By the 1890s the shipyard was heavily engaged in the construction of warships for the Royal Navy and also for export. The Royal Navy's first submarine, "Holland 1", was built in 1901, and by 1914 the UK had the most advanced submarine fleet in the world, with 94% of it constructed by Vickers. Vickers was also famous for the construction of airships and airship hangars during the early 20th century. Originally constructed in a large shed at Cavendish Dock, production later relocated to Barrow/Walney Island Airport. HMA No. 1, nicknamed the Mayfly is the most notable airship to have been built in Barrow. The first of its kind in the UK it came to an untimely end on 24 September 1911 when it was wrecked by wind during trials. Well-known ships built in Barrow include , the Japanese flagship during the 1905 Russo-Japanese War, the liner and the aircraft carriers and . It should also be noted that there was a significant presence of Vickers' armament division in Barrow with the huge Heavy Engineering Workshop on Michaelson Road supplying ammunition for the British Army and Royal Navy throughout both world wars. World War 1 brought significant temporary migration as workers arrived to work in the munitions factory and shipyard, with the town's population reaching to an estimated peak of around 82,000 during the War. Thousands of local men fought abroad during World War I, 616 were ultimately killed in action.