18" (45 cm) Torpedoes

18" (45 cm) Mark XII

Ship Class Used On Aircraft Launched
Date Of Design 1935
Date In Service 1937
Weight 1,548 lbs. (702 kg)
Overall Length 16 ft 3 in (4.953 m)
Negative Buoyancy about 230 lbs. (104 kg)
Explosive Charge 388 lbs. (176 kg) TNT
Range / Speed 1,500 yards (1,370 m) / 40 knots
3,500 yards (3,200 m) / 37 knots
Power Burner-cycle, about 140 hp @ 40 knots

An improved Mark XI. Standard airborne torpedo for the first half of World War II and still in limited use until the end.

18" (45 cm) Mark XIII

No details of this torpedo have been found and "Naval Weapons of World War Two" speculates that it may have never existed. Perhaps this mark number was not assigned because of superstition about unlucky numbers.

18" (45 cm) Mark XIV

Ship Class Used On Aircraft Launched
Date Of Design N/A
Date In Service 1938 (?)
Weight 1,630 lbs. (739 kg)
Overall Length N/A
Explosive Charge 375 lbs. TNT (170 kg)
Range / Speed 1,650 yards (1,500 m) / 45 knots
2,950 yards (2,700 m) / 41 knots
Power Whitehead wet-heater

Almost the entire stock of this model was lost with the surrender of Singapore. Considered to be less robust than the Mark XII. Use methylated spirits as fuel.

18" (45 cm) Mark XV

Ship Class Used On Aircraft Launched and some MTBs
Date Of Design 1942
Date In Service 1943
Weight 1,801 lbs. (817 kg)
Overall Length 17 ft 2.75 in (5.251 m)
Negative Buoyancy about 375 lbs. (170 kg)
Explosive Charge 545 lbs. (247 kg) Torpex
Range / Speed 2,500 yards (2,290 m) / 40 knots
3,500 yards (3,200 m) / 33 knots
Power Burner-cycle, about 140 hp @ 40 knots

Standard airborne torpedo in second half of World War II. 33 knot setting was used only on MTBs.

18" (45 cm) Mark XVI

Air launched circling electric torpedo that never saw service. Parachute dropped, speed of about 10 knots for 30 minutes. Development halted in 1943.

18" (45 cm) Mark XVII

Ship Class Used On Aircraft Launched
Date Of Design 1944
Date In Service 1945
Weight 1,874.5 lbs. (850 kg)
Overall Length 17 ft 3.4 in (5.268 m)
Negative Buoyancy 447 lbs. (203 kg)
Explosive Charge 600 lbs. (272 kg) Torpex
Range / Speed 2,500 yards (2,300 m) / 39-40 knots
Power Burner-cycle, about 140 hp @ 40 knots

An improved Mark XV in production at the end of the war. Used on Firebrands and land-based aircraft.

21" (53.3 cm) Torpedoes

21" (53.3 cm) Mark VIII and VIII**

Ship Class Used On All Submarines from the "O" Class on and MTBs
Date Of Design About 1925
Date In Service 1927
Weight 3,452 lbs. (1,566 kg)
Overall Length 21 ft 7 in (6.579 m)
Negative Buoyancy 804 lbs. (365 kg)
Explosive Charge Mark VIII:
750 lbs. (340 kg) TNT
Mark VIII**:
Originally: 722 lbs. (327 kg) TNT
Later: 805 lbs. (365 kg) Torpex
Range / Speed Mark VIII:
5,000 yards (4,570 m) / 40 knots
Mark VIII**:
5,000 yards (4,570 m) / 45.5 knots
7,000 yards (6,400 m) / 41 knots
Power Burner-cycle, 322 hp @ 45 knots

The Mark VIII was the first burner-cycle torpedo in service. The principal World War II version was the Mark VIII** and this torpedo was used far more than any other British torpedo during the war. 3,732 were fired by September 1944, 56.4% of the total. This torpedo was still in use in British ships as late as 1983 and is probably still used today in other navies.

21" (53.3 cm) Mark IX and IX**

Ship Class Used On Leander and later cruisers, "A" and later destroyer classes
Also replaced the old Mark VII in some 8" (20.3 cm) cruisers during the war
Date Of Design 1928
Date In Service 1930
Weight 3,732 lbs. (1,693 kg)
Overall Length 23 ft 10.5 in (7.277 m)
Negative Buoyancy 732 lbs. (332 kg)
Explosive Charge Mark IX and IX*:
750 lbs. (340 kg) TNT
Mark IX**:
Originally: 722 lbs. (327 kg) TNT
Later: 805 lbs. (365 kg) Torpex
Range / Speed Mark IX:
10,500 yards (9,600 m) / 36 knots
13,500 yards (12,350 m) / 30 knots
Mark IX*:
11,000 yards (10,050 m) / 36 knots
14,000 yards (12,800 m) / 30 knots Mark IX**:
11,000 yards (10,050 m) / 41 knots
15,000 yards (13,700 m) / 35 knots
Power Burner-cycle, 264 hp @ 41 knots

First appeared in 1930 and was considerably improved by 1939.

21" (53.3 cm) Mark X, X*, X**, X*** and X****

Ship Class Used On Mark X: Polish destroyers
Mark X*: ex-Brazilian Havant class destroyers
Mark X**: British MTBs
Mark X***: Dutch Submarines
Mark X****: Greek Submarines
The data that follows is specifically for the Mark X*
Date Of Design 1939
Date In Service 1940
Weight 3,571 lbs. (1,620 kg)
Overall Length 23 ft 7.5 in (7.200 m)
Negative Buoyancy Mark X*: 606 lbs. (275 kg)
Explosive Charge 661 lbs. (300 kg) TNT
Range / Speed 3,280 yards (3,000 m) / 47 knots
5,470 yards (5,000 m) / 43 knots
8,750 yards (8,000 m) / 36 knots
13,120 yards (12,000 m) / 29 knots
Power Wet-heater

Britain supplied modified torpedoes for ships from nations taken oven by the Axis powers. The principal differences between the various versions was the overall length.

21" (53.3 cm) Mark XI

Ship Class Used On Post-War Destroyers
Date Of Design 1942
Date In Service 1944
Weight 3,632 lbs. (1,647 kg)
Overall Length 22 ft 5 in (6.833 m)
Negative Buoyancy 734 lbs. (333 kg)
Explosive Charge 710 lbs. (322 kg) TNT
Range / Speed 5,500 yards (5,000 m) / 28 knots
Power Electric batteries

The Royal Navy had little interest in electric torpedoes prior to World War II as they had poor performance compared to the burner-cycle units already in service and there seemed to be little need for a trackless torpedo. After some German G7e-T2 torpedoes were captured in 1940, Britain started a low-priority development program, but not much was done until 1942 when there was a need for trackless torpedoes for use in the Mediterranean. The first prototype was ready for trials in May 1943 but the surrender of the Italians again lowered the developmental priority. The first production torpedo was finally issued in August 1944 and some were delivered to the Far East but the war ended before any were used in action. Used two batteries with 26 cells each and a total weight 1,475 lbs. (669 kg). The motor produced 98 BHP at 1,755 rpm and took 960 amps at 91 volts. If the batteries were not heated prior to firing, then the range was reduced to 4,500 to 5,000 yards (4,100 to 4,570 m) at 28 knots.

Sources

Data from:

  • "Naval Weapons of World War Two" by John Campbell
  • "Run the Gauntlet: The Channel Dash 1942" by Ken Ford
  • "From Fancy to Stingray: British Torpedoes since 1945" article by Antony Preston in "Warships Volume V"

Page History

04 July 2006 - Benchmark

28 December 2013 - Added photographs of Mark IX torpedo, Beaufort and Firebrand aircraft

26 July 2014 - Added photograph of Mark XV torpedo