Severe electric shock to train driver near Sutton Weaver, Cheshire - 23 Sep 2014

[whole diary]

[Chris from Nailsea]

From the Rail Accident Investigation Branch website:

Severe electric shock to a train driver near Sutton Weaver, Cheshire, on 23 September 2014

RAIB^▸ (Rail Accident Investigation Branch) is investigating an accident involving a train driver who received a severe electric shock from a damaged overhead line whilst walking on the track near his train. The accident occurred at about 19:00 hrs on 23 September 2014 on the line from Crewe to Liverpool. The driver was slowing his train on the approach to a signal which was displaying a red aspect when he observed a damaged section of overhead line and stopped his train before reaching it. He reported the damage to the signaller before leaving the cab of his train. Shortly afterwards the driver came close to, or made contact with, part of the damaged overhead line that was hanging down but still energised. He received a severe electric shock and was seriously injured.

As a result of the accident the electrical supply system detected a fault and breakers feeding the overhead line opened automatically, turning off the power supply. The driver was then attended to by the train manager and a doctor who was travelling on the train before the emergency services arrived.



RAIB^s investigation will consider the sequence of events and factors that may have led to the accident. This will involve consideration of the actions of those involved, the relevant rules and procedures, the design and maintenance of the overhead line equipment, and the way in which the aftermath was managed.

RAIB^s investigation is independent of any investigations by the safety authority or the railway industry. The RAIB will publish its findings, including any recommendations to improve safety, at the conclusion of its investigation. This report will be available on the RAIB website.

[TonyK]

I hope the driver recovers - seems the circuit breaker may have come to his aid.

[stuving]

I hope the driver recovers - seems the circuit breaker may have come to his aid.

Unlikely, on its own, to do that - the trip current is (from memory) something like 400 A as a minimum, and protects the system not people. That is way above the trip current of ELCBs (30 mA) in your home, which are there to prevent electrocution. And, of course, with the traction current return via the ground, earth leakage detection is not possible.

However, one of the factors that determines that trip current is the maximum voltage on earthed metalwork under fault conditions ("fault" in this context means a short circuit, usually to earth). That induced voltage is only there for a fraction of a second, until the breaker opens. I'm not sure what the limit is now, it used to be 430 V. So that's what is likely to have happened - if you are close enough to a flashover or contact from the overhead wiring to the track or train, you may still suffer injury.

[Chris from Nailsea]

The Rail Accident Investigation Branch (RAIB^▸ (Rail Accident Investigation Branch)) has now released its report into this incident, which is available on their website.

At 19:04 hrs on Tuesday 23 September 2014, a train driver received a severe electric shock at Sutton Weaver, Cheshire.
 
The train driver had stopped his train having seen damaged overhead power supply wires ahead of it. Following a call to the signaller, he left his train and came close to, or made contact with, an electrically live wire which had broken and was low hanging. The train driver suffered serious injuries.

This accident occurred because one of the overhead wires had broken, was hanging down and was electrically live. Two previous trains had come into contact with this hanging wire and consequently tripped the power supply circuit breakers. Each time the circuit breakers had been reset by the Electrical Control Operators in accordance with procedures to make the overhead wires electrically live again. The driver had left the train to obtain information as to his location to assist in restoring train services as he was trained to do, but did not see the broken wire.

The investigation found that the wire broke as some of its strands had fractured due to fatigue, likely initiated and progressed from a high stress area related to an attachment supporting the overhead wire.

The RAIB has made two recommendations. One is for Network Rail to extend the scope of its detailed overhead line examinations to inspect for signs of wire damage at these attachment positions.

The other recommendation is for RSSB^▸ (Rail Safety and Standards Board), who are the custodian of the railway Rule Book, to review whether clarification is needed relating to the actions that train crew should take if they are required to leave a train where the OLE^▸ (Overhead Line Equipment, more often "OHLE") is known to be damaged and still live.

Following a review of the actions of those involved in attending to the injured driver, one learning point has been made reminding train operators of the importance of contacting the signaller by the quickest means in emergency situations.