Type 42 destroyer
The Type 42 or Sheffield class was developed to provide the Royal Navy with a cost-effective, medium-sized guided-missile destroyer focused on fleet air defence. Conceived in the late 1960s after the cancellation of the more complex and expensive Type 82, the Type 42 was intended to protect naval task groups against airborne threats using the Sea Dart missile system.
While the smaller design allowed for more ships to be built within budget constraints, it imposed compromises in endurance, sea-keeping, and space for future weapons or sensor upgrades. Over its 38 years of service, the class underwent three production batches that addressed some of the class's limitations by lengthening the hull, improving radar and missile systems, and adding close-in weapon systems.
Two vessels, and, were lost in the 1982 Falklands War, prompting further modifications including enhanced damage control measures, updated electronic warfare suites and changes to material used in the ships' furnishings. The class served as the backbone of Royal Navy air defence and demonstrated a trade-off between affordability and capability reflecting broader Royal Navy strategic priorities during the Cold War and post-Cold War periods, concluding in 2013 when they were replaced by the more capable Type 45 destroyer.
In addition to British service, two Type 42s were built for the Argentine Navy. These two ships saw limited service, few upgrades and were eventually retired.
History
Following the cancellation of the Type 82 air-defence destroyers and the proposed CVA-01 aircraft carrier by the Labour Government in 1966, the Type 42 was conceived as a lighter, cheaper alternative with similar capabilities. The class was fitted with the GWS30 Sea Dart surface-to-air missile, first deployed on the sole Type 82 destroyer,. The ships also had a flight deck and hangar to operate an anti-submarine warfare helicopter, increasing their versatility compared to the Type 82, which had a flight deck but no hangar.Designed in the late 1960s to provide fleet air defence, fourteen vessels were constructed in three distinct batches. In addition to the Royal Navy ships, two were built to a Batch 1 specifications for the Argentine Navy. ARA was built in the Vickers Shipbuilding yard in Barrow-in-Furness, United Kingdom, and delivered August 1976. ARA was built at the AFNE Río Santiago Shipyard in Buenos Aires and commissioned in July 1981.
The class was budgeted at £19 million per hull but exceeded that limit and the original design proposal was £21 million. To cut costs, the first two batches had 47 feet removed from the bow forward of the bridge, reducing the beam-to-length ratio. These early Batch 1 ships performed poorly during sea trials in heavy weather, prompting a review. Batch 2 ships, beginning with, incorporated improved sensors and minor layout changes. The ninth hull,, was lengthened during construction, resulting in better seakeeping, and follow-on ships were built to this standard. Strengthening girders were added to the weather decks of Batch 1 and 2 ships, while Batch 3 vessels were built with an external strake to counter longitudinal cracking.
and were both sunk in the Falklands War. This was the first conflict since World War II in which surface warships of the same design served on opposing sides. Although there was no direct contact between the ships, both Santísima Trinidad and Hércules locked on to Sea Harrier, XZ451 piloted by Flt Lt Mortimer, with their Type 909 fire-control radars on the 1 May 1982, Mortimer retreated.
The final ship of the class,, was decommissioned on 6 June 2013. Hércules remained in service in a transport and amphibious role and was declared non-operational in 2020 and formally decommissioned in 2024, while Santísima Trinidad sank at her berth at the Port Belgrano Naval Base in January 2013, she was in poor condition before sinking, having been cannibalised to keep Hércules operational.
Design
The first batch was fitted with the Type 965 or Type 966 surveillance radar, both of which had a slow data rate. The Type 992Q radar, used for target designation for the gun and missile systems, lacked Moving Target Indication. Although British radar manufacturers offered to retrofit MTI, the modification was never carried out. Without MTI, the Type 992Q experienced difficulty in tracking aircraft when they were in front of land, or during snow or rain showers. In addition, the class had insufficient space for an efficient operations room.The class was armed with a single 4.5 inch Mark 8 naval gun, and earlier vessels carried six Ships Torpedo Weapon System torpedo launchers. The Argentine Santísima Trinidad was equipped with the MM38 Exocet for a broader anti-ship capability. The boat decks of the original design were replaced by special decks to install the missiles around the funnel. While this modification applied to both ARA ships, the launchers were never mounted on Santísima Trinidad.
There were three production batches. Batch 1 and Batch 2 ships displaced 4,820 tonnes, while Batch 3 displaced 5,200 tonnes. The Batch 3 ships were heavily upgraded, incorporating lessons from the Falklands War, although the Sea Wolf missile system was never fitted. Two Phalanx close-in weapon systems were mounted amidships to all surviving batches.
The electronics suite comprised either a Type 1022 D band long-range radar with Outfit LFB track extractor, or a Type 965P long-range air surveillance radar; one Type 996 E band/F band 3D radar for target indication with Outfit LFA track extractor, or a Type 992Q surface-search radar; two Type 909 I/J-band fire-control radars; and an Outfit LFD radar track combiner.
All ships were powered by Rolls-Royce TM3B Olympus and Rolls-Royce RM1C Tyne marinised gas turbines, in a COGOG arrangement, driving through synchronous self-shifting clutches into a double-reduction, dual-tandem, articulated, locked-train gear system, and then to two five-bladed controllable pitch propellers. Electrical power was supplied by four Paxman Ventura 16YJCAZ diesel generators, each producing 1 MW of three-phase electric power at 440 V, 60 Hz.
The lead ship,, was initially fitted with exhaust deflectors on her funnel tops to direct high-temperature exhaust gases sideways, reducing heat damage to overhead aerials. This created a prominent target for infrared homing missiles, so only Sheffield and the two Argentine ships, and, retained this feature. Subsequent ships were built with 'cheese grater' uptakes, which mixed machinery space ventilation air with the exhaust gases to reduce infrared signatures.
;Availability
In February 1998, the Minister of State for Defence, Dr John Reid, stated: "Type 42 destroyers achieved approximately 84 to 86 per cent average availability for operational service in each of the last five years. This discounts time spent in planned maintenance."
Operational history and service
The Type 42 class was designed to counter long-range strategic bombers from the former Soviet Long-Range Aviation and Soviet Naval Aviation, and to provide area defence for a carrier battle group.;1982 Falklands War
Five ships took part in the Falklands War: Sheffield, Coventry, Glasgow, Exeter and Cardiff. providing long-range air defence and achieving seven confirmed "kills". Coventry was credited with three aircraft: a Puma SA.330L and two A-4 Skyhawks. Exeter shot down four aircraft: two A-4 Skyhawks, a Learjet 35A and a Canberra bomber. Cardiff was involved in a friendly fire incident resulting in the loss of a British Gazelle helicopter.
Sheffield was hit by an Exocet air-to-surface missile launched by an Argentine Super Étendard on 4 May 1982 and sank six days later; Coventry was sunk by 3, 250 kg unguided bombs on the 25 May 1982, with two detonating. and Glasgow was disabled by a bomb that passed through her aft engine room without exploding, damaging fuel systems and disabling the cruising engines. These losses led to a reassessment to subsequent vessels.
;1991 Gulf War
On February 25, 1991, during Operation Desert Storm, Gloucester shot down an Iraqi Silkworm missile targeting USS Missouri.
;Task group deployments
Type 42s performed fleet contingency duties, including West Indies counter-drug operations, Falkland Islands patrols, NATO Mediterranean and Atlantic task group deployments, and Persian Gulf patrols. The increased deployment of Type 23 frigates in place of Type 42s to high-intensity operational areas reflected persistent serviceability and reliability problems, alongside growing obsolescence of their combat and machinery systems.
Construction programme
In May 1982, the Parliamentary Under-Secretary of State stated that the current replacement cost of a Type 42 destroyer of the Sheffield class was "about £120 million." In July 1984, the Parliamentary Under-Secretary of State stated: "the average cost of the three Type 42 destroyers currently under construction is £117 million at 1983–84 price levels."Running costs
Not including major refits and upgrades
Including refits and upgrades
In May 2000, the Minister of State for the Armed Forces stated: "The running costs of each of the Royal Navy's Type 42 destroyers for each of the past five years are contained in the following table. This includes repair and maintenance, manpower, fuel, and other costs such as port and harbour dues. Year-on-year variations are largely attributable to refit periods."| Ship | 1995–96 | 1996–97 | 1997–98 | 1998–99 | 1999–2000 |
| Birmingham | £32.28 million | £16.92 million | £17.38 million | £13.38 million | £10.39 million |
| Newcastle | £32.60 million | £31.60 million | £18.57 million | £13.90 million | £13.73 million |
| Glasgow | £14.70 million | £29.47 million | £26.36 million | £13.61 million | £12.65 million |
| Cardiff | £19.86 million | £41.2 million | £28.86 million | £13.20 million | £17.87 million |
| Exeter | £19.46 million | £15.72 million | £40.83 million | £12.76 million | £14.48 million |
| Southampton | £16.53 million | £20.37 million | £17.91 million | £39.09 million | £18.79 million |
| Nottingham | £18.70 million | £17.24 million | £19.08 million | £13.08 million | £32.74 million |
| Liverpool | £16.92 million | £20.75 million | £14.59 million | £14.79 million | £14.63 million |
| Manchester | £17.99 million | £19.40 million | £14.58 million | £12.22 million | £12.69 million |
| Gloucester | £19.33 million | £19.40 million | £13.89 million | £21.49 million | £15.77 million |
| York | £20.48 million | £19.79 million | £17.50 million | £11.78 million | £21.88 million |
| Edinburgh | £35.27 million | £19.29 million | £22.50 million | £13.00 million | £12.28 million |