Cable theft 'caused over 6,000 hours of train delays'
Train passengers were delayed by 6,088 hours over the last year because of cable theft, Network Rail has said.
The rail infrastructure body said the number of theft incidents in the 2010-11 financial year jumped by 52% to 995.
Thieves steal the cable to sell on to unscrupulous scrap yards, with the number of thefts strongly linked to the price of copper.
Network Rail said it had cost it £16.5m to replace stolen cable and compensate train operators for lost service.
The industry is combating the criminals with real-time motion-sensitive cameras hidden in the rail infrastructure.
The cables are used to control infrastructure such as signals and points, so if they are damaged the trains often cannot run.
The Association of Train Operating Companies says one franchise, Northern, had 1,435 trains cancelled last year because of theft, as well as 983 hours of delays for passengers.
"We have thousands of kilometres of track, we can't protect every single kilometer," said Dyan Crowther, director of operational services at Network Rail.
"We do a lot of analysis to identify hot spot locations, we know a lot about thieves, their profiles, what they do.
"So we try to put various tactical measures in various locations to try to apprehend them and prevent cable theft."
Some of those tactical measures to both deter and catch thieves are high-tech.
Small motion-activated cameras are being hidden amongst the stones, or ballast, along the tracks as well as in pipes or sleepers.
The cameras send the photos as soon as they're taken to a control centre, where they can then be forwarded to police on the ground, who can use the photos to identify the criminals.
The police say that many of the thefts are to fund drug or alcohol habits, rather than by organised crime.
But as the price of copper in particular rises, so more criminals get in on the act.
It's not that lucrative however. A scrapyard might pay around £5000 a tonne for copper. Depending on the cable, a thief might need hundreds of metres just to get a tonne of the metal.
The British Transport Police says the issue is their second highest priority, after terrorism.
And Alan Pacey, Assistant Chief Constable of British Transport Police warns people shouldn't risk it: "Firstly if you're thinking of it you may well end up seriously injured or killed.
"Secondly it isn't actually that profitable to you as an individual. And thirdly you're very likely these days to get caught and face pretty harsh sentences in the courts."
Because of the wide-ranging effects of cable theft, the courts often hand out sentences of several years.
And the police are also raising awareness of the problem with scrapyards.
They're trying to prevent rogue operators from having an 'ask no questions' approach to where the scrap has come from.