153310 at Lincoln in June 2011. ©Rept0n1x
The British Rail Class 153 "Super Sprinters" are single-coach railcars, converted from existing two-car Class 155 diesel multiple units. They were intended for use on rural and lesser used branch lines where passenger numbers do not justify longer trains, or to boost the capacity on trains to enable higher passenger volumes than a single two-car unit. Having been converted from existing 155s, the 153s feature an unusual smaller cab at one end, giving the vehicle an asymmetrical look. When working in multiple this end of the vehicle is often not on the leading end of the train. The fleet have seen use with all manner of operators across most of England, Wales and now Scotland. ScotRail currently intend to use the fleet as "Active Travel Carriages" providing more space for bicycles and leisure equipment on their highland services - for this purpose some of the class have been refitted with a different interior layout.
(Information provided via Wikipedia)