ENGINEERS WERE this week due to test a taylor made set of replacement points for the Camden Town junction where a train derailed last October.
Contractor Tubelines has installed the points, which include a narrower leading edge for the switchblade.
The points are to be tested at night using empty trains before they can be approved by London Underground (LUL) and the Health & Safety Executive.
LUL said this week that it had imposed tighter maintenance regimes for rail switches following the Camden Town derailment last October.
The new regime comes into force despite the fact that work on the Camden switch was done in a timely and competent way, according to a report by derailment investigators.
The report says that replacement of the left hand switchblade the night before the derailment contributed to the accident.
The report was published this week by a team made up of representatives of London Underground, Northern Line maintenance contractor Tubelines and rail union officials.
It says the gauge face on the new blade had not worn enough and had added to friction enabling train wheels to rise up the rail and come off.
Routine grinding to reshape the right hand 1968 British Rail designed blade also contributed, adds the report.
The cause of the accident, it concludes, lay with the design of switchblade used at the crossing.
The report says that derailment was only possible when the blade was part of a facing point, it was on a sharp curve, and was not worn and so it was able to create high levels of friction between the wheels.