Even before trials with the first Holland boat were completed, it became apparent that they would have limited speed and endurance on the surface and, as a result - which highlighted the changing attitude within the Admiralty - a larger submarine was ordered with the hope of overcoming these problems.
This, the submarine A1, although based on the Holland Class was of all-British design (Capt Bacon, now Inspecting Captain of Submarines, and Vickers, Sons and Maxim). She was 40 feet longer than the Hollands, and, at 207 tons, of about two-thirds greater displacement. Power was also increased.
Laid down in 1902, she was the first of a class of thirteen completed at Barrow between 1903 and 1905, except for A13 which was an experimental craft, fitted with diesel engines instead of petrol engines and completed in 1908.