To ask the Secretary of State for Transport, pursuant to the answer of 30 November, Official Report, column 433 what steps have been taken to eliminate sabotage as a cause of recent incidents of underground train doors opening while the train is in motion, with particular reference to the two incidents on 12 November; what safeguards are attached to the special keys which activate the doors; if, for each of the incidents listed by the previous answer for which no cause has been positively identified, he will give the suspected cause; and if he will make a statement.
Unauthorised interference with the operator's panel for opening the doors was one of the possibilities considered by London Underground Ltd. when investigating the recent incidents. Possible measures to prevent such interference are being considered by LUL and will be covered in the report referred to in my answer of 30 November at column 433. The special operators' keys are issued against a signature to those members of the staff who require them for their official duties. The cause of the incidents on 12 November is still under investigation by LUL; the probable cause of the others was given in my earlier answer.