The pilot programme to introduce a connecting tram-train service between Sheffield’s Supertram network and the neighbouring town of Rotherham using an under-used freight railway has been the cause of a great deal of frustration.
Launched in 2009, the scheme has been highlighted by some as an example of over-engineering and confused project management from some of the partners. What is often neglected, however, is that this was never intended as a scheme just to introduce the mode to the UK. Instead, it forms a greater exploration of the challenging of industry standards – as well as the implementation of new principles for connecting light rail to the railway.
The tram-train concept isn’t new to the UK. The first two Manchester Metrolink lines employed trams on former rail lines between Bury and Victoria, and Altrincham and Piccadilly, with a street-running connection through the city centre. Additionally, many of the challenges associated with inter-operability of light and heavy rail have been addressed with the Tyne & Wear Metro extension to Sunderland that opened in 2002.
As a little history, a previous tram-train proposal on the Penistone Line between Huddersfield and Sheffield – driven primarily by a desire to replace ageing diesel main line rolling stock – was abandoned in 2009 after it was found that suitable dual-fuel tram-trains would be too expensive due to the costs of developing a power pack that complied with the latest emissions standards. This led to the current pilot and the development of a framework of technical standards for lighter weight vehicles on the national rail network, examining operational practicalities, and importantly to gauge passenger perception.
With GBP60m (approx. EUR70m at 2010 rates) in committed funding from the UK Department for Transport (DfT), the tram-train pilot is very much a collaborative effort. National rail infrastructure manager Network Rail (NR) is leading on infrastructure construction and development of relevant technical standards; Sheffield tramway operator and maintainer Stagecoach Supertram and its client the South Yorkshire Passenger Transport Executive are responsible for the operational development and ongoing service provision. Main line rail operator Northern is a supportive stakeholder as the facility owner of Rotherham Central station.
After a two-year trial, if successful, the tram-train will become a permanent fixture; indeed, local project partner SYPTE is already investigating extensions – for example into the Lower Don Valley – as part of its current consultations to extend the benefits of Supertram service into the wider region.
Lessons from each stage of the pilot’s implementation are being shared with promoters across the UK, notably in Glasgow, South Wales and Greater Manchester. Simon Coulthard, Network Rail’s senior project sponsor, says: “The DfT has clear expectations and our objective is to help feed our learning into other schemes where possible, hopefully creating a path for others to follow.”
Risks and approvals
When the new service eventually opens in late 2018, passengers will be able to get onto a tram-train at Cathedral tramstop in central Sheffield and travel to Parkgate shopping centre via Rotherham Central station.
Currently two trains per hour run between Sheffield and Rotherham Central; the tram-train will offer three services every hour, seven days a week, with journey times for the 12km (7.5-mile) route (7km of tramway and 5km of railway) taking 25 minutes. The new fleet is capable of 80km/h (50mph) on the tramway and 100km/h (62mph) on NR metals. Stagecoach will operate the service as part of its current concession that runs until 2024.
Despite its long gestation period, the team delivering this pioneering scheme is bullish about the future as infrastructure construction nears completion. Within weeks of you reading this, the 160m physical connection between NR-managed freight tracks at Tinsley and the Supertram network at Meadowhall South will have been completed by lead contractor Carillion.
Concurrently, the last major civil works will have begun in central Rotherham. To allow sufficient clearance for electrification, the road bridge at College Road is to be demolished and replaced with a new deck; an 18-week programme is to begin on 14 April. The raising of this bridge is seen as the optimum solution as lowering the tracks would involve costly additional works at Rotherham Central, as well as increasing the risk of track flooding from the adjacent canalised River Don.
Two other bridges have required modest track lowering.
The route to Rotherham will be electrified as per the Supertram network at 750V dc. However, the requirement for a dual-voltage vehicle was seen as essential in the early stages of the pilot in anticipation of plans to electrify the Midland Mainline north of Sheffield by 2023 – although progress of this programme has since been delayed.
Such future-proofing is a key component of the pilot. Simpler solutions could have been chosen for many of the more complex efforts, but early route engineering showed that there would be too many costly challenges in electrifying at the 25kv ac of the main line network. Of course this also provides valuable learning in terms of lower-cost electrification for Network Rail, an organisation which had little modern experience in 750V dc overhead.
Around 80% of the stanchions are now erected, of both single and twin-track cantilever type. Although they look heavy-duty for tramway use, it has to be remembered that this is also about looking forward to potential 25kv ac electrification. Installation of the overhead wires themselves is due to begin later in the year but, unlike on a new-build tramway on a segregated alignment, this involves temporary closures of the railway so will be a more time-consuming process.
As an example, over 40 ‘off-the-shelf’ overhead line components are being adapted for a new purpose. Coulthard explains: “We maintain a catalogue of approved assets and components, so as we are changing use to 750V dc – and creating a few new components, too – we need to go through our product approval process before they can be added into the catalogue. A big part of that is demonstrating they are safe, both individually and as part of a system.” These approvals take time.
“The overhead line design has pushed the programme back, without a doubt,” he continues, “but there are so many elements we hadn’t foreseen and this is about establishing technical standards beyond the pilot.”
Permanent way completion
Elsewhere, trackworks are largely complete, including the new turnback siding and tramstop at Rotherham’s Parkgate shopping centre. Low-level platform extensions at Rotherham Central station are also underway.
Although both Network Rail and Stagecoach Supertram tracks share a common 1435mm gauge, key differences have required the development of a new wheel profile by Huddersfield University’s Institute of Railway Research to allow safe through-running while minimising both wheel and rail wear. With a deeper flangeback, the new profile removes the risk of derailment – particularly at switches and crossings – but this has required the installation of check rails 50mm higher than those normally found on NR tracks. As a non-standard profile it required approval from the UK’s Rail Safety and Standards Board – as described earlier, this process of deviations, approvals and safety assurance has been one of the key drivers of delays.
Helen Plummer, Project Manager for Supertram (on secondment from Turner & Townsend), explained that a rail replacement programme to address life-expired tram tracks has helped minimise longer-term disruption as it has allowed enhancements to the tramway with a rail profile suitable for tram-train that features deeper grooves. Around 22km (13.7 miles) of rail replacement has been completed already, but there is more to do and this is a factor which currently limits tram-train running to the convenient turnback at Cathedral.
Simon Coulthard is keen to point out that while the delays are regrettable, he also reinforces the message that: “Delays are obviously frustrating and there are some things we may have done differently, but we have deliberately taken on some complex challenges with the pilot to make sure we have as much relevant data as possible that we can share.”
Although many of those lessons relate to technical and operational considerations, Coulthard emphasises that “safety assurance is at the heart of everything we’re doing and this cannot be rushed or shortcut. Many of the elements of this scheme are new to the railway, and vice versa for the tramway, so the approvals process is something which has inevitably had impacts on the programme.”
Construction on the Tinsley Chord is nearing completion, and TAUT was granted access to the worksite in late March. The sinuous curve that joins tramway and railway offers an 80m curve radius to allow the vehicles to pick up speed before joining NR tracks, with a tighter 25m curve giving access to the Supertram line near Meadowhall South at the other end. Adding another level of complexity, the site of the chord (where 80lb tram rails join 113lb rail tracks) is hardly ideal for construction access, lying underneath a double-deck underpass for the M1 motorway. The land on which the new link sits belongs to Highways England and a lease/sub-lease arrangement has been negotiated between this government body, Network Rail and SYPTE – the effective ‘owner’ of the tramway.
While Network Rail and its contractors are building the new link, as the tram-trains will be operated by Stagecoach it will effectively be a tramway until it reaches the main line. However, it was stressed by both partners that they are “taking a common sense and practical approach to maintenance rather than saying the boundary is ‘here’”.
Signalling works to allow safe entry onto the rail network will also begin in May; this is one of the most crucial parts of the project – and one that requires the greatest safety assurances. In order to complete this work safely, trains will be diverted between Meadowhall and Swinton and will not stop at Rotherham Central; a bus replacement service will be offered.
The signalling at the interface has been designed to ensure that the changeover requires minimal interaction for both the driver and signaller; 25 new axle counters have also been installed to provide immunity from the effects of the electrification as the old track circuits would be affected by interference from the electric drives.
Arrival of the Citylink
Operationally, the new service poses its own challenges, as Dr Rob Carroll, Major Projects Manager for Stagecoach Supertram, told TAUT: “Drivers are receiving three dedicated days training with the new vehicles on the Supertram network initially, with more to come once the Tinsley Chord becomes available. Our drivers will be split into two pools, with 18-20 charged with regular operation of the new route to Rotherham.”
As the most visible part of the pilot, the new Stadler Citylink LRVs have been undertaking daytime trials across the Supertram system since early March, following early testing and validation from Christmas 2015.
Seven Citylink vehicles have been supplied by Stadler (formerly Vossloh España) – a need for four new trams was identified as far back as 2010 to enhance capacity on the network – and these are split into two groups, three dedicated to tramway use and four with the deeper tram-train wheel flange that allows running to Rotherham. Three tram-trains are required to provide the 20-minute service, with one in reserve as an operational spare.
Although passengers can’t ride on them just yet (this is due to start in the summer on the existing network), the response to the latest additions to the Supertram fleet as they pass through Sheffield’s streets seems positive. The drivers like them too, as Helen Plummer explains: “The brakes are sharper and the acceleration is good, too – despite the additional weight compared to a tram from the existing fleet.” For safe line of sight tramway operation, magnetic track brakes on all bogies provide deceleration rates of over 2.2m/s2.
As the centre of gravity is higher than the incumbent Siemens trams due to an extra 12 tonnes in overall weight – much of which is on the roof – a pneumatic secondary suspension system is fitted that also lowers the ride height slightly. New systems include air-conditioning, the ABB-supplied dual-voltage traction package and an onboard passenger counting system.
The new vehicles are 2.7m longer than the existing trams at 37.2m, which in part has driven modifications at Nunnery depot; these include additional stabling, stores and training facilities, as well a new crane and extended gantries to allow easier access to the Citylink’s roof-mounted equipment.
Onboard the new three-section articulated LRVs, care has been taken to ensure continuity with the existing roster as far as is practical. Aside from slightly narrower gangways, the main difference is a reduction in internal steps; while you still have a single step (unavoidable due to an additional powered bogie necessary to cope with Sheffield’s steep gradients), the transition for passengers is easier on the new vehicles. Each Citylink has a capacity for 88 seated and 150 standing and two wheelchair spaces.
The majority of the South Yorkshire order is described by Carroll as being ‘off the shelf’, although as a run-on from an order for Karlsruhe (Germany) this gives slight oddities such as a lack of driver’s cab doors that means operator access through the passenger saloon. Elsewhere in the cab the differences are obvious. Firstly, two high-definition monitors connected to external CCTV cameras replace the need for side mirrors, then you have the traction/brake lever which is on the other side of the operator’s chair. Otherwise the main difference is in the Train Protection and Warning System (TPWS), On-Train Monitoring Recorder and GSM-R communications system necessary for operation on the UK main line railway. Although the TPWS is active at all times, drivers will be required to manually activate the GSM-R system as they pass from tramway to railway.
Testing recovery procedures, bespoke couplers have been created and retrofitted at Nunnery depot to allow for any stranded tram-train to be recovered by an existing tram. Carroll adds that while it is “always preferable for recovery to be undertaken by a Citylink in the first instance, adaptor couplers are also being specified for any main line loco with a draw hook to recover one if necessary.”
Responding again to the questions of delays, Simon Coulthard repeats his earlier suggestion that while lessons learned along the way have extended the infrastructure delivery programme, this is far from a simple scheme: “People have suggested that you can just pick up technology used on the continent and implement it here, but it really isn’t that easy. We use different signalling and protection systems and have significant differences in track standards. We hope that we have identified the main challenges to introducing tram-train schemes in the UK and this will inform future schemes.”
Dr Rob Carroll adds with a smile: “We’re creating a template of things to avoid as much as a guidebook of how to do it. Everything we’re doing is documented for the benefit of others and we’re in regular contact with Manchester, Glasgow and South Wales.”
Renfrewshire Council, the Glasgow City Region Cabinet and Glasgow City Council, in partnership with Glasgow Airport, are looking to introduce tram-train in preference to a conventional light rail link between Glasgow Central station and Paisley Gilmour Street. Meanwhile, the South Wales Metro promoters have mooted a mix of heavy rail, street-running light rail and tram-train as part of a new intermodal mix for the Cardiff City Region. Transport for Greater Manchester has long-held ambitions for tram-train connectivity to increase capacity on regional rail routes serving the north-west; Transport for the West Midlands has shown keen interest; and aspirations exist for potential application between Nottingham and Derby as well. So once the pilot proves its worth, the promise for tram-train in the UK could be game-changing.
A recently-announced National Audit Office investigation into the reasons for the extended delivery schedule for the pilot isn’t distracting any of the partners. Coulthard concludes: “The NAO has the best interests of the taxpayer in mind and we’re fully engaged with them. Otherwise we remain head down and focused on delivering the scheme as safely and effectively as we can.”
Thanks to Simon Coulthard, Alan Beattie and Carl Scattergood of Network Rail, Helen Plummer and Dr Rob Carroll of Stagecoach Supertram, John Lawson and Lee Butler of Carillion, Paul Abell and Tim Kendell for their assistance
in the preparation of this article.
Feature originally appeared in TAUT April 2017 (952).