§ Mr. CohenTo ask the Secretary of State for Defence what guidance or position locating systems are to be used by the Vanguard class submarines or their Trident missiles.
§ Mr. SainsburyVanguard class SSBNs will be equipped with an electrostatically supported gyro navigator (ESGN), a gravity sensing system (GSS) and a range of radio and sonar navigational aids. The Trident D5 missile has a stellar aided inertial reference navigational system.