Note that the Class 150 dmu features a 2 stage transmission with a torque convertor.  The transition to lockout occurs at approximately 45 mph when accelerating and falls out of lockout at around 35 mph when decelerating.  Efficiency is low in the non-lockout stage especially if full throttle is used from a standing start. Later operating instructions dictated that only notch 2 should initially be used to avoid overheating the torque convertor.  The unit has a design speed of 75 mph although the te curves extend to 80 mph. Higher speeds in favorable conditions have been observed with a balancing speed of 83 mph on level track.. This is unlikely to be achieved with the degree of monitoring now in place.

BR Class 150 DMU.png

BR Class 150 TE Data