[1] However, there was a signal box at Wolf's Castle, because although most of the route was built as double track, a portion near the middle, which included Spittal Tunnel and the cutting through Treffgarne Gorge, was single-track, and it was necessary to have signal boxes at each end of the single-track section.

[2] The single-track section was later doubled, but although the temporary signal boxes at Spittal and Treffgarne closed with the introduction of full double-track working on 17 December 1906, Wolf's Castle signal box was retained to break the section, allowing two trains to proceed in the same direction between Clarbeston Road and Letterston simultaneously; there was also a crossover.

[4] It was situated 251 miles 55 chains (405.1 km) from Paddington (via the Severn Tunnel),[5] and was on a level stretch of line to the east of the signal box.

[5] The station nameboards stated "Wolf's Castle Halt for Treffgarne Rocks".

[8] The service was operated using GWR steam rail motors running between Fishguard Harbour and Neyland; there were three trains a day in each direction.