Most BR departmental (non-revenue earning wagons) were provided with aquatic codes and these were known as the Fishkind. Aquatic names enabled the operating staff to allocate resources to jobs. The ballast hopper wagon designated ‘Trout’ by BR had its origins in the 1920s.
Two batches of BR ‘Trout’ wagons were constructed by Metropolitan-Cammell Ltd. to Diagram 1/580. DB992035-56 were constructed at Lot 2118 between May and June 1949. These BR ‘Trout’ wagons featured a side and centre discharge for ballast and were unfitted.