B312450 is an open mineral wagon with a steel body, built for coal traffic.  It is one of 1,500 built to this lot, with 2,450 of this diagram built altogether.  It is vacuum braked and fitted with instanter couplings.

Typically these wagon types were withdrawn when this type of train was replaced by merry-go-round trains or if a colliery closed.  Withdrawn by British Rail at Bescot in November 1988.