BR
British Rail: the state corporation established under the Transport Act 1962 responsible for the operation, upkeep and stewardship of the national rail network infrastructure and freight and passenger train services until the railway was privatised between 1994 and 1997.
Bridge strike
An incident where a railway bridge has been struck by a road vehicle.
Broken rail
A rail which has a fracture through the full cross section or a substantial piece broken out of the railhead.
BTP
British Transport Police: a police service for rail operators, their staff and passengers in England, Wales and Scotland.