High Quality Content by WIKIPEDIA articles! HMS Folkestone was a Hastings class sloop of the Royal Navy that saw action in World War II. She was built by Swan Hunter and Wigham Richardson Ltd. of Wallsend-on-Tyne, laid down on 21 May 1929 and launched on 12 February 1930. She was commissioned on 25 June 1930 under the pennant number L22/U22.