The class was designed in the late 1960s to provide fleet area air-defence. In total fourteen vessels were constructed in three batches, three of which remain in service (Liverpool, Edinburgh and York). In addition, two ships were also built to the same specifications as the Batch 1 vessels for the Argentine navy one of which remains in service. The ships, along with the type 23 Frigates formed the backbone of the Royal Navy surface fleet, although their place is being taken by the Type 45 destroyers. Sheffield and Coventry were lost in the Falklands War to enemy action. (This was the first conflict when surface warships of the same design have been on opposite sides since the Second World War, when four Flower-class corvettes built for France in 1939, were taken over by the Kriegsmarine in 1940).
When the Type 82 air-defence cruisers were cancelled along with the proposed CVA-01 carrier by the Labour Government of 1966, the Type 42 was proposed as a lighter and cheaper design with similar capabilities to the Type 82. The class is fitted with the GWS30 Sea Dart surface-to-air missile first deployed on the sole Type 82, Bristol. The Type 42s were also given a flight deck and hangar to operate an anti-submarine warfare helicopter, greatly increasing their utility compared to the Type 82, which was fitted with a flight deck but no organic aviation facilities.
The design was budgeted with a ceiling of £19 million per hull, but soon ran over-budget. The original design at (£21 million) was similar to the lengthened 'Batch 3' Type 42s. To cut costs, the first two batches had 47 feet removed from the bow, and the beam-to-length ratio was reduced. These early Type 42s performed poorly during the contractor's sea trials particularly in heavy seas, and the hull was extensively examined for other problems. Strengthening girders were later designed into the weather deck structure in the batch 1 and 2 ships, and the batch 3 ships received an external 'strake' to counter longitudinal cracking. The batch 1 and batch 2 ships (Sheffield to Liverpool) were notoriously poor sea-keepers compared to the later, longer ships.
The first of class, Sheffield, was initially fitted with exhaust deflectors ("Loxton bends") on her funnel for the Rolls Royce Olympus TM1A turbine engines, to minimise damage to overhead aerials. As this provided a prominent target for the new infra-red homing missiles, these deflectors were removed during Sheffield's 1979-1980 refit in Portsmouth. All subsequent Olympus and Tyne uptakes were fitted with 'cheese graters' which mixed machinery space vent air with the engine exhaust to minimise infra-red signatures.
The Argentine versions of this class are both based at Puerto Belgrano; Santísima Trinidad is now being used to provide for spares for her heavily modified sister, Hércules, which has a new aft superstructure and hangar and Exocet missile launchers.
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 ageing 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 serviceability 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 (converted to marine use) 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.
|Displacement:||Batch 1 & 2:
3,500 long tons (3,600 t) standard,
4,100 long tons (4,200 t) or 4,350 tonsfull 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)
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
|Installed power:||50,000 shp|
|Propulsion:||Rolls-Royce Tyne RM1A cruise gas turbines, (8,000 shp (6 MW))|
|Speed:||30 knots (Olympus)
18 knots (Tyne)
|Boats and landing
|Complement:||Batch 1 & 2: 253 (inc 24 officers)
or 274, accommodation for
Batch 3: 301 (inc 26 officers)or 314
Batch 1, 2 & 3: 24 officers and 229 ratings
Radar Type 1022/965P air surveillance,
1× Westland Lynx HAS / HMA Armed with
|Aviation facilities:||Flight deck and enclosed hangar for embarking one helicopter|