S Class Submarines

Designed for short-range operations in coastal waters to replace the 'H' class submarines which were nearing the end of their service lives, the S class had increased speed and improved endurance to provide a larger radius of operations. They were extremely reliable and manoeuvrable and could dive in under 30 seconds. They were single-hull saddle-tank boats in which all fuel was carried in internal tanks.

The First Group of four S Class submarines had their 3" guns sited on a forward extension of the conning tower, but the second group's gun was mounted on the submarine's casing. In the later boats, for service primarily in the Far East, the 3" gun was replaced by a 4". The boats built during the war were partly or, in later production, wholly of welded construction.

To further extend their range of operations, the boats sent to the Far East had some of their ballast tanks converted into oil fuel tanks. This increase in oil fuel stowage was, however, specifically built into the third class of boats.

A large number of this class were still in service at the end of World War Two. Many with long active service were soon sold for breaking up and others expended as targets. Several were transferred, loaned or sold to foreign navies - one to the Netherlands, three to Portugal, four to France and two to Israel. Many still remained as part of the British submarine fleet until well into the 1960s. Sea Devil was the last S boat in full commission (1965).

Some interesting technical information about the S Class's Paxman diesels is here.

Losses were relatively high, with seventeen S boats lost. There were twelve S boats at the start of the war and of those there were only three left by the end of war. Seagoing men usually had a few songs to sing, and submariners also had their own, generally quieter versions. One of these was 'Twelve Little S-Boats', the story of those original 'S'-boats:

Twelve little 'S'-boats 'go to it' like Bevin, Starfish goes a bit too far - then there were eleven.
Eleven watchful 'S'-boats doing fine and then, Seahorse fails to answer - so there are ten.
Ten stocky 'S'-boats in a ragged line, Sterlet stops and drops out - leaving us nine.
Nine plucky 'S'-boats, all pursuing fate, Shark, is overtaken - now we are eight.
Eight sturdy 'S'-boats, men from Hants and Devon, Salmon now is overdue- so the number's seven.
Seven gallant 'S'-boats, trying all their tricks, Spearfish tries a newer one - down we come to six.
Six tireless 'S'-boats fighting to survive, No reply from Swordfish - so we tally five.
Five scrubby 'S'-boats, patrolling close inshore, Snapper takes a short cut - now we are four.
Four fearless 'S'-boats, too far out to sea, Sunfish bombed and scrap-heaped - we are only three.