# American 21-inch torpedo

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 U.S. Navy. American 21-inch torpedoes are 533 millimeters (21in) in diameter.
Ship classes that carried 21-inch torpedoes include:
* Allen M. Sumner-class destroyers
* Atlanta-class cruisers
* Bagley-class destroyers
* Balao-class submarines
* 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
* Ethan Allen-class submarines
* Farragut-class destroyers
* Forrest Sherman-class destroyers
* Fletcher-class destroyers
* Gato-class submarines
* Gearing-class destroyers
* George Washington-class submarines
* Gleaves-class destroyers
* Glenard P. Lipscomb-class submarine
* Grayback-class submarines
* Gridley-class destroyers
* Halibut-class submarine
* James Madison-class submarines
* John C. Butler-class destroyer escorts
* Lafayette-class submarines
* Lexington-class battlecruisers - canceled
* Los Angeles-class submarines
* Mahan-class destroyers
* Mitscher-class destroyer leaders
* Narwhal-class submarine
* Nautilus-class submarine
* Norfolk-class destroyer leader
* O'Brien-class destroyers
* Ohio-class submarines
* Omaha-class cruisers
* Permit-class submarines
* Porter-class destroyers
* PT boats
* R-class submarines
* Rudderow-class destroyer escorts
* S-class submarines
* Sailfish-class submarines
* Sampson-class destroyers
* Sargo-class submarines
* Seawolf-class submarine (1957)
* Seawolf-class submarines (1997)
* Sims-class destroyers
* Skate-class submarines
* Skipjack-class submarines
* Somers-class destroyers
* South Dakota-class battleships - canceled
* Sturgeon-class submarines
* T-1-class submarines
* Tambor-class submarines
* Tang-class submarines
* Tench-class submarines
* Tennessee-class cruisers
* Tucker-class destroyers
* Tullibee-class submarine
* V-boat submarines
* Virginia-class battleships
* Virginia-class submarines
* Wickes-class destroyers
| Name | Country | In service date | Platform / target | Dimensions | Warhead | Propulsion | Performance |
| Mark 1 (Bliss-Leavitt) | US | 1904–1922 | Surface / Surface | 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 | Surface / Surface | 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 | Surface / Surface | 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 | Surface / Surface | Diameter: 21 in (53 cm) Length: 21.3 ft (6.5 m) Weight: 2,600 lb (1,200 kg) | 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 | Surface & submarine / Surface | 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 | Submarine / Surface | Diameter: 21 in (53 cm) Length: 16.2 ft (4.9 m) Weight: 2,215 lb (1,005 kg) | 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 | 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 | 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) | Mod.0: 507 lb (230 kg) TNT Mod.6: 643 lb (292 kg) Torpex | Turbine | Mod.0: Low: 31.1 kn (57.6 km/h) Range: 9,000 yd (8,200 m) Mod.3: 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) | Mod 0: 494 lb (224 kg) TNT Mod.3: 801 lb (363 kg) TNT or 825 lb (374 kg) HBX | Turbine | Mod.0: 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) Mod.3: Low: 26.5 kn (49.1 km/h) Range :14,000 yd (13,000 m) Medium: 33.5 kn (62.0 km/h) Range: 9,000 yd (8,200 m) High: 45 kn (83 km/h) Range: 4,500 yd (4,100 m) |
| Mark 16 | US | 1943–1975 | Submarine / Surface | Diameter: 21 in (53 cm) Length: 20.5 ft (6.2 m) Weight: 3,895 lb (1,767 kg) Mod.1: 3,922 lb (1,779 kg) Mod.3: 4,000 lb (1,800 kg) Mod.8: 4,155 lb (1,885 kg) | Mk.16 Mod.7 Mod.0: 1,260 lb (570 kg) Torpex Mod.1 and 3: 746 lb (338 kg) Torpex or HBX (later used HBX-3) 960 lb (440 kg) Torpex (later used HBX) Mod.8: 1,260 lb (570 kg) HBX | Turbine | Mod.0: Speed: 46.2–51.6 kn (85.6–95.6 km/h) Range: 7,000 yd (6,400 m) Mod.1: Range: 11,000–12,500 yd (10,100–11,400 m) Mod.3: Range: 13,700 yd (12,500 m) Mod.8: same range as Mod.1 or Mod.3 |
| Mark 17 | US | 1944–1950 | Surface / Surface | Diameter: 21 in (53 cm) Length: 24 ft (7.3 m) Weight: 4,600 lb (2,100 kg) | Mod.3: 879.5 lb (398.9 kg) HBX | Turbine | Speed: 46.5 kn (86.1 km/h) Range :18,000 yd (16,000 m) |
| Mark 18 | US | 1943–1950 | Submarine / Surface | Diameter: 21 in (53 cm) Length:20.4 ft (6.2 m) Weight: 3,154 lb (1,431 kg) | 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) | 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) | Mod.2: 585 lb (265 kg) HBX | Electric | Speed: 19.6 kn (36.3 km/h) Range: 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) | 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 | | Surface / 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 & Aircraft / 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) | 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 | 1950–1959 | 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 45 Mod 0 | US | 1963–1976 | Submarine / Submarine & surface | Diameter: 21 in (53 cm) Length: 18.9 ft (5.8 m) Weight: 2,400 lb (1,100 kg) | 11 kiloton W34 nuclear warhead | Electric | Speed: 40 kn (74 km/h) Range: 15,000 yd (14 km) |
| Mark 45 Mod 1 | US | 1976-? | Submarine / Submarine & surface | Diameter: 21 in (53 cm) Length: 18.9 ft (5.8 m) Weight:2,400 lb (1,100 kg) | conventional | Electric | Speed: 40 kn (74 km/h) Range: 15,000 yd (14 km) |
| Mark 48 | US | 1972–present | Submarine / Submarine & surface | Diameter: 21 in (53 cm) | 650 lbs | Piston engine, pump jet | |