Type 42 Sheffield class destroyer

The Type 42 or Sheffield class, are guided missile destroyers used by the British Royal Navy and the Argentine Navy. The first ship of the class was ordered in 1968 and launched in 1971, and today three ships remain active in the Royal Navy and one in the Argentinian Navy. Two of the class (Sheffield and Coventry) were sunk in the Falklands War of 1982.

The Type 42 destroyer was built to fill the gap left by the cancellation of the large Type 82 destroyer. It was intended to fulfil the same role, with similar systems on a smaller and more cost effective hull. The ships are primarily carriers for the GWS-30 Sea Dart surface-to-air missile system. Although described as obsolete, it still proved effective against modern missile threats during the 1991 Gulf War.

The Type 42 is also equipped with a 4.5 inch Mark 8 naval gun and six torpedo launchers. Two Vulcan Phalanx Mk 15 Close-In Weapons Systems (CIWS) were fitted to British type 42s after the loss of Sheffield to an Exocet missile. There have been three batches of ships, batch 1 & 2 displacing 4,820 tonnes and batch 3 (sometimes referred to as the Manchester class) displacing 5,200 tonnes. The batch 3 ships were heavily upgraded, though the planned Sea Wolf missile systems were never fitted. Because of their more general warfare role, the two Argentine ships have been fitted with the MM38 Exocet, and not with a CIWS.

The electronics suite includes one Type 1022 D-band long range radar with Outfit LFB track extractor or one Type 965P long range air surveillance radar, one Type 996 E/F-band 3D target indication radar with Outfit LFA track extractor or type 992Q surface search, two Type 909 I/J-band fire control radars and an Outfit LFD Radar Track Combiner.

In recent years the importance of the aging Type 42 destroyers has increased. The UK has adopted an increasingly expeditionary defence policy and the deletion of the Sea Dart missile systems from the Invincible-class aircraft carriers has made the role of escort ships all the more important. However the deployment of Type 23s in lieu of Type 42s to high-intensity mission areas has become more prevalent as servicability and reliability issues have dogged Type 42s availability as has obsolescence of their combat and machinery system equipment. The 2010 Strategic Defence and Security Review (SDSR) sounded a death knell for these venerable warships and it is forecast they will all be reduced to extended readiness ready for retirement by 2013.

All ships are propelled by Rolls Royce TM3B Olympus and Rolls Royce RM1C Tyne marinised gas turbines, arranged in a COGOG (Combined Gas or Gas) arrangement, driving through synchronous self-shifting clutches into a double reduction, dual tandem, articulated, locked-train gear system and out through two five-bladed controllable pitch propellers. All have four Paxman Ventura 16YJCAZ diesel generators, each generating 1 Megawatt of three-phase 440V 60 Hz power.

Class overview
Name:	Type 42
Builders:	Several different
Operators:	Royal Navy Argentine Navy
Preceded by:	Type 82 (RN) Sumner class (ARA)
Succeeded by:	Type 45 (RN) Almirante Brown class (ARA)
In service:	1975
Building:	0
Completed:	16
Active:	4
Laid up:	0
Lost:	2 (Falklands War)
Retired:	10
Preserved:	0
General characteristics
Class and type:	Guided missile destroyer
Displacement:	Batch 1 & 2: 3,500 long tons (3,600 t) standard, 4,100 long tons (4,200 t) or 4,350 tons full load Batch 3: 3,500 long tons (3,600 t) standard, 4,775 long tons (4,852 t) or 5,350 tons full load
Length:	Batch 1 & 2: 119.5 m (392 ft) waterline, 125 m (412 ft) or 125.6 m (412 ft) overall Batch 3: 132.3 m (434 feet) waterline, 141.1 m (462.8 ft) overall
Beam:	Batch 1 & 2: 14.3 m (47 ft) Batch 3: 14.9 m (49 ft)
Draught:	Batch 1, 2 & 3: 4.2 m (13.9 ft) keel, 5.8 m (19 feet) screws
Decks:	8
Installed power:	50,000 shp
Propulsion:	2 shafts COGOG; 2 x Rolls-Royce Olympus TM3B high-speed gas turbines, (50,000 shp (37.5 MW)) 2 x Rolls-Royce Tyne RM1A cruise gas turbines, (8,000 shp (6 MW))
Speed:	30 knots (Olympus) 18 knots (Tyne)
Boats and landing craft carried:	2
Complement:	Batch 1 & 2: 253 (inc 24 officers) or 274, accommodation for 312 Batch 3: 301 (inc 26 officers) or 314 Batch 1, 2 & 3: 24 officers and 229 ratings
Sensors and processing systems:	Radar Type 1022/965P air surveillance, Radar Type 996/992Q 3-D surveillance, 2× Radar Type 909 GWS-30 fire-control, Radar Type 1007 navigation, Sonar Type 2050 / 2016 search, Sonar Type 162 bottom profiling,
Armament:	1× Twin launcher for GWS-30 Sea Dart missiles (22 missiles on batch 1 and 2, 40 missiles on batch 3) 1× 4.5 inch Mark 8 naval gun 2× 20 mm Phalanx CIWS (not on Argentine ships) 2× Oerlikon / BMARC 20 mm L/70 KBA guns in GAM-B01 single mounts 4× MM38 Exocet anti-ship missile launchers (only on Argentine ships) 2× 3-tube STWS-1 launchers for 324 mm (12.75") A/S torpedoes (only on Argentine ships)
Aircraft carried:	1× Westland Lynx HAS / HMA Armed with 4× anti ship missiles 2× anti submarine torpedoes
Aviation facilities:	Flight deck and enclosed hangar for embarking one helicopter