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Uk tram-train: Learning lessons


The successful launch of tram-train services from Sheffield Cathedral to Rotherham Parkgate on 25 October 2018 was an historic occasion for the UK railway industry.

Britain’s first true tram-train operation has not only opened up new journey opportunities for those in the Sheffield City Region, but will also provide a useful new transport option for the expanding urban regions looking to reduce congestion and emissions. Most importantly, this pilot is proving popular with travellers, the real way to gauge success.

It seems so easy looking back, but behind the smooth operation lies a huge amount of work to enable it to happen.

‘Why is it so hard, they do it in Germany – just get on with it’ is an oft-asked question by those not directly involved, such as politicians and other commentators. As has been shown many times with major or innovative projects, the devil is in the detail, usually glossed over by those not responsible for giving the approval to enter service. Just think back to the London Underground’s Jubilee line extension to Stratford in the 1990s, the current cross-capital Crossrail scheme, and many schemes in between that have been bedevilled by those ignoring the detail.

Unlike normal rail projects, the introduction of tram-train to the UK broke many rules for main line operation and required special approvals to run. Hopefully when proven by this pilot, this will be the start of many more similar services that have the potential to connect street tramways to new destinations on the main line.

A brief history of tram-train

The tram-train concept was developed in Germany’s Karlsruhe to connect its urban tramway to failing suburban lines; as a consequence of improved service frequencies and additional tramstops near residential areas, ridership grew dramatically.

This ‘pilot’ project that began in the late 1980s broke many of the rules in Germany at the time and there was a considerable amount of safety work required before it gained the approval of the then Deutsche Bundesbahn for services to operate. The concept soon spread around Germany with similar operations in Saarbrücken, Nordhausen and Kassel. It is also used across Europe, with schemes in France, the Netherlands, Spain and Denmark.

In late 2006 a study tour was arranged by ACoRP (the Association for Community Rail Partnerships) to learn about tram-train, which led to a visit to Kassel for executives from the UK Department for Transport, Network Rail and NedRail in 2007. The delegates all saw great potential in what they saw and the idea of a UK pilot was soon born, with the aim of having tram-trains running as a demonstration within six months. It became apparent that this was not going to be possible as, for a start, Kassel was not able to supply one of its diesel-electric bi-mode tram-train vehicles in time. But the concept was sold and now had three influential champions.

At this early stage no tram owner or operator was involved and the project was being led by the heavy rail industry. Many have asked why this was the case: surely a tram operator would understand the operation of tram-like vehicles much better than a bunch of heavy rail people? But it was decided that with the cultural differences, it was much better to have a ‘pull’ from the main line, where most of the problems would arise, rather than having them resisting a ‘push’ from an unwelcome tram operator.

First steps in the UK

A limited budget was proposed, with a view to learning as much as we could with a pilot project and thus saving money and time as well as easing the approvals process for future tram-train schemes. These objectives looked at the costs, differences and revisions to standards required to enable tram-like vehicles to run on the UK’s mainline, understanding the complexities at the interface between the two systems, and the all-important passenger perception.

A prerequisite for this project was for heavy rail engineers and operators to understand the intricacies of light rail and vice versa. This immediately led those leading the exercise to ask ‘why are there delineated heavy rail and light rail engineers and operators?’ There are many similarities and some differences, all with good reasons.

With relatively few tramways in Great Britain, certainly even fewer a decade ago, the industry cannot support more than a handful of career light rail design engineers by itself – there just aren’t enough projects. Thus heavy rail designers will naturally become involved with new tramway projects. It therefore seems logical that the training for future railway engineers should include both light and heavy rail engineering, not forgetting metros, all of which have their own peculiarities.

Heavy rail also has defined standards that cover virtually all aspects of design, whereas there are relatively few in tramways, limiting the guidance that can be found easily.
This pilot had to transcend this aspect by obtaining deviations to heavy rail standards
and combining approvals processes to save duplication and potential conflicts.

Identification of major issues

At the start of any rule-breaking project, it is essential to identify the major issues that need to be resolved and the rules that need to be broken. Initial discussions with the Karlsruhe technical consultancy TTK enabled us to learn from the German experience and identify where the ‘Karlsruhe Model’ could act as a useful guide and where the differences for a UK solution would be needed.

For example, German mainline track, signalling and electrification standards have significant differences to the UK’s, adding to the difficulties in implementing a UK pilot. We soon learnt whilst travelling around the European railways that each country operates to different standards and signalling principles – it is no wonder then that the EU introduced its Railway Interoperability Directives. However, in Britain there are significant similarities in what we were seeking to achieve with the extension of Tyne & Wear Metro trains over the main line to Sunderland and the learning from this service was included.

Documenting the learning

Ian Ambrose is responsible within Network Rail for collating the learning from the pilot and has been involved in the commissioning stage. He describes how this was accomplished within the requirements of both heavy rail and tramway approval processes, ensuring safety on both networks:

A key objective of the pilot is to document and share lessons learned in the design, build, commissioning and operation stages of the introduction of tram-train operation in the UK across the rail and light rail industries.

The successful conclusion of the commissioning stages and subsequent entry into service has provided sufficient evidence to demonstrate that the issues and concerns relating to the operation of a light rail vehicle on the main line network have been overcome. The rigorous testing undertaken on both the South Yorkshire Supertram Limited (SYSL) and Network Rail (NR) networks under the Common Safety Method – Risk Evaluation and Assessment (CSM-RA) – the current approval regime for all new railway infrastructure and vehicles – has shown that Citylink vehicles can operate safely on existing and appropriately modified main line infrastructure alongside both freight and passenger traffic.

Under current legislation, approvals for tramway vehicles and infrastructure are covered by the Safety Verification method under The Railways and Other Guided Transport Systems (Safety) Regulations 2006 (as amended) (ROGS). This applies to both railways and tramways. For more detail it is advisable to consult the UKTram publication A guide to promoters planning to operate Light Rail and other non-mainline vehicles on Network Rail-managed infrastructure1, a plain-English version of the RSSB report Non-mainline vehicles: Guidance on regulatory requirements – T1049.

As tram-train vehicles and some of the new infrastructure are exempt from the Railway (Interoperability) Regulations 2011, one of the most significant achievements of the project has been to enable both the Safety Verification and CSM-RA processes to be undertaken as a single activity, completed in time for both operation on the tramway (September 2017) and the railway (May 2018).   

Following the successful introduction into service on the existing tramway, detailed commissioning plans were prepared for the full Cathedral to Parkgate service. Incorporating the new infrastructure (primarily the electrification, as dc overhead systems are uncommon on the national network in the UK), the low-height platforms at Rotherham Central and Parkgate, and the vehicles, this also included obtaining approval for the deviations from UK Railway Group Standards required from the relevant Standards Committees.

At the same time working instructions were developed for operating over the boundary between SYSL and NR infrastructure, the so-called Tinsley Chord. This required a collaborative approach between operations and maintenance staff of both undertakings due to a number of boundary issues identified through the design of the connection between the two networks. A similar approach was used for the operation and management of Rotherham Central station which is unusual in having two station facility owners: the South Yorkshire Passenger Transport Executive (SYPTE) for the tram-train service platforms and rail operator Northern for the rest, although all maintenance and operational activity is undertaken by Northern staff.

Following the completion of electrification testing, vehicle commissioning could begin. Critical issues here were gauging – checking the clearances between any lineside structures and the vehicles and the wheel/rail interface. Could the new Citylink vehicles safely operate on the railway, particularly through switches and crossings? We also verified vehicle recovery procedures to ensure that a failed Citylink could be safely returned to SYSL’s Nunnery depot, and double-checked the power supply to ensure it was sufficient to enable the timetable to be operated reliably. These tests, carried out overnight during the months of May, June and July 2018, were also used for the driver trainers to familiarise themselves with the route and the operating instructions.

All these tests were efficiently completed, with gauging undertaken by the SYSL infrastructure team and wheel/rail interface monitoring by the Institute of Rail Research from Huddersfield University, while a DB Cargo Class 66 diesel-electric locomotive and a second Citylink both successfully recovered a ‘failed’ tram-train. During the test period it was usefully discovered that in the event of the NR substation being out of action, there was sufficient power from the SYSL overhead supply to enable a Citylink to return under its own power from Parkgate to the tramway. A whole-route risk assessment was also carried out in preparation for the intensive driver training undertaken during July and August.

Assistance with the training covering main line operation was provided by NR and East Midlands Trains (a subsidiary of Stagecoach, which also operates the Supertram network). The final preparation for the start of public service was a period of ghost-running to prove the robustness of the timetable. After two incident-free weeks, the decision to start passenger service was taken, driven by the availability of the Sheffield City Region Mayor and then-Transport Minister Jo Johnson MP.

Lessons learnt and some improvements for the future

Based on this commissioning experience, the following recommendations can be applied for future projects:

The plan developed for the Citylink provides a useful template for the commissioning and entry into service of tram-train vehicles.

Such a plan should be developed during the design and build stage to incorporate emerging issues or requirements.

It should also be closely aligned to the commissioning plan for any associated
new infrastructure.

All members of the project alliance should be involved in the plan review process.

During the test programme, given the innovative nature of tram-train vehicles and their operation, observers from the relevant disciplines in both the tram operator and NR should be in attendance.

Where overnight possessions are required, careful management is essential to optimise the time available and to avoid delaying either the first tram or train service of the following day.

Communication with all parties to enable entry into the possession on time is crucial. Late arrival for briefings or at the handover site by critical staff can cause significant delays. Unfortunately, 35-45 minutes delay was not uncommon during the tests.

The combination of the test team, driver trainers and observers onboard the vehicles throughout the programme enabled a number of issues to be managed and modifications to be requested. These included:

Optimising VIS (Vehicle Identification System) loop magnet positions to improve detection, particularly on curves.

Optimising the stopping positions at signals and platforms to improve sighting and access.

Identifying additional or missing infrastructure signage.

Revised clearances for lineside equipment

Additional hazards identified through route risk assessment processes.

Improved positioning of mirrors, particularly at Tinsley Junction access on to the tramway.

Suggestions to improve briefing on changes to other operators.

OLE resilience and the associated ability to be less reliant on third-party recovery when power fails at Ickles substation, through coasting or power from SYSL substations.

Additionally, the processes to prevent wrong routing were found to be robust, minimising the risk of either a tram or a train going off route. Where a detection failure occurred it always resulted in the signal not clearing – i.e. right-side failure.

For damaged, missing or incorrectly positioned infrastructure items – crucial for driver route learning –  the Close Call system worked very well. This system was launched in 2011 to allow anyone working within the rail industry to record and manage conditions and behaviours that, under different circumstances, could have led to injury or harm. A reporting system from SYSL to the NR Project Manager was used for changes and other points were recorded on observation sheets for later review at the regular learning review meetings.

Following the start of service, a comprehensive set of monitoring and evaluation tests are being undertaken to further improve industry capability to deliver future tram-train schemes; an ongoing review of the timetabled running time has identified some revisions that will improve the service.

So after a tricky passage through governmental changes, cultural differences, deviations to standards and interference from other projects, this pilot is now proving itself to passengers. These lessons can now be used to save money and time on future tram-train and light rail projects around Great Britain.

So let’s celebrate and look forward to tram-train becoming ‘Business as Usual’ in connecting tramways to the country’s railway network.


Article originally appeared in TAUT 974 (Feb 2018).