February 15, 2016

Cross-border ERTMS: conquering the final frontier

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With at least two sets of national rules and numerous location-specific technical considerations to contend with, cross-border ERTMS deployments can represent a daunting challenge for infrastructure managers. Keith Barrow looks at two key projects which are seeking to streamline international train movements on the Rhine-Alpine Corridor.

THE line between Zevenaar in the Netherlands and Emmerich in Germany is a key international freight artery, carrying high volumes of traffic from the port of Rotterdam to Germany's industrial Ruhr region and to terminals further afield in central and southern Europe. The line is also part of European Railfreight Corridor A (Rhine-Alpine), making it a priority for the installation of ETCS.

The opening of the 159km Betuweroute in 2007 created an ETCS-equipped dedicated freight corridor between Rotterdam and Zevenaar, but it also added to the complexity of cross-border operation. Electrically-hauled trains would switch from the 25kV 50Hz ac of the Betuweroute to the 1.5kV dc system at Zevenaar East, where they also switched from ETCS Level 2 to the legacy Dutch ATB train protection system. The train would then switch to the German PZB system at the border and change to the German 15kV ac 16.7Hz electrification system at Emmerich.

SBBExtending the 25kV ac electrification and ETCS Level 2 to Emmerich would streamline operations by eliminating the need for locomotives to operate for a short distance on ATB and 1.5kV dc electrification.

Dutch infrastructure manager Prorail and its German counterpart DB Networks are implementing the migration in several phases while the line remains fully operational. "This line is a bit of a challenge when it comes to ERTMS," Mr Henri van Houten, manager of Prorail's ERTMS Expert Group told delegates at the European Railway Agency's recent ERTMS conference in Lille. "We are not only installing ETCS, but removing the class B system, changing the electrification, optimising the track layout for freight traffic, and adding a third track."

At present eight locomotive types equipped with six different versions of ERTMS software (mostly SRS version 2.3.0d) operate on the Betuweroute. All of these variations would need to be accommodated on the Zevenaar - Emmerich line and be compatible with trackside equipment.

The two infrastructure managers were dealing with more than just a national border. Operational, signalling, GSM-R, radio block centre (RBC), interlocking, electrification, and ETCS interfaces were all situated at different locations. On the signalling side, the line would be used by trains equipped with ETCS Level 2 Baseline 2 and 3, trains with or without PZB, and non-compliant trains with switchable PZB magnets controlled by the RBC.

The project team would have to consider differing operational rules and engineering rules in the two countries, GSM-R overlap, and variation in approval processes, documentation, and testing regimes.

With all these factors to consider from both sides, how could the two infrastructure managers achieve harmonised operation across the border? "The TSI, which applies in both countries, provides a framework for how ETCS should operate," explains DB Networks ETCS manager Mr Reiner Behnsch. "We have a lot of technical and operating rules in Germany which have been around a lot longer than ETCS and these have been extended incrementally over the years, which puts constraints on ETCS and cross-border operation."

This issue led to the development of the BTSF specification for the operation of ETCS in Germany and this is the basis for all engineering and maintenance rules governing the use of the technology on the German network.

On the Dutch side the situation was similar, albeit with different rules. "The question was how we could find an operational scheme valid across the border which preserves the traffic running there, accommodates all the different locomotives, and satisfies the operating people in both countries," Behnsch says. "A 65-page Interface Requirement Specification (IRS) defines operations on this particular border crossing. Planning rules and approval processes are still national because they are not approval processes for ETCS, they are there for control, command, interlocking, and compatibility issues."

In both countries project-specific documentation was produced and discussed with the National Safety Authorities (NSAs) and Notified Bodies (NoBos). This resulted in a common approval process for the Zevenaar - Emmerich border crossing, taking into account all interfaces between ETCS and legacy systems and all operating interfaces. "We will have to do this for each border, and the processes might look a bit different for each border with a specific IRS for each crossing, but we hope to use it elsewhere in the future," Behnsch says.

Germany's NSA, the Federal Railway Authority (EBA) agreed to cross accept the authorisation for onboard equipment from its Dutch counterpart, the Environmental and Transport Inspectorate (ILT) as the basis for the German certification.

Phasing

The first phase of the project was completed in December 2014, when the line between the 25kV ac/1.5kV dc voltage changeover (VCO) at Zevenaar East and the German border switched from ATB to ETCS Level 2 Baseline 2.3.0d, completing the rollout of ETCS on the line from Rotterdam. This made the Netherlands the first country on the Rotterdam/Zeebrugge - Mannheim - Basel - Genoa corridor to fully implement ERTMS on its section of the route. The work was carried out by Strukton using Alstom ERTMS equipment.

The second phase is due to be completed at the end of this year and involves converting the line from Zevenaar East to a point 5km beyond the border to 25kV ac. The remainder of the line into Emmerich will switch to 15kV ac at this point, but PZB will remain in operation on the German section of the line.

In the third phase, which will be completed by the end of 2018, a third track will be constructed on the Dutch side. By the end of 2026, the third track will be extended to Emmerich and Oberhausen and the German section of the route will be equipped with ETCS Level 2 Baseline 3, which will be overlaid on the existing PZB.

In addition to freight trains the line is used by international passenger services. DB already uses multi-system ICE 3M high-speed trains on services from Germany to Amsterdam, and Abellio Rail NRW has ordered seven multi-system Stadler Flirt 3 EMUs in readiness for the extension of Düsseldorf - Emmerich services to Arnhem in 2017. These trains will be equipped with ETCS Level 2, PZB, and ATB.

"From a global point of view this is just a short extension of an existing ETCS-equipped line, which has been operating successfully for several years," says van Houten. "Borders are still challenging in Europe, but ERTMS is not the main challenge anymore."

Swiss-Italian links

Further south on the Rhine-Alpine Corridor, progress is being made towards the introduction of ETCS across the Swiss-Italian border and in this case migration is taking place at three locations at the southern end of the Gotthard corridor.

On the line from Bellinzona in Switzerland to Luino in Italy, the Swiss Signum system controls train movements as far as the yard at Luino, around 10km inside Italian territory, where it fringes with the Italian SCMT automatic train protection system. The same border location issues which affect the Zevenaar - Emmerich crossing are also apparent here, with the organisational and train control boundaries situated in different places. Switzerland's Federal Transport Office (BAV) is the NSA only as far as the national border, where the line comes under the jurisdiction of Italy's National Railway Safety Agency (ANSF). Likewise, Swiss Federal Railways (SBB) is infrastructure manager for the line on Swiss territory, with Italian Railway Network (RFI) controlling the remainder of the route to Luino. The complexity of this situation means close cooperation between stakeholders on both sides of the border is vital.

Later this year the line from Ranzo on the Swiss side of the border to Luino will migrate to ETCS Level 1 Limited Supervision (LS) with Euroloop data transmission and Euro-Signum and Euro-ZUB automatic train control. An ETCS Level 1 Full Supervision (FS) overlay on SCMT will be rolled out on the line beyond Luino to Milan after 2020.

On the line from Brig to Domodossola, Signum currently extends as far as the yards at Domodossola in Italy. This will be upgraded later this year to ETCS Level 1 LS + Euroloop/Euro-Signum/ EuroZUB, with ETCS L1 FS/SCMT on the Italian side.

The third border crossing is Chiasso, where Viaggiatori marshalling yard on the Swiss side is already equipped with ETCS L1 LS + Euroloop/Euro-Signum/ EuroZUB. This year Chiasso will switch to ETCS L1 LS/SCMT and on the Italian side the line to Milan will migrate to ETCS Level 2/SCMT in 2018.

SBB says the implementation of ETCS at this crossing has been challenging for a number of reasons, including the implementation of SCMT on a Swiss interlocking, implementation of ETCS Level 1 on Italian signals, and the connection of Chiasso station to RFI's Chiasso - Milan ETCS Level 2 rollout.

Swiss engineering rules for ETCS L1 LS were developed solely for use with Swiss signalling systems, and there were no rules governing the operation of this technology in Italy, necessitating a specific solution for Italian signals at Chiasso station. SBB will replace the interlocking at Chiasso in 2018 and this will need to be linked to an ETCS Level 2 RBC. Any trains starting from Chiasso and heading towards Milan will have to be announced to the RBC, which in turn will give the interlocking permission for the train to run on a line equipped with ETCS Level 2.

SBB and RFI signed a memorandum of understanding in mid-2012 which provided a foundation for joint working on cross-border ETCS projects, leading ultimately to the development of a cooperation contract assigning responsibilities to each side, which was signed in 2015. Since 2012, meetings have been held between RFI and SBB ETCS experts with the support of a joint steering committee and management board.

Initial state documentation was drafted in 2012-13, which led to the creation of implementation concept documents including ETCS Level 1 LS requirements, which were finalised by the two sides last year.

This development of ETCS Level 1 LS requirements for use in Italy was not without difficulty. Standard Swiss ETCS Level 1 LS engineering did not comply with ANSF standards. During the study phase the two NSAs decided to adapt the Swiss engineering standards for application in Italy using SCMT at Safety Integration Level 4 (SIL 4) as a reference system, but this needed to be achieved without changing the operational rules for Swiss drivers on these lines. To answer both of these requests it was necessary to rewrite the standard requirements.

SBB and RFI engineering rules for ETCS Level 1 LS were based on differing parameters in a number of areas including safety requirements, release speed, operating speed in speed restriction (SR) mode, and speed supervision.

Field works are due to be completed on the Swiss-Italian projects by June, with testing scheduled for completion a month later. ETCS is due to go into commercial operation on the Ranzo - Luino line in October and the Brig - Domodossola line the following month.

"Historical factors such as system borders reduce the solution space for ETCS and complicate cross-border ETCS projects," says SBB ERTMS project manager Mr Urs Mosele. "The different laws and rules of each country concerning safety and operation impede the implementation of ETCS at borders and its ability to guarantee unhindered network access. Without the cooperation of all stakeholders - especially transport ministries and NSAs - there is a risk that border crossing projects may not be successful."

Mosele calls for a common procedure for placing trackside equipment into service on international corridors and common requirements for safety standards. He also warns that unless trackside systems permitting dynamic transition are adopted, trains may be forced to stop at borders to change ETCS train data. In addition, he highlights the need for common requirements for safety standards to reduce the complexity of cross-border projects.

As these projects demonstrate, collaborative approaches can prove highly successful in breaking down barriers when it comes to deploying ERTMS across international frontiers. However, they also exemplify the hideous complexity that stands in the way of achieving anything close to the European ideal of interoperability. The transfer of certain responsibilities from the NSAs to ERA should make life simpler, but national rules and local operating conditions will continue to make every border crossing a unique proposition with its own set of challenges. In this respect, the experience being gained today will be vital to the success of future deployments.

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