Zonegreen Technical Director Christian Fletcher has contributed his specialist knowledge to the latest edition of the prestigious Railway Gazette International
The changing face of depot management
Reform of the European rail industry has had many far-reaching effects over the past decade or more, and it is clear that the gradual retrenchment of the vertically-integrated state railway has led to numerous activities being ‘unbundled’. Depot operation and rolling stock maintenance are no exception, as third-party providers from both the train operating and railway supply sectors have taken responsibility for many workshops and heavy repair facilities.
Aftersales contracts that stipulate ongoing maintenance and availability requirements as well as basic rolling stock production have become more common. As a result, train operators can now contractually require a vehicle manufacturer or engine supplier to deliver a given level of availability, with penalties invoked if targets are not reached.
These contracts normally demand the maximum number of trains to be in service at any one time, placing considerable pressure on depots to achieve rapid turnarounds.
“This in turn has compelled depot managers to focus on their internal processes to drive greater efficiency — can more work be done in an overnight shift, for example”
As railways develop a greater knowledge of service contracts, whole-life costs and asset management, the need has emerged for more sophisticated depot equipment. This includes obvious tools such as a wheel lathe or washing plant, but the modern depot also often features a suite of devices for remote monitoring of rolling stock in service and supervision of the depot itself.
Given the increasing pressure to meet tight deadlines, it is also essential that maintenance is carried out safely, so most modern depots have specialist interlocking equipment to help eliminate high-risk activities, for example by preventing train movements when the workshop doors are closed, or refusing access to roof-level platforms whilst overhead power lines are energised.
Supervision from a PC screen
Being able to assess the amount of work required in advance is key to meeting ever-shorter timescales for planned maintenance. One major aid is the real-time data feed transmitted from onboard components, which can be displayed graphically on a standard PC in the operations room.
With the evolution of planning software and the use of train identification tagging, it is possible to install readers at the depot entrance to collect the ID of an incoming train.
“The software displays the depot layout on a large screen, and interactive menus provide the depot controller with an overview of the maintenance history of the vehicle as well as the tasks to be performed during the current visit”
Operational data can also be shared within the depot itself, allowing supervisors to manage a large site easily, and providing an important archive in the event of a safety-related incident or a delay in returning a vehicle to traffic. The only hardware required is a small interface panel mounted on or next to the equipment being monitored, a network cable and a PC at the supervisor’s chosen location.
A peer-to-peer networking tool such as Echelon’s LonWorks platform would be particularly suitable for such applications, because of the ability to span a wide area using a twisted-pair network cable.
Among the depot functions commonly monitored this way are:
• bogie drop and access bridges;
• wheel lathe and access bridges;
• overhead power supply status;
• yard switches and pointwork (in addition to the basic signalling interlockings already provided, which often do not integrate with the overall depot supervisory network);
• washing plant;
• jacks and heavy lifting gear;
• workshop doors.
Increased adoption of secure high-bandwidth information and communication networks should enable rail operators to deepen their relationship with maintenance providers and depot owners by sharing more data online. This would allow best practice to be spread across several depots and assist with the harmonisation of fleet maintenance at more than one location.