Editing British Rail BEMU

{{Short description|Experimental battery electric multiple unit}}
{{Use dmy dates|date=January 2017}}
{{Use British English|date=January 2017}}
{{Infobox train
| background       = #012545;color:white
| name             = British Rail BEMU
| image            = Railcar at Milton of Crathes (geograph 1821382).jpg
| imagealt         = 
| imagesize        = 300px
| caption          = Battery Multiple Unit at Milton of Crathes
| interiorimage    = 
| interiorimagealt = 
| interiorcaption  = 
| service          = 1958–1966
| manufacturer     =
| factory          = Derby Works - converted to battery at [[Cowlairs railway works|Cowlairs]]
| family           = [[British Rail Derby Lightweight|Derby Lightweight]]
| replaced         = Steam locomotives and carriages
| yearconstruction = 1956 - converted 1958
| yearservice      = 
| refurbishment    = 
| yearscrapped     = 
| numberconstruction= 
| numberbuilt      = 1 set (2 cars)
| numberservice    = 
| numberpreserved  = 1 set (2 cars)
| numberscrapped   = 
| formation        = {{abbr|DMBS|Driving Motor Brake Second}}-{{abbr|DTC|Driving Trailer Composite}}
| fleetnumbers     = 
| capacity         = 12 first<br>105 second (initially 31 + 86)
| operator         = [[British Railways]]
| depots           = 
| lines            =

| carbody          = Steel
| trainlength      = 
| carlength        = {{convert|57|ft|6|in|m|2|abbr=on}}
| width            = 
| height           = 
| floorheight      = 
| platformheight   = 
| entrylevelorstep = 
| doors            = 2 on each side
| art-sections     = 
| maxspeed         = {{convert|60|mph}}
| weight           = DMBS: {{long ton|37|10}}<br>DTC: {{long ton|32|10}}
| acceleration     = 
| deceleration     = 
| traction         = 
| engine           = 2 x {{convert|100|kW}} [[Traction motor#Mounting of motors|nose-suspended motors]]
| poweroutput      = 
| transmission     = 
| aux              = 
| powersupply      = [[Chloride Electrical Storage Company|Chloride Batteries Ltd]]
| hvac             = 
| electricsystem   = 216 lead-acid cells, 440 V, 1070 A·hr
| collectionmethod = 
| uicclass         = 
| aarwheels        = 
| bogies           = 
| brakes           = 
| safety           = 
| coupling         = 
| multipleworking  = 
| gauge            = {{RailGauge|ussg}}
}}
The '''British Rail BEMU''' was an experimental two-car [[battery electric multiple unit]] (BEMU), converted from the [[British Rail Derby Lightweight|prototype Derby Lightweight]] [[Diesel multiple unit]]s. The train was powered by many [[lead–acid battery|lead-acid batteries]], and was used on the [[Deeside Railway]] from [[Aberdeen]] to [[Ballater]] in [[Scotland]] from April 1958 until it was finally withdrawn in December 1966. The [[North of Scotland Hydro-Electric Board]] initiated the design and was a joint sponsor. The board promised to supply power at three [[farthing (British coin)|farthings]] per unit for a fixed two-year period.<ref name=mullay>{{cite magazine |last1=Mullay|first1=Alexander|title=Batteries Included |magazine=The Railway Magazine|date=August 2004|pages=56–58}}</ref> It provided an 11kV supply to a charger at Aberdeen's platform 1 and a 6.6kV supply to a charger at Ballater.<ref name=rm>{{cite magazine |magazine=The Railway Magazine |date=June 1958 |pages=419–420 |title=First Battery Railcars on BR |issue=686 |volume=104 }}</ref>

==Career==
The estimated cost of the fit-out was £50,000, with the two coaches accounting for almost half of that. Because each set of batteries weighed about eight tons, the underframe of the carriages needed strengthening,<ref name=rm/> at a budgeted cost of £2,000. Motors, conduits and cabling were costed at £5,000.<ref name=mullay/>

Power was provided from two Siemens-Schuckert compensated motors each rated at 100 kW which were nose suspended onto motor bogie. The control equipment is similar to that employed on the German battery railcars and was supplied by Siemens-Schuckert (Great Britain), Limited. It consists of apparatus manufactured by Siemens-Schuckert and Schaltbau in Germany. Control is effected by series-parallel arrangements with three positions of field weakening and with facilities for cutting out either motor. The battery consisted of 216 lead-acid Chloride Batteries rated at 440V 1,070 Ampere Hour. <ref>{{Cite book |url=http://archive.org/details/sim_modern-transport_1958-04-12_79_2037 |title=Modern Transport  1958-04-12: Vol 79 Iss 2037 |date=1958-04-12 |publisher=Modern Transport Publ Co Ltd |others=Internet Archive |language=English}}</ref>

The unit was equipped with a new type of battery in the early 1960s, but subsequently suffered a series of small fires in the battery areas and was withdrawn from service.{{Citation needed|date=February 2018}} It returned to use for a period before closure of the line in 1966.

==Departmental use and preservation==
The train then spent a short time in storage at Inverurie Works, and at Hyndland Shed in [[Glasgow]], before being transferred to departmental use as test train "Gemini" (or "Laboratory 16") for use at the [[Railway Technical Centre]], at Derby.<ref name=mullay/> It lasted in this role until it was withdrawn in 1984, and was eventually bought for preservation at the proposed [[Transperience|West Yorkshire Transport Museum]], where it was returned to working order. The museum placed it on loan to the [[East Lancashire Railway]] in 1994 where, after asbestos was removed and the batteries refurbished, it was used on some services until 2000.<ref name=mullay/> After the museum went into liquidation, the unit was purchased by the [[Royal Deeside Railway]] near Crathes, in 2001. It is now back in Scotland, where it is undergoing refurbishment.

Details are as follows:
{| class="wikitable"
!colspan=2|Vehicle Nos.
!align=left rowspan=2|Location
!align=left rowspan=2|Comments
!colspan=2|Departmental Nos.
|-
!DMBS
!DTC
!DMBS
!DTC
|-
|79998
|79999
|[[Royal Deeside Railway]]
|Used as test train "Gemini" (Lab 16).
|975003
|975004
|}

==References==
{{Reflist}}

==External links==
*[http://preserved.railcar.co.uk/RoyalDeeside.html Photos at Royal Deeside Railway]
*[http://www.old-dalby.com/mtesting-index.htm Dave Coxon's website]{{dead link|date=January 2025|bot=medic}}{{cbignore|bot=medic}} - Photographs from the unit's time as the BR Automatic Train Operation test train.
*[https://web.archive.org/web/20101008041932/http://railcar.co.uk/hisOthers/BMUintro.htm Railcar Association] – BEMU ()
{{British Rail EMU}}

[[Category:British Rail electric multiple units|BEMU]]
[[Category:Train-related introductions in 1958]]