The concept of Tram Train is a vehicle that operates as a tram on the tramway and a train on heavy rail, offering a seamless journey to the passenger into the heart of city centres and relieving capacity from mainline stations while taking the passengers where they want to go. The first Tram Train was in Karlsruhe, Germany, in the early 1990s and has spread successfully to several other European cities – but not yet to the UK. Writes Dr Robert Carroll, Major Projects Manager Stagecoach Supertram
The Tyne and Wear extension to Sunderland tackled many of the challenges that arise with the interworking of light and heavy rail but has resulted in operational limitations that reduce track capacity and limit future development of the route.
To demonstrate that the benefits of Tram Train can be realised in the UK without the limitations imposed at Sunderland, the
Tram Train pilot project was set up by the Department for Transport (DfT) with Network Rail, Northern Rail, Stagecoach Supertram and South Yorkshire Passenger Transport Executive (SYPTE) as partners.
In June 2013, Transport Minister Norman Baker gave the final approval for the contracts between project partners. In 2016, the project will deliver the operation of Tram Trains three times an hour from Cathedral tram stop, in the centre of Sheffield, to a new stop at Parkgate retail park in Rotherham. The vehicle will operate on the tramway to Meadowhall South then utilise a new connection on to Network Rail calling at Rotherham Central station. Stagecoach Supertram will operate the new service on behalf of SYPTE as part of its current concession that runs until 2024.
The challenge set by the DfT is to introduce the pilot service while learning as much as possible about the application of Tram Train on the national rail network, allowing the operation of light rail vehicles to be spread to other locations in the UK. Where necessary this includes challenging current practices and standards after a risk-based analysis to allow safe operation.
The trams (or trains)
To operate the service, seven new vehicles are being procured by SYPTE from Vossloh España of Valencia, Spain. That factory’s previous products for the UK include the class 67s (when the works were part of Alstom) and the class 68s for DRS which are currently being built.
The Tram Train vehicles are part of the Citylink family and are similar to those currently being supplied to Karlsruhe. However, those for Sheffield-Rotherham will be a dual voltage version (750V DC and 25kV AC) to allow for continued operation once future electrification of the Midland Mainline north of Sheffield has been approved and implemented. Three vehicles will be used to operate the Tram Train service every 20 minutes, three vehicles will be used to provide additional capacity on the tramway, and the seventh vehicle will be a maintenance spare. Maintenance will initially be carried out by Vossloh using the current tram maintenance depot at Nunnery which will be modified to accommodate them.
The three-section Citylink vehicles are 37.2 metres long, 2.65 metres wide and are low floor at the doors – providing level access – with raised seating areas above the four conventional bogies. They are able to accommodate 88 seated and 150 standing passengers with wheel chair spaces provided between the doors. The vehicles will be compliant with Rail Vehicle Accessibility Regulations (RVAR) 2010 and will be fitted with saloon air conditioning and an integrated passenger counting system.
The tramway in Sheffield presents some challenges not normally encountered on railways including 25-metre radius horizontal curves, 165-metre vertical curves (sag) and gradients of up to 10%. The vehicles are to be equipped for both tramway and railway operations requiring duplication of certain systems such as communication and safety equipment and will include GSM-R, TPWS/ AWS and OTMR as well as tram radio and routing equipment. For safe tramway operation under line of sight rules, magnetic track brakes are fitted to all bogies providing deceleration rates of over 2.2m/s2. Delivery of the first vehicle is expected in mid 2015.
The infrastructure changes required to accommodate the new service are being led by Network Rail on the national rail network and by SYPTE and Stagecoach Supertram on the tramway. The tramway infrastructure at the Meadowhall South Junction will be installed by Network Rail.
The design for the infrastructure is at the end of GRIP 4, Single Option Development, and will progress to GRIP 5, Detailed Design, later in the year. Carrilion has been awarded early contractor involvement but the actual GRIP 5 contractor is still to be confirmed.
The junction between the two systems is being designed and constructed by Network Rail with support from the other partners.
This will have a double-lead junction from the tramway into an island platform that will be used by Tram Trains only, and then onto a bidirectional line over the river Don that connects with the existing single track line (Engineers Line Reference WME) on the Rotherham side of the M1 Tinsley Viaduct.
The signalling at the interface will be designed to ensure that the changeover between the two systems is safe and requires minimal interaction for the driver and signaller. Network Rail will also be building a turn back siding with a tram stop at Parkgate and low level platform extensions to Rotherham Central station.
The line will be electrified throughout at 750V DC. An assessment of whether some or all of the route should be electrified at 25kV AC in anticipation of Midland Mainline electrification north of Sheffield, which is not yet a committed scheme, revealed that this was not cost effective due to the different systems required. The design is being implemented taking into account the future requirements and delivering synergies where possible.
Although the gauge of both Network Rail and Stagecoach Supertram tracks are 1,435mm, there are key differences which require a wheel profile to be designed that allows safe through running while minimising the degradation of both wheel and rail on both networks. The initial work by Huddersfield University has demonstrated that the tyre profile of the current Supertram vehicle would present a derailment risk on Network Rail’s switch blades, therefore a deeper wheel flange is required that reduces this risk.
As the Supertram system is now 20 years old and the rails have been maintained in accordance with the tram wheel profile, certain locations require rail replacement to accommodate the Tram Train service. However SYPTE and Stagecoach Supertram are just commencing a programme of rail replacement to replace 22km of embedded track over the next five years that includes all areas where the Tram Train will operate. VolkerRail is carrying out phase 1 of the replacement work in 2013. The remainder of phase 1 and rail supply in 2014 is still to be tendered by SYPTE. Phase 2 will start in 2017/18.
The rail profile chosen for replacement is 55G2 which has a wider and deeper groove than the originally installed 35G-TF ensuring future compatibility for the Tram Train.
Following the start of service in 2016, a pilot period will run where the performance of the Tram Train on both Network Rail and the Supertram networks will be monitored. This will be holistic and ensure that data is captured to allow others to learn from the operation. This data will include such things as operational performance, public and staff feedback, maintenance costs, wheel and rail wear. More important will be capturing and sharing lessons learnt from the project as it is set up, ensuring that the wider industry benefits from this experience and learning.
To allow other Tram Train promoters to maximise the benefits of the project, a website will be set up to disseminate what the partners learn from the project.