There have been a number of 21 inch torpedoes in service with the United States. These have been used on ships and submarines of the US Navy. American "21 inch" torpedoes are actually 21 inch (533 mm) in diameter.
Ship classes that carried 21 inch torpedoes include:
- Allen M. Sumner-class destroyers
- Bagley-class destroyers
- Barbel-class submarines
- Barracuda-class submarines
- Benham-class destroyers
- Benjamin Franklin-class submarines
- Benson-class destroyers
- Cachalot-class submarines
- Caldwell-class destroyers
- Cassin-class destroyers
- Chester-class cruisers
- Clemson-class destroyers
- Colorado-class battleships
- Connecticut-class battleships
- Dealey-class destroyer escorts
- Farragut-class destroyers
- Forrest Sherman-class destroyers
- Fletcher-class destroyers
- Gearing-class destroyers
- Gleaves-class destroyers
- Grayback-class submarines
- Gridley-class destroyers
- John C. Butler-class destroyer escorts
- Lexington-class battlecruisers
- Mahan-class destroyers
- Mitscher-class destroyers
- O'Brien-class destroyers
- Ohio-class submarines
- Omaha-class cruisers
- Permit-class submarines
- Porter-class destroyers
- Rudderow-class destroyer escorts
- S-class submarines
- Sailfish-class submarines
- Sampson-class destroyers
- Sargo-class submarines
- Sims-class destroyers
- Skate-class submarines
- Skipjack-class submarines
- Somers-class destroyers
- South Dakota-class battleships
- Sturgeon-class submarines
- T-1-class submarines
- Tambor-class submarines
- Tang-class submarines
- Tennessee-class cruisers
- Tucker-class destroyers
- Virginia-class battleships
- Wickes-class destroyers
| Name | Country | In service date | Platform / target | Dimensions | Warhead | Propulsion | Performance |
|---|---|---|---|---|---|---|---|
| CAPTOR mine |  US |
1979 | Encapsulated torpedo ASW mine | Diameter:21 in (53 cm) Length:12.1 ft (3.7 m) Weight:2,061 lb (935 kg) |
97 lb (44 kg) PBXN-103 |
Reciprocating external combustion, Otto fuel II | Speed:28 kn (52 km/h) Range:7.3 km (8,000 yd) |
| Mark 1 (Bliss-Leavitt) | US |
1904-1922 | Submarine / Surface ship | Diameter:21 in (53 cm) Length:16.4 ft (5.0 m) Weight:1,500 lb (680 kg) |
200 lb (91 kg) Guncotton |
Single vertical turbine wheel | Speed:27 kn (50 km/h) Range:4,000 yd (3.7 km) |
| Mark 2 (Bliss-Leavitt) | US |
1905-1922 | Submarine / Surface ship | Diameter:21 in (53 cm) Length:16.4 ft (5.0 m) Weight:1,500 lb (680 kg) |
200 lb (91 kg) Guncotton |
Turbine (contra-rotating) | Speed:26 kn (48 km/h) Range:3,500 yd (3.2 km) |
| Mark 3 (Bliss-Leavitt) | US |
1906-1922 | Submarine / Surface ship | Diameter:21 in (53 cm) Length:16.4 ft (5.0 m) Weight:1,500 lb (680 kg) |
200 lb (91 kg) Guncotton |
Turbine (contra-rotating) | Speed:26 kn (48 km/h) Range:4,000 yd (3.7 km) |
| Mark 8 (Bliss-Leavitt) | US |
1911-1945 | Submarine / Surface ship | Diameter:21 in (53 cm) Length:21.3 ft (6.5 m) Weight:2,600 lb (1,200 kg) |
Mk.8 Mod 4 466 lb (211 kg) TNT |
Turbine | Speed:36 kn (67 km/h) Range:16,000 yd (15,000 m) |
| Mark 9 (Bliss-Leavitt) | US |
1915-1945 | Submarine / Surface ship | Diameter:21 in (53 cm) Length:16.4 ft (5.0 m) Weight:2,015 lb (914 kg) |
Mk.9 210 lb (95 kg) TNT |
Turbine | Speed:27 kn (50 km/h) Range:7,000 yd (6,400 m) |
| Mark 10 | US |
1915-1945 | Surface / Surface ship | Diameter:21 in (53 cm) Length:16.2 ft (4.9 m) Weight:2,215 lb (1,005 kg) |
Mk.10 Mod.3 497 lb (225 kg) TNT |
Steam turbine | Speed:36 kn (67 km/h) Range:3,500 yd (3,200 m) |
| Mark 11 | US |
1926-1945 | Surface / Surface ship | Diameter:21 in (53 cm) Length:22.6 ft (6.9 m) Weight:3,511 lb (1,593 kg) |
Mk.11 500 lb (230 kg) TNT |
Turbine | Low:27 kn (50 km/h) Range:15,000 yd (14,000 m) Medium:34 kn (63 km/h) Range:10,000 yd (9,100 m) High:46 kn (85 km/h) Range:6,000 yd (5,500 m) |
| Mark 12 | US |
1928-1945 | Surface / Surface ship | Diameter:21 in (53 cm) Length:22.6 ft (6.9 m) Weight:3,505 lb (1,590 kg) |
Mk.11 500 lb (230 kg) TNT |
Turbine | Low:27.5 kn (50.9 km/h) Range:15,000 yd (14,000 m) Medium:35.5 kn (65.7 km/h) Range:10,000 yd (9,100 m) High:44 kn (81 km/h) Range:7,000 yd (6,400 m) |
| Mark 14 | US |
1938 | Submarine / Surface | Diameter:21 in (53 cm) Length:20.5 ft (6.2 m) Weight:3,209 lb (1,456 kg) |
Mk.16 Mod.6 643 lb (292 kg) HBX |
Wet Heater | Low:31.1 kn (57.6 km/h) Range:9,000 yd (8,200 m) High:46.3 kn (85.7 km/h) Range:4,500 yd (4,100 m) |
| Mark 15 | US |
1938-1956 | Surface / Surface | Diameter:21 in (53 cm) Length:24 ft (7.3 m) Weight:3,841 lb (1,742 kg) |
Mk.7 Mod.3 825 lb (374 kg) HBX |
Turbine | Low:26.5 kn (49.1 km/h) Range:15,000 yd (14,000 m) Medium:33.5 kn (62.0 km/h) Range:10,000 yd (9,100 m) High:45 kn (83 km/h) Range:6,000 yd (5,500 m) |
| Mark 16 | US |
1943-1975 | Submarine / Surface | Diameter:21 in (53 cm) Length:20.5 ft (6.2 m) Weight:4,000 lb (1,800 kg) |
Mk.16 Mod.7 746 lb (338 kg) HBX |
Turbine | Speed:46.2 kn (85.6 km/h) Range:11,000 yd (10,000 m) |
| Mark 17 | US |
1944-1950 | Destroyer / Surface | Diameter:21 in (53 cm) Length:24 ft (7.3 m) Weight:4,600 lb (2,100 kg) |
Mk.17 Mod.3 879.5 lb (398.9 kg) HBX |
Turbine | Speed:46 kn (85 km/h) Range:18,000 yd (16,000 m) |
| Mark 18 | US |
1943-1950 | Submarine | Diameter:21 in (53 cm) Length:20.4 ft (6.2 m) Weight:3,154 lb (1,431 kg) |
Mk.18 Mod.3 575 lb (261 kg) HBX |
Electric | Speed:29 kn (54 km/h) Range:4,000 yd (3,700 m) |
| Mark 19 | US |
Submarine / Surface | Diameter:21 in (53 cm) Length:20.5 ft (6.2 m) Weight:3,240 lb (1,470 kg) |
Mk.20 800 lb (360 kg) Torpex |
Electric, secondary battery | Speed:29 kn (54 km/h) Range:4,000 yd (3,700 m) | |
| Mark 20 | US |
Submarine / Surface | Diameter:21 in (53 cm) Length:20.5 ft (6.2 m) Weight:3,100 lb (1,400 kg) |
Mk.20 500 lb (230 kg) TNT |
Electric motor | Speed:33 kn (61 km/h) Range:3,500 yd (3.2 km) | |
| Mark 22 | US |
Submarine / Surface | Diameter:21 in (53 cm) Length:20.5 ft (6.2 m) Weight:3,060 lb (1,390 kg) |
500 lb (230 kg) HBX |
Electric | Speed:29 kn (54 km/h) Range:4,000 yd (3.7 km) | |
| Mark 23 | US |
1943-1946 | Submarine / Surface | Diameter:21 in (53 cm) Length:20.5 ft (6.2 m) Weight:3,259 lb (1,478 kg) |
Mk.16 Mod.6 643 lb (292 kg) HBX |
Turbine | Speed:46.3 kn (85.7 km/h) Range:4,500 yd (4.1 km) |
| Mark 26 | US |
Submarine / Surface | Diameter:21 in (53 cm) Length:20.5 ft (6.2 m) Weight:3,200 lb (1,500 kg) |
Mk.26 410–450 kg (900–1,000 lb) HBX |
Electric, seawater battery | Speed:40 kn (74 km/h) Range:6,000 yd (5.5 km) | |
| Mark 28 | US |
1944-1960 | Submarine / Surface | Diameter:21 in (53 cm) Length:20.5 ft (6.2 m) Weight:2,800 lb (1,300 kg) |
Mk.28 Mod.2 585 lb (265 kg) HBX |
Electric | Speed:19.6 kn (36.3 km/h) for 6 minutes at 4,000 yd (3.7 km) |
| Mark 29 | US |
Submarine / Surface | Diameter:21 in (53 cm) Length:20.5 ft (6.2 m) Weight:3,200 lb (1,500 kg) |
Mk.28 Mod.2 550 lb (250 kg) HBX |
Electric | Low:21 kn (39 km/h) Range:12,000 yd (11,000 m) High:28 kn (52 km/h) Range:4,000 yd (3,700 m) | |
| Mark 31 | US |
Destroyer / Surface | Diameter:21 in (53 cm) Length:20.5 ft (6.2 m) Weight:2,800 lb (1,300 kg) |
Mk.31 500 lb (230 kg) HBX |
Electric | Speed:29 kn (54 km/h) Range:4,000 yd (3.7 km) | |
| Mark 33 Mod.0 | US |
Submarine / Submarine & surface | Diameter:21 in (53 cm) Length:6.9 ft (2.1 m) Weight:1,795 lb (814 kg) |
550 lb (250 kg) HBX |
Electric | Low:12.5 kn (23.2 km/h) Range:19,000 yd (17,000 m) High:18.5 kn (34.3 km/h) Range:5,000 yd (4,600 m) | |
| Mark 35 | US |
1949-1960 | Surface / Surface | Diameter:21 in (53 cm) Length:6.9 ft (2.1 m) Weight:1,770 lb (800 kg) |
Mk.35 Mod.2 or 3 270 lb (120 kg) HBX |
Electric, primary seawater battery | Speed:27 kn (50 km/h) Range:15,000 yd (14 km) |
| Mark 36 Mod.0 | US |
1949-1960 | Surface / Surface | Diameter:21 in (53 cm) Length:20.5 ft (6.2 m) Weight:4,000 lb (1,800 kg) |
Mk.36 800 lb (360 kg) HBX-1 |
Electric | Speed:47 kn (87 km/h) Range:7,000 yd (6.4 km) |
| Mark 41 Mod.0 | US |
Aircraft / Submarine | Diameter:21 in (53 cm) Length:10 ft (3.0 m) Weight:1,327 lb (602 kg) |
Mk.41 150 lb (68 kg) HBX |
Electric, seawater battery | Speed:25 kn (46 km/h) Range:8,000 yd (7.3 km) | |
| Mark 48 | US |
1972 | Anti-submarine Anti-surface | Diameter:21 in (53 cm) | 650 lbs | Piston engine, pump jet |
The original article can be found at American 21 inch torpedo and the edit history here.