Balao-class submarine

USS Balao
Class overview
Builders	Portsmouth Naval Shipyard, Cramp Shipbuilding Company, Mare Island Naval Shipyard, Electric Boat Company, Manitowoc Shipbuilding Company[1]
Operators	list error: <br /> list (help)  United States Navy  Italian Navy  Turkish Navy  Hellenic Navy  Peruvian Navy  Argentine Navy  Chilean Navy  Bolivarian Navy of Venezuela  Republic of China Navy  Royal Canadian Navy  Brazilian Navy  Royal Netherlands Navy  Spanish Navy
Preceded by	Gato class
Succeeded by	Tench class
Built	1942–1946[2]
In commission	1943–1975[2]
Completed	120[1]
Cancelled	70[1]
Active	1[1]
Lost	11[1]
Retired	109[1]
Preserved	8[1]
General characteristics
Type	Diesel-electric submarine
Displacement	1,526 tons (1,550 t) surfaced,[1] 2,391–2,424 tons (2,429–2463 t) submerged[1]
Length	311 ft 6 in–311 ft 10 in (94.9–95.0 m)[1]
Beam	27 ft 3 in–27 ft 4 in (8.3 m)[1]
Draft	16 ft 10 in (5.13 m) maximum[1]
Propulsion	list error: <br /> list (help) 4 × diesel engines driving electrical generators (Fairbanks-Morse or General Motors);[1] 2 × 126-cell Sargo batteries;[3] 4 × high-speed electric motors with reduction gears or 2 × low-speed electric motors (Elliott Company or General Electric)[1] two shafts;[1] 5,400 shp (4,000 kW) surfaced,[1] 2,740 shp (2,040 kW) submerged[1]
Speed	20.25 knots (38 km/h) surfaced,[3] 8.75 knots (16 km/h) submerged[3]
Range	11,000 nautical miles (20,000 km) surfaced @ 10 knots (19 km/h)[3]
Endurance	48 hours @ 2 knots (3.7 km/h) submerged,[3] 75 days on patrol
Test depth	400 ft (120 m)[3]
Complement	10 officers, 70–71 enlisted men[3]
Armament	10 × 21-inch (533 mm) torpedo tubes 6 forward, 4 aft 24 torpedoes[4] 1 × 5-inch (127 mm) / 25 caliber deck gun[4] Bofors 40 mm and Oerlikon 20 mm cannon

The Balao-class was a successful design of United States Navy submarine used during World War II, and with 120^[5] units completed, the largest class of submarines in the United States Navy. An improvement on the earlier Gato-class, the boats had slight internal differences. The most significant improvement was the use of thicker, higher yield strength steel in the pressure hull skins and frames,^[6] which increased their test depth to 400 feet (120 m). Tang actually achieved a depth of 612 ft (187 m) during a test dive,^[7] and exceeded that test depth when taking on water in the forward torpedo room while evading a destroyer.^[8][9]

The Balaos were similar to the Gatos, 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, Captain Andrew McKee and Commander Armand Morgan, met to explore increasing diving depth in a redesigned Gato. A switch to a new High-Tensile Steel (HTS) alloy, combined with an increase in hull thickness from 9/16 inch (14.3 mm) to 7/8 inch (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 the Bureau 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.^[10]

The propulsion of the Balao-class submarines was generally similar to that of the preceding Gato-class. Like their predecessors, they were true diesel-electric submarines: their four diesel engines powered electrical generators, and electric motors drove 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. Fairbanks-Morse supplied Model 38D8⅛ opposed piston engines, and General Motors' Cleveland Diesel division supplied Model 16-248 and 16-278A V16 engines. Earlier Fairbanks-Morse boats received a 9-cylinder version of the Model 38D8⅛, while boats from USS Sand Lance (SS-381) onward received 10-cylinder engines. Earlier GM boats received Model 16-248 engines, but beginning with USS Perch (SS-313) Model 16-278A engines were used. In each case, the newer engines had greater displacement than the old, but were rated at the same power; they operated at lower mean effective pressure for greater reliability. Both the F-M and GM engines were two-stroke cycle types.

Two submarines, USS Unicorn (SS-429) and USS Vendace (SS-430), were to receive Hooven-Owens-Rentschler (H.O.R.) diesels, which proved unreliable on previous classes, but both boats were cancelled.

Two manufacturers supplied electric motors for the Balao-class. Elliott Company motors were fitted primarily to boats with Fairbanks-Morse engines. General Electric motors were fitted primarily to boats with General Motors engines, but some Fairbanks-Morse boats received GE motors. Allis-Chalmers motors 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-speed electric 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 with hydrophones. Eighteen late Balao-class submarines received low-speed double armature motors which drove the shafts directly and were much quieter, but this improvement was not universally fitted until the succeeding Tench-class.^[11] The new direct drive electric motors were designed by the Bureau of Ships' electrical division under Captain Hyman G. Rickover, and were first equipped on Sea Owl.^[12] As the diesel engines were not directly connected to the shafts, the electric motors drove the shafts all the time.

Many targets in the Pacific War were sampans or otherwise not worth a torpedo, so the deck gun was an important weapon. Early Balaos began their service with a 3 inch (76 mm)/50 caliber gun or a 4 inch (102 mm)/50 caliber gun removed from old S-class submarines. Due to war experience, most were re-armed with a 5 inch (127 mm)/25 caliber gun (converted from mountings removed from battleships) from late 1943, and some boats later had two of these weapons. USS Spadefish (SS-411), commissioned in March 1944, was the first newly built submarine with the purpose-built 5 inch/25 submarine mount. Additional anti-aircraft guns included single 40 mm Bofors and twin 20 mm Oerlikon mounts, usually one of each.

The Balaos began to enter service in mid-1943, as the many problems with the Mark 14 torpedo were being solved. They were instrumental in the Submarine Force's near-destruction of the Japanese merchant fleet and significant attrition of the Imperial Japanese Navy. One of the class, USS Archer-Fish (SS-311), brought down what remains the largest warship sunk by a submarine, the Japanese aircraft carrier Shinano (59,000 tons). USS Tang (SS-306), the highest-scoring of the class, sank 33 ships totaling 116,454 tons, as officially revised upward in 1980.^[13]

It should be noted that SS-361-364 were completed by Manitowoc as Gatos, due to an unavoidable delay in Electric Boat's development of Balao-class drawings. Manitowoc was a follow yard to Electric Boat, and was dependent on them for designs and drawings.^[14]

Nine Balaos were lost in World War II, while two were lost in postwar accidents. Additionally, it should be noted that USS Lancetfish (SS-296) flooded and sank pierside at the Boston Navy Yard on 15 March 1945, about a month after commissioning but reportedly still incomplete. She was raised, decommissioned, and reportedly not completed or repaired.^[1][15][16] Postwar, she was listed as a Reserve Fleet submarine until stricken in 1958 and scrapped in 1959.

Name and hull number	Fate
USS Capelin (SS-289)	Lost December 1943, cause unknown, possibly naval mine or attack by minelayer Wakataka
USS Cisco (SS-290)	Lost to air attack and gunboat Karatsu (ex-USS Luzon) 28 September 1943
USS Escolar (SS-294)	Lost between 17 October and 13 November 1944, probably to enemy mine
USS Tang (SS-306)	Lost 25 October 1944 due to circular run of own torpedo
USS Shark (SS-314)	Lost 24 October 1944 to attack by Japanese destroyer Harukaze
USS Barbel (SS-316)	Lost to air attack 4 February 1945
USS Bullhead (SS-332)	Lost to air attack 6 August 1945
USS Cochino (SS-345)	Lost to accidental fire 26 August 1949
USS Kete (SS-369)	Lost March 1945, cause unknown, possibly to mine or enemy action
USS Lagarto (SS-371)	Lost 3 May 1945 to attack by Japanese minelayer Hatsutaka
USS Stickleback (SS-415)	Lost 28 May 1958 in collision with USS Silverstein (DE-534)

Postwar, 55 Balaos were modernized under the Fleet Snorkel and Greater Underwater Propulsion Power (GUPPY) programs, with some continuing in US service into the early 1970s.^[17] 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, and USS Tusk (SS-426) remains active in Taiwan's Republic of China Navy as the Hai Pao.

Interested in maintaining a ready pool of trained Reservists, the Navy assigned at least 58 submarines from 1946 to 1971 to various coastal and inland ports (even in Great Lakes ports like Cleveland, Detroit, and Chicago), where they served as training platforms during the Reservists' weekend drills. At least 20 Balao-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.^[18][19]

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. 46 Balao-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 (HMCS Grilse (SS-71)), and 1 to Taiwan.^[20]

At the end of World War II, the US submarine force found itself in an awkward position. The 111 remaining Balao-class submarines, designed to fight an enemy that no longer existed, were obsolescent despite the fact they were only one to three years old. The German Type XXI U-boat, with a large battery capacity, streamlining to maximize underwater speed, and a snorkel, was the submarine of the immediate future. The Greater Underwater Propulsion Power Program (GUPPY) conversion program was developed to give some Balao- and Tench-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 36 Balao-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.^[21]

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 the lead-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.^[22] All GUPPYs received a snorkel, with a streamlined sail and bow. Also, the electric motors were upgraded to the direct drive double-armature type, along with modernized electrical and air conditioning systems. All except the austere GUPPY IB conversions for foreign transfer received sonar, fire control, and Electronic Support Measures (ESM) upgrades.^[23]

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.

Two Tench-class boats, Odax and Pomodon, were converted as prototypes for the GUPPY program in 1947. Their configuration lacked a snorkel and was not repeated.

This was the first production GUPPY conversion, with most conversions occurring in 1947-49. Thirteen Balao-class boats 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. Nine Balao-class boats 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. Nineteen Balao-class boats received this upgrade, six immediately prior to foreign transfer. Most Fleet Snorkel conversions occurred 1951-52. Notably, the original pair of Sargo batteries was 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 that received additional upper bow sonar. A few boats initially retained a 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. Thirteen Balao-class boats 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 two Gato-class and two Balao-class boats prior to transfer to foreign navies in 1953-55. They lacked the sonar and electronics upgrades of other GUPPY conversions.

Nine submarines, six of them Balaos, were upgraded from GUPPY II to GUPPY III in 1959-63 as part of the Fleet Rehabilitation and Modernization II (FRAM II) program. All except Tiru, 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. Tiru was lengthened only 12.5 feet, and both forward diesel engines were removed.^[24] 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-4 Passive Underwater Fire control Feasibility Study (PUFFS) sonar system, with its three tall domes topside, was fitted. Additionally, fire control upgrades allowed the Mark 45 nuclear torpedo to be used.

The advent of the Kamikaze demonstrated the need for a long range radar umbrella around the fleet. Radar picket destroyers 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. Ten fleet submarines were converted for this role 1946-53 and redesignated SSR as radar picket submarines. USS Burrfish (SSR-312) was the only Balao-class SSR. They were lengthened by 24 feet to provide additional space for an air control center and had powerful air search and height finding radars installed, with the after torpedo room converted into an electronics space with torpedoes and tubes removed. They also received a streamlined "sail" in place of the traditional conning tower fairwater. The most extensive SSR conversion was the "Migraine III" configuration. Unfortunately, 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. Burrfish was decommissioned in 1956 and, with her radar equipment removed, transferred to Canada as HMCS Grilse (SS-71) in 1961.^[25]

The Regulus nuclear cruise missile program of the 1950s provided the US Navy with its first strategic strike capability. It was preceded by experiments with the JB-2 Loon missile, a close derivative of the German V-1 flying bomb, beginning in the last year of World War II. Submarine testing of Loon was performed 1947-53, with USS Cusk (SS-348) and USS Carbonero (SS-337) converted as 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. Cusk was eventually fitted with a watertight hangar for one missile. Following a brief stint as a cargo submarine, USS Barbero (SSG-317) was converted in 1955 to carry two surface-launched Regulus missiles and was redesignated as an SSG, joining the Gato-class Tunny in this role. She made strategic deterrent patrols with Regulus until 1964, when the program was discontinued in favor of Polaris.^[26] A number of fleet boats were equipped with Regulus guidance equipment 1953-64, including Cusk and Carbonero following the Loon tests.

USS Sealion (SS-315) and USS Perch (SS-313) were converted to amphibious transport submarines in 1948 and redesignated as SSPs. Initially, they were equipped with a watertight hangar capable of housing a Landing Vehicle Tracked (LVT), and retained one 5 inch (127 mm)/25 caliber deck gun for shore bombardment. Both torpedo rooms and one engine room were gutted to provide space for embarked Special Operations Forces (SOF) and their equipment. Snorkels were fitted. Due to the extra personnel, to avoid excessive snorkeling they were equipped with a CO2 scrubber and extra oxygen storage. Initially, a squadron of 12 SSPs was considered, capable of landing a reinforced Marine battalion, but only two SSPs were actually converted. Perch landed British commandos on one raid in the Korean War, and operated in the Vietnam War from 1965 until assignment to Naval Reserve training in 1967 and decommissioning in 1971, followed by scrapping in 1973. Perch was replaced in the Pacific Fleet transport submarine role by USS Tunny (LPSS-282) in 1967 and USS Grayback (LPSS-574) in 1968. Sealion operated in the Atlantic, deploying for the Cuban Missile Crisis and numerous SOF-related exercises. She was decommissioned in 1970 and expended as a target in 1978. The LVT hangar and 5" 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.^[27][1]

Baya was 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 extension aft of the forward torpedo room, with 40-foot swing-out arrays near the bow. Later, three large domes were installed topside for a wide aperture array.^[28]

USS Barbero (SSA-317) was converted to a cargo submarine and redesignated as an SSA in 1948. The forward engine room, after torpedo room, and all reload torpedo racks were gutted to provide cargo space. The experiment was short-lived, and she was decommissioned in 1950. In 1955, she was converted to a Regulus missile submarine and redesignated as an SSG.^[29]

As of 2007 USS Tusk (SS-426), a Balao-class submarine, was one of the last two operational submarines in the world built during World War II. It was transferred to Taiwan's Republic of China Navy in the early 1970s. The Tench-class ex-USS Cutlass (SS-478) is the other one. They are named Hai Pao and Hai Shih, respectively, in Taiwanese service.^[30][31]

A total of 125 US submarines were cancelled during World War II between 29 July 1944 and 12 August 1945. References vary considerably as to how many of these were Balaos and how many were Tenches. Some references simply assume all submarines numbered after SS-416 were Tench-class; however, USS Trumpetfish (SS-425) and USS Tusk (SS-426) were completed as Balaos.^[32][33] This yields 10 cancelled Balao-class, SS-353-360 and 379-380. The Register of Ships of the U. S. Navy differs, considering every submarine not specifically ordered as a Tench to be a Balao, and further projecting SS-551-562 as a future class.^[1] This yields 70 cancelled Balao-class, 43 cancelled Tench-class, and 12 cancelled future class. Two of the cancelled Balao-class submarines, Turbot and Ulua, were launched incomplete and served for years as experimental hulks at Annapolis and Portsmouth Navy Yard. Two of the cancelled Tench-class boats, Unicorn and Walrus, were also launched incomplete, never commissioned, but listed with the Reserve fleet until scrapped in 1958. The cancelled hull numbers were SS-353-360, 379-380, 427-434, 436-437, 438-474, 491-521, and 526-562.

A scale model GUPPY-type submarine numbered "509" was used in several movie and television productions in the 1960s through 1980s, including the movie "Firefox".

Eight Balao-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, like Batfish and Pampanito, encourage youth functions and allow a group of volunteers to sleep overnight in the crew's quarters. The following is a complete list of Balao-class museum boats:

• USS Batfish (SS-310) at War Memorial Park in Muskogee, Oklahoma
• USS Becuna (SS-319) at Independence Seaport Museum in Philadelphia, Pennsylvania
• USS Bowfin (SS-287) at USS Bowfin Submarine Museum & Park in Honolulu, Hawaii
• USS Clamagore (SS-343) at Patriot's Point in Mount Pleasant, South Carolina
• USS Ling (SS-297) at New Jersey Naval Museum in Hackensack, New Jersey
• USS Lionfish (SS-298) at Battleship Cove in Fall River, Massachusetts
• USS Pampanito (SS-383) at San Francisco Maritime National Historical Park in San Francisco, California, which played the part of the fictional Balao-class USS Stingray in Down Periscope
• USS Razorback (SS-394) at Arkansas Inland Maritime Museum in North Little Rock, Arkansas

• List of lost United States submarines

• Friedman, Norman (1995). U.S. Submarines Through 1945: An Illustrated Design History. Annapolis, Maryland: United States Naval Institute. ISBN 1-55750-263-3.
• Friedman, Norman (1994). U.S. Submarines Since 1945: An Illustrated Design History. Annapolis, Maryland: United States Naval Institute. ISBN 1-55750-260-9.
• Lenton, H.T. American Submarines. New York: Doubleday, 1973.
• Silverstone, Paul H., U.S. Warships of World War II, Ian Allan, 1965, ISBN 0-87021-773-9.
• Gardiner, Robert and Chesneau, Roger, Conway's all the world's fighting ships 1922-1946, Conway Maritime Press, 1980. ISBN 0-83170-303-2.
• O'Kane, Richard H., Clear the Bridge!: The War Patrols of the U.S.S. Tang, 1989 edition, Presidio Press, 1989, ISBN 978-0-89141-346-2. Different pagination than 1977 edition.

• Fleet Type Submarine Training Manual San Francisco Maritime Museum
• GUPPY and other diesel boat conversions page
• Navsource.org fleet submarines photo index page
• http://www.fleetsubmarine.com/sublist.html
• DiGiulian, Tony Navweaps.com later 3"/50 caliber gun
• DiGiulian, Tony Navweaps.com 4"/50 caliber gun
• DiGiulian, Tony Navweaps.com 5"/25 caliber gun