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
London Underground infrastructure were originally maple wood, then aluminium from 1963, and this had been replaced with plastic or rubber following an increase in serious injuries following falls. However, following the King's Cross fire, aluminium treads have been used. There are 426 escalators on the London Underground system and the longest, at , is at Angel. The shortest, at Stratford, gives a vertical rise of . There are 184 lifts across the Underground, with 72 stations having step-free access from street to train. Major efforts have taken place to improve accessibility across the Underground, with the Jubilee line extension having lifts from opening