United States S-class submarine

The United States' S-class submarines, often simply called S-boats (sometimes "Sugar" boats, after the then contemporary Navy phonetic alphabet for "S"), were the first class of submarines built to a United States Navy design.

The United States Navy commissioned 51 S-Class submarines from 1920 to 1925. The first S-boat, USS S-1 (SS-105), was commissioned in 1918 and the last numerically, USS S-51 (SS-162), in 1922. The last of the class actually commissioned was USS S-47 (SS-158) in 1925. The S class is subdivided into four groups of different designs:
 * Group I (S-1 class, or "Holland" type):S-1 and S-18–S-41, built by Bethlehem Steel at Fore River Shipyard in Quincy, Massachusetts and Union Iron Works in San Francisco, California, as subcontractor for Electric Boat Company (Elco).
 * Group II (S-3 class, or "Navy Yard" type):S-3-S-17, built at the Portsmouth Navy Yard and Lake Torpedo Boat at Bridgeport, Connecticut.
 * Group III (S-42 class): S-42-S-47, built at Fore River.
 * Group IV (S-48 class): S-48-S-51, built by Lake.

S-2 was a prototype built by Lake, and was not repeated.

S-1, S-2, and S-3 were prototypes built to the same specification: S-1 designed by Electric Boat (Elco), S-2 by Lake, and S-3 by the Bureau of Construction and Repair (later Bureau of Ships). The Lake boat was considered inferior. The Elco and BuC&R designs were put into production.

The first S-boat, S-1, was launched on 26 September 1918, by Bethlehem at Fore River, but not commissioned until 5 June 1920.

The S-boats were improvements over the O- and R-boats. They were substantially larger. Compared to the R-boats, Group I S-boats were 33 ft longer, with 3 ft more beam, 2 ft more draft, and 60% greater displacement. This allowed for greater range, larger engines and higher speed, and more torpedo reloads, though the number of forward torpedo tubes was still four. Seven of the Group II and all the Group IV boats had an additional stern tube. Group IV was also longer and had less draft. In 1923, USS S-1 (SS-105) experimented with a seaplane (an idea the Japanese would adopt).

Service
These boats saw service in World War II in both the Atlantic and the Pacific. Smaller and slower than many of the submarines produced for war service, and lacking the range for Pacific Ocean patrols (as well as being 20 years old), they were used in reconnaissance and supply roles, as well as for coastal defense, such as in the Alaska theater during the aftermath of the Battle of the Aleutian Islands. They were withdrawn in mid-1943 as fleet submarines became available, and were relegated to ASW training. Most of the surviving boats were scrapped in 1946.

In World War II, S-class boats did not use the newer Mark 14 torpedo, standard in fleet submarines, due to shorter torpedo tubes, relying on the World War I-vintage Mark 10, instead. (Due to production shortages, many fleet boats used Mark 10s, also.) Since the Mark 14 suffered from a high failure rate early in the war, this was not necessarily a disadvantage.

Some were transferred to other navies, such as the six transferred to the British Royal Navy. These were mostly used for training in anti-submarine warfare and removed from service by mid-1944.

Group I

 * Displacement: 854 tons surfaced; 1,062 tons submerged
 * Length: 219 ft
 * Beam: 20 ft
 * Draft: 16 ft
 * Propulsion: 2 × New London Ship and Engine Company (NELSECO) diesels, 600 hp (448 kW) each; 2 × Electro-Dynamic (S-1, S-30-S-35), Ridgway (S-18, S-20 through S-29), or General Electric (S-36 through S-41) electric motors, 750 hp each; 120 cell Exide battery; two shafts.
 * Bunkerage: 168 tons oil fuel
 * Speed: 14.5 knots (27 km/h) surfaced; 11 knots (20 km/h) submerged
 * Range: 5,000 miles (8,000 km) at 10 knots (19 km/h) surfaced
 * Test depth: 200 ft (61 m)
 * Armament (as built): 4 × 21 in (533 mm) torpedo tubes (bow, 12 torpedoes); 1 × 4 in (102 mm)/50 cal deck gun
 * Crew: 42 officers and men
 * Boats in Group: S-1, S-18 through S-41

Group II

 * Displacement: 876 tons surfaced; 1,092 tons submerged
 * Length: 231 ft
 * Beam: 21 ft
 * Draft: 13 ft
 * Propulsion: 2 × M.A.N (S-3 through S-13) or Busch-Sulzer (S-14 through S-17) diesels, 1,000 hp (746 kW) each; 2 × Westinghouse electric motors, 600 hp (447 kW) each; 120-cell Exide battery; two shafts.
 * Speed: 15 knots (28 km/h) surfaced; 11 knots (20 km/h) submerged
 * Bunkerage: 148 tons oil fuel
 * Range: 5000 nmi at 10 kn surfaced
 * Test depth: 200 ft (61 m)
 * Armament (as built): 4 × 21 in (533 mm) torpedo tubes (bow, 12 torpedoes) or (S-11 through S-13) 5 (four forward, one aft, 14 torpedoes); 1 × 4 in (102 mm)/50 cal deck gun
 * Crew: 42 officers and men
 * Boats in Group: S-3 through S-17

Group III

 * Displacement: 906 tons surfaced; 1,126 tons submerged
 * Length: 216 ft, 225 ft overall
 * Beam: 20 ft
 * Draft: 16 ft
 * Propulsion: 2 × NELSECO diesels, 600 hp (448 kW) each; 2 × Electro-Dynamic electric motors, 750 hp each; 120 cell Exide battery; two shafts.
 * Speed: 15 knots (28 km/h) surfaced; 11 knots (20 km/h) submerged
 * Bunkerage: 185 tons oil fuel
 * Range: 5000 nmi at 10 kn surfaced
 * Test depth: 200 ft (61 m)
 * Armament (as built): 4 × 21 in (533 mm) torpedo tubes (bow, 12 torpedoes); 1 × 4 in (102 mm)/50 cal deck gun
 * Crew: 42 officers and men
 * Boats in Group: S-42 through S-47

Group IV

 * Displacement: 903 tons surfaced; 1230 tons submerged
 * Length: 240 ft, 266 ft overall
 * Beam: 21 ft
 * Draft: 13 ft
 * Propulsion: 2 × Busch-Sulzer diesels, 900 hp (670 kW) each; 2 × Ridgway electric motors, 750 hp each; 120 cell Exide battery; two shafts.
 * Bunkerage: 177 tons oil fuel
 * Speed: 14.5 knots (27 km/h) surfaced; 11 knots (20 km/h) submerged
 * Range: 8000 nmi at 10 kn surfaced
 * Depth: 200 ft (61 m)
 * Armament (as built): 4 × 21 in (533 mm) torpedo tubes (bow, 12 torpedoes); 1 × 4 in (102 mm)/50 cal deck gun
 * Crew: 42 officers and men
 * Boats in Group: S-48 through S-51

S-2

 * Displacement: 800 tons surfaced; 977 tons submerged
 * Length: 207 ft overall
 * Beam: 19 ft
 * Draft: 16 ft
 * Propulsion: 2 × diesels, 900 hp (670 kW) each; 2 × electric motors, 750 hp each; two shafts.
 * Speed: 15 knots (28 km/h) surfaced; 11 knots (20 km/h) submerged
 * Range: 8000 nmi at 10 kn surfaced
 * Depth: 200 ft (61 m)
 * Armament (as built): 4 × 21 in (533 mm) torpedo tubes (bow, 12 torpedoes); 1 × 4 in (102 mm)/50 cal deck gun
 * Crew: 42 officers and men

S-boat fates
All S-boats were scrapped after World War II except those listed below.

Lost at sea between wars

 * USS S-4 (SS-109) - Sunk 1927 later raised, recommissioned, and served before being finally sunk 1936
 * USS S-5 (SS-110) - lost September 1, 1920
 * USS S-51 (SS-162)-sunk 1925; raised and later scrapped 1930

Scrapped between World War I and World War II

 * USS S-2 (SS-106)
 * USS S-3 (SS-107)
 * USS S-6 (SS-111)
 * USS S-10 (SS-115)
 * USS S-19 (SS-124)
 * USS S-50 (SS-161)

Transferred to the Royal Navy during World War II

 * USS S-1 (SS-105) to RN as P 552 in 1942, removed from service Jan 1944; scrapped 1945
 * USS S-21 (SS-126) (as P 553) Sunk as target 23 March 1945
 * USS S-22 (SS-127) (as P 554) scrapped 1945
 * USS S-24 (SS-129) (as P 555) destroyed 1947
 * USS S-25 (SS-130) (as P 551, later transferred to the Polish Navy as ORP Jastrząb-scuttled after hit by friendly fire 2 May 1942
 * USS S-29 (SS-134) (as P 556) scrapped 1947

Lost during World War II

 * USS S-26 (SS-131) was destroyed in a collision with USS SC-460 in the Gulf of Panama 24 January 1942
 * USS S-27 (SS-132), USS S-36 (SS-141), and USS S-39 (SS-144) were wrecked when they ran aground
 * USS S-28 (SS-133) wrecked 4 July 1944 by a flooding casualty off Pearl Harbor
 * USS S-44 (SS-155) lost to enemy action 7 October 1943
 * USS S-49 (SS-160) stricken and sold for scrap 1931; hulked 1936; hulk reacquired by the U.S. Navy for "experimental purposes"; foundered and sank in the Patuxent River 16 December 1942