ALL the attacks have taken place near access gates to the track used by maintenance workers. The gates are normally locked but there are thought to be about 10,000 keys in circulation among rail workers.
In some of the attacks, cables are understood to have been removed from lineside boxes and severed before being replaced making it difficult for engineers to locate the fault.
Initially the saboteur broke open the signal boxes but later began using a key which opens them all. He has struck on different days of the week and at different times, though mostly after the trains have stopped running.
After eight attacks in six weeks last year, he mysteriously stopped and the system returned to normal. But when a signal box went up in flames in Kitts Green on September 8 this year and another at Water Orton station in Warwickshire the following night, police and railway operators realised with sinking hearts that he was back.
Those two attacks affected 150 services and caused 15,000 minutes of delays to trains through the Midlands.
On September 26, six lineside location boxes near Small Heath were set ablaze, knocking out the signalling along 20 miles of the line and causing prolonged delays to commuters travelling from 22 railway stations.
With the line through Small Heath closed completely for 10 days, 1,500 passengers had to be diverted on a circuitous route, including a bus journey of about seven miles.
THE most recent attack was a fire in a brick-built signal relay room at 2am in the Rugeley area on the West Coast main line, which resulted in nearly 160 trains being cancelled and more than 25,000 minutes of delay for nearly 1,000 trains.
Police have interviewed more than 300 people and Network Rail has written to all current and former staff in the West Midlands appealing for information. The company has also installed extra CCTV cameras and deployed a helicopter with heatseeking equipment on night-time patrols of key signal junctions.
A spokesman for Virgin Trains, the operating company which along with Central Trains has been most affected, said yesterday: "It's very difficult for us to think of any way we can help combat it. This person is being extremely selfish and very unfair to anyone who travels by train.
"In the first three days alone after the last attack, we cancelled 115 trains and there were many others which didn't do their whole journey. We have had to use buses for parts of journeys.
"Obviously, passengers are not happy but they are aware of the reason for the problem and that it is not of our making. We are grateful to them for the patience and understanding they have shown." So what could have caused the well of bitterness that is driving the rail wrecker to create such commuter chaos? According to forensic psychologist Mike Berry, senior lecturer at Manchester Metropolitan University, who has helped police draw up offender profiles, it is definitely the work of a seriously angry man.
"It is an act of aggression and it is personal, " he says. "It is not the act of some kid, who would have done something spectacular to attract attention, nor is it likely to be a tryout for an act of terrorism, as that would only take one or two attacks to make sure it worked, not 12.
"This is very methodical, carefully planned and controlled but not showy.
He travels quite a distance so he is pretty determined. I should think he is in his 30s, probably single and living alone. He may have stopped between June 2004 and September this year because he had a girlfriend or something else in his life that distracted him, or he may have been in prison.
"He has probably lost something, quite likely his job. Or he is maybe someone who is involved in one of those small private railways and who resents the giant Network Rail.
"My guess would be that he is still employed on the railways, or has been very recently, which gives him up-todate knowledge of how the system works. He may even wear the proper protective clothing when he goes on his arson raids so that no one would take much notice if they see him." The saboteur may have graduated from cutting cables to setting fire to them because heat damage takes longer to repair, according to Lynsey Gozma, a forensic psychologist who specialises in arson at the University of Surrey.