What is British Rail Class 35?
{{Infobox Locomotive |name = British Rail Class 35 |powertype = Diesel-hydraulic |image = WSR 7017 79-08.JPG |caption = Preserved D7017 at Minehead in 1979 |roadnumber = D7000–D7100 |nicknames = Hymek |builder = [[Beyer, Peacock and Company|Beyer Peacock (Hymek) Ltd]] |builddate = 1961–1964 |serialnumber = 7894–7938, 7949–8004 |gauge = {{RailGauge|ussg|lk=on|al=on}} |primemover = Bristol-Siddley / Maybach MD870 |transmission = Hydraulic. Stone-Maybach Mekydro type 6184U |whytetype = B-B |uicclass = B'B' |wheeldiameter = {{convert|3|ft|9|in|m|3|abbr=on}} |minimumcurve = |trainbrakes = Vacuum |locobrakeforce = {{convert|57|LTf|kN|sigfig=3|abbr=on|lk=in}} |wheelbase = {{convert|36|ft|0|in|m|abbr=on}} |length = {{convert|51|ft|8+1/2|in|m|abbr=on}} |width = {{convert|8|ft|10|in|m|abbr=on}} |height = {{convert|12|ft|10|in|m|abbr=on}} |locoweight = {{convert|75|LT|sigfig=3|lk=on}} |topspeed = {{convert|90|mph|0|abbr=on}} |poweroutput = ''Engine:'' {{convert|1700|bhp|sigfig=3|abbr=on|lk=on}} |tractiveeffort = ''Maximum:'' {{convert|46600|lbf|kN|1|abbr=on}} |fuelcap = {{convert|800|impgal|abbr=on|lk=on}} |trainheating = [[Steam generator]] |axleloadclass = [[Route availability]] 6 |multipleworking = Yellow Triangle |railroad = [[British Railways]] |retiredate = 1971–1975 }} The [[British Rail]] '''Class 35''' is a class of mixed traffic [[B-B]] [[diesel locomotive]] with [[hydraulic transmission]]. On account of their Mekydro-design hydraulic transmission units, the design became known as the '''Hymeks'''. The type was developed for the [[Western Region of British Railways|Western Region]] of British Railways, which had opted for lightweight locomotives with hydraulic transmission when allocated funds under the British Railways [[British rail#1955 Modernisation Plan|Modernisation Plan]] of 1955. One hundred and one of the class were built between 1961 and 1964 when it became apparent that there was a requirement for a medium power diesel-hydraulic design for both secondary passenger work and freight