The use of numbers rather than names for Royal Navy submarines was common up to and including the first two years of WWII. Winston Churchill issued a directive that they should all be allocated proper names for reasons of morale, pride and the camaraderie of their crews. P 311 was the last 'T' Class submarine not to have been allocated a name which was to have been HMS Tutankhamen, but the planned renaming ceremony was overtaken by her tragic loss.
In a 1942 speech to the House of Commons, Churchill, paid special tribute to the men of the submarine service who were facing significant losses. One famous line read, "Of all the branches of men in the armed forces, there is none which shows more devotion and faces grimmer perils than the submariner's." Even in those dark days no one could imagine the terrible price to be paid by the wars end. By the time hostilities were over we would lose 81 submarines and over 5,000 submariners to preserve our freedom.
Each year in Liverpool, a submarine memorial service is held at St. Nicks, the 800 year-old sailor's church on the waterfront. It is a strange thing that down over the years, past, and even today, surviving WWII submarine veterans have always affectionately referred to those boats by their original numbers and never by the names they were later allocated.