Balao-class Submarine

### Operators

United States, Italy, Turkey, Greece, Peru, Argentina, Chile, Venezuela, Taiwan, Canada, Brazil, Netherlands, Spain

### Commissioned

1943-present

The ***Balao* class** was a design of United States Navy submarine used during World War II, and with 120 boats 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.

### Design

The *Balao*s were similar to the *Gato*s, 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 *Balao*s incorporated the fairwater, conning tower and periscope shears reduction efforts that were being retrofitted to the *Gato*s 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, many *Balao*s 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 *Balao*s looked exactly alike.

### Armament

* 10 × 21-inch (533 mm) torpedo tubes
	+ 6 forward, 4 aft
	+ 24 torpedoes
* 1 × 5-inch (127 mm) / 25 caliber deck gun
* Bofors 40 mm and Oerlikon 20 mm cannon

### Ships in Class

* USS Balao
* USS Billfish
* USS Bowfin
* USS Cabrilla
* USS Capelin
* USS Cisco
* USS Crevalle
* USS Devilfish
* USS Dragonet
* USS Escolar
* USS Hackleback
* USS Lancetfish
* USS Ling
* USS Lionfish
* USS Manta
* USS Moray
* USS Roncador
* USS Sabalo
* USS Sablefish
* USS Seahorse
* USS Skate
* USS Tang
* USS Tilefish
* USS Apogon
* USS Aspro
* USS Batfish
* USS Archerfish
* USS Burrfish
* USS Perch
* USS Shark
* USS Sealion
* USS Barbel
* USS Barbero
* USS Baya
* USS Becuna
* USS Bergall
* USS Besugo
* USS Blackfin
* USS Caiman
* USS Blenny
* USS Blower
* USS Blueback
* USS Boarfish
* USS Charr
* USS Chub
* USS Brill
* USS Bugara
* USS Bullhead
* USS Bumper
* USS Cabezon
* USS Dentuda
* USS Capitaine
* USS Carbonero
* USS Carp
* USS Catfish
* USS Entemedor
* USS Chivo
* USS Chopper
* USS Clamagore
* USS Cobbler
* USS Cochino
* USS Corporal
* USS Cubera
* USS Cusk
* USS Diodon
* USS Dogfish
* USS Greenfish
* USS Halfbeak
* USS Dugong
* USS Eel
* USS Espada
* USS Jawfish
* USS Ono
* USS Garlopa
* USS Garrupa
* USS Goldring
* USS Hardhead
* USS Hawkbill
* USS Icefish
* USS Jallao
* USS Kete
* USS Kraken
* USS Lagarto
* USS Lamprey
* USS Lizardfish
* USS Loggerhead
* USS Macabi
* USS Mapiro
* USS Menhaden
* USS Mero
* USS Needlefish
* USS Nerka
* USS Sand Lance
* USS Picuda
* USS Pampanito
* USS Parche
* USS Bang
* USS Pilotfish
* USS Pintado
* USS Pipefish
* USS Piranha
* USS Plaice
* USS Pomfret
* USS Sterlet
* USS Queenfish
* USS Razorback
* USS Redfish
* USS Ronquil
* USS Scabbardfish
* USS Segundo
* USS Sea Cat
* USS Sea Devil
* USS Sea Dog
* USS Sea Fox
* USS Atute
* USS Spikefish
* USS Sea Owl
* USS Sea Poacher
* USS Sea Robin
* USS Sennet
* USS Piper
* USS Threadfin
* USS Spadefish
* USS Trepang
* USS Spot
* USS Springer
* USS Stickleback
* USS Tiru
* USS Trumpetfish
* USS Tusk
* USS Turbot
* USS Ulua