Due to due to an unexpected and significant increase in wheel bearing faults on the existing 40 year- old fleet of trains, there was considerable disruption to Merseyrail services in June. The faults affected a far higher number of trains than usual which meant Merseyrail had less trains to run services with. As a result of this, reduced timetables were temporarily put in place.
What is a wheel bearing fault?
In general terms, wheel bearing failures are attributable to electrical current passing through them. This leads to mechanical damage to the contact surfaces within the bearings.
This type of problem is a known phenomenon within the railway industry and while Merseyrail trains do experience these faults, about two a month, the rate of failure and extent of damage seen on the fleet on this occasion was unprecedented.
Who was responsible for sorting this out?
Merseyrail is responsible for the delivery of train services under a concession contract with the Combined Authority.
Stadler Rail Services Ltd is responsible for the maintenance of the fleet of trains under a sub-contract with Merseyrail.
While the Combined Authority was not responsible, Metro Mayor Steve Rotheram called for all industry partners to come together to address the situation without delay with the aim of recovering the network to the standards that passengers expect and deserve.
What happened to fix the problem?
The Combined Authority instructed Merseyrail and Stadler to address the problem immediately and to carry out a robust investigation into the cause of the wheel bearing faults.
They responded firstly to ensure that safety was not compromised and completed tests of the whole fleet. Skilled technicians were assigned to ride and assess the trains to detect vulnerable bearings. Those trains that were identified as having bearings issues were then removed from service, so they could be replaced. Resources were mobilised to ensure the trains could be returned to service as soon as possible.
What caused the problem?
A joint investigation was launched which included Network Rail and several industry experts with relevant specialist knowledge.
The Combined Authority understands that numerous tests of both the trains and infrastructure are ongoing. Unfortunately to date this investigation has not yet precisely identified the root cause of the problem but has been able to eliminate many of the potential causes. The Combined Authority will ensure that all parties continue to collaborate until the work is completed and investigation report produced.
Could this issue have been foreseen or prevented?
Wheel bearing faults are not uncommon. However, it was the scale of the wheel bearings failures that was highly unusual in the fleet. A team of engineers and experts from the wider industry are working hard to understand the root cause of this to prevent it happening in the future.
Are the trains safe?
Yes. Merseyrail, like the rest of the rail industry, must comply with the highest safety standards to operate. All the trains are subject to regular, robust safety checks and passengers should continue to travel with confidence.
Could this happen with the new trains?
The new, state of the art trains are being built to the highest standards. Over time and as with any fleet of trains, wheel bearing faults are a possibility but there shouldn’t be a repeat of the scale of faults experienced in June.
Why couldn’t the new trains be used to provide services?
The new fleet is not yet ready for service. We’re working hard with partners with the aim of starting the phased introduction into service later this year. Look out for more information about this in the coming months.