsubmarines: their fourdiesel enginespoweredelectrical generators, andelectric motorsdrove the shafts. There was no direct connection between the main engines and the shafts.
Balao-class submarines received main engines from one of two manufacturers.General MotorsCleveland Model16-278A V-type diesels orFairbanks-Morse38D 8-1/8nine-cylinderopposed-piston engine. TheGeneral MotorsCleveland Model16-248 V-type as original installations, while boats fromSand Lanceonward received 10-cylinder engines. Earlier General Motors boats received Model 16-248 engines, but beginning withPerchModel 16-278A engines were used. In each case, the newer engines had greaterdisplacementthan the old, but were rated at the same power; they operated at lowermean effective pressurefor greater reliability.Both the Fairbanks-Morse and General Motors engines weretwo-stroke cycletypes.
Two submarines,UnicornandVendace, were to receiveHooven-Owens-Rentschler(H.O.R.) diesels, which proved unreliable on previous classes, but both boats were cancelled.
Two manufacturers supplied electric motors for theBalaoclass.Elliott Companymotors were fitted primarily to boats with Fairbanks-Morse engines.General Electricmotors were fitted primarily to boats with General Motors engines, but some Fairbanks-Morse boats received General Electric motors.Allis-Chalmersmotors were to be used in SS-530 through SS-536, but those seven boats were cancelled before even receiving names.
Earlier submarines carried four high-speedelectric motors(two per shaft), which had to be fitted with reduction gears to slow their outputs down to an appropriate speed for the shafts. This reduction gearing was very noisy, and made the submarine easier to detect withhydrophones. Eighteen lateBalao-class submarines received low-speed doublearmaturemotors which drove the shafts directly and were much quieter, but this improvement was not universally fitted until the succeedingTenchclass.The newdirect driveelectric motors were designed by theBureau of Ships' electrical division under CaptainHyman G. Rickover, and were first equipped onSea Owl.On all US World War II-built boats, as the diesel engines were not directly connected to the shafts, the electric motors drove the shafts all the time.
Many targets in thePacific Warweresampansor otherwise not worth a torpedo, so thedeck gunwas an important weapon. EarlyBalaos began their service with a4-inch (102 mm)/50 caliber Mk. 9 gun. Due to war experience, most were re-armed with a5-inch (127 mm)/25 caliber Mk. 17 gun, similar to mounts on battleships and cruisers but built as a "wet" mount with corrosion resistant materials, and with power-operated loading and aiming features removed. This conversion started in late 1943, and some boats had two of these weapons beginning in late 1944.Spadefish, commissioned in March 1944, was the first newly built submarine with the purpose-built 5-inch (130 mm)/25 submarine mount. Additionalanti-aircraftguns included single40 mm Boforsand twin20 mm Oerlikonmounts, usually one of each.
Like the previousTambor/GarandGatoclasses, theBalaoclass could substitute mines in place of torpedoes. For the Mk 10 and Mk 12 type mines used in World War II, each torpedo could be replaced by as many as two mines, giving the submarine a true maximum capacity of 48 mines. However, doctrine was to retain at least four torpedoes on mine laying missions, which further limits the capacity to 40 mines, and this is often stated as the maximum in various publications. In practice during the war, submarines went out with at least 8 torpedoes, and the largest minefields laid were 32 mines. Post-war, the Mk 49 mine replaced the Mk 12, while the larger Mk 27 mine was also carried which only allowed one mine replacing one torpedo.
This was the most numerous US submarine class; 120 of these boats were commissioned from February 1943 through September 1948, with 12 commissioned postwar. Nine of the 52 US submarines lost in World War II were of this class, along with five lost postwar, including one in Turkish service in 1953, one in Argentine service in theFalklands Warof 1982, and one in Peruvian service in 1988.Also,Lancetfishflooded and sank while fitting out at theBoston Naval Shipyardon 15 March 1945. She was raised but not repaired, and was listed with thereserve fleetpostwar until struck in 1958. Some of the class served actively in the US Navy through the middle 1970s, and one (Hai Paoex-Tusk) is still active in Taiwan'sRepublic of China Navy.
SS-361 through SS-364 were initially ordered asBalao-class, and were assigned hull numbers that fall in the middle of the range of numbers for theBalaoclass (SS-285 to SS-416 & 425–426).Thus, in some references they are listed with that class.However, they were completed byManitowocasGatos, due to an unavoidable delay inElectric Boat's development ofBalao-class drawings. Manitowoc was a follow yard to Electric Boat, and was dependent on them for designs and drawings.Also,USSTrumpetfish(SS-425)andUSSTusk(SS-426)are listed with theTenchclass in some references, as their hull numbers fall in the range of that class.
A total of 125 U.S. submarines were cancelled during World War II, all but three between 29 July 1944 and 12 August 1945. The exceptions were threeTench-class boats, cancelled 7 January 1946. References vary considerably as to how many of these wereBalaos and how many wereTenches. Some references simply assume all submarines numbered after SS-416 wereTenchclass; however,Trumpetfish(SS-425)andTusk(SS-426)were completed asBalaos.This yields 10 cancelledBalao-class, SS-353-360 and 379–380. TheRegister of Ships of the U. S. Navydiffers, considering every submarine not specifically ordered as aTenchto be aBalao, and further projecting SS-551-562 as a future class.This yields 62 cancelledBalaoclass, 51 cancelledTenchclass, and 12 cancelled future class. Two of the cancelledBalao-class submarines,Turbot(SS-427)andUlua(SS-428), were launched incomplete and served for years as experimental hulks atAnnapolisandNorfolk, Virginia. The cancelled hull numbers, including those launched incomplete, were SS-353–360 (Balao), 379–380 (Balao), 427–434 (Balao), 436–437 (Tench), 438–474 (Balao), 491–521 (Tench), 526–529 (Tench), 530–536 (Balao), 537–550 (Tench), and 551–562 (future).
TheBalaos began to enter service in mid-1943, as the many problems with theMark 14 torpedowere being solved. They were instrumental in the Submarine Force's near-destruction of theJapanesemerchant fleet and significant attrition of theImperial Japanese Navy. One of the class,Archerfish, brought down what remains the largest warship sunk by a submarine, theShinano(59,000 tons).Tang, the highest-scoring of the class, sank 33 ships totaling 116,454 tons, as officially revised upward in 1980.
NineBalaos were lost in World War II, while two US boats were lost in postwar accidents. In foreign service, one in Turkish service was lost in a collision in 1953, one in Peruvian service was lost in a collision in 1988, andCatfishwas sold to the Argentinian Navy. She was renamed the ARASanta Fe(S-21) and was lost in the 1982Falklands Warafter being damaged, when she sank while moored pierside.Santa Fewas refloated and disposed of a few years after the war by being taken out to deep water and scuttled.
Additionally,Lancetfish, commissioned but incomplete and still under construction, flooded and sank pierside at theBoston Navy Yardon 15 March 1945, after a yard worker mistakenly opened the inner door of an afttorpedo tubethat already had the outer door open. No personnel were lost in the accident and she was raised, decommissioned, and never completed or repaired.Her 42 days in commission is the record for the shortest commissioned service of any USN submarine. Postwar, she was laid up in theReserve Fleetuntil stricken in 1958 and scrapped in 1959.
Postwar, 55Balaos were modernized under the Fleet Snorkel and Greater Underwater Propulsion Power (GUPPY) programs, with some continuing in US service into the early 1970s. The lastBalao-class submarine in United States service wasUSSClamagore(SS-343), which was decommissioned in June 1975.Seven were converted to roles as diverse as guided-missile submarines (SSG) and amphibious transport submarines (SSP). 46 were transferred to foreign navies for years of additional service, some into the 1990s, andTuskremains active inTaiwan'sRepublic of China NavyasHai Pao.
Interested in maintaining a ready pool of trainedreservists, the Navy assigned at least 58 submarines from 1946 to 1971 to various coastal and inland ports (even inGreat Lakesports likeCleveland,Chicago, andDetroit), where they served as training platforms during the Reservists' weekend drills. At least 20Balao-class boats served in this capacity. In this role, the boats were rendered incapable of diving and had their propellers removed. They were used strictly as pierside trainers. These were in commission but classed as "in service in reserve", thus some were decommissioned and recommissioned on the same day to reflect the change in status.
The large numbers of relatively modern, but surplus U.S. fleet submarines proved to be popular in sales, loans, or leases to allied foreign navies. 46Balao-class submarines were transferred to foreign navies, some shortly after World War II, others after serving nearly 30 years in the US Navy. These included 17 to Turkey, 2 to Greece, 3 to Italy, 2 to the Netherlands, 5 to Spain, 2 to Venezuela, 4 to Argentina, 5 to Brazil, 2 to Chile, 2 to Peru, 1 to Canada and 1 to Taiwan.One of the Venezuelan boats,ARV Carite(S-11) formerlyUSSTilefish(SS-307), featured in the 1971 filmMurphy's Warwith some cosmetic modification.
At the end ofWorld War II, the US submarine force found itself in an awkward position. The 111 remainingBalao-class submarines, designed to fight an enemy that no longer existed, were obsolete despite the fact they were only one to three years old. TheGermanType XXI U-boat, with a large battery capacity, streamlining to maximize underwater speed, and a snorkel, was the submarine of the immediate future. TheGreater Underwater Propulsion Power Program(GUPPY) conversion program was developed to give someBalao- andTench-class submarines similar capabilities to the Type XXI. When the cost of upgrading numerous submarines to GUPPY standard became apparent, the austere "Fleet Snorkel" conversion was developed to add snorkels and partial streamlining to some boats. A total of 36Balao-class submarines were converted to one of the GUPPY configurations, with 19 additional boats receiving Fleet Snorkel modifications. Two of the GUPPY boats and six of the Fleet Snorkel boats were converted immediately prior to transfer to a foreign navy. Most of the 47 remaining converted submarines were active into the early 1970s, when many were transferred to foreign navies for further service and others were decommissioned and disposed of.
Although there was some variation in the GUPPY conversion programs, generally the original two Sargo batteries were replaced by four more compact Guppy (GUPPY I and II only) or Sargo II batteries via significant re-utilization of below-deck space, usually including removal of auxiliary diesels. All of these battery designs were of thelead-acid type. This increased the total number of battery cells from 252 to 504; the downside was the compact batteries had to be replaced every 18 months instead of every 5 years. The Sargo II battery was developed as a lower-cost alternative to the expensive Guppy battery.All GUPPYs received a snorkel, with a streamlined sail and bow. Also, the electric motors were upgraded to thedirect drivedouble-armaturetype, along with modernized electrical and air conditioning systems. All except the austere GUPPY IB conversions for foreign transfer received sonar,fire control, andElectronic Support Measures(ESM) upgrades.
The Fleet Snorkel program was much more austere than the GUPPY modernizations, but is included here as it occurred during the GUPPY era. The GUPPY and Fleet Snorkel programs are listed in chronological order: GUPPY I, GUPPY II, GUPPY IA, Fleet Snorkel, GUPPY IIA, GUPPY IB, and GUPPY III.
TwoTench-class boats were converted as prototypes for the GUPPY program in 1947. Their configuration lacked a snorkel and was not repeated, so noBalaosreceived this conversion.
This was the first production GUPPY conversion, with most conversions occurring in 1947–49. ThirteenBalao-class boats (Catfish,Clamagore,Cobbler,Cochino,Corporal,Cubera,Diodon,Dogfish,Greenfish,Halfbeak,Tiru,Trumpetfish, andTusk) received GUPPY II upgrades. This was the only production conversion with Guppy batteries.
This was developed as a more cost-effective alternative to GUPPY II. NineBalao-class boats (Atule,Becuna,Blackfin,Blenny,Caiman,Chivo,Chopper,Sea Poacher, andSea Robin) were converted in 1951–52. The less expensive Sargo II battery was introduced, along with other cost-saving measures.
The Fleet Snorkel program was developed as an austere, cost-effective alternative to full GUPPY conversions, with significantly less improvement in submerged performance. Twenty-threeBalao-class boats (Bergall,Besugo,Brill,Bugara,Carbonero,Carp,Charr,Chub,Cusk,Guitarro,Kraken,Lizardfish,Mapiro,Mero,Piper,Sabalo,Sablefish,Scabbardfish,Sea Cat,Sea Owl,Segundo,Sennet, andSterlet) received this upgrade, six immediately prior to foreign transfer. Most Fleet Snorkel conversions occurred 1951–52. Unlike the GUPPY conversions, the original pair of Sargo batteries were not upgraded. Each boat received a streamlined sail with a snorkel, along with upgraded sonar, air conditioning, and ESM. The original bow was left in place, except on three boats (Piper,Sea Owl, andSterlet) that received additional upper bow sonar equipment.A few boats initially retained the 5"/25 deck gun, but this was removed in the early 1950s.
This was generally similar to GUPPY IA, except one of the forward diesel engines was removed to relieve machinery overcrowding. ThirteenBalao-class boats (Bang,Diodon,Entemedor,Hardhead,Jallao,Menhaden,Picuda,Pomfret,Razorback,Ronquil,Sea Fox,Stickleback, andThreadfin) received GUPPY IIA upgrades in 1952–54. One of these,Diodon, had previously been upgraded to GUPPY II.
This was developed as an austere upgrade for twoGato-class and twoBalao-class boats (HawkbillandIcefish) prior to transfer to foreign navies in 1953–55. They lacked the sonar and electronics upgrades of other GUPPY conversions.
Nine submarines, six of themBalaos (Clamagore,Cobbler,Corporal,Greenfish,Tiru, andTrumpetfish), were upgraded from GUPPY II to GUPPY III in 1959-63 as part of theFleet Rehabilitation and ModernizationII (FRAM II) program. All exceptTiru, the pilot conversion, were lengthened by 15 feet in the forward part of the control room to provide a new sonar space, berthing, electronics space, and storerooms.Tiruwas lengthened only 12.5 feet, and both forward diesel engines were removed.The other GUPPY IIIs retained all four engines. A taller "Northern" sail was included, to allow improved surfaced operations in rough seas; this was also backfitted to some other GUPPYs. The BQG-4Passive Underwater Fire Control Feasibility Study(PUFFS) sonar system, with its three tall domes topside, was fitted. Additionally, fire control upgrades allowed theMark 45 nuclear torpedoto be used.
The advent of thekamikazedemonstrated the need for a long range radar umbrella around the fleet.Radar picketdestroyers and destroyer escorts were put into service, but they proved vulnerable in this role as they could be attacked as well, leaving the fleet blind. A submarine, though, could dive and escape aerial attack. Four submarines including theBalao-class boatThreadfinprototyped the concept at the end of World War II but were not used in this role.Ten fleet submarines were converted for this role 1946-53 and redesignated SSR as radar picket submarines.Burrfishwas the onlyBalao-class SSR. Experiments on the first two SSR submarines under the appropriately namedProject Migraine Ishowed that placement of the radars on the deck was inadequate and that more room was needed for electronics. ThusBurrfishwas given the Migraine II (projectSCB 12) conversion, which placed aCombat Information Center(CIC) in the space formerly occupied as the aft battery room. The after torpedo room was stripped and converted into berthing, and the boat lost two of her forward torpedo tubes to make room for additional berthing and electronics. The radars were raised up off the deck and put on masts, giving them a greater range and hopefully greater reliability.
The SSRs proved only moderately successful, as the radars themselves proved troublesome and somewhat unreliable, and the boats' surface speed was insufficient to protect a fast-moving carrier group. The radars were removed and the boats reverted to general purpose submarines after 1959.Burrfishwas decommissioned in 1956 and, with her radar equipment removed, transferred to Canada as HMCSGrilse(SS-71) in 1961.
TheRegulusnuclearcruise missileprogram of the 1950s provided the US Navy with its first strategic strike capability. It was preceded by experiments with theJB-2 Loon missile, a close derivative of theGermanV-1 flying bomb, beginning in the last year ofWorld War II. Submarine testing of Loon was performed 1947–53, withCuskandCarboneroconverted in toguided-missile submarinesas test platforms in 1947 and 1948 respectively. Initially the missile was carried on the launch rail unprotected, thus the submarine was unable to submerge until after launch.Cuskwas eventually fitted with a watertight hangar for one missile and redesignated as an SSG. Following a brief stint as a cargo submarine,Barberowas converted in 1955 to carry two surface-launched Regulus missiles and was redesignated as an SSG, joining theGato-classTunnyin this role. She madestrategic deterrent patrolswith Regulus until 1964, when the program was discontinued in favor ofPolaris.A number of fleet boats were equipped with Regulus guidance equipment 1953–64, includingCuskandCarbonerofollowing the Loon tests.
SealionandPerchwere converted to amphibious transport submarines in 1948 and redesignated as SSPs. Initially, they were equipped with a watertight hangar capable of housing aLanding Vehicle Tracked(LVT), and retained one 5-inch (130 mm)/25 caliber deck gun for shore bombardment. Both torpedo rooms and one engine room were gutted to provide space for embarkedSpecial Operations Forces(SOF) and their equipment. Snorkels were fitted. Due to the extra personnel, to avoid excessive snorkeling they were equipped with aCO2scrubberand extra oxygen storage. Initially, a squadron of 12 SSPs was considered, capable of landing a reinforced Marine battalion, but only twoBalao-class SSPs (out of four overall) were actually converted.PerchlandedBritish commandoson one raid in theKorean War, and operated in theVietnam Warfrom 1965 until assignment toNaval Reservetraining in 1967 and decommissioning in 1971, followed by scrapping in 1973.Perchwas replaced in the Pacific Fleet transport submarine role byTunnyin 1967 andGraybackin 1968.Sealionoperated in the Atlantic, deploying for theCuban Missile Crisisand numerous SOF-related exercises. She was decommissioned in 1970 and expended as a target in 1978. The LVT hangar and 5-inch (130 mm) gun were removed from both boats by the late 1950s. They went through several changes of designation in their careers: ASSP in 1950, APSS in 1956, and LPSS in 1968.
Bayawas redesignated as an auxiliary submarine (AGSS) in 1949 and converted to a sonar test submarine in 1958–59 to test a system known as LORAD. This included a 12-foot (3.7 m) extension aft of the forward torpedo room, with 40-foot (12 m) swing-out arrays near the bow. Later, three large domes were installed topside for a wide aperture array.
Barberowas converted to a cargo submarine and redesignated as anSSAin 1948. The forward engine room, after torpedo room, and all reload torpedo racks were gutted to provide cargo space. From October 1948 until March 1950, she took part in an experimental program to evaluate her capabilities as a cargo carrier. Experimentation ended in early 1950, and she was decommissioned into the reserve on 30 June 1950. In 1955, she was converted to a Regulus missile submarine and redesignated as an SSG.
As of 2007Tusk, aBalao-class submarine, was one of the last two operational submarines in the world built during World War II. The boat was transferred toTaiwan'sRepublic of China Navyin the early 1970s. TheTench-class ex-Cutlassis the other one. They are namedHai PaoandHai Shih, respectively, in Taiwanese service.
SixBalao-class submarines are open to public viewing. They primarily depend on revenue generated by visitors to keep them operational and up to U.S. Navy standards; each boat gets a yearly inspection and a "report card". Some boats, likeBatfishandPampanito, encourage youth functions and allow a group of volunteers to sleep overnight in the crew's quarters.
The following is a complete list ofBalao-class museum boats:
USSClamagore(SS-343)served as a museum boat atPatriots PointinCharleston, South Carolinauntil being closed in 2021 and scrapped two years later. Additionally theUSSLing(SS-297)is aground in the Hackensack River at the site of the formerNew Jersey Naval Museum. As of 2022, efforts to find a new home for this vessel have been unsuccessful.