Guppy2

Name/Hull Nbr

USS Catfish (SS339)

USS Clamagore (SS343)

USS Cobbler (SS344)

USS Cochino (SS345)

USS Corporal (SS346)

USS Cubera (SS347)

USS Diodon (SS349)

USS Dogfish (SS350)

USS Greenfish (SS351)

USS Halfbeak (SS352)

USS Tiru (SS416)

USS Trumpetfish (SS425)

USS Tusk (SS426)

USS Cutlass (SS478)

USS Sea Leopard (SS483)

USS Odax (SS484)

USS Sirago (SS485)

USS Pomodon (SS486)

USS Remora (SS487)

USS Volador (SS490)

USS Amberjack (SS522)

USS Grampus (SS523)

USS Pickerel (SS524)

USS Grenadier (SS525)

Class

Balao

Tench

From Guppy I

Tench

From Guppy I

Tench

Conversion Yard/Year

Mare Island - 1949

Philadelphia - 1948

Electric Boat - 1949

Electric Boat - 1948

Philadelphia - 1948

Mare Island - 1948

Philadelphia - 1948

Portsmouth - 1948

Electric Boat - 1948

Mare Island - 1948

Portsmouth - 1948

Philadelphia - 1948

Philadelphia - 1949

Portsmouth - 1951

Philadelphia - 1949

Mare Island - 1951

Mare Island - 1947

Portsmouth - 1948

Portsmouth - 1947

Boston - 1950

Portsmouth - 1949

Boston - 1951

The Guppy II conversion was generally similar to the Guppy I with the major difference being the sail.

The addition of three new masts, snorkel induction, snorkel exhaust and ESM mast, required more room in the upper portion of the sail. The structure was changed to support the new masts. There were two different sails approved by BuShips. The Portsmouth Sail had a thinner top, curved trailing edge, square windows and a sharper lower forward edge. It was put on all boats which used the government plans for the conversion. The EB sail had a straight trailing edge, round windows, a wider top and a more rounded forward edge. Some boats with a Portsmouth sail had the SV-radar with the large screen. Those boats needed extra room to house the screen, thus had a buldge at the sail top. Later mods put the SS or SS2 radars on these and other boats which had a smaller screen and had an indicator with interlocks which allowed the mast to be housed only with the screen in certain angular positions.

All boats converted during the Guppy II program which had high speed drive motors with reduction gear had these replaced with low speed direct drive motors of 2500 hp per shaft. The battery wells were enlarged to accept 504 guppy cells in four batteries. The boats had their bows replaced and the entire superstructure streamlined.

The conversion to the Guppy II models started in 1947 and lasted for 5 years.