HMS R12 was a British R class submarine

British R class submarine

The R-class submarines were a class of 12 small British diesel-electric submarines built for the Royal Navy during World War I, and were forerunners of the modern hunter-killer submarines, in that they were designed specifically to attack and sink enemy submarines, their battery capacity and hull...

 built by Cammell Laird

Cammell Laird

Cammell Laird, one of the most famous names in British shipbuilding during the nineteenth and twentieth centuries, came about following the merger of Laird, Son & Co. of Birkenhead and Johnson Cammell & Co. of Sheffield at the turn of the twentieth century.- Founding of the business :The Company...

 at Birkenhead

Birkenhead

Birkenhead is a town within the Metropolitan Borough of Wirral in Merseyside, England. It is on the Wirral Peninsula, along the west bank of the River Mersey, opposite the city of Liverpool...

. She was laid down on 1 December 1917 and launched on 9 April 1918. R12 was commissioned on 29 October 1919. She came too late to see any combat in World War I

World War I

World War I , which was predominantly called the World War or the Great War from its occurrence until 1939, and the First World War or World War I thereafter, was a major war centred in Europe that began on 28 July 1914 and lasted until 11 November 1918...

, like most of the other R class submarines. R12 was paid off in December 1919, and sold on 21 February 1923 to J. Smith.