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Signal collaboration

Collaboration is the name of the game these days. Joint ventures and deep alliances are becoming essential as companies strive to deliver turn-key projects which involve a variety of skills and disciplines.

Carillion is at the forefront of this mini- revolution. The infrastructure specialist has recently been awarded a share in a £2 billion electrification framework by Network Rail, a contract it won in partnership with the Austrian firm SPL Powerlines.

The company has also received a framework contract for the development and design of the European Train Control System (ETCS) for use in the UK. This time, Carillion is in partnership with Bombardier in a joint venture named Infrasig.

The new organisation is well placed to fulfil this contract as Bombardier has a great deal of experience on the continent with both ETCS and ERTMS (European Rail Traffic Management System – basically ETCS controlled using a GSM/R radio network) in a variety of differing applications.

A world first

One good example of this is the Västerdalsbanan in Sweden – the first European railway to employ an ERTMS level 3 regional traffic control system. This replaced the previous token block system and is a variant of ERTMS for low density, regional lines.

The Västerdalsbanan is in central Sweden, approximately 350 km north of both Gothenburg and Stockholm. The 134 km line runs from Repbäcken to Malung with six stations (currently closed as the line is freight-only) and 33 level crossings. Today, the line is controlled by one dispatcher situated in Gävle, 200km away. Eight freight trains per day traverse the line, running at a maximum speed of 90km/h.

Previously, nine dispatchers controlled this non-electrified line without support from a centralised traffic centre or Automatic Train Protection (ATP), using only GSM/R for voice communication. Bombardier was awarded a contract to implement its Interflo 550 solution as part of a frame work agreement covering 13 regional lines in Sweden. The Västerdalsbanan is the first pilot line project being implemented for the customer, Trafikverket.

Designed for regional lines, Interflo 550 is a flexible, modularised wayside train control system which provides the capacity, adaptability and cost-effectiveness needed for secondary lines. It offers the option for future growth while ensuring safe and efficient train operation.

Simple technology

Regional lines are commonly characterised as operating mixed-mode and low-density traffic, with extended headways, often in remote areas and/or very harsh environments. For this reason it can be difficult to justify the investment in traditional train control systems.

These criteria demand that cost, performance and reliability are of the highest standard. Interflo 550 allows vehicles equipped with ETCS to operate seamlessly between regional and adjacent lines without any additional onboard systems or configuration except for the possible need of a Specific Transmission Module.

The new system adds a new, highly cost- effective dimension to Automatic Train Protection (ATP) applications by using modules and practices derived from Bombardier’s ERTMS development programme. It addresses component cost and availability by employing commercial off-the-shelf products that are readily available, keenly priced and will support migration in the future without the threat of obsolescence.

Designed as an integrated system for manual or automatic control of traffic, the modular construction of Interflo 550 simplifies maintenance and modification. All the software modules can be integrated on one platform, a benefit which assists delivery and supports the robust nature of its operation. The necessary wayside control systems, primarily for operating point motors, can be factory-assembled and brought on site factory-tested and ready for operation. Train dispatchers control and monitor traffic flow via workstations. The complete operational situation can be displayed on large panels to combine with the main operational network.

Better control, lower cost

The equipment was initially installed as an overlay, allowing the possibility to test and prove the system whilst the legacy manual token system was in control of the line during hours of operation. Now that it is complete, the ERTMS Regional system consists of a traffic control centre (Radio Block Centre and interlocking) in Borlänge and a central traffic control centre in Gävle. The installation has the flexibility to allow for future growth in system size or levels of automation. Sharing data with other systems is also a simple task and can contribute to better traffic management.

The need to have ERTMS functionality for operation from the regional lines to the main lines was a critical part of the customer’s decision. Further key aims were to achieve cost reductions of up to 50% in the signalling systems and overall cost reductions approaching 60% providing fully automated operation and increased traffic capacity around the clock. Under a framework agreement, additional regional lines will be equipped with Interflo 550 until 2016 and beyond.

Using Bombardier’s experience of installing ERTMS on secondary lines to save cost, and Carillion’s knowledge of the British railway infrastructure, the new Infrasig company is set to bring the advantages of these new signalling systems to routes around the UK.


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