A design weakness of earlier classes solved by the Tench re-design were the ballast tank vent riser pipes that passed through the interior of the boat in the forward and after torpedo rooms.

Solving this problem initially proved quite difficult, but ultimately required the complete rearrangement of the ballast tanks.

#7 MBT, after stability and buoyancy calculations were run, was found to be redundant and was converted to a variable fuel oil/ballast tank, increasing the class's surfaced range.

The maximum is often stated as 40 mines in various publications because the authors simply used previous limitations of the Gato and Balao classes, and included the four torpedo doctrine.

Ghazi (ex-Diablo (SS-479)) was lost in Pakistani service on 4 December 1971 during the Indo-Pakistani Naval War of 1971, possibly due to a minelaying accident.

The Cramp Shipbuilding Company of Philadelphia, struggling with workforce problems and supply issues with its Balaos, was also not awarded any contracts.

Some references simply assume all submarines numbered after SS-416 were Tench class; however, Trumpetfish (SS-425) and Tusk (SS-426) were completed as Balaos.

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.

Two of the cancelled Tench-class boats, Unicorn, and Walrus, were launched incomplete, never commissioned, but listed with the reserve fleet until struck in 1958 and scrapped in 1959.

Two additional boats (Cutlass and Diablo) entered Japanese waters on their first war patrols immediately after the 13 August 1945 cease-fire.

Postwar, 24 of the 29 Tenches were modernized under the Fleet Snorkel and Greater Underwater Propulsion Power (GUPPY) programs, with most continuing in US service into the early 1970s.

[17] 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 such as Cleveland, Detroit, and Chicago), where they served as training platforms during the Reservists' weekend drills.

[18][19][20] 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.

Argonaut was sold to the Royal Canadian Navy in 1968, renamed HMCS Rainbow, decommissioned in 1974, and returned to the US for scrapping in 1977.

[21] As of 2020 the Taiwanese Hai Shih-class had largest weapons load[vague] of any conventional submarines in the world.

The 29 Tench-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.

A total of 16 Tench-class submarines were converted to one of the GUPPY configurations, with 8 additional boats receiving Fleet Snorkel modifications.

Most of the 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.

All Tench-class GUPPYs received sonar, fire control, and Electronic Support Measures (ESM) upgrades.

An advantage of streamlining was that active sonar detection range against a GUPPY was reduced by about 10%, and the higher submerged speed also severely impacted anti-submarine warfare efforts.

The Fleet Snorkel program was developed as an austere, cost-effective alternative to full GUPPY conversions, with significantly less improvement in submerged performance.

Eight Tench-class boats received this upgrade (Argonaut, Diablo - immediately prior to foreign transfer to Pakistan as Ghazi, Irex, Medregal, Requin, Runner, Spinax, and Torsk).

This was generally similar to GUPPY IA, except one of the forward diesel engines was removed to relieve machinery overcrowding.

This was developed as an austere upgrade for two Gato-class and two Balao-class boats prior to transfer to foreign navies ( 2 each to Italy and The Netherlands ) in 1953–55.

[26] A taller "Northern" sail was included for improved surfaced operations in rough seas; this was also backfitted to some other GUPPY and Fleet Snorkel boats.

The BQG-4 Passive Underwater Fire Control Feasibility Study (PUFFS) sonar system, with three tall "Shark fin" domes topside, was fitted.

Four submarines including the Tench-class boat Remora prototyped the concept at the end of World War II but were not used in this role.

[30] Tigrone would be converted under Migraine II (aka project SCB 12) in 1948, and the other two would be upgraded to this standard with powerful air search and height finding radars installed on masts, and with the after torpedo room converted into an electronics space with torpedoes and tubes removed.