British Rail Class 401

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British Rail Class 401
2090 at London Waterloo in 1986
In service1935–1971[1]
ManufacturerSouthern Railway
Order no.
  • HO806
  • HO898
  • HO903
  • HO948
  • HO949[2]
Built at
Entered service1935[2]
Number built152 sets
Number preserved1 set
Number scrapped151 sets
Formation2-car sets:
  • 2111 (DMBTL)
  • 2115 (DMBTL)
  • 2700 (DTCL)
  • 2701 (DTCL)[2]
Design code2-BIL
Fleet numbers2001–2152
Car body constructionSteel-panelled wooden-framed body on steel underframe
Train length129 ft 6 in (39.47 m)
Car length62 ft 6 in (19.05 m)[2]
Width9 ft 3 in (2.82 m)[3]
Maximum speed75 mph (121 km/h)[3]
  • 74 long tons 15 cwt (75.9 t) (total)
  • 43 long tons 10 cwt (44.2 t) (MBSL)
  • 31 long tons 5 cwt (31.8 t) (DTCL)[3]
Traction motors
  • 2 × MV339
  • 2 × EE507C (MV339 replacements)
  • 2 × EE339 (as built)[2]
Power output2x 275 hp (205 kW) (as built)
550 hp (410 kW) (total, as built)[3]
2 x 250 hp (186 kW) (replacement)
500 hp (373 kW) (total, replacement) name=TRC1 />
Electric system(s)750 V DC Third rail[3]
Current collector(s)Contact shoe
UIC classificationBo′2′+2′2′
Braking system(s)Automatic air
Coupling systemScrew[3]
Multiple workingSR Standard system (1936 Type)
Track gauge4 ft 8+12 in (1,435 mm)

The Southern Railway (SR) gave the designation 2-BIL to the DC third rail electric multiple units built during the 1930s to work long-distance semi-fast services on the newly electrified lines from London to Eastbourne, Portsmouth and Reading. This type of unit survived long enough in British Rail ownership to be allocated TOPS Class 401.


The 2-BIL units (2-car Bi-Lavatory stock) were so-called because each set had two lavatories, one in each car. They were built in four batches, each for service on newly electrified lines:

Units Built Intended Use
2001–2010 1935 London to Eastbourne
2011–2048 1936 London Waterloo to Alton and Portsmouth slow services
2049–2116 1937 Portsmouth to Bognor Regis
2117–2152 1938 London Waterloo to Reading

The different batches were broadly similar, though in the first one, the driving motor brake car had a smaller brake compartment and seven full compartments, rather than six-and-a-half in the later batches.

Several of the cars were destroyed in World War II at various points on the system. Some unit numbers were withdrawn, while others received a single replacement car from the small batch of postwar all-steel 2-HAL units which were built as replacements.


The first two batches of 2-BIL stock were subject to the EMU renumbering scheme implemented during January and February 1937. The renumbering of these units, and the original formations of all 2-BIL units, are set out in the table below (*Unit 1890 was renumbered 1900 in January 1936):

Units (pre-1937) Units (post-1937) DMBT DTC
1890 / 1900* 2010 10567 12101
1891–1899 2001–2009 10568 to 10576 12102 to 12110
1901–1920 2011–2030 10577 to 10596 12034 to 12053
1954–1971 2031–2048 10597 to 10614 12054 to 12071
- 2049–2077 10615 to 10643 12072 to 12100
- 2078–2152 10644 to 10718 12111 to 12185

The first ten 2-BIL units (2001 to 2010) had an earlier form of multiple unit control. They were compatible with the 4-LAV units of the same era, but not with the remainder of the 2-BIL sets. They normally operating from Brighton, where the 4-LAV were also based, on local services. The remaining sets spent their lives on the services for which they were constructed, although they were fully mixed in operation, and it was common for units to be exchanged between areas of operation even within a day's normal work. Commuter services into London Waterloo, Victoria and London Bridge found them typically marshalled up to 8-car units.

An unusual feature of their operation in the 1950s and 1960s was that there were about 30 more diagrams for these units than sets actually existed, while for the subsequent 2-HAL units (Class 402) there were more than 30 spare units, so a significant number of the daily 2-BIL diagrams were operated by the latter units, typically marshalled together as one of the sets in a full 8-car formation.


In 1963, a 7-coach trailer set was formed by placing five former 4-SUB trailer cars between the two driving cars from unit 2006. The set was intended for use on the Oxted line, where it was hauled by diesel locomotives.

The motors from former DMBS car number 10573 were removed, and the whole set was re-wired to enable the hauling diesel locomotive to provide the electric train heating. Six out of nine compartments of one of the 4-Sub Trailer Second cars (number 11485) were refitted as first class compartments, thereby making it a Trailer Composite.

The set was originally numbered 900 in the old hauled carriage set number series, but this was amended in February 1966 to 701 in the new series for trailer control units. Despite this, and its designation as 7-TC (7-car Trailer Control stock), it was not a real trailer control unit in that a locomotive could not be operated remotely from the unit's driving cars.

The unit was stored from December 1967 and then withdrawn in April 1969. However, while the two driving cars were scrapped the following year, all five trailers were reused in other units. Four returned to 4-SUB formations, but 11485 underwent a further conversion, this time to a 4EPB Trailer Second, and was renumbered 15084. Full details of the 7-TC formation, the origin of the individual cars and their subsequent disposal are set out in the table below:

Carriage Number Carriage Type Former Unit Re-use/Disposal
10573 TBS (ex-DMBS) 2-BIL 2006 Scrapped (1970)
10351 TS 4-SUB 4328 4-SUB 4132
10353 TS 4-SUB 4352 4-SUB 4364
11485 TC (ex-TS) 4-SUB 4115 4-EPB 5115 (as TS 15084)
10349 TS 4-SUB 4346 4-SUB 4132
10346 TS 4-SUB 4329 4-SUB 4131
12107 TC (ex-DTC) 2-BIL 2006 Scrapped (1970)

Accidents and incidents[edit]

  • On 1 August 1962, unit No.2088 was derailed at Barnham, West Sussex when a set of points moved under it due to an electrical fault. Thirty-eight people were injured.[4]


After withdrawal in 1971, various 2-BIL units in company with 2-HAL units were noted at Stratford in east London destined for scrapping by Kings of Norwich, or being hauled west for scrapping in the Newport area.[5]


Only one 2-BIL unit has survived into preservation, namely number 2090, formed of carriages 10656[6] and 12123,[7] which is in the care of the National Railway Museum, York. This unit is also one of only two pre-war main line EMUs in existence, which are still in original formation. The other is the Class 503, which is kept at the Locomotive Storage Ltd facility in Margate.[8]

Unit number
(current in bold)
DMBTK DTCK Built Livery Location
2090 - 10656 12123 1937 Eastleigh BR(S) Malachite Green National Railway Museum


  1. ^ Originally 3rd class seating.


  1. ^ "2-car units for main line semi-fast and stopping services (2 Bil)". Southern Electric Group. Archived from the original on 4 December 2013. Retrieved 29 September 2013.
  2. ^ a b c d e f Longworth 2015, pp. 38–40, 213–215, 240–242
  3. ^ a b c d e f g h i "Class 401". The Railway Centre. Archived from the original on 14 October 2007. Retrieved 25 February 2016.{{cite web}}: CS1 maint: unfit URL (link)
  4. ^ Earnshaw, Alan (1989). Trains in Trouble: Vol. 5. Penryn: Atlantic Books. p. 41. ISBN 0-906899-35-4.
  5. ^ "Motive power miscellany". Railway World. Vol. 32, no. 378. Shepperton: Ian Allan. November 1971. p. 508.
  6. ^ "Motor coach, driving trailer composite, SR 2-Bil Unit". Our collection. National Railway Museum. Retrieved 30 July 2023.
  7. ^ "Motor brake 3rd, SR 2-Bil Unit". Our collection. National Railway Museum. Retrieved 30 July 2023.
  8. ^ "Last surviving Mersey Rail Class 503 train arrives at Locomotive Storage in Margate". 30 May 2018.


  • Longworth, Hugh (2015). British Railways Electric Multiple Units to 1975. Oxford Publishing Co. ISBN 9780860936688. OCLC 923205678.
  • Marsden, Colin J. (1983). Southern Electric Multiple-Units 1948–1983. Shepperton, Surrey: Ian Allan Limited. pp. 41–45, 92. ISBN 0-7110-1314-4.

Further reading[edit]

External links[edit]