Safety on the London Underground The earliest attack on the London Underground was in 1885, when a bomb exploded on a Metropolitan line train at Euston Square station. The Provisional IRA (and its predecessors) carried out over ten separate attacks between 1939 and 1993. As a response to growing 'Mumbai-Style' terrorist attack threats, the British Transport Police has its own detachment of armed officers who will regularly patrol both the Underground’s stations and its trains. Various regulations aim to improve safety on the Tube. Smoking was allowed in certain carriages in trains until 9 July 1984. In the middle of 1987 smoking was banned for
Circle line (London Underground) the stations are shared with one or more of the three other sub-surface lines, namely the District, Hammersmith & City and Metropolitan lines. On the Circle and Hammersmith & City lines combined, over 114 million passenger journeys were recorded in 2011/12. The first section became operational in 1863 when the Metropolitan Railway opened the world's first underground line between Paddington and with wooden carriages and steam locomotives. The same year a select committee report recommended an "inner circle" of lines connecting the London railway termini, and the Metropolitan District Railway (commonly known as the District Railway) was formed to build