British Rail Class 123

From Wikipedia, the free encyclopedia
Jump to: navigation, search
British Rail Class 123
Mixed 4 car DMU Class 123 124 at Manchester Piccadilly.jpg
A mixed four car diesel-mechanical multiple unit formed from a class 123 driving motor corridor second, 2 class 124 trailer brake corridor seconds, and a class 123 driving motor corridor second number at Manchester Piccadilly on 10 March 1984.
In service 1963–1984
Manufacturer Swindon Works
Number built 40 (Ten 4-car units)
Number scrapped All
Capacity 24 First class, 176 Second class seats (units with buffet 32 second class less)
Operator(s) British Rail
Car length 64 ft 11 14 in (19.793 m)
Width 9 ft 3 in (2.82 m)
Height 12 ft 9 12 in (3.899 m)
Maximum speed 70 mph (113 km/h)
Weight 146.75 long tons (149.10 t; 164.36 short tons)
Prime mover(s) 230 hp (172 kW), 2 per power car
Power output 920 hp (686 kW)
Bogies B4
Multiple working Blue Square
Track gauge 4 ft 8 12 in (1,435 mm)

The Class 123 was a design of Diesel Multiple Unit built for British Rail in 1963. They were built by British Rail at Swindon Works, and designed like all Swindon units as inter-city sets. Ten of the four-car sets were built and introduced in 1963. The units bear a visible similarity to the British Rail Class 309; however, there is no 'relation' here as the two types were built by different manufacturers for different markets.

Swindon-built DMUs, including the Class 123 and 124, had a structure and internal construction with much more in common with BR coaching stock (British Rail Mark 1) than they do with many DMU classes. The carriage underframes were longer (Mk1 standard main-line 63 ft 6 in (19.35 m) frames, vs the 57 ft 0 in (17.37 m) frames common to most 1st generation DMUs) and the units were provided with Mk1-style "Pullman" gangways instead of the "British Standard Gangways" fitted to most contemporary DMUs of the period. It was also unusual for a first-generation DMU to sport a front end gangway. None of these units survive today.

Table of orders and numbers
Lot No. Type Diagram Qty Fleet numbers Notes
30703 Driving Motor Brake Open Second (DMBSL) 566 10 52086–52095 32 seats, 2 lavatories
30704 Driving Motor Corridor Second (DMSK) 574 10 52096–52105 7 compartments (56 seats), 2 lavatories
30705 Trailer Corridor Composite (TCK) 567 10 59818–59827 4 first class and 3 second class compartments: 24 & 24 seats; 2 lavatories
30706 Trailer Open Second with lavatory (TSL) 568 5 59235–59239 64 seats, 2 lavatories
30707 Trailer Buffet Second (TSLRB) 569 5 59828–59832 32 seats, 8 seats in buffet area, 1 staff lavatory

Further Use[edit]

One of the buffet cars, 59831 was rebuilt as a Class 309 AC EMU griddle car, and renumbered 69108. It replaced a griddle car that had developed an underframe fault


  • Motive Power Recognition: 3 DMUs. Colin J. Marsden
  • British Rail Fleet Survey 8: Diesel Multiple Units- The First Generation. Brian Haresnape

Further reading[edit]

External links[edit]