The first use of welding in British shipbuilding came in 1917, when the Quasi Arc Company installed welding equipment at the Cammell Laird shipyard in Birkenhead. The first all-welded ship built in Britain was the Fullagar, built by Cammell Laird, and completed in 1920. However, through the 1920s and 1930s, many British shipbuilders did not invest in welding equipment. Business was slow, thanks to naval treaties and the Great Depression, so shipyards were unwilling to spend money on expensive welding equipment and risk strikes from their heavily unionised workforce. Mitigating against this, though, was the influence of the Admiralty. Bound by the tonnage limits imposed by the naval treaties, the Admiralty sought to increase the use of welding, as a welded ship weighed about 10-15% less than an equivalent riveted one. As such, they began to issue specifications calling for welded parts by 1930. Achilles, launched in 1931, was the first RN warship to include a significant amount of welding. Over the course of the 1930s, the RN steadily increased the use of welding - the Ark Royal, launched in 1937, was over 75% welded. In 1938, the RN commissioned its first all-welded ship, the minesweeper Seagull. WWII brought welding fully into the mainstream, thanks to the need to rapidly expand the shipbuilding industry using a workforce that were not sufficiently skilled for riveting. In 1942, the yard of J. Samuel White, bombed earlier in the war, was commissioned to build an all-welded series of destroyers. Later in the year, the Shipyard Development Committee (SDC) was set up to encourage British yards to adopt welding, amongst other things. It spent ~£7 million to encourage the use of welding, setting up training schemes and paying for new equipment. Welding took hold in the British shipbuilding industry as a result, but did not have complete domination of the market until the 1960s - companies like Harland and Wolff were still building riveted ships up to 1960.

On ships, welding was always used for structural elements - frames, bulkheads and decks - rather than for armour. Armour plate was bolted into place. This allowed damaged plates to be easily removed and replaced. It allowed the use of backing materials to catch splinters and the like (though this was less important by WWII, thanks to changes in armour metallurgy). It also prevented damage to one plate spreading to other plates connected to it. Armour bolts were typically long, and had a neck to ensure that the thread of the screw was not the thinnest, most vulnerable part.