The Pacer series was the result of an experiment to assess the viability of using bus parts to create a diesel multiple unit.
The initial prototype, known as LEV-1, was a joint project by the British Rail Research Division and Leyland Motors and used a bus body mounted on modified freight vehicle underframe (HSFV1).
This was followed by the two-car prototype class 140, which was built in 1980 at British Rail Engineering Limited (BREL)'s  Derby Litchurch Lane Works.
The Pacer series was the result of an experiment to assess the viability of using bus parts to create a diesel multiple unit. The initial prototype, known as LEV-1, was a joint project by the British Rail Research Division and Leyland Motors and used a bus body mounted on modified freight vehicle underframe (HSFV1). This was followed by the two-car prototype class 140, which was built in 1980 at British Rail Engineering Limited (BREL)'s  Derby Litchurch Lane Works.
Pacer (British Rail)