BR Catfish and Dogfish ballast hopper wagons. The Catfish and Dogfish wagons were designed as British Railways standard ballast hopper wagons. The smaller 19 ton Catfish design had bottom hopper doors to deliver the load between the rails only. The larger 24 ton Dogfish design was equipped with three outlet gates to allow ballast to be dropped between the rails or onto the sleeper ends to either side of the track.
Both types were built in significant numbers and we in widespread use until more modern wagons arrived in the late 1980s. Many heritage railways purchased examples on withdraw and continue to use them for track ballasting.