HMS Ajax (S125)

HMS Ajax is a proposed Astute-class nuclear-powered fleet submarine of the Royal Navy and will be the seventh in her class. She will be the ninth vessel of the Royal Navy to bear the name, after the Greek hero Ajax.

The confirmation for the seventh and final Astute-class boat was given in the Strategic Defence and Security Review of October 2010, although an order has yet to be placed. On 11 December 2012 the British government announced that long-lead items had been ordered for boats 6 & 7.

Propulsion system
A confusing press release suggested that Ajax would have the same PWR3 nuclear reactor as the Successor class SSBNs but in October 2012 it was confirmed that she would have a PWR2 like the rest of the Astute class. Ajax's nuclear reactor will not need to be refuelled during the boat's 25 year service. Since the submarine can replenish her air supply and purify water underway and while submerged, she will be able to circumnavigate the planet without resurfacing. The submarine's main limitation will be from the three months supply of food carried for the 98 officers and ratings.

Weapons
Ajax will carry a mix of 38 weapons in six 21-inch (533 mm) torpedo tubes;
 * BGM-109 Tomahawk Block IV cruise missiles. Range of 1350 nmi.
 * Spearfish torpedoes.