# British 18-inch torpedo

There have been a number of 18-inch (45cm) torpedoes in service with the Royal Navy of the United Kingdom.
These have been used on ships of the Royal Navy and aircraft of both the Fleet Air Arm and Royal Air Force, while Royal Navy surface ships and submarines use 21-inch torpedoes.
The British 18-inch torpedoes were 17.72 inches (45.0 cm) in diameter, beginning with the "Fiume" Whitehead torpedo of 1890.

## 45 cm "Fiume" (Whitehead) torpedo

First introduced into British service in 1894.
* Year : about 1888
* Weight : 845 lb (383 kg)
* Length : 11 ft 8 in (3.56 m)
* Warhead : 118 lb (54 kg) wet gun-cotton
* Performance : 26.5 knots (49.1 km/h; 30.5 mph) for 800 yd (730 m)
* Propulsion : Compressed air

## Mark V

Used on the River-class and 1905 Tribal-class destroyers.
* Year : about 1899
* Weight : 1,353 lb (614 kg)
* Warhead : 296 lb (134 kg) including pistol
* Propulsion : Compressed air

## Mark VI

Used on destroyers of the early 1900s.
* Year : about 1904
* Performance : 28.5 knots (52.8 km/h; 32.8 mph) for 4,000 yd (3,700 m) or 41 knots (76 km/h; 47 mph) for 1,000 yd (910 m)
* Propulsion : Compressed air

## Mark VII and VII*

Introduced on the 1908 members of the 1905 Tribal class 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 (150 kg) TNT
* Performance :
** Mark VII : 30 knots (56 km/h; 35 mph) for 6,000–7,000 yd (5,500–6,400 m) 41 knots (76 km/h; 47 mph) for 3,000 yd (2,700 m)
** Mark VII* : 29 knots (54 km/h; 33 mph) for 7,000 yd (6,400 m) 35 knots (65 km/h; 40 mph) for 5,000 yd (4,600 m)
* Propulsion : Wet-heater

## 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 (150 kg) TNT
* Propulsion: Wet heater
* Performance: 35 knots (65 km/h; 40 mph) for 2,500 yd (2,300 m)

## Mark XI

* Year: 1934
* Aircraft carried
* Dimensions: 17.72 in (450 mm) dia.
* Warhead: 465 lb (211 kg) TNT
* Propulsion: Burner cycle
* Performance: 35 knots (65 km/h; 40 mph) for 2,500 yd (2,300 m)

## Mark XII

Aircraft launched, used by Fleet Air Arm and RAF Coastal Command.

## Mark XIV

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

## Mark XV

* Year: 1942
* Operators: Fleet Air Arm, RAF Coastal Command, Royal Navy
* Role: Aircraft and Motor Torpedo Boats, 1943 onwards
* Dimensions: 17.69 in (449 mm) × 17 ft 2.7 in (5.250 m)
* Warhead: 545 lb (247 kg) Torpex
* Propulsion: Burner cycle
* Performance: 40 knots (74 km/h; 46 mph) for 2,500 yd (2,300 m) or 33 knots (61 km/h; 38 mph) for 3,200 yd (2,900 m)

## Mark XVI

Electric torpedo project not completed.

## Mark XVII

* United Kingdom, 1944
* Aircraft launched
* Operated by FAA, RAF Coastal Command, Blackburn Firebrand
* Dimensions: 17.72 in (450 mm) × 17 ft 3 in (5.26 m)
* Warhead: 600 lb (270 kg) Torpex
* Propulsion: Burner cycle
* Performance: 40 knots (74 km/h; 46 mph) for 2,500 yd (2,300 m)

## Mark 30 Dealer

An air-dropped passive acoustic homing torpedo known as "Dealer". The program was initiated in 1943, with the goal of developing a parachute-dropped ASW weapon. At the end of the Second World War the "Dealer" project was renamed "Dealer A" and became further branched out into the 21-inch "Bidder" and 18-inch "Dealer B" projects. Thus, the Mark 30 Dealer was developed alongside the Mark 20 Bidder and shared elements of its design. The original design for the Dealer torpedo (Dealer A) had no control surfaces, being steered by two propellers that varied in speed, in a manner similar to the Italian-supplied LT 350 used by Germany. Pitch control was achieved by moving the battery fore and aft. Dealer A did not see service use, but its successor, Dealer B (Mark 30 Mod 0), a conventional design of a passive acoustic homing finned torpedo using contra-rotating propellers, achieved a high hit rate against submerged targets during trials in 1953 and was issued starting in June 1954. Since Dealer A never entered service, Dealer B was simply called "Dealer". Approximately 1200 units were built in total, with the weapon serving in both the RN and RAF until 1970. The Mark 30 Mod 1, a successor design, had several improvements but this program was canceled in 1955 in favor of purchasing Mark 43 Mod 3 torpedoes from the United States. The reason for this decision was the impending retirement of the Avro Shackleton and Fairey Gannet aircraft, with no adequate replacement; the upcoming Westland Wasp ASW helicopter was incapable of carrying the Mark 30. Although the decision to retire the aircraft were stalled, the Mark 30 Mod 1 would not see development. Trials with the Mark 44 in 1956 indicated that the hit rate was approximately four times worse than the Mark 30 Dealer in its original form, but nonetheless, the British government went ahead with their decision, placing a contract with the Plessey Company for standardizing the American torpedoes for British use. The Mark 43 was intended to serve as a stopgap until the arrival of the Mark 44, but this did not occur until 1966. In 1957, preliminary work was being done on a 14-inch, 25-knot active/passive homing aerial torpedo for helicopter delivery, using the motor of the Mark 30. This, much like the Mark 30 Mod 1, was passed up in favor of American torpedoes and the Mark 21 Pentane, which in turn would be cancelled shortly thereafter. Additionally, beginning in the mid-1960s, there was a project for a Mark 31 aerial torpedo successor to the Mark 30, designed to surpass the Mark 44. This project would be cancelled in 1971 in favor of purchasing the Mark 46.
Specifications:
Mark 30 Mod 0
* Entered service: 1954
* Weight: 646 lb (293 kg)
* Length: 8 ft 0.5 in (2.451 m)
* Explosive charge: 90 lb (41 kg) Torpex
* Range and speed: 9,000 yd (8,200 m) at 12.5 kn (23.2 km/h), 2,500 yd (2,300 m) at 19 kn (35 km/h)

## Project Camrose

Project for a rocket-propelled torpedo with the function of an anti-torpedo countermeasure, initiated in 1951. A proposal for "Camrose" was drawn up soon after the end of the Second World War, but research only commenced in 1951 after a study was published detailing the feasibility of anti-torpedo torpedoes. The concept envisioned a rocket-like weapon launched in salvos from the decks of surface vessels, which would dive into water and proceed for some distance at a speed of 50 knots. An acoustic influence fuze would listen for hostile torpedoes in its vicinity, and detonate its warhead when a weapon were detected within 45 feet (14 m). The resulting explosion would either destroy, damage, or sufficiently incapacitate the incoming weapon. The "Camrose" would have an effective range of approximately 1,200 yards (1,100 m). Rocket propulsion using solid fuel motors was selected due to its low cost compared to piston engines, as well as the instant no-maintenance readiness of the weapon, and the viability of propulsion while airborne. The initial concept considered 15-inch or 16-inch diameter bodies due to the practical problems of using larger bodies and being able to launch them in sufficient numbers; ultimately, the 18-inch Mark 15 torpedo was chosen for conversion to rocket propulsion instead. In 1952, the project's priority was greatly downgraded, which delayed prototype development. In 1954, the acoustic influence fuze was deemed to be sufficiently workable. Between 1953 and 1955, "Camrose" was developed in cooperation with the "Bootleg" rocket-propelled torpedo, using the test vehicles of the other project. In 1955, the "Camrose" project was canceled due to an assessment that warships would not be capable of carrying sufficient units of the countermeasure to defend themselves against hostile torpedoes. A fundamentally similar concept is the ASW rocket, such as the RBU.

## Project Bootleg

Project for an aerial rocket-propelled ASuW non-homing torpedo, initiated in 1950. Developed by Vickers-Armstrong. Trials of prototype units began in 1952. The development of "Bootleg" was motivated by the introduction of Sverdlov class cruisers, which featured new sophisticated anti-air artillery (for more information, see Sverdlov crisis). The weapon would approach the vicinity of the target while airborne, then impact the water and proceed towards the target as a high-speed torpedo, with a projected underwater speed of 65 knots. Upon integration with the "Camrose" project, functional prototypes were tested, called DTVs (Dynamic Test Vehicles) and ERVs (Experimental Rocket Vehicles). The initial concept used an 18-inch body, but the actual prototype weapon would increase the body diameter to 20 inches. Both "Bootleg" and "Camrose" had a similar appearance of a conventional torpedo with a ducted nozzle which did not have propellers, instead having a solid rocket motor with a high aspect ratio. The method of employment for the "Bootleg" would have involved a high-speed strike aircraft such as the Westland Wyvern or Blackburn Buccaneer tossing the weapon at an enemy warship from approximately 5,000 yards (4,600 m) or more, with the torpedo's motor igniting immediately, in flight. After traversing most of the distance while airborne, the torpedo would dive at high speed and reach the target underwater.
A test of the "Bootleg" ERV in 1954 demonstrated another potential of the weapon. The ERV was launched underwater, from a depth of 15 feet, at the Arrochar torpedo range in Loch Long, Scotland. It accelerated to 60 knots within two seconds, dived to a depth of 50 feet, then shot to the surface, emerging approximately 150 yards from the firing point after six seconds. Climbing at an angle of some 30 degrees to the horizontal, the ERV attained a maximal altitude of 200 feet, and after 14 seconds of flight, dived again some 900 yards from the point at which it emerged from the surface. This demonstrated a potential use as a high-speed submarine-launched ASuW torpedo with an airborne component, compatible with 21-inch launch tubes, capable of far higher speeds than any existing conventional torpedo; the airborne segment had an effective speed of over 114 knots.
The "Bootleg" project was defunded and canceled alongside "Camrose" in 1955. The Red Angel anti-ship rocket was favored instead, due to its lower cost and greater simplicity. The basic fire control problem for "Bootleg" was deemed more complex.
Specifications:
Bootleg ERV
* Prototype date: 1953
* Weight: 1,730 lb (780 kg)
* Diameter: 20 inches (51 cm)
* Length: 12 ft 6 in (3.81 m)
* Explosive charge: 575 lb (261 kg) Torpex
* Range and speed: Approximately 5,000 yd (4,600 m) at 300–500 kn (560–930 km/h) while airborne, approximately 1,000 yd (910 m) at 70 kn (130 km/h) while underwater