Why are the Queen Elizabeth Class of Aircraft Carriers fitted with the 20mm Phalanx Close In Weapons System (CIWS)?

The Queen Elizabeth Class (QEC) of aircraft carriers have been fitted with the 20 mm Phalanx Close In Weapons System (CIWS) manufactured by Raytheon rather than the 30 mm Goalkeeper CIWS manufactured by Thales (previously Signaal) to maintain the commonality of fit so as to minimise any additional costs of maintenance and support by having a single CIWS capability in-service across the RN fleet.

The Goalkeeper CIWS was only in service with the former HMS Invincible and HMS Illustrious aircraft carriers – HMS Ark Royal had been fitted with the Phalanx CIWS. The Goalkeeper CIWS had an out of service date of March 2017, and all three ships of the Invincible class have since been disposed of.