40987 Electric problem with coupling on 170 units

August 2010 in Network Rail and Suppliers

Rules and procedures Work environment Rolling stock Equipment Central West Midlands

Coupling electronic devices on Class 170 units, particularly at Birmingham New Street station, are of concern to a reporter.

Correct procedures are followed by Drivers when coupling multiple sets of 170 units and departing Birmingham New Street. However, when the train goes over heavy point work or tight bends the train's brakes are automatically applied. This is because the electric pins in the plugs of the coupling devices appear to be moving slightly out of the connections. Once the train comes to a halt

Drivers then have to uncouple and couple the units again before continuing the movement.  Undertaking the re-coupling can be risky; often, the front cab is in the tunnel which means Drivers are unable to contact the Signaller. Also, Drivers have to climb in and out of every cab which involves going onto the track every time, presenting a slip, trip, fall hazard. The reporter states that re-coupling is required almost every time the 170 units depart Birmingham New Street station. The problem also occurs at Tyseley station.

Although Network Rail have tried to resolve this longstanding issue by having trains depart from different platforms to avoid the point work, this has, unfortunately, not been successful.  Ideally, the reporter would like the couplings made more robust or adjusted eliminating the movement in them that makes the brakes apply. As the problem appears to occur when multiple sets are in operation as a short term measure a suggestion is that the units are reduced to two sets.  This would mean the areas where Drivers have to walk when recoupling
and the associated hazards present are minimised.

Could all parties consider the following:

• What steps are being taken to address the issue about the maintenance of electric pins on the Class 170 units?
• What long term resolutions are being considered and how soon is it envisaged a permanent resolution will be found?
• What measures can be put in place so that the safety issues highlighted can be mitigated?
• Can the short term suggestion made by the reporter be considered in the meantime?

Response from CrossCountry Trains

In terms of the Driver's actions necessary if a spurious brake application occurs, it is a requirement of Drivers to be able to safely walk on or about the line in connection with their duties. Personal Protective Equipment (PPE) is provided in the form of a high visibility vest, lamp, safety shoes etc and walking would be confined to the distance between centre cabs of a formation in order to split and re-couple the train. Contact with the Signaller should be via the most expeditious means using Signal Post Telephones (SPT), National Radio Network (NRN) or mobile phone.

Whilst not a desirable occurrence for many reasons, it is possible to undertake the
uncoupling/re-coupling safely as long as rules and procedures are followed correctly.

This issue has received a significant amount of attention. There are presently a number of actions being pursued both associated with the infrastructure and the rolling stock with progress monitored on a bi-weekly conference call. With
regards specifically to the electrical coupler pins, the maintenance regime is robust and any defective pins are changed out.

A longer term resolution is being considered associated with a micro-switch, an integral part of the coupler, which is believed to be causing the spurious brake applications. In the meantime the micro-switch is being adjusted to
the maximum permitted tolerance before it operates and causes a brake application. Efforts have also been made to alter the route the
trains take out of Birmingham New Street to assist in the interim period.

Response from London Midland

What steps are being taken to address the issue about the maintenance of electric
pins on the Class 170 units?

The root cause of this issue has still not been proven. There is no common denominator with the failures other than the geographical location (Derby Road tunnel). The couplers involved in the incidents are always checked and tested afterwards and they have been found to pass the gauging and functional tests and all equipment is found to be operating within specification. At the present time there is no proof either way that the incidents are down to faulty couplers or faults with the track.

We have set up a joint working group involving London Midland (LM) and CrossCountry (XC) and Network Rail representatives (engineering, production and operations) in order to put actions in place to get to the bottom of the problem and ensure that we are doing as much as we can.

The key actions are as follows:

• LM has arranged for their Birmingham New Street technicians to meet these late night departures and watch them off the platform.
• XC are liaising with Network Rail over the possibility of using a different route out of Birmingham New Street via the Stour tunnel. This avoids travelling through the reverse curve off platforms seven, eight or nine and through the Derby Road tunnel.
• LM and XC are keeping detailed records of all coupling incidents including On Train Monitoring Recorder (OTMR) downloads and train formation details to see if there are any emerging trends i.e rogue units.
• XC Driver Team Managers are reviewing all OTMR downloads.
• LM are reviewing their maintenance policy of couplers in detail to see if any
  improvements can be made, however it should be noted that no real issues have been identified yet with the current regime. Maintenance is done to the manufacturer's recommendations, using correct lubricants, tooling and components specified by the original equipment manufacturer. LM is also talking to otheroperators and maintainers to establish any industry best practices.
• LM and XC have recently undertaken a fleet wide special check of the uncouplingarm micro-switch settings to ensure that on all couplers the uncoupling arm travel is set to its maximum tolerance before it activates and brings the brakes on. This has also now been incorporated into routine maintenance.
• XC is currently liaising with Network Rail to arrange sending a measurement train ortrolley through the Derby Road tunnel to confirm the status of the track geometry.
• Both LM and XC are reviewing whether there are any potential modifications that can be made to the couplers. However as there has been no specific failure modeidentified then this would involve a potential major design change. A change inoperating practice is therefore the preferred method of resolving this issue.

What long term resolutions are being considered and how soon is it envisaged a
permanent resolution will be found?
The potential long term resolutions are highlighted in the points made above. If the issue can be resolved by a change in operating practice (e.g a different route out of Birmingham New Street or reduction in the size of the vehicle rakes) then this would be the simplest and most cost effective solution. XC and Network Rail
would need to provide timescales for this. If it is identified that there are issues with the track condition or geometry then this will need to be addressed by Network Rail.

If it is agreed that a modification to the vehicles is required then the timescales
would be in the region of six months or greater (taking into account engineering design work, vehicle safety approvals and modifying couplers on circa 75 vehicles).

What measures can be put in place so that the safety issues highlighted can be
mitigated?

In line with the details highlighted above, various work streams are underway to mitigate against these issues.

Can the short term suggestion made by the reporter be considered in the meantime?
The suggested short term solution of a reduction in the size of the vehicle rakes would need to be considered by XC and Network Rail.

Response from Network Rail

Network Rail would like to thank the reporter for bringing their concerns to our attention. We have been working very closely with the Train Operating Companies (TOCs) involved to find a solution to this problem.

We do recognise the issues raised by the reporter. We have checked the track and track geometry and we are satisfied that these both meet all necessary standards. We have altered the platforming of some of the trains that have suffered the uncoupling problems.

This has reduced but not eliminated the number of times these incidents occur. We will continue to work closely with the TOCs to find a solution to this problem.