What is British Rail Class EF1?
{{Infobox Locomotive |name = NER Classes EF1 and EB1 |powertype = Electric |image = Electric railway journal (1916) (14758510085).jpg |caption = |builder = [[North Eastern Railway (UK)|North Eastern Railway]] |serialnumber = |buildmodel = |builddate = 1914-1919 |totalproduction = 10 |whytetype = |aarwheels = [[Bo-Bo]] |uicclass = |gauge = {{track gauge|sg}} |wheelbase = |length = {{convert|39|ft|4|in|m|abbr=on}} |width = |height = |weightondrivers = |wheeldiameter = {{convert|4|ft|mm|abbr=on}} |locoweight = {{convert|74|t|abbr=on}} |locotenderweight = |fueltype = |fuelcap = |tendercap = |consumption = |watercons = |electricsystem = 1500V DC |collectionmethod = [[Pantograph (rail)|Pantograph]] |primemover = |enginetype = 4 x 275hp, [[Siemens]] |aspiration = |displacement = |boiler = |boilerpressure = |feedwaterheater = |firearea = |tubearea = |fluearea = |tubesandflues = |fireboxarea = |totalsurface = |superheatertype = |superheaterarea = |cylindercount = |cylindersize = |rearcylindersize = |hpcylindersize = |lpcylindersize = |valvegear = |transmission = |maxspeed = |poweroutput = {{convert|820|kW|hp|abbr=on}} |tractiveeffort = |factorofadhesion = |locobrakes = |trainbrakes = |operator = [[North Eastern Railway (UK)|North Eastern Railway]] <BR /> [[London and North Eastern Railway|LNER]] <BR /> [[British Railways]] |operatorclass = LNER & BR: EB1 |numinclass = 10 |fleetnumbers = NER: 3-12 <BR />LNER: 6490-6499 <BR />BR: 26502-26511 |officialname = |nicknames = |locale = |deliverydate = |firstrundate = |lastrundate = |retiredate = April 1964 |restoredate = |scrapdate = |currentowner = |disposition = |notes