HMS ''M4'' was an M-class submarine of the

Royal Navy The Royal Navy (RN) is the United Kingdom's naval warfare force. Although warships were used by English and Scottish kings from the early medieval period, the first major maritime engagements were fought in the Hundred Years' War against F ...

built by

Armstrong Whitworth Sir W G Armstrong Whitworth & Co Ltd was a major British manufacturing company of the early years of the 20th century. With headquarters in Elswick, Newcastle upon Tyne, Armstrong Whitworth built armaments, ships, locomotives, automobiles and a ...

Newcastle Upon Tyne Newcastle upon Tyne ( RP: , ), or simply Newcastle, is a city and metropolitan borough in Tyne and Wear, England. The city is located on the River Tyne's northern bank and forms the largest part of the Tyneside built-up area. Newcastle is ...

, and laid down in 1917. ''M4'' was cancelled and sold as an incomplete hulk on 30 November 1921.

References

* * British M-class submarines Ships built on the River Tyne World War I submarines of the United Kingdom Ships built by Armstrong Whitworth 1919 ships {{UK-mil-ship-stub