Class 101

The Class 101 family was the largest fleet of 1st generation DMU built for British Railways in the 1950s, however originally only the AEC engined DMBS and DMCL were Class 101 (see information box for explanation of codes). Leyland engined motor cars were Class 102, the DTCLs were Class 144/147, the TSLs Class 162/164, the TBSLs Class 168 and the TCLs Class 171! [1] Later on the various cars were reclassified as just Class 101. The DMU could operate in either 2, 3 or 4 car sets with interchangeable trailers (and with trailers in other classes) depending on the needs of the service and served all over the BR network allocated to every region except the Southern [2].

Number built: 637 cars in 2- 3- and 4-car sets
Built: 1956-59
Builder: Metro-Cammell
Engine: 2 BUT (AEC) or Leyland 6-cyl (originally Class 102) diesels per power car
Some DMBS originally fitted with Rolls-Royce diesels
Power: 300 hp (224 kW)
Formation: (Variable) Driving Motor Brake Standard (DMBS)+[Trailer Brake
Standard (TBS)/Trailer Standard Lavatory (TSL)/Trailer Composite
Lavatory (TCL)/Trailer Brake Second Lavatory (TBSL)]+Driving
Motor Composite Lavatory (DMCL)/Driving Trailer Composite
Lavatory (DTCL)

The Class 101 was one of the longest lived 1st generation DMUs surviving in service until 2003 [3]. In later years many of the trailers lost their first class accommodation and were reclassified as TSLs. Some trailers also originally had buffet facilities but these later had the buffets removed and/or were withdrawn.

Originally the Class 101s were delivered in British Railways green then later BR Blue and the blue/grey white/blue variations in the 1970s. In later years the Class 101s wore sector liveries (Network SE and Regional Railways) as well as various PTE liveries. Over forty cars have been preserved although only two of these are centre car trailers. A sister class of Rolls-Royce powered DMUs was also built as the Class 111 (though a couple of 101 power cars did had Rolls-Royce engines too!)
DMBS 51188 and DMC 51505 at Wirksworth

DMBS E50253 at Duffield

[1] Colin J. Marsden, DMU and EMU Recognition Guide (Ian Allan, 2013), p. 36
[2] Brian Haresnape, Diesel Multiple Units: the First Generation (Ian Allan, 1985), p. 31
[3] Gavin Morrison, British Railway DMUs in Colour (Ian Allan, 2010), p. 13

Class 458 4-JOP

The Class 458 4-JOP (Juniper Outer-suburban Porterbrook) was built for South West Trains in the late 1990s to replace some Class 411s, although for the Southern 750v DC third rail network they were "future proofed" with provision to support a pantograph and overhead electric collection though do not carry one yet [1]. Their entry into service as 458/0 was fraught with technical difficulties with serious usage on the Waterloo to Reading and Guildford-Ascot routes not happening for several years and after many modifications [2]. The unreliability saw SWT plump for the "Desiro" Class 444/450s instead of more 458s to replace the majority of its "slam door" EMU fleet [3].

Number built: 30 4-car sets
(rebuilds) 36 5-car sets
Built: 1999-02
(rebuilds) 2013-6
Builder: Althom (Washwood Heath)
(rebuilds) Wabtec (Doncaster) & Brush Traction (Loughborough)
Engine: 6 Althom ONIX 800 traction motors
Power: 2, 172 hp (1, 620 kW)
Formation: (original) Driving Motor Composite Open (DMCO)+
Pantograph Standard Open (PSO)+Motor Standard Open (MSO)+DMCO
(rebuilds) Driving Motor Standard Open (DMSO)+PSO+MSO+TSO+DMSO

In 2011 after the withdrawal of the similar Class 460 from the Gatwick Express it was decided to use cars from the 460 to strengthen the 458s as 5 car trains (5-JOP). The trains were also refurbished and rebuilt with an improved appearance and full gangways. 5 "new" 458/5s (as they became known) were also created from spare rebuilt 460 cars. Work is still ongoing on conversions as well as repairs to a fire damaged unit [4] and should be complete sometime in 2016 [5].
SWT 458 535 at Clapham Junction

SWT 458 534 and friend at Clapham Junction

[1] "Class 458" Southern Electric Group <>
[2] Colin J. Marsden, DMU and EMU Recognition Guide (Ian Allan, 2013), p. 356
[3] "Train firm to replace new fleet", BBC News <>
[4] "Fire damaged 458 under repair", Railways Illustrated Issue 157 (March 2016)
[5] "458/5 programme nears completion", Today's Railways UK Issue 171 (March 2016)

Class 122 [Updated]

Twenty of these single car railcars were built in the late 1950s for branch lines in the Western, London Midland and Scottish Regions of British Rail [1]. Unlike the similar Class 121 railcars 9 unpowered driving trailers (originally classified as Class 150 [2]) were also built to supplement the single railcars, these could be hauled by the Class 122 in times of higher demand. Technically they are very similar to the Class 119 also built by the GRCW Company but with a BR Derby style high density layout [3].

Number built: 29 (20 motor, 9 trailers)
Built: 1958
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 [4].

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 [5].
M55006 at Wirksworth on the EVR

Another view of M55006 at Wirksworth

[1] Brian Haresnape, Diesel Multiple Units: The First Generation (Ian Allan, 1985) p. 54
[2] Class 122, <>
[3] Colin J. Marsden, DMU and EMU Recognition Guide (Ian Allan, 2013) p. 81
[4] Gavin Morrison, British Railways DMUs in Colour (Ian Allan, 2010) p. 20
[5] Colin J. Marsden (ed.), "The Birth of the DMU", Modern Locomotives Illustrated No. 207 June-July 2014 (The First Generation Multiple Units), p. 19