Balao-class submarine

The Balao-class was a successful design of United States Navy submarine used during World War II, and with 120 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, which increased their test depth to 400 feet (120 m). Tang actually 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.

Balao-class submarine
Class Ship
Type Submarine
Manufacturer HMNB Portsmouth
Origin United States of America
Country Name Origin Year
United States of America 1943
Country Name Operational Year Retirement Year
Argentina 1943 1975 View
Bolivia 1943 1975 View
Brazil 1943 1975 View
Canada 1943 1975 View
Chile 1943 1975 View
China 1943 1975 View
Greece 1943 1975 View
Italy 1943 1975 View
Netherlands 1943 1975 View
Peru 1943 1975 View
Spain 1943 1975 View
Turkey (Ottoman Empire) 1943 1975 View
United States of America 1943 1975 View
ManufacturerName Production From Production To Quantity
HMNB Portsmouth View
William Cramp & Sons View
Mare Island Naval Shipyard View
General Dynamics Electric Boat View
Manitowoc Shipbuilding Company View

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.

The Balaos incorporated the conning tower fairwater and periscope shears reduction efforts that were being retrofitted to the Gatos and the preceding classes in the original design, refining the reductions and reducing the fairwater to the smallest practical size. By the time the boats began to slide down the ways, lessons learned from patrol reports had been worked into the design and the bridge and fairwater 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, many Balaos 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 two Balaos looked exactly alike.

Ships in Class

  • USS Tiru (SS-416)
  • USS Stickleback (SS-415)
  • USS Springer (SS-414)
  • USS Spot (SS-413)
  • USS Trepang (SS-412)
  • USS Spadefish (SS-411)
  • USS Threadfin (SS-410)
  • USS Piper (SS-409)
  • USS Sennet (SS-408)
  • USS Sea Robin (SS-407)
  • USS Sea Poacher (SS-406)
  • USS Sea Owl (SS-405)
  • USS Spikefish (SS-404)
  • USS Atule (SS-403)
  • USS Sea Fox (SS-402)
  • USS Sea Dog (SS-401)
  • USS Sea Devil (SS-400)
  • USS Sea Cat (SS-399)
  • USS Segundo (SS-398)
  • USS Scabbardfish (SS-397)
  • USS Ronquil (SS-396)
  • USS Redfish (SS-395)
  • USS Razorback (SS-394)
  • USS Queenfish (SS-393)
  • USS Sterlet (SS-392)
  • USS Pomfret (SS-391)
  • USS Plaice (SS-390)
  • USS Piranha (SS-389)
  • USS Pipefish (SS-388)
  • USS Pintado (SS-387)
  • USS Pilotfish (SS-386)
  • USS Bang (SS-385)
  • USS Parche (SS-384)
  • USS Pampanito (SS-383)
  • USS Picuda (SS-382)
  • USS Sand Lance (SS-381)
  • USS Nerka (SS-380)
  • USS Needlefish (SS-379)
  • USS Mero (SS-378)
  • USS Menhaden (SS-377)
  • USS Mapiro (SS-376)
  • USS Macabi (SS-375)
  • USS Loggerhead (SS-374)
  • USS Lizardfish (SS-373)
  • USS Lamprey (SS-372)
  • USS Lagarto (SS-371)
  • USS Kraken (SS-370)
  • USS Kete (SS-369)
  • USS Jallao (SS-368)
  • USS Icefish (SS-367)
  • USS Hawkbill (SS-366)
  • USS Hardhead (SS-365)
  • USS Guitarro (SS-363)
  • USS Guavina (SS-362)
  • USS Goldring (SS-360)
  • USS Garrupa (SS-359)
  • USS Garlopa (SS-358)
  • USS Ono (SS-357)
  • USS Jawfish (SS-356)
  • USS Espada (SS-355)
  • USS Eel (SS-354)
  • USS Dugong (SS-353)
  • USS Halfbeak (SS-352)
  • USS Greenfish (SS-351)
  • USS Dogfish (SS-350)
  • USS Diodon (SS-349)
  • USS Cusk (SS-348)
  • USS Cubera (SS-347)
  • USS Corporal (SS-346)
  • USS Cochino (SS-345)
  • USS Cobbler (SS-344)
  • USS Clamagore (SS-343)
  • USS Chopper (SS-342)
  • USS Chivo (SS-341)
  • USS Entemedor (SS-340)
  • USS Catfish (SS-339)
  • USS Carp (SS-338)
  • USS Carbonero (SS-337)
  • USS Capitaine (SS-336)
  • USS Dentuda (SS-335)
  • USS Cabezon (SS-334)
  • USS Bumper (SS-333)
  • USS Bullhead (SS-332)
  • USS Bugara (SS-331)
  • USS Brill (SS-330)
  • USS Chub (SS-329)
  • USS Charr (SS-328)
  • USS Boarfish (SS-327)
  • USS Blueback (SS-326)
  • USS Blower (SS-325)
  • USS Blenny (SS-324)
  • USS Caiman (SS-323)
  • USS Blackfin (SS-322)
  • USS Besugo (SS-321)
  • USS Bergall (SS-320)
  • USS Becuna (SS-319)
  • USS Baya (SS-318)
  • USS Barbero (SS-317)
  • USS Barbel (SS-316)
  • USS Sealion (SS-315)
  • USS Shark (SS-314)
  • USS Perch (SS-313)
  • USS Burrfish (SS-312)
  • USS Archerfish (SS-311)
  • USS Batfish (SS-310)
  • USS Aspro (SS-309)
  • USS Apogon (SS-308)
  • USS Tilefish (SS-307)
  • USS Tang (SS-306)
  • USS Skate (SS-305)
  • USS Seahorse (SS-304)
  • USS Sablefish (SS-303)
  • USS Sabalo (SS-302)
  • USS Roncador (SS-301)
  • USS Moray (SS-300)
  • USS Manta (SS-299)
  • USS Lionfish (SS-298)
  • USS Ling (SS-297)
  • USS Lancetfish (SS-296)
  • USS Hackleback (SS-295)
  • USS Escolar (SS-294)
  • USS Dragonet (SS-293)
  • USS Devilfish (SS-292)
  • USS Crevalle (SS-291)
  • USS Cisco (SS-290)
  • USS Capelin (SS-289)
  • USS Cabrilla (SS-288)
  • USS Bowfin (SS-287)
  • USS Billfish (SS-286)
  • USS Balao (SS-285)

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. 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.

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

End notes