Type 42

The Type 42 destroyer provides the air defence for the Royal Navy. There are eleven of the class in service with the British fleet. A total of fourteen vessels were originally built. Of those, two were lost in the Falklands War, with a third being scrapped after becoming worn out.

In the early 21st century the design is showing its age. Its primary weapon is the Sea Dart surface to air missile. The Sea Dart is a medium range SAM, capable of engaging targets up to 30-35 miles from the ship. It has been updated several times after its deficiencies were shown graphically in the Falklands; the missile's computer system crashed in battle situations due to flawed programming. Sea Dart demonstrated a capability against missiles in the 1991 Gulf War. Two Iraqi Silkworm missiles were fired at the American battleship USS Missouri. One crashed, and the other was engaged by the Type 42 HMS Gloucester. Both Sea Darts fired by the Gloucester impacted the Silkworm. The most serious problem with the Sea Dart system is its rail-based launcher. Compared to the more modern vertical launch system, as seen in the Ticonderoga class cruisers and Arleigh Burke class destroyers in the United States Navy, and the Type 23 frigate in the Royal Navy, the rail-based launcher is very slow. This leads to the danger of saturation by a multi-axis coordinated missile attack.

The ship's other weapons systems include 12.75" torpedo tubes, a 4.5" gun and the Phalanx close in weapons system (CIWS). The CIWS was added after the Falklands War as a last ditch defence against missiles that have evaded the Sea Dart system. However, it is verging on obsolescent against the most modern anti-ship missiles.

The ships are all scheduled to be out of service by 2014. They are to be replaced by the Type 45. The first six Type 45s have been ordered, but it is unclear whether twelve in total will be ordered since rumours of defence cuts swirl around in the United Kingdom.