4 ballistic missile submarines (SSBN) carry the nation’s nuclear deterrent while the attack submarines (SSN) are arguably the most important of all the RN’s conventional assets.
Ballistic missile submarines
The RN’s submarines that carry the Trident ballistic missile with nuclear warheads are based at Faslane in Scotland. One is always on patrol to provide the nation’s Continuous at Sea Deterrent (CASD). Commissioned in the 1990s the government is committed to their replacement and have given the go ahead for design work to begin on the new submarines.
Designed primarily to destroy other submarines but are also very effective against surface ships and when carrying Tomahawk cruise missiles, can attack land targets. Probably the most important (and invulnerable) of all naval units, submarines are crucial to naval warfare. The number of RN SSNs has dwindled to 7. This means there are only 2 or 3 actually available for operations at any given time.
7 new Astute class submarines are on order but the programme has been severely delayed and over-budget. HMS Astue is now fully operational and the second boat HMS Ambush has been commissioned.