Two Trafalgar Class Fleet Submarines

The Trafalgar class submarines were, until the introduction of the Astute class, the Royal Navy's most advanced nuclear fleet submarines (SSNs).

The Trafalgar class includes seven boats: Trafalgar (S107), Turbulent (S87), Tireless (S88), Torbay (S90), Trenchant (S91), Talent (S92), and Triumph (S93).

It is an attack submarine and is essentially a refinement of the Swiftsure class, designed six years later than its predecessor. The first Trafalgar class submarine was completed in 1983.

The major improvements include a new reactor core and the Type 2020 sonar. Internal layout is near identical to the Swiftsure, and it is only 2½ metres longer.

Rather than the seven-bladed propeller used by the Swiftsures, Trafalgar class submarines use pump-jet propulsion - a high-pitch, low-revolution propeller which is much quieter but much heavier than conventional propeller designs. Development of this system was not complete in time for installation in the class's name-ship vessel, HMS Trafalgar, and so the pump-jet was first used in the second in the class, HMS Turbulent.