J Class Submarines
Larger and more powerful than previous British submarines
J Class submarines took part in actions against German surface vessels and submarines off the Tyne and Gibraltar.
The Royal Navy developed the J Class shortly before World War I, following incorrect reports that Germany was planning submarines that were fast enough to operate alongside surface fleets. Seven were produced.
Although they were larger and more powerful than previous British submarines – they were no match for RN surface vessels and operated independently during the war.
J Class submarines took part in actions against German surface vessels and submarines off the Tyne and Gibraltar. Between them, the submarines sank a U-boat, and heavily damaged two battleships. HMS J6 was lost to friendly shelling.
After the war, the six surviving vessels were gifted to the Royal Australian Navy, arriving in Sydney on 15 July 1919.
It was immediately obvious the submarines needed urgent maintenance and repair. Four successfully completed peacetime exercises during 1920. Despite a rigorous program of refitting, by 1921 a report to the RAN on the J Class’ condition was damning:
- J1 Sydney Battery unsafe and must be replaced (could not dive).
- J2 Sydney Heavy engine and battery defects, to enter refit when J3 completed.
- J3 Sydney Most defects made good, new batteries arrived Cockatoo and unpacked.
- J4 On Service, battery due for replacement December 1921.
- J5 On Service, battery due for replacement February 1922.
- J7 New battery due in May, defects will be made good by December 1921.
The J Class design featured four bow tubes and two beam tubes for 18-inch (457 mm) torpedoes, becoming the first British submarines to carry four bow tubes. They could dive to a depth of 91 metres and carried five officers and 40 seamen.
J Class were capable of 19 knots (35 km/h) surfaced and 9.5 knots (17.6 km/h) submerged.
In early 1922, the operational boats completed exercises at Geelong and J3 and J4 participated in fleet exercises in Hobart, but it was clear the fleet had reached the end of its usefulness. All the boats were progressively de-stored and sold off for disposal. J1, J2, J4, and J5, were scuttled in Bass Strait and the remaining two submarines, J3 and J7, were sunk as breakwaters inside Port Phillip Bay.