Vandals were responsible for more than 1,137 accidents on the railways last year - including over 200 cases of arson.
Heavy objects such as lumps of iron and other trackside debris have been dragged on to the lines in deliberate attempts to derail passenger trains.
The Health and Safety Executive said the proportion of "vandal-induced" accidents rose from 51 per cent in 1996-97 to 61 per cent in 1997-98.
Frank Davies, chairman of the Health and Safety Commission, said: "If this dangerous behaviour continues, I believe that it is only a matter of time before there will be a major train accident and loss of life."
Mr Davies said the HSE was particularly concerned in the rise in attacks on scheduled services. Of the 619 incidents of damage to cab windscreens, 514 were caused by missiles thrown by vandals. Last year, the rail regulator was badly shaken when an object thrown from the trackside smashed into the cab he was riding in.
The private train companies and Railtrack, which owns the track and signals, both promised to find ways of cutting the risk from vandals.
A spokesman for the Central Rail Users' Consultative Committee, the passenger watchdog, pointed out that "the courts seem too often to take an over- lenient view in cases of trespass and vandalism".
The HSE said the worst area for vandalism was the outskirts of northern industrial cities - while arson had particularly affected the south-east England services of Connex South East and Connex South Central.
Excluding suicides and trespasser deaths, the number of people killed on the railways jumped from an all-time low of 25 in the 12 months to March 1997 to 47 last year.
The death statistics included seven who were killed in the train crash in Southall, west London, in September 1997. Only one passenger had been killed in the 1996-97 period.
Vic Coleman, HSE's chief inspector of railways said the incidents of vandalism that were recorded were only those where damage had occurred and that the true figure was probably "considerably worse".Reuse content