Tigerfish (torpedo)

Tigerfish
Type	Mark 24-Mod-0: Heavyweight ASW torpedo Mark 24-Mod-1 and 2: Heavyweight dual-purpose ASW and ASuW torpedo
Place of origin	United Kingdom
Service history
In service	1979–present (withdrawn from Royal Navy 2004)
Used by	Royal Navy Brazilian Navy Turkish Naval Forces Chilean Navy Venezuelan Navy
Production history
Manufacturer	Marconi Underwater Systems Ltd (Mod 2 Variant)
Specifications
Mass	1,550 kg (3,417 lb)
Length	6.5 m (21 ft)
Diameter	533 mm (21 in)
Maximum firing range	39 km (43,000 yd) at low speed 13 km (14,000 yd) at high speed
Warhead	Torpex
Warhead weight	134 to 340 kg (295 to 750 lb)
Engine	Electrical chloride silver-zinc oxide batteries
Maximum speed	35-knot (65 km/h; 40 mph)
Guidance system	Wire-guided to point of passive sonar target acquisition and passive terminal homing sonar. Option of using active acquisition and homing.
Launch platform	submarine

The Mark 24 Tigerfish was a heavyweight acoustic homing torpedo used by the Royal Navy (RN) during the 1980s and 90s. Conceptual development dates to the mid-1950s, and formally started in 1959 with a target introduction date in 1969. A lengthy development process led to a greatly reduced performance requirement, including the removal of anti-surface capabilities. The first prototype "Tiger Fish" examples were delivered in 1967.

The Tigerfish was fitted with both active and passive sonar and could be remotely controlled through a thin wire which connected it to the launching submarine. Wire guidance permits a torpedo to be launched on-first-warning, i.e. when a target is first detected at long range. This permits the torpedo the time needed to close the range while target course and speed is being updated by the submarine's superior sensors and transmitted 'down-the-wire'. The torpedo can also be reassigned to another target or recalled. Typically, wire-guided torpedoes initially run at low speed in order to maximize their range and to minimize their self-generated noise while they close the range and speed up during the attack phase.

Testing in 1969 revealed many problems, especially with the seeker system. An upgrade program was ordered, producing the Mod 1 which regained the surface-attack mode. Testing from 1975 led to a production order in 1977, but it was not until 1983 that these officially entered service. Service during the 1982 Falklands War revealed serious reliability problems. A more significant upgrade program followed, the Consolidation Programme, which addressed the complete weapon system including the fire control system. This emerged as the much more reliable Mod 2, which entered service in 1987. A final upgrade series, Mod 2*, entered service in 1992. A simplified inexpensive version, Mod 3, was not produced.

While Tigerfish was being deployed, a new project was started that more closely followed the original performance requirement, and ultimately greatly surpassed it. This became the much more capable Spearfish torpedo, which began replacing Tigerfish starting in 1988. The last examples of the Tigerfish retired in RN service in 2004. Tigerfish was also operated by Turkey, Chile, Brazil, Colombia and Indonesia. A total of 2,184 Mk. 24s were produced.