King’s Cross crash driver fell into ‘microsleep’

The driver of a Great Northern Class 387 electric multiple unit (EMU) which collided with buffers at London King’s Cross on August 15 fell into a ‘microsleep’ in the last few seconds of the train’s approach, according to the Rail Accident Investigation Branch (RAIB).

In a Safety Digest issued on October 23, it said the driver reported being aware of passing the Train Protection Warning System (TPWS) sensor, but then briefly closed her eyes because they felt tired and were stinging. When she reopened them, she was close to the buffer stops, and although an emergency brake application was made, it was too late to prevent the collision.

The train’s data recorder showed it passed the TPWS overspeed sensor at 9.2mph, considerably less than the intervention threshold of 12.5mph. Four passengers and one member of staff reported minor injuries, and the train and buffer stops suffered minor damage.

The RAIB found that the driver was fatigued because the journey was at the end of a ‘relatively demanding’ night shift - her first after a period of rest days - and because she was insufficiently well rested. Although she had a 40-minute nap during a stopover at Letchworth sidings earlier in the day, she reported that she did not feel sufficiently rested and took another 10-minute nap at Royston before the 0513 train departed.

The RAIB says Great Northern’s fatigue risk management procedure is dated October 2010 and has not been updated in light of fresh guidance on fatigue risk published by the Office of Rail and Road and Rail Safety Standards Board in 2012.

The Safety Digest says the accident “demonstrates the importance of effective and comprehensive fatigue risk management on the part of both individuals and organisations, including not just controls on working hours but also suitablytimed breaks, preparation for duty and the appropriate use of mitigations.”