HMS Vengeance (S31)

HMS Vengeance returning to HMNB Clyde in 2007
History
United Kingdom
Name:	HMS Vengeance
Laid down:	1 February 1993
Launched:	19 September 1998
Commissioned:	27 November 1999
In service:	12 February 2001
Homeport:	HMNB Clyde
Motto:	Safe by my strength
Badge:
General characteristics
Class and type:	Vanguard-class submarine
Displacement:	15,900 tonnes, submerged
Length:	149.9 m (491 ft 10 in)
Beam:	12.8 m (42 ft 0 in)
Draught:	12 m (39 ft 4 in)
Propulsion:	1 × Rolls-Royce PWR2 nuclear reactor 2 × GEC turbines; 27,500 shp (20.5 MW) 1 × shaft, pump jet propulsor 2 × auxiliary retractable propulsion motors 2 × WH Allen turbo generators (6 MW) 2 × Paxman diesel alternators; 2,700 shp (2.0 MW)
Speed:	In excess of 25 knots (46 km/h; 29 mph), submerged
Range:	Only limited by food and maintenance requirements.
Complement:	135
Sensors and processing systems:	BAE Systems SMCS Kelvin Hughes Type 1007 I-band navigation radar Thales Underwater Systems Type 2054 composite sonar suite comprising:  Marconi/Ferranti Type 2046 towed array sonar  Type 2043 hull-mounted active and passive search sonar  Type 2082 passive intercept and ranging sonar Pilkington Optronics CK51 search periscope Pilkington Optronics CH91 attack periscope
Electronic warfare & decoys:	Two SSE Mk10 launchers for Type 2066 and Type 2071 torpedo decoys RESM Racal UAP passive intercept
Armament:	4 × 21 in (533 mm) torpedo tubes for: Spearfish heavyweight torpedoes 16 ballistic missile tubes for: 16 × Lockheed Trident II D5 SLBMs (carrying up to 48 nuclear warhead)

HMS Vengeance is the fourth and final Vanguard-class submarine of the Royal Navy. Vengeance carries the Trident ballistic missile, the UK's nuclear deterrent.

Vengeance was built at Barrow-in-Furness by Vickers Shipbuilding and Engineering Ltd (now BAE Systems Submarine Solutions), was launched in September 1998, and commissioned in November 1999.

Before she was commissioned, the British Government stated that once the Vanguard submarines became fully operational, they would only carry 200 warheads.

Vengeance carries the unopened "last instructions" (letters of last resort) of the current British Prime Minister that are to be used in the event of a national catastrophe or a nuclear strike.

On 31 March 2011, while on a training exercise Vengeance suffered a blockage in her propulsor causing a reduction in propulsion. The boat returned to Faslane naval base on the surface under her own power. According to the MOD the problems were not nuclear related.

In 2012, Vengeance started a 40 month refit at HMNB Devonport near Plymouth which refueled her reactor and re-newed her machinery and electronics. During that period her sister ship Vigilant took her place in the patrol rotations. She sailed from Devonport on 4 December 2015, her place in refit being taken by Vanguard.Vengeance then went through trials from January 2016 to June 2016 and fired an unarmed D5 missile during her Demonstration and Shakedown Operation (DASO) which allowed her to return to the fleet. Whilst the firing of the missile was a success, the missile itself suffered a failure during flight and the test was terminated.