Balao-class submarine

The Balao class was a successful design of United States Navy submarine used during World War II. An improvement on the earlier Gato class, the boats had slight internal differences. The most significant improvement was the use of higher yield steel in the pressure hull, which increased their test depth to 400 feet (120 m). There were 132 submarines ordered in this class (ten cancelled toward the end of World War Two).

Propulsion

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 diesel engines and the shafts.

Balao class submarines received diesel engines from one of two manufacturers. Fairbanks-Morse supplied Model 38D8-⅛ opposed piston engines, and General Motors' Electro-Motive Diesel division supplied Model 16 V16 engines. Earlier Fairbanks-Morse boats received a 9 cylinder version of the Model 38D8-⅛, 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.

Two submarines, Unicorn (SS-429) and Vendace (SS-430), were to receive Hooven-Owens-Rentschler (H.O.R.) diesels, 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. A handful of 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.

As the diesel engines were not directly connected to the shafts, the electric motors had to drive the shafts all the time. On the surface, with all diesel generators in operation, the full electric plant was used to produce 5,400 shp. However, due to limited battery capacity, only half of the electric plant was used underwater: one motor per shaft on four motor boats, and one armature per motor on two motor boats.

External links

Museums

• USS Batfish (SS-310) USS Batfish museum - youth group friendly! Stay over night!
• USS Becuna (SS-319)
• USS Bowfin (SS-287)
• USS Clamagore (SS-343)
• USS Ling (SS-297)
• USS Lionfish (SS-298) Photos on board the Balao Submarine USS Lionfish (SS-298)
• USS Pampanito (SS-383)
• USS Razorback (SS-394)

Information Sites

• USS Bang (SS-385): Website dedicated to perpetuate the memory of USS BANG, and the men that served aboard her.
• USS Sea Robin (SS-407): A website dedicated to the USS Sea Robin and her former crew.
• seapoacher.com: USS Sea Poacher Association Official Website