A progressive refinement of the F-class, the G-class continued the trend of US submarines that could not only serve with the battle fleet but also undertake independent patrols far from the US mainland. Laid down in 1919, they were commissioned during 1921. Five; G-1
, were built and carried hull numbers SS-20 to SS-24.
The G-class was 188 feet long, with an 18 foot beam and a nominal draft of 14 feet. They displaced 570 tons surfaced, and 696 tons submerged. They were armed with four 18” bow torpedo tubes with stowage for up to nine torpedoes and a Mk.14 3”/50 deck gun. Atlas-Imperial again supplied the diesel engines which produced 1,550 horsepower. Speeds were 16 knots surfaced and 12 knots submerged. Range increased to 5,000 nautical miles while surfaced and 200 nautical miles submerged. Normal crew complement was 32.
Following a brief stint in the peacetime fleet, the G-class continued in service through the War of the Americas – with two being lost; G-4
in 1923, and G-2
in 1925. Followed the war the class was caught up in the postwar draw-down of forces and were retired and scrapped beginning in 1928.
H and J-class (US):
(SS-25) was a one-off prototype which served as the progenitor of all US submarines built during the War of the Americas but never saw combat herself – serving until 1930 as a training vessel. She was followed by the very similar J-class (the letter I was skipped) which was not only the first to enter service after the outbreak of war but was also the first class with more than five boats ordered. Ten; J-1
were built – all entered service by the end of 1923. Hull numbers ran from SS-26 to SS-35.
was 205 feet long, with a 20 foot beam and a nominal draft of 14 feet. She displaced 690 tons surfaced, and 842 tons submerged. She was the first US submarine to carry 21” torpedoes and mounted four bow tubes and was the last not fitted with a deck gun until the Swordfish
class of 1950. Her diesel engines were rated at 1,900 horsepower. Speeds were 15 knots surfaced and 13 knots submerged. Range was 5,000 nautical miles and crew numbered 32.
The J-class was 205 feet long, with a 20 foot beam and a nominal draft of 14 feet. They displaced 700 tons surfaced, and 861 tons submerged. They were armed with four 21” bow torpedo tubes with stowage for up to nine torpedoes and were fitted with a Mk.14 deck gun forward of the conning tower. Horsepower was rated at 1,950 but speed and range remained the same as with H-1
. Normal crew complement was 35.
As the first group of the so-called “fleet boats”, the J-class was heavily involved in the first half of the War of the Americas but was normally utilized as commerce raiders. Five; J-1, J-4, J-5, J-8
were sunk, and one; J-7
, was lost off the Marianas to an accident – most likely an internal explosion – in 1926. After the war the four surviving boats continued to serve until 1932, when they were sold to Peru, where they remained on active duty in limited commission until 1950.
The highly successful J-class was followed by another group of ten boats. The K-class, which entered service in 1924, was a progressive refinement on the J-class differing primarily in mounting a heavier 4” deck gun and a stern torpedo tube for the first time. Ten; K-1
were built. Hull numbers ran from SS-36 to SS-45.
The K-class was 227 feet long, with a 21 foot beam and a nominal draft of 15 feet. They displaced 890 tons surfaced, and 1,095 tons submerged. They were armed with five 21” torpedo tubes – mounted as four bow tubes and one stern tube – and a 4”/50 Mk.12 deck gun. Two Atlas-Imperial diesels rated at a total of 2,440 horsepower drove these boats to 16 knots surfaced while their electric motors were capable of 14 knots submerged. Range surfaced remained 5,000 nautical miles. Crew complement was 37.
Like their immediate predecessors, the K-class was used largely in commerce raiding missions and accounted for much of the Confederate shipping lost during 1924-25. They paid a heavy price, however, as all but three; K-1, K-2,
, were lost to convoy escorts. When the war ended in 1927 the remaining boats continued to serve in the peacetime navy until 1934, when they were decommissioned and scrapped.
The last war-built US submarine class – the L-class entered service between 1925 and 1926. They were based on the K-class design but were larger and heavier with additional spare torpedoes and increased storage for supplies allowing longer duration patrols. A total of forty; L-1
, were built. Hull numbers ran from SS-46 to SS-85.
The L-class was 242 feet long, with a 21 foot beam and a nominal draft of 15 feet. They displaced 965 tons surfaced, and 1,197 tons submerged. They were armed with six 21” torpedo tubes – four forward, and two aft – with storage for eleven reload torpedoes and a 4” Mk.12 deck gun. Two diesels (Eigner Motor Company in the first 20 boats; Atlas-Imperial in the rest) rated at a total of 2,670 horsepower gave this class a surfaced speed of 16 knots while submerged speed was 14 knots. Range was 5,000 nautical miles while improved batteries allowed a submerged range of 300 nautical miles. Crew complement was 40.
Unlike earlier US submarines, the L-class was usually deployed either with the battle fleet or on independent patrol far into the Western Pacific. Nearly half the class was stationed out of Guam supported by submarine tenders and saw considerable action during the Battle of Subic Bay. Sixteen; L-4, L-7, L-8, L-10, L-12, L-14, L-16, L-17, L-18, L-20, L-22, L-29, L-30, L-34, L-37,
, were lost during the conflict. Following the armistice, the survivors continued to serve in the postwar fleet until 1938, when they were retired and scrapped over the next two years. One, L-23
(SS-68) – a veteran of the Battle of Subic Bay – was preserved as a memorial in Bremerton, Washington.
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