There have been a number of 18 inch torpedoes in service with the United Kingdom. These have been used on ships of the Royal Navy

Royal Navy

The Royal Navy is the naval warfare service branch of the British Armed Forces. Founded in the 16th century, it is the oldest service branch and is known as the Senior Service...

 and aircraft of both the Fleet Air Arm

Fleet Air Arm

The Fleet Air Arm is the branch of the British Royal Navy responsible for the operation of naval aircraft. The Fleet Air Arm currently operates the AgustaWestland Merlin, Westland Sea King and Westland Lynx helicopters...

 and Royal Air Force

Royal Air Force

The Royal Air Force is the aerial warfare service branch of the British Armed Forces. Formed on 1 April 1918, it is the oldest independent air force in the world...

. Note that the British "18 inch" torpedoes were 17.72 inches (45 cm) in diameter, beginning with the "Fiume" (Whitehead

Robert Whitehead

Robert Whitehead was an English engineer. He developed the first effective self-propelled naval torpedo. His company, located in the Austrian naval centre in Fiume, was the world leader in torpedo development and production up to the First World War.- Early life:He was born the son of a...

) torpedo of 1890.

45 cm "Fiume" (Whitehead) torpedo

First introduced into British service in 1894.

• Year : about 1888
• Weight : 845 lb (383.3 kg)
• Length : 11 in 8 in (3.56 m)
• Warhead : 118 lb (53.5 kg) wet gun-cotton
  Nitrocellulose
  Nitrocellulose is a highly flammable compound formed by nitrating cellulose through exposure to nitric acid or another powerful nitrating agent. When used as a propellant or low-order explosive, it is also known as guncotton...
  
  
• Performance : 26.5 knots (14.4 m/s) for 800 yd (731.5 m)
• Propulsion : Compressed air

18 inch Mark V

Used on the River class

River class destroyer

The River-class destroyer was a heterogeneous class of torpedo boat destroyer built to assorted builders' designs for the Royal Navy at the turn of the 20th century, which saw extensive service in World War I...

 and 1905 Tribal class

Tribal class destroyer (1905)

The Tribal or F class was a class of destroyer built for the Royal Navy. Twelve ships were built between 1905 and 1908 and all saw service during World War I, where they saw action in the North Sea and English Channel as part of the 6th Flotilla and Dover Patrols.-Design:The preceding River or E...

 destroyers.

• Year : about 1899
• Weight : 1353 lb (613.7 kg)
• Warhead : 296 lb (134.3 kg) including pistol
• Propulsion : Compressed air

18 inch Mark VI

Used on Destroyers of the early 1900's.

• Year : about 1904
• Performance : 28.5 knots (15.5 m/s) for 4000 yd (3,657.6 m) or 41 knots (22.3 m/s) for 1000 yd (914.4 m)
• Propulsion : Compressed air

18 inch Mark VII and VII*

Introduced on the 1908 members of the 1905 Tribal class

Tribal class destroyer (1905)

The Tribal or F class was a class of destroyer built for the Royal Navy. Twelve ships were built between 1905 and 1908 and all saw service during World War I, where they saw action in the North Sea and English Channel as part of the 6th Flotilla and Dover Patrols.-Design:The preceding River or E...

 destroyers. Used by torpedo boats built before the First World War and destroyers. Used by RAF flying boats in the 1920s.

• Year : 1907
• Warhead : 320 lb (145.1 kg) TNT
• Performance :
  • Mark VI :
    30 knots (16.3 m/s) for 6000 yard
    41 knots (22.3 m/s) for 3000 yd (2,743.2 m)
  • Mark VI* :
    29 knots (15.8 m/s) for 7000 yd (6,400.8 m)
    35 knots (19.1 m/s) for 5000 yd (4,572 m)
• Propulsion : Wet-heater

18 inch Mark VIII

• Year: 1913
• Role: Submarines and aircraft (Note: During World War II and after the Mk.VIII was a 21 inch torpedo)
• Warhead: 320 lb (145.1 kg) TNT
• Propulsion: Wet heater
• Performance: 35 knots (19.1 m/s) for 2500 yd (2,286 m)

18 inch Mark XI

• Year: 1934
• Aircraft carried
• Dimensions: 17.72 in (45 cm) dia.
• Warhead: 465 lb (210.9 kg) TNT
• Propulsion: Burner cycle
• Performance: 35 knots (19.1 m/s) for 2500 yd (2,286 m)

18 inch Mark XII

Aircraft launched

Aerial torpedo

The aerial torpedo, airborne torpedo or air-dropped torpedo is a naval weapon, the torpedo, designed to be dropped into water from an aircraft after which it propels itself to the target. First used in World War I, air-dropped torpedoes were used extensively in World War II, and remain in limited...

, used by Fleet Air Arm

Fleet Air Arm

The Fleet Air Arm is the branch of the British Royal Navy responsible for the operation of naval aircraft. The Fleet Air Arm currently operates the AgustaWestland Merlin, Westland Sea King and Westland Lynx helicopters...

 and RAF Coastal Command

RAF Coastal Command

RAF Coastal Command was a formation within the Royal Air Force . Founded in 1936, it was the RAF's premier maritime arm, after the Royal Navy's secondment of the Fleet Air Arm in 1937. Naval aviation was neglected in the inter-war period, 1919–1939, and as a consequence the service did not receive...

.

18 inch Mark XIV

The Mark XIV was an aircraft-launched torpedo. Stocks were lost with the fall of Singapore.

18 inch Mark XV

• Year: 1942
• Operators: Fleet Air Arm, RAF Coastal Command, Royal Navy
• Role: Aircraft and Motor Torpedo Boat
  Motor Torpedo Boat
  Motor Torpedo Boat was the name given to fast torpedo boats by the Royal Navy, and the Royal Canadian Navy.The capitalised term is generally used for the Royal Navy boats and abbreviated to "MTB"...
  
  s, 1943 onwards
• Dimensions: 17.72 in (45 cm) × 17 inch
• Warhead: 545 lb (247.2 kg) Torpex
  Torpex
  Torpex is a secondary explosive 50% more powerful than TNT by mass. Torpex is composed of 42% RDX, 40% TNT and 18% powdered aluminium. It was used in the Second World War from late 1942. The name is short for Torpedo Explosive', having been originally developed for use in torpedoes...
  
  
• Propulsion: Burner cycle
• Performance: 40 knots (21.8 m/s) for 2500 yd (2,286 m) or 33 knots (18 m/s) for 3500 yd (3,200.4 m)

18 inch Mark XVII

• United Kingdom, 1944
• Aircraft launched
• Operated by FAA, RAF Coastal Command, Blackburn Firebrand
  Blackburn Firebrand
  |-See also:-References:NotesBibliography* Brown, Eric, CBE, DCS, AFC, RN.; Green William and Swanborough, Gordon. "Fairey Swordfish". Wings of the Navy, Flying Allied Carrier Aircraft of World War Two. London: Jane's Publishing Company, 1980, p. 157–167. ISBN 0-7106-0002-X.* Buttler, Tony....
  
  
• Dimensions: 17.72 in (45 cm) × 17 inch
• Warhead: 600 lb (272.2 kg) Torpex
  Torpex
  Torpex is a secondary explosive 50% more powerful than TNT by mass. Torpex is composed of 42% RDX, 40% TNT and 18% powdered aluminium. It was used in the Second World War from late 1942. The name is short for Torpedo Explosive', having been originally developed for use in torpedoes...
  
  
• Propulsion: Burner cycle
• Performance: 40 knots (21.8 m/s) for 2500 yd (2,286 m)

18 inch Mark 30

An air-dropped passive acoustic homing torpedo known as "Dealer" and "Dealer B". "Dealer" did not see service use, but its successor, "Dealer B" (the Mark 30 Mod 0), was issued from June 1954. Considered very successful with approximately 1,200 being built, it served in both the Royal Navy and RAF until 1970. The Mark 30 Mod 1 had several improvements, but this program was cancelled in 1955 in favour of purchasing Mark 43 Mod 3 torpedoes from the USA.

• Length: 8 ft (2.4 m)
• Weight: 646 lb (293 kg)
• Performance: 12.5 knots (6.8 m/s) for 3000 yd (2,743.2 m) or 19 knots (10.3 m/s) for 830 yd (759 m)

External links

• Geoff Kirby, A History of the Torpedo in the Early Days