The signal box at Welshpool (formerly known as Welshpool North before the south box closed in 1931) was to a London and North Western Railway Company design (although Welshpool station was on the Cambrian Railways) and dated from the re-signalling scheme of 1897. When built, the box had a LNWR tumbler frame, but this was replaced by a second-hand Dutton frame, with standard GWR 5-bar tappet interlocking, after the south box was closed. It was superceded in October 1988 by the introduction of Radio Electronic Token Block signalling and was demolished.
For further information on the types and designs of signal boxes see: The Signalling Study Group, The Signal Box - A Pictorial History and Guide to Designs, OPC, 1986.
B.A.Malaws, RCAHMW, 22 August 2006.