United States of America
Torpedoes Pre-World War II
Updated 10 November 2014

14.2" (36 cm) Howell
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WTUS_PreWWII_Silletto_pic.jpg

Torpedo Boat Stilletto launching a Howell torpedo about 1890
NARAL Picture

Ship Class Used On Small surface ships
Date Of Design Started in 1870
Date In Service 1895
Weight 580 lbs. (263 kg)
Overall Length 132 in (3.353 m)
Explosive Charge 100 lbs. (45.4 kg) wet gun-cotton
Range / Speed 200 yards (180 m) at 24 knots, then slower out to a maximum of 800 yards (730 m)
Power 131 lbs. (59 kg) steel flywheel spun up to 10,000 rpm
Guidance Pendulum operated rudder for anti-roll, directional stability and depth control
Notes:  The first USA torpedo, it was smaller and cheaper than the British Whitehead and required no air flask, a difficult thing for the USA to manufacture at the time.  As it was flywheel powered, this torpedo did not leave a wake and could steer a straighter course than the Whitehead as its flywheel acted as a gyroscope.  The flywheel was spun up by a small steam turbine mounted on the torpedo tube and drove two shafted propellers.  The propellars were variable pitch and were designed to maintain a constant forward speed as the flywheel slowed.  Thirty torpedoes were ordered in 1889 with twenty more being ordered in 1894.  Placed in service in 1895 and removed in 1903.  Difficulties and delays in production led the Navy to investigate the Whitehead torpedoes.
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"Short" Whitehead 18" (45 cm) Mark 1
3.55 m x 45 cm Whitehead
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WTUS_PreWWII_Oregon_Torpedo_Tube_pic.jpg

Torpedo Tube and Torpedoes on USS Oregon (B-3)
Detroit Publishing Company Collection Photograph
Library of Congress Photograph ID LC-D4-20532

WTUS_PreWWII_Maine_Torpedo_Tube_pic.jpg

Torpedo Tube on USS Maine (B-10)
Detroit Publishing Company Collection Photograph
Library of Congress Photograph ID LC-D4-20532

Ship Class Used On Surface Ships
Date Of Design about 1888
Date In Service 1894
Weight 845 lbs. (383 kg)
Overall Length 140 in (3.556 m)
Explosive Charge 118 lbs. (53.5 kg) wet gun-cotton
Range / Speed 800 yards (730 m) / 26 knots
Power Air-flask (cold running) compressed air powered, three cylinder, radial Brotherhood pattern engines.
Guidance Preset Rudder adjustment, had poor directional stability with a contractual requirement for horizontal deviation of no more than +/- 24 yards (22 m) at 800 yards (730 m)
Notes:  The US Navy negotiated for the Whitehead torpedo patent rights with a license to build torpedoes in the USA being granted in 1891.  The Navy awarded a contract to the E.W. Bliss company on 19 May 1891 for 100 torpedoes to an improved Whitehead design.  Compared to the Howell, they were much better depth-keepers but less accurate.

Nomenclature Note:  Somewhat confusingly, the Whitehead Mark 1 and Mark 2 torpedoes were built both in a 3.55 m (140 inch) version and in a 5.0 m (197 inch) version.  The shorter ones were known as the "3.55 m x 45 cm Whitehead" torpedoes while the longer ones were known as the "5.0 m x 45 cm Whitehead" torpedoes.  The Whitehead Mark 3 was built only in a 3.55 m (140 inch) version.  The longer torpedoes and the Mark 3 were redesigned with letter codes in 1913, as described below.

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"Long" Whitehead 18" (45 cm) Mark 1 or Type B
5.0 m x 45 cm Whitehead
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Ship Class Used On Surface Ships
Date Of Design 1896
Date In Service 1898
Weight 1,160 lbs. (526 kg)
Overall Length 197 in (5.004 m)
Explosive Charge 220 lbs. (100 kg) wet gun-cotton
Range / Speed 1,000 yards (910 m) / 27.5 knots
Power Air-flask (cold running) compressed air powered, three cylinder, radial Brotherhood pattern engines.
Guidance
(see Notes)
Early production:  Preset Rudder adjustment, had poor directional stability with a contractual requirement for horizontal deviation of no more than +/- 24 yards (22 m) at 800 yards (730 m)
Later production:  Mark 1 Mod 1 gyro
Notes:  Manufactured by Bliss, these were a longer version of the basic design.  Also known as the "5.0 m x 45 cm Whitehead" when first manufactured, it was designated as the "Type B" in 1913.  After tests with the Whitehead Mark 3 torpedo (described below), the last forty of these "Long" Mark 1 torpedoes were given a gyro which had been patented by Ludwig Obry in 1896.  This improved the horizontal deviation by 300 percent compared to the earlier Mark 1 torpedoes to +/- 8 yards (7 m) at 800 yards (730 m).  However, this gyro proved very hard to maintain.
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"Short" Whitehead 18" (45 cm) Mark 2
3.55 m x 45 cm Whitehead
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WTUS_PreWWII_Destroyer_Torpedo_pic.jpg

18" (45 cm) Torpedo on USN Torpedo Boat
Detroit Publishing Company Collection Photograph
Library of Congress Photograph ID LC-D4-20351

WTUS_PreWWII_Destroyer_Tube_pic.jpg

18" (45 cm) Torpedo and Torpedo Tube on USN Torpedo Boat
Detroit Publishing Company Collection Photograph
Library of Congress Photograph ID LC-D4-20352

Ship Class Used On Surface Ships
Date Of Design 1895
Date In Service 1896
Weight 845 lbs. (383 kg)
Overall Length 140 in (3.556 m)
Explosive Charge 118 lbs. (53.5 kg) wet gun-cotton
Range / Speed 800 yards (730 m) / 28 knots
Power Air-flask (cold running) compressed air powered, three cylinder, radial Brotherhood pattern engines.
Guidance Preset Rudder adjustment, had poor directional stability with a contractual requirement for horizontal deviation of no more than +/- 24 yards (22 m) at 800 yards (730 m)
Notes:  Minor improvement of the Whitehead Mark 1.
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"Long" Whitehead 18" (45 cm) Mark 2 or Type C
5.0 m x 45 cm Whitehead
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WTUS_PreWWII_Conneticut_afterbody_pic.jpg

Unidentified Torpedo afterbody on USS Connecticut B-18 circa 1909
U.S. Naval Historical Center Photograph # NH 63012

Ship Class Used On Surface Ships
Date Of Design about 1896
Date In Service about 1898
Weight 1,232 lbs. (559 kg)
Overall Length 197 in (5.004 m)
Explosive Charge 132 lbs. (60 kg) wet gun-cotton
Range / Speed 1,500 yards (1,370 m) / 28.5 knots
Power Air-flask (cold running) compressed air powered, three cylinder, radial Brotherhood pattern engines.
Guidance Mark 1 Mod 1 gyro
Notes:  Developed from the 197 inch (5 m) Whitehead Mark 1, but used 20 percent more air pressure to obtain a significantly greater range.  Designated Type C in 1913.
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Whitehead 18" (45 cm) Mark 3 or Type A
3.55 m x 45 cm Whitehead
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WTUS_PreWWII_Mark-3_pic.jpg

Whitehead 18" (45 cm) Mark 3 torpedo being launched at Newport Torpedo Station in 1894
In the background is USS Cushing D-1
U.S. Naval Historical Center Photograph # NH 82831

WTUS_PreWWII_A2_pic.jpg

18" (45 cm) torpedo being loaded into USS A-2 (ex-Adder) SS-3 about 1912
U.S. Naval Historical Center Photograph # NH 90188

WTUS_PreWWII_Kansas_torpedo_pic.jpg

Hoisting a torpedo aboard USS Kansas B-21 about 1909
U.S. Naval Historical Center Photograph # NH 82775

Ship Class Used On Surface Ships and Submarines
Date Of Design about 1898
Date In Service about 1900
Weight 845 lbs. (383 kg)
Overall Length 140 in (3.556 m)
Explosive Charge 118 lbs. (53.5 kg) wet gun-cotton
Range / Speed 800 yards (730 m) / 27.5 knots
Power Air-flask (cold running) compressed air powered, three cylinder, radial Brotherhood pattern engines.
Guidance Mark 1 Mod 1 gyro
Notes:  This was the first US torpedo to be equipped with a gyro which greatly improved accuracy, otherwise it was a minor improvement of the Whitehead Mark 2.  .  The A through D class submarines originally fired this torpedo, but the C and D classes were modified around 1912 to use any of the longer, more powerful 204 inch (5.2 m) torpedoes.
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Bliss-Leavitt 21" (53.3 cm) Mark 1
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WTUS_PreWWII_Whipple_pic.jpg

Twin 18" (45 cm) torpedo tubes on USS Whipple (D-15) in June 1918
Note 6-pdr gun in the background
U.S. Naval Historical Center Photograph # NH 41761

Ship Class Used On Surface Ships
Date Of Design 1900
Date In Service Mod 1:  1904
Mod 2:  1905
Weight 1,500 lbs. (680 kg)
Overall Length 197 in (5.004 m)
Explosive Charge 200 lbs. (91 kg) wet gun-cotton
Range / Speed Mod 1:  4,000 yards (3,660 m) / 27 knots
Mod 2:  4,000 yards (3,660 m) / 26.5 knots
Power Single stage turbine engine, alcohol fired dry heater
Guidance Mod 1:  Unknown
Mod 2:  Mark 2 Mod 2 gyro
Notes:  F.M. Leavitt was a Bliss engineer.  This design was a substantially improved torpedo, the first to use air heating which gave it much greater range than the compressed cold-air powered Whitehead.  This new torpedo had a two stage, single wheel turbine set perpendicular to the propeller shaft to in an attempt to avoid torque problems, but the design still produced an unbalanced torque and unwanted gyroscopic effects.  These tended to make the torpedo roll.  Used a single 4-blade propeller.  The original Bliss-Leavitt Mark 1 was an experimental torpedo with two built in 1903 but not issued to the fleet.  200 more were ordered on 4 November 1905.  Fifty additional torpedoes of the Mod 1 improved design were ordered on the same date.  By 1912 all Mark 1 and Mark 1 Mod 1 torpedoes had been converted to the Bliss-Leavitt Mark 1 Mod 2 standard (no details available) and then redesignated as Torpedo Mark 1 in 1913.
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Bliss-Leavitt 21" (53.3 cm) Mark 2
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WTUS_PreWWII_Whitehead_pic.jpg

Torpedo at the Newport Torpedo Station, Rhode Island circa 1908-1919
Photograph from National Photo Company
Library of Congress Photograph ID LC-DIG-npcc-19910 and LC-DIG-npcc-32496

Ship Class Used On Surface Ships
Date Of Design about 1904
Date In Service 1905
Weight 1,900 lbs. (862 kg)
Overall Length 197 in (5.004 m)
Explosive Charge Mod 0:  207 lbs. (94 kg) wet gun-cotton
Mod 1:  183 lbs. (83 kg) wet gun-cotton
Range / Speed 3,500 yards (3,200 m) / 26 knots
Power Two-stage turbine engine, alcohol fired dry heaters
Guidance Mark 5 gyro
Notes:  Introduced two countra-rotating turbine wheels which drove contra-rotating propellers to overcome the unbalanced torque of the Mark 1.  This propulsion system eliminated the rolling problem at a slight cost in range and speed.  This propulsion arrangement was used on all subsequent USA torpedoes until after World War II.  Designated as Torpedo Mark 2 in 1913.
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Bliss-Leavitt 21" (53.3 cm) Mark 3
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WTUS_PreWWII_Virginia_pic.jpg

Torpedoes aboard a Virginia Class battleship in 1911
Note the contra-rotating propellers
Photograph copyrighted by N. Moser
Library of Congress Photograph ID LC-USZ62-103266

Ship Class Used On Surface Ships
Date Of Design about 1909
Date In Service about 1910
Weight 1,500 lbs. (680 kg)
Overall Length 197 in (5.004 m)
Explosive Charge 218 lbs. (99 kg) wet gun-cotton
Range / Speed 4,000 yards (3,660 m) / 26 knots
Power Turbine engine, alcohol fired dry heaters
Guidance Mark 5 Mod 2 gyro
Notes:  Basically a Bliss-Leavitt Mark 2 with increased range.  208 ordered in 1909 and 1910.  Designated as Torpedo Mark 3 in 1913.
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Bliss-Leavitt 18" (45 cm) Mark 4
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Ship Class Used On Submarines
Date Of Design about 1910
Date In Service about 1912
Weight 1,547 lbs. (702 kg)
Overall Length 197 in (5.004 m)
Explosive Charge Mod 0:  200 lbs. (91 kg) wet gun-cotton
Mod 1:  199 lbs. (90 kg) wet gun-cotton
Range / Speed Mod 0:  2,000 yards (1,830 m) / 30 knots
Mod 1:  3,000 yards (2,740 m) / 29 knots
Power Turbine engine, alcohol fired dry heaters
Guidance Mod 0:  Mark 4 Mod 3 gyro
Mod 1:  Mark 2 Mod 2 gyro
Notes:  First USA torpedo designed specifically for submarines.  Twenty-one inch (53.3 cm) torpedoes were too heavy and too bulky for the submarines of the time.  For that reason, this torpedo was designed as a scaled down version of the Bliss-Leavitt Mark 3.  Designated as Torpedo Mark 4 in 1913.  Used by C and D class submarines.
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Whitehead 18" (45 cm) Mark 5
Whitehead 5.2 m x 45 cm
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WTUS_PreWWII_Flusser_pic.jpg

18" (45 cm) Torpedo Tube on USS Flusser D-20 about 1916
Note the hinged "spoon" on the end of the tube, which helped to guide the torpedo as it cleared the tube
U.S. Naval Historical Center Photograph # NH 79484

Ship Class Used On Destroyers, Torpedo Boats and other small ships
Date Of Design 1908
Date In Service about 1910
Weight 1,452 lbs. (659 kg)
Overall Length 204 in (5.182 m)
Explosive Charge 199 lbs. (90 kg) wet gun-cotton
Range / Speed 4,000 yards (3,660 m) / 27 knots
2,000 yards (1,830 m) / 36 knots
1,000 yards (910 m) / 40 knots
Power Dry heater system (hot running), four cylinder reciprocating engine
Guidance Mark 1 Mod 3 gyro
Notes:  First torpedo in US service that was built by a foreign company.  Manufactured by the Whitehead facility in Weymouth, UK.  Later, this design was manufactured under license by the US and became the first torpedo built at the Newport Facility.  First major improvement to the original Whitehead engine in that a heater was used for the air feed, which increased the range by a factor of five.  This was the first US torpedo that could be set for any one of three speeds.  However, the speed had to be set before the torpedo was loaded into the tube, which limited its tactical flexibility.  This was the last piston engine used in USN torpedoes until the Mark 46.  Replaced by the Bliss-Leavitt Mark 7.
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Bliss-Leavitt 18" (45 cm) Mark 6
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WTUS_PreWWII_H5_pic.jpg

Bow torpedo room on Submarine H-5 (SS-148) about 1919
Note the two torpedoes in the lower storage racks
U.S. Naval Historical Center Photograph # NH 4674

WTUS_PreWWII_Walke_pic.jpg

Firing a torpedo from USS Walke (D-34) in 1914
U.S. Naval Historical Center Photograph # NH 92539

WTUS_PreWWII_Walke_hoist_pic.jpg

Hoisting a torpedo aboard USS Walke (D-34) about 1914
Note the contra-rotating propellers, the trolley and the "spoons" on the launching tubes
U.S. Naval Historical Center Photograph # NH 92541

Ship Class Used On Destroyers, Cruisers and E through H class submarines
Date Of Design about 1908
Date In Service about 1911
Weight 1,800 lbs. (616 kg)
Overall Length 204 in (5.182 m)
Explosive Charge 200 lbs. (90 kg) wet gun-cotton
Range / Speed 2,000 yards (1,830 m) / 35 knots
Power Turbine engine, alcohol fired dry heaters
Guidance Mark 6 gyro
Notes:  The Bliss-Leavitt Mark 6 introduced a new turbine configuration in which the wheels were horizontal.  This configuration has been the most common choice for USN torpedo turbine systems ever since.  100 were ordered in 1909.
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Bliss-Leavitt 18" (45 cm) Mark 7
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WTUS_PreWWII_K-8_pic.jpg

Loading a torpedo aboard K-8 (S-39) about 1915
U.S. Naval Historical Center Photograph # NH 100767

Ship Class Used On "K," "O" and "R" Class Submarines
Date Of Design 1910
Date In Service 1912
Weight Mod 0 (submarines):  1,588 lbs. (720 kg)
Overall Length 204 in (5.182 m)
Explosive Charge Mod 0:  205 lbs. (93 kg) TNT
Range / Speed Mod 0:  4,000 yards (3,650 m) / 32 knots
Power Wet-Heater
Guidance Mark 7 gyro
Notes:  First wet-heater (water spray into combustion chamber) torpedo in the US Navy.  240 ordered in 1912.  Still being used by old submarines during World War II.  Some Mark 7 torpedoes were modified for use by aircraft (see below).
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Bliss-Leavitt 18" (45 cm) Mark 7 Type D (Short Torpedo)
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WTUS_PreWWII_R-6L_pic.jpg

Dummy Mark 7 Type D being dropped from a Curtis R-6L sometime during 1919
US Navy Photograph

Ship Class Used On Submarines
Aircraft
Date Of Design About 1916
Date In Service 1917
Weight 7D - 1,036 lbs. (470 kg)
Overall Length 120 in (3.048 m)
Explosive Charge 7D - 200 lbs. (90 kg) TNT
Range / Speed 7D - 2,000 yards (1,800 m) / 35 knots
Power Wet-heater
Notes:  Smaller version of the Mark 7 developed to fit the shorter torpedo tubes on old submarines.  Never deployed for that purpose, but used during early aircraft tests.  After a series of drops with dummy torpedoes, on 14 July 1919 a live Type D was successfully launched from an R-6L Navy floatplane.  43 more Type D torpedoes were launched from planes during the next 12 months.
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Bliss-Leavitt 18" (45 cm) Mark 7 Mods A, 2A and 5A (Aircraft)
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WTUS_PreWWII_aircraft_mk7_pic.jpg

Aircraft version of the Mark 7 being dropped by a DT-2 torpedo plane during trials in the mid-1920s
Note the longer length compared to the Mark 7 Type D above

Ship Class Used On Aircraft
Date Of Design 1920
Date In Service 1920
Weight 7D Mod A - 1,593 lbs. (723 kg)
7D Mod 2A - 1,736 lbs. (787 kg)
7D Mod 5A - 1,628 lbs. (738 kg)
Overall Length 204 in (5.182 m)
Explosive Charge 7D Mod A - 205 lbs. (93 kg) TNT
7D Mod 2A - 319 lbs. (145 kg) TNT
7D Mod 5A - 326 lbs. (148 kg) TNT or TPX
Range / Speed 7D Mod A - 3,200 yards (2,930 m) / 31 knots
7D Mod 2A - 6,000 yards (5,490 m) / 30 knots
7D Mod 5A - 3,500 yards (3,200 m) / 35 knots
Power Wet-Heater
Guidance Mark 7 Mod 2 gyro
Notes:  The first experimental USN aircraft drops with Mark 7 torpedoes were made in May 1920 at the Naval Air Station, Anacostia, Maryland, using two Mark 7 Mod 5 torpedoes.  Air speed for these drops is believed to have been 50 to 55 knots at altitudes of 18 and 30 feet (5 and 9 m).  It was found that the torpedo dropped from 30 feet (9 m) was badly damaged while the one dropped from 18 feet (5 m) was not.  Torpedoes were then modified by strengthening them for shock, installation of exploder safety pin and attachment of a nose drogue.

The first mass torpedo practice against a live target was conducted off the Virginia capes on 22 September 1922 by 18 PT aircraft of Torpedo and Bombing Plane Squadron One.  The squadron attacked the designated target, Arkansas (BB-33), which was one of a formation of three battleships which were maneuvering while running at full speed.  The attack lasted over a 25 minute period during which time the aircraft approached the ships from both sides and released 17 Mark 7 Mod 1 "A" torpedoes at distances of 500 to 1,000 yards (450 to 900 m).  Eight hits were made on the designated target.  Subsequent analysis emphasized the artificialities which prevented the practice from demonstrating combat capability of either the surface or air units, but the outstanding fact demonstrated was that torpedoes could be successfully launched from aircraft and be made to run straight.

During trials in 1924, Mark 7 torpedoes were successfully launched from DT-2 torpedo planes at an air speed of 95 knots and from an altitude of 32 feet (10 m).

Aircraft torpedoes of this type were eventually replaced by the Mark 13.

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Bliss-Leavitt 21" (53.3 cm) Mark 8
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WTUS_PreWWII_Farragut_pic.jpg

Torpedoes intended for USS Farragut DD-300 and USS Thompson DD-305
Picture taken about 1925
U.S. Naval Historical Center Photograph # NH 82563

Ship Class Used On Flush-deck destroyers
Date Of Design About 1914
Date In Service 1915
Weight Mods 0, 1, 2, 2A and 2B:  2,761 lbs. (1,252 kg)
Mods 3A and 3B:  3,050 lbs. (1,383 kg)
Mod 8:  3,176 lbs. (1,441 kg)
Overall Length Mods 0, 1, 2, 2A and 2B:  248 in (6.299 m)
Mods 3A and 3B:  250 in (6.350 m)
Mod 8:  256.3 in (6.510 m)
Explosive Charge Mods 0, 1, 2, 2A and 2B:  321 lbs. (146 kg) TNT
Mods 3A and 3B:  385 lbs. (175 kg) TNT
Mod 8:  466 lbs. (211 kg) TNT
Range / Speed Mods 0, 1, 2, 2A and 2B:  10,000 or 12,500 yards (9,140 or 11,430 m) / 27 knots
Mods 3A and 3B:  13,500 yards (12,340 m) / 27 knots
Mod 8:  15,000 yards (13,720 m) / 29 knots
Power Wet-heater
Guidance Mark 8 Mod 1 gyro
Notes:  First 21" x 21' (53.3 cm x 6.5 m) USN torpedo.  Later versions starting in 1923 - Mod 5, 6 and 8 - had much larger warheads.  These torpedoes were still being used on older destroyers and PT boats during World War II.  It is possible that a higher speed setting was available for the torpedoes issued to PT boats.  This torpedo was supplied to Britain for use on Lend-Lease Destroyers in 1940.  Torpedoes issued to Britain are listed as having a warhead of 380 lbs. (172 kg) TNT and a range of 14,000 yards (12,800 m) at 27 knots.
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Bliss-Leavitt 21" (53.3 cm) Mark 9
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Ship Class Used On Mod 1:  World War I-era Battleships
Mod 1B:  Submarines
Date Of Design About 1912
Date In Service 1915
Weight Mod 1:  2,059 lbs. (934 kg)
Mod 1B:  2,377 lbs. (1,078 kg)
Overall Length 196 in (5.004 m)
Explosive Charge Mod 1:  210 lbs. (95 kg) TNT
Mod 1B:  395 lbs. (179 kg) Torpex
Range / Speed Mod 1:  9,000 yards (8,230 m) / 27 knots
Mod 1B:  5,500 yards (5,030 m) / 34.5 knots
Power Wet-heater
Guidance Mark 8 Mod 1 gyro
Notes:  A short torpedo developed for the submerged tubes on battleships.  Originally known as the Bliss-Leavitt Mark 3 Mod 1.  Used by "R" and "S" class submarines in World War II.  Last torpedo built by Bliss.
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21" (53.3 cm) Mark 10
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Ship Class Used On World War I-era Submarines
Date Of Design About 1917
Date In Service About 1918
Weight Mod 0:  2,050 lbs. (930 kg)
Mod 3:  2,215 lbs. (1,005 kg)
Overall Length 183 in (4.953 m)
Explosive Charge Mod 0:  400 lbs. (181 kg) TNT
Mod 3:  497 lbs. (225 kg) TNT or 485 lbs. (220 kg) Torpex
Range / Speed Mod 0:  5,000 yards (4,570 m) / 30 knots
Mod 3:  3,500 yards (3,200 m) / 36 knots
Power Wet-heater
Guidance Mark 13 Mod 1 gyro
Notes:  Last torpedo designed by Bliss and manufactured by the Naval Torpedo Station at Newport.  Still used by "S" class submarines during World War II.
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21" (53.3 cm) Mark 11
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WTUS_Milwaukee_torp_pic.jpg

USS Milwaukee CL-5 launching a torpedo ca. 1925
U.S. Naval Historical Center Photograph # NH 85126

Ship Class Used On Destroyers and Cruisers
Date Of Design About 1924
Date In Service 1926
Weight Mod 0:  3,511 lbs. (1,593 kg)
Mod 1:  3,521 lbs. (1,597 kg)
Overall Length 271 in (6.883 m)
Explosive Charge 500 lbs. (227 kg) TNT
Range / Speed 6,000 yards (5,500 m) / 46 knots
10,000 yards (9,150 m) / 34 knots
15,000 yards (13,700 m) / 27 knots
Power Wet-heater
Guidance Mark 12 Mod 1 gyro
Notes:  First torpedo entirely developed by Newport Station.  It appears to have been of heavier construction than previous torpedoes.
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21" (53.3 cm) Mark 12
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Ship Class Used On Destroyers and Cruisers
Date Of Design about 1927
Date In Service 1928
Weight 3,505 lbs. (1,590 kg)
Overall Length 271 in (6.883 m)
Explosive Charge 500 lbs. (227 kg) TNT
Range / Speed 7,000 yards (6,400 m) / 44 knots
10,000 yards (9,150 m) / 34.5 knots
15,000 yards (13,700 m) / 27.5 knots
Power Wet-heater
Notes:  A modified Mark 11 with the only difference being a reduction in the high speed setting to improve reliability.  Approximately 100 manufactured.
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Data from
"Torpedo:  The Complete History of the World's Most Revolutionary Naval Weapon" by Roger Branfill-Cook
"Naval Weapons of World War Two" by John Campbell
"US Naval Weapons" and "US Submarines through 1945:  An Illustrated Design History" both by Norman Friedman
"Ship Killers:  A History of the American Torpedo" by Thomas Wildenberg and Norman Polmar
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"A Brief History of U.S. Navy Torpedo Development" sometimes called OP 353W or TD5436 on line at HNSA
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Naval Undersea Museum
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Special help from Tom Apple
Page History

28 August 2008 - Benchmark
12 January 2009 - Added information on aircraft use of the Mark 7 torpedoes, added pictures of Virginia class battleship and Whitehead torpedo
26 June 2010 - Added information on Mark 8 torpedoes supplied to Britain and corrected typographical errors
18 December 2010 - Updated data tables to include guidance systems and other information
10 November 2014 - Added additional information