Trafalgar-class submarine

The Trafalgar-class are a class of nuclear-powered fleet submarines in service with the Royal Navy. The name Trafalgar refers to the Battle of Trafalgar fought between the Royal Navy and the combined fleets of France and Spain. The class are a direct follow on from the Swiftsure-class and were, until the introduction of the Astute-class, the Royal Navy's most advanced nuclear fleet submarines. With five boats in commission and two retired, they form the back bone of the Royal Navy's nuclear-powered ‘hunter-killer’ submarine force. HMS Torbay, Trenchant, Talent, and Triumph have been fitted with the Sonar 2076 system, which the Royal Navy describes as the most advanced sonar in service with any navy in the world.

Submarines from the class have seen service in a wide range of locations, and have fired missiles at targets in Afghanistan, Iraq and Libya.

Background
The first Trafalgar-class submarine, HMS Trafalgar, was ordered on 7 April 1977 and completed in 1983. Turbulent was ordered on 28 July 1978; Tireless on 5 July 1979; Torbay on 26 June 1981; Trenchant on 22 March 1983; Talent on 10 September 1984; and finally Triumph on 3 July 1986. In 1982, Jane's Fighting Ships recorded: "Estimated cost of fourth submarine £175 million including equipment and weapon system when fitted." In 1986, Jane's recorded that the average cost for this class was £200 million at 1984-5 prices.

In 1993 Triumph sailed to Australia, covering a distance of 41000 mi whilst submerged and without any forward support. This marked the longest solo deployment by any British nuclear submarine.

Three of the Trafalgar-class boats have been involved in conflicts which on each occasion saw the launch of live cruise missiles. In 2001 HMS Trafalgar (S107) took part in Operation Veritas, the attack on Al-Qaeda and Taliban forces following the 9/11 attacks in the United States, becoming the first Royal Navy submarine to launch Tomahawk cruise missiles against Afghanistan. On 16 April 2003, HMS Turbulent (S87) was the first Royal Navy vessel to return home from the invasion against Iraq, Operation Telic. She arrived in Plymouth flying the Jolly Roger after having launched thirty Tomahawk cruise missiles.

In March 2011, HMS Triumph (S93) participated in Operation Ellamy, firing Tomahawk cruise missiles on 19 March and again on 20 March  at Libyan air defence targets. The MOD also confirmed that on 24 March a further series of missiles were fired into Libya by a Trafalgar-class submarine at air defence targets around the city of Sabha. The boat involved this attack was later revealed to have also been Triumph. Triumph returned to Devonport on the 3 April 2011 flying a Jolly Roger adorned with six small Tomahawk axes to indicate the missiles fired by the submarine in the operation.

The class is based at HMNB Devonport, in the city of Plymouth, England.

The Trafalgar-class was to be replaced by the Future Fleet Submarine, however this project was effectively cancelled in 2001 and replaced by the Maritime Underwater Future Capability. The Astute-class submarine will eventually replace the Trafalgar class as well as the now-retired Swiftsure. it is planned that the last Trafalgar-class submarines will remain in service until 2022.

Service problems
The Trafalgar class have suffered from a number of technical difficulties. In 1998, Trenchant experienced a steam leak, forcing the crew to shut down the nuclear reactor. In 2000, a leak in the reactor primary cooling circuit was discovered on Tireless, forcing her to proceed to Gibraltar on diesel power. The fault was found to be due to thermal fatigue cracks, requiring the other Trafalgar-class boats, and some of the remaining Swiftsure-class boats, to be urgently inspected and if necessary modified. In August 2000 it was revealed that with Tireless still at Gibraltar, Torbay, Turbulent, Trenchant and Talent were at Devonport for refit or repair and with Trafalgar undergoing sea trials, only one boat, Triumph, was fully operational. By 2005, refits had reportedly corrected these problems.

In 2007, a small explosion aboard Tireless resulted in the death of two sailors and injury of another. The accident took place while the submarine was submerged under the Arctic icecap during a joint British-American exercise. An oxygen candle in the forward section of the submarine was thought to be responsible for the accident.

In 2013 the Defence Nuclear Safety Regulator reported thet the reactor systems were suffering increasing technical problems due to ageing, requiring effective management. An example was that Tireless had had a small radioactive coolant leak for eight days in February 2013.

Potential Export
In 1987, the Canadian White Paper on Defence recommended the Canadian Armed Forces purchase 10 to 12 Rubis- or Trafalgar-class submarines under a technology transfer programme. The choice of submarine type was due to be confirmed before Summer 1988. The stated goal was to deploy a three-ocean navy to assert Canadian sovereignty over Arctic waters. The plan was abandoned in April 1989 and the Canadian Forces eventually acquired four of the Royal Navy's diesel-electric Upholder-class submarines.

Characteristics
The Trafalgar class is a refinement of the Swiftsure class and was designed six years later than its predecessor. The design includeds a new reactor core and Type 2020 sonar (now replaced by Sonar 2076 on some boats). The internal layout is almost identical to the Swiftsure, and is only 2.5 metres longer. However at a dived displacement of 5,300 tonnes the Trafalgar class is significantly larger. Some major improvements over the Swiftsure class include several features to reduce underwater radiated noise. These comprise a new reactor system, a pumpjet propulsion system rather than a conventional propeller, and the hull being covered in anechoic tiles which are designed to absorb sound rather than reflect it, making the boats quieter and more difficult to detect with active sonar. Like all Royal Navy submarines, the Trafalgar class have strengthened fins and retractable hydroplanes, allowing them to surface through thick ice.

The Trafalgar class is equipped with 5 x 21-inch (533 mm) torpedo tubes with accommodation for a mixture of 30 weapons;
 * Tomahawk land-attack cruise missiles - range over 1,500 miles (2,500 km)
 * Spearfish wire-guided heavyweight torpedoes

The introduction of the 2076 towed array passive search sonar equipped on at-least four boats of the Trafalgar class has significantly improved their capabilities. BAE claims that the 2076 represents a "step change" over previous sonars and is the world's most advanced and effective sonar system.

Boats of the class
The first of the submarines to be taken out of active service was Trafalgar, which was decommissioned on 4 December 2009.