Class 141 (141113). The British Rail Class 141 was the first production model of the Pacer diesel multiple unit railbus family of vehicles. It was built in 1984. British Rail wanted to replace its aging first generation diesel multiple units. It needed something to run on its lightly used branch lines. It was decided to develop a vehicle with a high level of commonality with the widely used Leyland National bus. Several prototypes were constructed and evaluated, before an order was placed with B