European Train Control System
The European Train Control System is a train protection system designed to replace the many incompatible systems used by European railways, and railways outside of Europe. ETCS is the signalling and control component of the European Rail Traffic Management System.
ETCS consists of 2 major parts:
- trackside equipment
- on-board equipment
The need for a system like ETCS stems from more and longer running trains resulting from economic integration of the European Union and the liberalisation of national railway markets. At the beginning of the 1990s there were some national high speed train projects supported by the EU which lacked interoperability of trains. This catalysed the Directive 1996/48 about the interoperability of high-speed trains, followed by Directive 2001/16 extending the concept of interoperability to the conventional rail system. ETCS specifications have become part of, or are referred to, the Technical Specifications for Interoperability for control-command systems, pieces of European legislation managed by the European Union Agency for Railways. It is a legal requirement that all new, upgraded or renewed tracks and rolling stock in the European railway system should adopt ETCS, possibly keeping legacy systems for backward compatibility. Many networks outside the EU have also adopted ETCS, generally for high-speed rail projects. The main goal of achieving interoperability had mixed success in the beginning.
History
The European railway network grew from separate national networks with little more in common than standard gauge. Notable differences include voltages, loading gauge, couplings, signalling and control systems. By the end of the 1980s there were 14 national standard train control systems in use across the EU, and the advent of high-speed trains showed that signalling based on lineside signals is insufficient.Both factors led to efforts to reduce the time and cost of cross-border traffic. On 4 and 5 December 1989, a working group including Transport Ministers resolved a master plan for a trans-European high-speed rail network, the first time that ETCS was suggested. The commission communicated the decision to the European Council, which approved the plan in its resolution of 17 December 1990. This led to a resolution on 91/440/EEC as of 29 July 1991, which mandated the creation of a requirements list for interoperability in high-speed rail transport. The rail manufacturing industry and rail network operators had agreed on creation of interoperability standards in June 1991. Until 1993, the organizational framework was created to start technical specifications that would be published as Technical Specifications for Interoperability. The mandate for TSI was resolved by 93/38/EEC. In 1995, a development plan first mentioned the creation of the European Rail Traffic Management System.
Because ETCS is in many parts implemented in software, some wording from software technology is used. Versions are called system requirements specifications. This is a bundle of documents, which may have different versioning for each document. A main version is called baseline.
Baseline 1
The specification was written in 1996 in response to EU Council Directive 96/48/EC of 23 July 1996 on interoperability of the trans-European high-speed rail system. First the European Railway Research Institute was instructed to formulate the specification and about the same time the ERTMS User Group was formed from six railway operators that took over the lead role in the specification. The standardisation went on for the next two years and it was felt to be slow for some industry partners – 1998 saw the formation of Union of Signalling Industry, including Alstom, Ansaldo, Bombardier, Invensys, Siemens and Thales that were to take over the finalisation of the standard.In July 1998, SRS 5a documents were published that formed the first baseline for technical specifications. UNISIG provided for corrections and enhancements of the baseline specification leading to the Class P specification in April 1999. This baseline specification has been tested by six railways since 1999 as part of the ERTMS.
Baseline 2
The railway companies defined some extended requirements that were included to ETCS, leading to the Class 1 ''SRS 2.0.0 specification of ETCS. Further specification continued through a number of drafts until UNISIG published the SUBSET-026 defining the current implementation of ETCS signalling equipment – this Class 1 SRS 2.2.2 was accepted by the European Commission in decision 2002/731/EC as mandatory for high-speed rail and in directive 2004/50/EC as mandatory for conventional rail. The SUBSET-026 is defined from eight chapters where chapter seven defines the ETCS language and chapter eight describes the balise telegram structure of ETCS Level 1. Later UNISIG published the corrections as SUBSET-108, that was accepted in decision 2006/679/EC.The earlier ETCS specification contained a lot of optional elements that limited interoperability. The Class 1 specifications were revised in the following year leading to SRS 2.3.0 document series that was made mandatory by the European Commission in Decision 2007/153/EEC on 9 March 2007. Annex A describes the technical specifications on interoperability for high-speed and conventional rail transport. Using SRS 2.3.0 a number of railway operators started to deploy ETCS on a large scale, for example the Italian Sistema Controllo Marcia Treno is based on Level 1 balises. Further development concentrated on compatibility specification with the earlier Class B systems leading to specifications like EuroZUB that continued to use the national rail management on top of Eurobalises for a transitional period. Following the experience in railway operation the European Union Agency for Railways published a revised specification Class 1 ''SRS 2.3.0d'' that was accepted by the European Commission in Decision 2008/386/EC on 23 April 2008.
This compilation SRS 2.3.0d was declared final in this series. There were a list of unresolved functional requests and a need for stability in practical rollouts. So in parallel started the development of Baseline 3 series to incorporate open requests, strip off unneeded stuff and combine it with solutions found for Baseline 2. The structure of functional levels was continued.
Baseline 3
While some countries switched to ETCS with some benefit, German and French railway operators had already introduced modern types of train protection systems so they would gain no benefit. Instead, ideas were introduced on new modes like "Limited Supervision" that would allow for- a low-cost variant,
- a new and superior model for braking curves,
- a cold movement optimisation and
- additional track description options.
The ERA work programme concentrated on the refinement of the test specification SRS 3.3.0 that was to be published in July 2013. In parallel the GSM-R specification was to be extended into a GSM-R Baseline 1 until the end of 2013. The German Deutsche Bahn since announced equipping at least the TEN Corridors running on older tracks to be using either Level 1 Limited Supervision or Level 2 on high-speed sections. Work continued on Level 3 definition with low-cost specifications and the integration of GPRS into the radio protocol to increase the signalling bandwidth as required in shunting stations. The specifications for ETCS Baseline 3 and GSM-R Baseline 0 were published as recommendations SRS 3.4.0 by the ERA in May 2014 for submission to the Railway Interoperability and Safety Committee in a meeting in June 2014. The SRS 3.4.0 was accepted by the European Commission with the amending decision 2015/14/EU on 5. January 2015.
Stakeholders such as Deutsche Bahn have opted for a streamlined development model for ETCS – DB will assemble a database of change requests to be assembled by priority and effect in a CR-list for the next milestone report that shall be published on fixed dates through ERA. The SRS 3.4.0 from Q2 2014 matches with the MR1 from this process. The further steps were planned for the MR2 to be published in Q4 2015 and the MR3 to be published in Q3 2017. Each specification will be commented on and handed over to the RISC for subsequent legalization in the European Union. Deutsche Bahn has expressed a commitment to keep the Baseline 3 specification backward compatible starting at least with SRS 3.5.0 that is due in 2015 according to the streamlined MR2 process, with the MR1 adding requirements from its tests in preparation for the switch to ETCS. The intention is based on plans to start replacing its PZB train protection system at the time.
In December 2015, the ERA published the Baseline 3 Release 2 series including GSM-R Baseline 1. The is not an update to the previous Baseline 3 Maintenance Release 1. The notable change is the inclusion of EGPRS in the GSM-R specification, corresponding to the new Eirene FRS 8 / SRS 16 specifications. Additionally includes the ETCS Driver Machine Interface and the SRS 3.5.0. This Baseline 3 series was accepted by European Commission with decisions 2016/919/EC in late May 2016. The decision references ETCS SRS 3.6.0 that was subsequently published by the ERA in a Set 3 in June 2016. The publications of the European Commission and ERA for SRS 3.6.0 were synchronized to the same day, 15 June. The Set 3 of is marked as the stable basis for subsequent ERTMS deployments in the EU.
The name of Set 3 follows the style of publications of the decisions of the European Commission where updates to the Baseline 2 and Baseline 3 specifications were accepted at the same time – for example decision 2015/14/EU of January 2015 has two tables "Set of specifications # 1 " and "Set of specifications # 2 ". In the decision of May 2016 there are three tables: "Set of specifications # 1 ", "Set of specifications # 2 ", and "Set of specifications # 3
". In that decision the SRS and DMI are kept at 3.4.0 for Set 2 while updating Set 3 to SRS and DMI 3.6.0. All three of the tables are updated to include the latest EIRENE FRS 8.0.0 including the same GSM-R SRS 16.0.0 to ensure interoperability. In that decision the SRS is kept at 2.3.0 for Set 1 – and the decision of 2012/88/EU was repealed that was first introducing the interoperability of Set 1 and Set 2 based on GSM-R Baseline 0.
Introduction of Baseline 3 on railways requires installation of it on board, which requires re-certification of trains. This will cost less than first ETCS certification, but still at least €100k per vehicle. This makes Baseline 3 essentially a new incompatible ETCS which requires replacement of electronic equipment and software onboard and along the track when installing. Trains with ETCS Baseline 3 are allowed to go on railways with Baseline 2 if certified for it, so railways with ETCS do not need to change system urgently.
The first live tests of Baseline 3 took place in Denmark July 2016. Denmark wants to install ERTMS on all its railways, and then use Baseline 3.
British freight and passenger operators have signed contracts to install Baseline 3 in their trains, the first around 2020.