Reference.com's glossary of UK railway terminology

Baby Warship : North British D6300 class locomotives which used one engine coupled to a hydraulic transmission, making them effectively half a D600 Warship or NBL D800 Warship.

Barbie : Livery of First Group's bus and rail companies up until Feb 2006 – the name comes from the purple and pink packaging of Barbie dolls. First Group are now favouring Neon schemes

Bed pan : a name used for the service that used to operate between Bedford and London St. Pancras; this service has subsequently been replaced by cross-London service on the Thameslink route.

Black Five: LMS Stanier Class 5 4-6-0. One of the largest classes of steam locomotives built in the UK, named from their black 'mixed-traffic' livery and 'Class 5' power rating.

Blood and Custard : Name applied to the Carmine and Cream livery used on BR's coaches during the 1950s and 60s

Bodysnatcher : Class 57 locos – made by transplanting a General Motors reconditioned power unit and alternator into a Class 47 bodyshell. Term used especially by Brush bashers who have not come to terms with their favourite locos being treated in this way.