|Number built:||29 (20 motor, 9 trailers)|
|Builder:||Gloucester Railway Carriage & Wagon Company|
|Engine:||2 BUT (AEC/Leyland) 6-cyl diesels|
|Power:||300 hp (220 kW)|
|Formation:||Driving Motor Brake Second (DMBS)+Driving Trailer Second (DTS) [Optional]|
They served until the mid-1990s in passenger service on lightly loaded routes such as the Stourbridge shuttle and the pre-electrified branch to Redditch .
In the privatisation era a number continued in departmental service as route learning and test cars for a number of years though all have been withdrawn from that role now. Eight have been preserved though none of the unpowered trailers have survived. Three Scottish Region Class 122s were converted to carry parcel traffic for a time and reclassified Class 131 .
|M55006 at Wirksworth on the EVR|
|Another view of M55006 at Wirksworth|
 Brian Haresnape, Diesel Multiple Units: The First Generation (Ian Allan, 1985) p. 54
 Class 122, Railcar.co.uk <http://railcar.co.uk/type/class-122/>
 Colin J. Marsden, DMU and EMU Recognition Guide (Ian Allan, 2013) p. 81
 Gavin Morrison, British Railways DMUs in Colour (Ian Allan, 2010) p. 20
 Colin J. Marsden (ed.), "The Birth of the DMU", Modern Locomotives Illustrated No. 207 June-July 2014 (The First Generation Multiple Units), p. 19