Editing Vanguard-class submarine (section)

===Propulsion===
A new [[pressurized water reactor|pressurised water reactor]], the [[Rolls-Royce plc|Rolls-Royce]] [[Rolls-Royce PWR|PWR 2]], was designed for the ''Vanguard'' class. The PWR 2 has double the service life of previous models, and it is estimated that a ''Vanguard''-class submarine could circumnavigate the world 40 times without refuelling. Furthermore, during their long-overhaul refit periods, a 'Core H' reactor is fitted to each of the boats, ensuring that none of the submarines will require further re-fuelling for the rest of their service lives.<ref name="Janes"/> The reactor drives two [[General Electric Company plc|GEC]] [[steam turbine]]s linked to a single shaft [[pump jet]] propulsor, giving the submarines a maximum submerged speed of over {{convert|25|kn|km/h mph}}. Auxiliary power is provided by a pair of 6&nbsp;MW steam-turbine generators supplied by WH Allen, (later known as NEI Allen, Allen Power & Rolls-Royce), and two 905 kWb [[Paxman (engines)|Paxman]] diesel generators for provision of backup power supply.<ref>{{cite web |url=http://www.paxmanhistory.org.uk/paxsubs.htm |title=Paxman Submarine Engines |author=Richard Carr |publisher=Paxman History Pages |date=19 November 2014 |access-date=24 September 2015 |quote=One engine drives a Brush alternator with a rating of 850 kW. The AC output from this provides auxiliary power for the ship's service (hotel) load. The other Valenta is coupled to a Brush generator with a rating of 750 kW, providing DC output for propulsion in the event of failure or non-availability of the main propulsion system (emergency "get you home").}}</ref>