Challenges To Ertms In Europe

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The article describes the challenges to ERTMS in Europe

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Challenges To Ertms In Europe

  1. 1. euRope | signalling Tackling the challenges to standard train control ETCs Some decisive action needs to be taken soon in order to ensure the evolution of a truly standardised european Train Control System. Frank Walenberg, Rob te Pas and lieuwe Zigterman* O bservers of the European railway scene could be forgiven for thinking that there is something seriously wrong, as operators and the supply industry struggle to adopt the European Rail Traffic Manage- ment System. Progress is slow, and it is clear that implementation of ETCS is taking place in small steps. Some progress has been made towards interoperability. The legal framework is in place, and the insti- tutions are largely established both in the member states and at the Eu- ropean level. The first interoperable lines have been put into operation, and traffic is starting to grow. This should pave the way for interoper- ability to move from ‘pragmatic’ to the systems operational. So today, A DB Class 189 ‘full’ implementation. But whilst the we have a ‘consolidated’ version locomotive undertaking end vision is clear, it seems that not and something referred to as 2.2.2 ETCS tests at enough attention has been paid to ‘Corridor’. It is clear that the differ- the Wegberg- Photos: DB Schenker common international migration ent suppliers, who are all members Wildenrath circuit. strategies, and the interoperabil- of Unisig, have been implement- ity issues that arise when railways ing slightly different functionalities have reached different stages of based on identical specifications. implementation. To try and make sense of the ETCS Level 2 is now in com- confusion, the European Railway to implement this by updating the mercial operation in Switzerland, Agency, as designated System Au- equipment and software on existing Italy, the Netherlands and Spain, thority for ETCS, published a new rolling stock and infrastructure. amongst others, and many more SRS Version 2.3.0 on March 7 2007. Meanwhile, ERA is working to- railways have Level 1 installations However, it became evident that this wards Version 3.0.0, which will in- to a greater or lesser degree. Most of was incomplete, so a debugged ver- clude functional updates requested these are based on System Require- sion (2.3.0D) was officially adopted by many different parties. For exam- ments Specification Version 2.2.2, on May 24 2008. Suppliers and infra- ple, RFI of Italy is asking for radio but with local modifications to get structure managers are now trying infill and SBB wants Level 1 with Limited Supervision. The indus- * Frank Walenberg is Director of KeMA Rail Transport Certification, where try’s current expectation is that the Rob te Pas is principal Consultant and lieuwe Zigterman is Senior Assessor. Version 3.0.0 specifications will be signed off by December 2012, and that the suppliers will have their products tested and approved three years later. This would allow for op- eration using 3.0.0 to start in 2016. Putting this in a positive light, the ETCS community is in the throes of a learning process to settle specifica- tions that can guarantee unified, and hence compatible, implementation. Railway Gazette International | March 2009 33
  2. 2. signalling | euRope conditions, but only after one or more ‘abnormal’ events. system integration When a new line or an upgraded route is taken into service, many con- ditions have to be met. It is not suffi- cient simply to equip track and trains with ETCS and GSM-R, the two main components of Ertms. This is because the infrastructure consists of numer- ous subsystems such as bridges and tunnels, power supply and stations, while there are countless different types of rolling stock. Operational procedures are markedly different too. Fig 1 illustrates how the different TSIs apply to the railway and its sub- systems. The upper half of the diagram concerns Conformity Assessment at the subsystems level as determined in interoperability legislation. Note that significant elements of the operating This Vossloh But the learning process is continu- which is the permitted speed limit in railway are not covered by TSIs, for G1206 operated ous, and the railway sector may not ‘unfitted’ mode where the on-board example interlockings and train de- by Dutch open- access company be well equipped to manage it. equipment is not working. This was tection systems. ACTS is equipped seen as a failure mode that would Each TSI still has an Annex which with ETCS Level Ertms in practice only occur on rare occasions. In one lists a number of ‘Open Points’. In 2 for use on the Betuwe Route. sample country the permitted speed relation to Ertms, Annex G of Com- Concerned by the various national is 10 km/h, but one of its neighbours mission Decision 2006/860/EC men- differences in Ertms implementa- allows 100 km/h, another 160 km/h. tions (amongst many other items) the tion, in 2007 ERA commissioned Each country claims its choice is following: KEMA Rail Transport Certification based on sound arguments, but it • requirements for reliability and to undertake a study of experience would be hard to explain to a driver availability; with implementing Ertms, with a why such important changes oc- • requirements for safety and safety particular focus on safety approval cur when his train crosses a border. analysis; procedures. This study was con- In most cases these differences will • odometry functional interface ducted in co-operation with RINA only become apparent to the driver specification; (Italy), Cetren (Spain) and Attica under specific failure conditions, • version management. Advies (Netherlands). which makes the issue potentially For the time being, the TSI requires One of the most important find- quite serious. Most railway accidents each member state to define its own ings was that system integration is do not happen in normal operating requirements in these areas. In theory, not well covered by the European regulations. This is the responsibility of individual member states, and as a result, many national procedures TSI TSI (Notional, TSI TSI TSI Regulatory technical Non- remain in place. OPE CCS open points) ENE RST INF Step 1. Conformity TSI That is bad enough, but there is parts worse. As agreement could not be assessment conditions reached on all aspects of ETCS, the Onboard assembly Trackside assembly key players invented National Values to identify parameters where coun- tries may (and do) choose different standards. A good example is ‘V_nvunfit’, CCS integration Operational Step 2. Putting conditions into service System integration Technical specifications for interoperability Putting into service ope = Traffic operational & Management; CCS = Control, Command & Signalling eNe = energy; Fig 1. How the TSIs apply to the railway and its subsystems. The upper half of the RST = Rolling Stock; diagram concerns Conformity Assessment at the subsystems level as determined in INF = Infrastructure European legislation on interoperability, and the lower half shows the steps required when a railway enters service. 34 Railway Gazette International | March 2009
  3. 3. euRope | signalling these national requirements should HSL-Zuid between Belgium and the function correctly in each country, be exchanged at European level, and Netherlands. even when operating in degraded at some point in the future, the EU The TSI assumes that each Class mode. In a typical example, the sys- hopes this may lead to a consensus. B system is controlled via a Specific tems for countries X and Y are put The lower half of Fig 1 shows the Transmission Module. The Unisig into ‘sleeping mode’ when the train steps required when a railway is taken Subsets in Versions 2.2.2 and 2.3.0 dis- is running in country Z. The systems into operation. The first is to integrate tinguish between an STM-European needed in countries X or Y are woken the lineside and onboard equipment and an STM-National. The former is up by an ‘activation event’ which oc- (CCS integration). Integration of all the ideal from the point of view of in- curs as the train enters that country. other subsystems then follows, with tegration, as it only handles the track But the ETCS designers have as- a period of trial operation before the interface, while all logic processing sumed that the whole European net- line can enter commercial service. for multiple STMs would be concen- work is being equipped with ETCS, The study showed that each mem- trated in the on-board European Vi- or at least with transition balises ber state goes about implementation tal Computer. An STM-National, by at each border crossing. Thus the in its own way. There are no common contrast, more or less maintains the Class B systems for countries X and rules for the period of trial running. existing ATP system, which is simply Y, which are not active in country Z, No common criteria are defined to switched on or off by the EVC. are not put in sleeping mode but are specify when a new line can be put So far only a limited number of simply switched off. They would then into service, and there is no common STM-N modules have been devel- be switched on again by a transition approach to safety testing. oped, and we do not know of any balise. There also are significant varia- STM-E. There are even suggestions Yet in reality transition balises have tions in the way that safety approvals that the provision for STM-E could not yet been fitted at all relevant bor- are handled compared with what is be removed from the Version 3.0.0 ders. If a train re-enters country X required in the certification process specifications. for interoperability. In some cases as- At present, there is no provision sessment by the Independent Safety for co-ordination between different Assessor is seen as part of the interop- STM-Ns. A specific example high- erability certification, while in others lights what may happen. When op- a separate ISA assessment is given the erating on a Class B system, the CCS highest priority before a line enters TSI defines which STM should be commercial service, and interoper- used. As defined in Annex A of both ability is left until later. the High Speed and Conventional In either case there is little experi- TSIs, the ETCS kernel determines the ence of assessment for international level of safety provided, either ETCS cross-acceptance. Apart from deci- or ‘Level-STM’. sions by Notified Bodies about ISA Starting a train from cold, a driver acceptance, the legislative ground for must input the appropriate level. Se- safety cross-acceptance is weakened lecting ‘Level-STM’ brings up a list of by different views about assessors’ available STMs on the DMI, and the qualifications and liability. driver can then choose the correct at such a border, the Class B system A Euroantenna Looking at operations, current system. However, it is possible to se- remains switched off. This border fixed to the underside of practice is that bilateral agreements lect the wrong one. For example, on would still be equipped with the ‘old’ the train for are negotiated between infrastruc- a Thalys train in the Netherlands, a activation code for a sleeping Class B communication ture managers and railway undertak- driver could select the STM for Bel- system, but this would not be ‘heard’ with balises. ings as well as between infrastructure gium, which would mean that the sys- by a train running with the system managers in neighbouring coun- tem would operate to TBL1 specifica- switched off. Once again, there is a tries. But these agreements are not tions, as a warning system rather than risk that the level of safety could fall standardised. a train protection system. The driver as a result of STMs being controlled would expect the Dutch ATB to pro- by ETCS. Multiple Class B systems tect his train, reducing the speed to We are concerned that the speci- 40 km/h if no ATB signal is received. fications do not consider the prob- The CCS TSI distinguishes between However, STM TBL1 only introduces lem of transitions between existing the Class A system (ETCS), and Class emergency braking if train speed ex- national systems in sufficient detail. B national train protection systems. ceeds 160 km/h, and the train protec- Chapter 4 of Subset 026 includes the Rolling stock for international serv- tion system in the Netherlands would ETCS Transition Table for all ETCS ices is usually equipped with several not function until an ETCS balise was modes, including STM-E and STM- Class B systems to run in different passed, which would reset the system. N, but there are no transitions from countries. For example, a Thalys So in some circumstances the intro- one STM mode to another: transi- PBA trainset is fitted with the French duction of ETCS, and particularly the tions SESE and SNSN have been KVB and TVM, the Belgian TBL and control of STMs by ETCS, may actu- omitted! Crocodile, as well as the old and new ally reduce the level of safety. Our experience suggests that inter- versions of the Dutch ATB. The PBKA national freight traffic, on Corridor trainsets also have PZB/LZB inductive Border transitions A between Rotterdam and Genova train control to operate in Germany. for example, is already encountering Thalys trains are now being fitted with When trains cross several borders, such transition problems. And with ETCS Level 2 so that they can run on it is clearly important for the ATP to the profusion of traction leasing, Railway Gazette International | March 2009 35
  4. 4. signalling | euRope infrastructure manager, whose choice is needed to reduce this tendency. of trackside equipment is influenced Harmonisation of the European by the characteristics of the rolling railway network is clearly a long- stock using the routes being fitted. term task, because of the enormous To date there is no agreement costs involved. Interoperability is on braking curves in the TSIs. The not a goal in itself, but is intended Ertms User Group has taken the lead to create the conditions for an open in the search for agreement on a com- railway market. Nor does it solve the mon braking model, and while this financial problems of further intro- process is well in hand, agreement on duction and implementation of in- braking curves in the TSIs must await teroperable technologies. The next the issue of Version 3.0.0. Yet while steps towards creating a true mar- agreement on a common braking ket largely depend on the political model may be within reach, there is will to define and support effective no sign of an agreement on the pa- migration strategies. Future success The cab of an locomotives are likely to be used in rameters to be used in the model. will also depend on feedback from ETCS-equipped many countries, meaning that doz- Meanwhile, each operator or roll- experience, the ability to monitor Vossloh G2000 locomotive. ens of transitions between Class B ing stock manufacturer has to decide and measure progress with interop- systems will have to be taken into which braking curves to apply, and erability, and to recognise the rea- account. the Notified Body then has to assess sons for any lack of progress. the choices made. In our experience, We believe that some decisions Operators affected the braking curves adopted in recent need to be taken urgently to progress years are often ultra-conservative — the evolution of Ertms. To that Infrastructure managers acting every party seems to want to increase end, we would like to offer some only within their own country prefer the safety margin. This leads to brak- suggestions: to install balises which command and ing curves which lengthen headways • allow a ‘sleeping’ mode for Class B accept only those systems that apply significantly. In extreme cases, the al- systems: in that country. For example, the on- lowable braking distance for a freight • agree on the inclusion of ‘foreign’ board equipment on a train entering train running at 100 km/h can be as Class B systems in the ‘priority lists’ the Netherlands will be instructed much as 2 km. for transition packages; by a balise to switch to ATB, and no • explicitly address the need for alternative is permitted. When ap- The way ahead SESE and SNSN transitions, proaching either the Betuwe Route or to accommodate border crossings HSL-Zuid, the train will receive Level Ertms is not the only driver of between STM operations in differ- 2 commands, with Level 1 as a fall- interoperability, but is perhaps the ent countries; back on HSL-Zuid. most important, and the most visible • eliminate National Values, or agree As a consequence, if the ETCS fails, sign of progress. The gradual devel- a smaller range for different speed and is not able to switch to Level 0, opment of a global market for ETCS values; the driver must isolate the equipment also offers an important incentive for • continue working to establish com- by breaking seals. Depending on his European suppliers to improve their mon braking parameters. actions, he might then be permit- competitiveness. We have learned that the path to- ted to continue the trip with no ac- The separation of responsibility for wards an interoperable European rail- tive train protection. If the transition infrastructure management and train way is long and arduous, and much balises on the approach to the Betuwe operations is a cornerstone of Eu- still lies ahead of us. We can choose to Route also allowed for ATB (as a sec- ropean railway policy, aimed at im- return to the multi-national route of ondary option in the priority list), the proving the attractiveness and com- the past or we can choose a route that system might switch to ATB, which petitiveness of the rail sector. But as leads to a true European railway. So would provide a degree of protection a consequence of this approach, the much effort has already been put into by limiting train speed to a maximum new concepts of interoperability, TSIs the introduction of Ertms, and this of 40 km/h. and certification are essential to re- progress should not be put at risk. The consequences of choices made store a systems structure. Strict appli- The decision time is now. l by infrastructure managers will af- cation of these instruments is needed fect train operators, especially freight to reach a stable structure. In par- glossary of Ertms companies, all across Europe. As ticular, TSI-OPE needs to be applied terminology these companies operate in a genu- more strictly. And it is important to inely competitive market, they do not recognise that the interoperability of Ertms = european Rail Traffic Manage- spend time discussing Ertms and all subsystems can only really be dem- ment System eTCS = european Train Control System its complications. They simply want onstrated through certification. FRS = Functional Requirements to run their trains. Confusion about the definition Specification of interoperability and other issues STM = Specific Transmission Module Braking curve parameters seem to be making the application DMI = Driver Machine Interface of TSIs difficult, creating openings SRS = System Requirements Another key issue is the question for some countries to continue their Specification eRA = european Railway Agency of braking parameters. This involves national approaches. Further devel- Unisig = Consortium of principal eTCS the ETCS equipment manufacturer, opment of the TSIs, to improve their signalling suppliers the rolling stock supplier and the completeness and ease of application, 36 Railway Gazette International | March 2009

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