COMPUTER FILES hold the key to the collapse of a Kirow rail mounted crane on to a busy south London railway line early on Monday morning, safety officials said this week.
The crane is entirely computer controlled with lift details, load, radii and propping entered by the driver.
Its on-board computer system is capable of shutting down lifting operations if the crane is overloaded.
The Kirow KRC810 high capacity crane toppled over just after midnight on Monday, damaging track between Waterloo station and Clapham Junction in south London. No one was hurt.
The crane was being used for a routine points lifting operation at the time by contractor Balfour Beatty, as part of line and points renovation work.
Specialist engineers from the German manufacturer flew to London on Tuesday to help investigations into the collapse.
'Once the Kirow engineers have downloaded the computer datalog it should give clues for the direction of an investigation, ' said a spokesman for Her Majesty's Railway Inspectorate.
'This should indicate just what was happening when the incident occurred and whether operational, mechanical or line factors are important.'
Accident clearance, a delay in completing the work and some damage to the lines meant severe disruption to South West Trains' services into one of London's busiest station on Monday.
Complete restoration of the full service might take until Thursday morning, said a Network Rail spokesman.
A Kirow spokesman said the crane type had so far operated without incident in Europe.
Around a dozen units in varying sizes have been sold by the Leipzig based manufacturer.
Another large model is working in the US.
The Kirow crane can lift an 85t maximum load when 'propped', or outrigged, either side of the track. It can also operate in free travelling mode with loads up to 45t, moving, for example, a prefabricated points or track section into position.
The jib can work in a horizontal position with clearance of just 4m, letting it work under catenary lines.