Rail Interoperability in Spain. ERTMS real deployment 1 I.J. Iglesias. Presenting Author, 1 A. Berrios, 1 A. Arranz, 1 M. Cambronero1, 2 J.A.Jimenez, 2 C.Arias, 2 I.Ribera, 3 D.Molina, 3 J.Tamarit and 3 J.Bueno Coauthors 1 ADIF. Railways Infrastructure Manager, Madrid, Spain. 2 Renfe Operadora. Spanish Railways operator, Madrid, Spain. 3 CEDEX Studies and Experimentation Centre of Public Works and Transportation (Fomento) Ministry, Madrid, Spain Abstract This paper shows how, at the time being, the rail interoperability is a reality in Spain by means of presenting the current implementation of ERTMS/ETCS (European Rail Traffic Management System/European Train Control System) in the new Spanish high speed lines. This has been done in the frame of the very ambitious Spanish high speed program which consists on the construction and putting in operation of approximately 9.000 Km of new HSLs in the period 2005-2020, with a total investment of around 83.000 M. The role of Spain as pioneer in implementing the new signaling system is clearly highlighted in this paper. 1.- Introduction The main issue of this paper is to show how the real interoperability among almost the totality of ERTMS/ETCS suppliers is being successfully tested in Spain, presenting the behavior of lines in commercial operation as well as the new lines to be open during the next years. The success of ETCS real deployment is a clear demonstration that nowadays the rail interoperability is a fact, and this paper highlight the role played by the Spanish railways as pioneers in the real implementation of the system, solving the problems derived from the intervention of many suppliers, as well as for the non stability of the ETCS specifications. The paper will clearly differentiate the role played by the main Spanish actors who have actively contributed to this deployment: 1) ADIF (Spanish railways infrastructure Manager) in his role of planning, constructing, testing and exploiting the lines. 2) Renfe Operadora (Spanish public rail operator) by the acquisition of new HS trains with many different ETCS equipments and 3) Finally CEDEX Rail Interoperability lab, by means of testing all the EVCs at lab and solving the main interoperability issues appeared during the tests. This paper would like to point out the role played by the Railways General Directorate of the Spanish Ministry of Public Works and Transportation, as the System Authority of the lines implementing interoperable systems. 2.- The Spanish Infrastructure and Transport Strategic Plan 2005-2020 (PEIT) The Spanish High Speed Program is very ambitious and it is based on the Spanish Infrastructure and Transport Strategic Plan 2005-2020 (PEIT) that foreseen the construction of almost 10.000 km of new HS lines with a total investment of 108.766 M for railways in this period. This high investment is divided in four chapters: 1) High Speed Lines 83.450 M, 2) Maintenance and improving of conventional network 18.000M, 3) Levels crossing suppression 3.560 M and 4) New rolling stock 3.750 M. Figure 1 shows the new high speed lines foreseen at PEIT. In this plan the new lines won t be exclusively for passenger s traffic but also for mixed freight-passengers traffic. Furthermore some of the old lines could be also dedicated to freight traffic, with the target of increasing the rate of freight transportation by railways, which at present time is very low in Spain (around 3%). The previous mentioned investment for railways represents a percentage of 44% of the total investment foreseen in Spain for Infrastructures and transport modernization in the period 2005-2020. Based on it, Spanish railways have clearly bet for implementing ERTMS/ETCS in this network. The first steps of this important challenge are detailed in this paper.
HIGH PERFORMANCES RAIL NETWORK HORIZON 2020 Exclusively passengers Autonomic Communities Mixed network:freight and passengers CURRENT CONVENTIONAl NETWORK Figure 1: New High Speed lines foreseen at PEIT(Spanish Infrastructure and Transport Strategic Plan 2005-2020). This plan includes both passengers and mixed traffic HSL. 3.- Interoperability in Spain. ERTMS In the frame of this ambitious High Speed Program, Spain decided in 2000 to install ERTMS in all the new lines with the target of promoting the open market among all the signaling systems suppliers. This high risk decision was adopted as the only possible solution to really migrate in the future to a real open rail market following the future railways model: rail network will be constructed and administrated by a public institution and rail operation will be done by both public and private companies. The installation of an unique, interoperable and public system as ETCS is the only way to open the access of new rail operators by avoiding the restriction caused by the installation of a private proprietary signaling system. Although the most impressive part of Spanish program are the new high speed lines, also the conventional lines will be renewed and in all of them the new ETCS system will be progressively installed replacing the old ASFA Spanish signaling system. Obviously this process will be very long, and although in some cases as Madrid and Barcelona commuter lines this replacement is going to be done in the near future, the whole network replacement will take a long time. Another important pending issue in Spain is the Iberian gauge (1665 mm) which is wider than the standard UIC gauge (1435 mm). All the new high speed lines are UIC gauge (including the first one Madrid-Seville in operation from 1992), but the rest of the network lines (including Portuguese network) are Iberian gauge, making more complex the achievement of a real interoperability inside the Iberian peninsula. By this reason Spain is one of the countries more advanced in the variable gauges trains, as well as in the installations that modify the train gauge. At least ten of these facilities are now in operation, allowing train transfers between both networks, and therefore facilitating the
interoperability inside Spain. Trains CAF (S-120) and Talgo (S-130) are variable gauge trainsets, currently in operation at speeds up to 250 km/h. For all the previous reasons Spain is one of the countries which have clearly bet on the ETCS/ERTMS as the only way of achieving real interoperability. The decision of installing this signaling system in Spain is not only justified by the technical interoperability but also by the competitivity allowed by the installation of this system: ERTMS/ETCS is the only signaling system which allow the open competition among different suppliers, and therefore is the best solution to start the development of a so ambitious high speed network as the Spanish one. Spain, as it is clearly shown in this paper, has been the pioneer on installing both ERTMS levels 1 and 2 with different suppliers for track and train equipments. This way, started in 2000, has been plenty of obstacles: ETCS specifications migration from 2.0.0 to 2.2.2, different interpretation by different suppliers, a lot of change request continuously adding possible modifications, a lot of discussions to achieve agreements among competitors, new version 2.3.0.etc, etc However, although the way has been hard, at the time being it can be said that interoperability for level 1 is a fact (trains in commercial operation are circulating with ETCS from May 2006 with a high rate of reliability and punctuality) and for level 2 it will be a reality in the first semester of 2008. 4.- ERTMS High Speed Lines in Spain: current and future situation ADIF as the Spanish Railways Administrator has the task of both building and managing not only the HSL but the totality of the national lines. Therefore ADIF has the mandate of the Spanish Government to build and put in operation the new lines foreseen by PEIT and shown in figure 1. Figure 2 shows the ADIF prediction up to 2015. Some of this lines are currently in commercial operation, some of then are in a very advanced status of construction, and the rest have been already started building. SPANISH HIGH SPEED LINES Dotted tine Commercial operation End 2007 End 2008 End 2009 End 2010 Sistema Foreseen LZB 2010-2015 LZB System Continuous line ERTMS System Figure 2: ADIF High Speed Lines in commercial operation and lines foreseen up to 2015. However as this paper is mainly focused in the ETCS Interoperability the attention will be focused in the lines already in commercial operation, or in the lines under ETCS tests, where the problems arisen form the participation of many suppliers can be clearly shown. The following table (Table I) summarizes the current (January 2008) status of those lines:
Line ETCS Supplier ETCS Level/ Speed Length Current situation Future issues Trains operating in this line Track equipment. High Speed Lines.UIC Gauge Madrid- Lleida Ansaldo (CSEE) 1/300Km/h 2/350 Km/h 480 Km Commercial Operation L1 May 2006 L2 in operation at first semester 2008 S-102, S-103 and S-120 Lleida-Roda Thales 1/300Km/h 2/350 Km/h 92 Km Commercial Operation L1 Dec 2006 L2 in operation at the end of 2008 S-102, S-103 and S-120 Roda- Barcelona Thales 1/300Km/h 2/350 Km/h 80 Km Under final Tests Commercial operation: 2008 March S-102, S-103. Zaragoza- Huesca Alstom 1/200 Km/h 80 Km Commercial operation with ASFA ERTMS L1 operation. Mid 2008 S-102 and S- 104 Madrid- Valladolid Thales 1/300Km/h 2/350 Km/h 180 Km Commercial Operation December 2007 L1 L2 in Operation at the end 2008. S-102 and S- 130 Córdoba- Málaga Invensys 1/300Km/h 2/350 Km/h 155 Km Commercial Operation LSTM (LZB) December 2007 (also L1 equipped) L2 in Operation at the end 2008. S-100, S-102 and S-103 Conventional lines. Spanish Gauge Albacete-La Encina Bombardier 1-2 220 Km/h 90 Km Under tests Commercial operation : End 2008 Alaris Madrid Commuter lines Thales /Dimetronic L1 and L2 160 Km Under development Commercial Operation Mid 2009 Civia. Total length: 1317 Km. High speed lines: 1067. Conventional (Spanish gauge) lines: 250 Km. Table I. Lines equipped with ETCS, already in operation or under test or development. As it is shown in the previous table all the current ETCS suppliers have taken part in these Spanish lines (Thales and Dimetronic lines are equipped with Siemens eurobalises), and therefore all the aspects related to interoperability have been mainly tested there. Main problems detected during the tests and real implementation are described in this paper. Figure 3 Madrid-Tarragona (Roda) High Speed line
5.- High Speed trains equipped with ETCS To complement the role performed by ADIF, Renfe Operadora, the public Spanish rail operator, have started testing a big number of HS trains, equipped with different ETCS suppliers. Table II summarizes this information: Train 100 102 103 104 Class Serie 100 Serie 102 Serie 103 Serie 104 Serie 120 Serie 130 Train supplier Alstom Talgo - Bombardier Siemens Alstom - CAF CAF - Alstom Talgo - Bombardier Fleet 18 + 6 Composition 2 power heads 8 cars 16 30 2 power heads 12 cars 26 20 13 12 16 ** 8 cars 4 cars 4 cars 45 2 power heads 11 cars Length (m) 200,15 200,24 200,32 107,1 107,3 185,2 Speed (km/h) 300 330 350 250 250 ( 220 ) * 250 ( 220 ) * Seats 328 (+1 hp) 314 (+2 hp) 346 (+2 hp) 402 (+2 hp) 236 (+1 hp) 229 (+1 hp) 237 (+1 hp) 298 (+1 hp) Type of power Synchronous Asynchronous Asynchronous Asynchronous Asynchronous Asynchronous Signalling ERTMS-LZB- ASFA ERTMS-STM LZB- ASFA ERTMS-STM LZB- ASFA ERTMS - LZB - ASFA ERTMS supplier Alstom Siemens Siemens Alstom ERTMS - ASFA Ansaldo-CSEE Transport ERTMS-STM LZB- EBICAB-ASFA Bombardier Commercial service 1992 2005 2007 2004 2006 2007 *Speed in conventional lines (Iberian gauge). Trains S-120 and S-130 have variable gauge systems. Table II. Renfe High Speed trains equipped with ETCS in commercial operation. Additionally to this table Renfe is installing Invensys-Dimetronic ETCS equipment in 10 Alaris trains (series 490) which will circulate in the track Albacete-La Encina (spanish gauge). At the time being the six trains described in the previous table are in commercial operation in the lines as it is also described in table I. Table II summarizes the results, related to reliability, punctuallity obtained with the trains more time operating (Siemens S-103 and Talgo S-102) The combination of these trains with the ADIF s lines show the complexity of the Spanish HS program from the point of view of Interoperability. This clearly shows the role played by Spain as a Real Interoperability Lab, as well as the resolution of all the problems appeared during the setting up process has allowed the fact of start operating commercial lines with ETCS. Figures 4 and 5 show the cab of S-102 and S-103 respectively, both equipped with ERTMS/ETCS. Figure 4. Talgo S-102 train cabin equipped with ETCS
Figure 5. Siemens S-103 train cabin equipped with ETCS Finally table III summarizes the results, related to incidences for both ETCS and STM-LZB obtained with the trains which started before the commercial operation (Siemens S-103 and Talgo S-102) Talgo-S-102 Siemens S-103 ETCS STM LZB ETCS STM LZB Commercial Operation May- 2006 Nov-2007 June 2007 June 2007 Total circulations 9,219 80 1,592 471 Total Kms 3,670,126 118,855 840,576 223,494 N er of Incedences 31* 17 3 10 KM/ Incidences 118,391.16 6,991.47 280,192.00 22,349.40 *16 of the 31 incidences were due to odometry problems (with ice and snow) already solved. 6.- Interoperability cross table Table III. ETCS and STM-LZB first exploitation data.. As a summary of the two previous paragraphs, table IV describes the real state of interoperability in Spain by means of showing in a cross analysis both the current and future implementations of ETCS in track and on board installations: CROSS INTEROPERABILITY IN SPAIN TRACK EQUIPMENT Alstom Ansaldo Bombardier Invensys (Siemens balise) Thales (Siemens balise) AlstomS-104 YES YES YES Ansaldo S-120 YES YES YES Bombardier S-130 Under tests Under tests InvensysAlaris trains YES ON BOARD EQUIPMENT SiemensS-102/S-103 YES YES YES YES Thales No on board unit from Thales Table IV. Cross Interoperability in Spain. ETCS lines versus ETCS trains.
7.- Field Tests Before starting the lines commercial exploitation with different trains, it was necessary to perform some tests to assure the same interpretation of the specifications, as well as to demonstrate interoperability among all the existing suppliers. The first phase of this process was performed at CEDEX Rail Interoperability Lab in 2004 and 2005, where all the existing EVCs (European Vital Computer) from Ansaldo, Siemens, Alstom, Invensys and Bombardier were tested in a laboratory simulated track and also in a laboratory track reproducing Madrid-Lleida line. These tests are better explained in paragraph 8, but it is necessary to point out the importance of having performed these lab tests before start testing equipments on real track. Obviously, all the ETCS equipments on board or on track are previously tested by the suppliers. EVCs are tested in supplier s lab and track installation is tested by means of performing validation tests done by the supplier with an EVC selected by him. However, before putting in operation any line in Spain, it was decided (mainly based on the results obtained at CEDEX lab) that some additional tests were necessary to demonstrate the correct integration of the whole system composed by the on board equipment and the track installation. These system integration tests have been called Complementary Tests and have been defined jointly by ADIF, RENFE, CEDEX and TIFSA under the coordination of the Ministry of Fomento (Public Works and Transportation). This group has created the ETCS Complementary Validation Tests by means of first creating a set of Test Cases based on the functionality implemented in the two first Spanish lines (Madrid-Lleida and Lleida-Tarragona). The aim of these Test cases is to check the integration of an On Board Unit in a Spanish line. These tests are not exhaustive nor intend to demonstrate the safety of the system, because these two issues shall be demonstrated by the suppliers with the corresponding certification and safety case processes. The working group has created a total number of 215 Test Cases when a new On Board Unit is going to be tested either in a new line or in an already validated line. These test cases summarize the most important functionality of the Spanish lines with the aim of demonstrating the correct integration between on board and track ETCS subsystems. The Test cases have to be translated into scenarios in each specific line, tacking into account the specific routing and functionality implemented in each line. Obviously, the translation into scenarios would try to minimize the number of runs to be performed on the line. Typical time to perform the whole set of test Cases for a new EVC takes around 3 weeks, depending on the specific functionality of each line. As the process of testing in the real line is expensive and it takes a long time, it was decided to reduce the number of Test Cases when a new line is going to be tested with an already validated On Board unit. In this case the number of Test Cases has been reduced to 69 and the total time can vary between 4 and 6 labour days. The third situation is the case that an On Board Unit (OBU) which was validated in another ETCS line is going to operate in a new line (already validated with a different OBU), the number of Test Cases to be executed is 57 which means scenarios execution during 4-6 days. Finally in some cases like trains S-102 (Talgo) and S-103(Siemens) the same OBU has been installed in a different train. In this case if train S-102 has been already tested in a line, the test cases to be executed with train S-103 in the same line are only those affecting the train behaviour and not the OBU functionality. In this case only 20 test cases are necessary (those affecting Odometry, Train Interface Unit and braking) Table V summarised the previous figures. Naturally this table is just an orientation, because both the number of Test Cases and the time to execute the corresponding scenarios can vary in function of the functionality implemented in different ETCS lines. These are the values currently used in Spain but they can be increased or decreased in future lines depending if these lines implement more or less ETCS functionalities than the present ones.
In general the definition of both Test case and scenario could be the following: 1) A Test Case defines an specific ETCS functionality to be tested. The same test case can generate different tests because although it represents the same functionality, this can be tested with different variable values depending on the line specific implementation, i.e. timers, commercial stops, transitions 2) An scenario is the practical implementation of the test case in the real Track. It is necessary to perform a detailed analysis of the track to implement these test cases and also to concatenate several test cases in an unique scenario with the aim of minimizing the testing time. Number of Test Cases Scenarios (very variable in different lines) Typical number of testing days New OBU over a new line 215 aprox 21 3 weeks Already validated OBU over a new line 69 Aprox 15 4-6 days Already validated OBU over a new line(already validated with another OBU) A different train equipping an OBU already validated in this line 57 Aprox 14 4-6 days 20 Aprox 5 1-2 days Table V. Number of Test Cases and execution time for the Integration tests: ETCS Complementary Validation Tests Finally we point out the importance of creating a working group where all the major ETCS actors as well as the Spanish ETCS experts worked together to define those Test cases and Scenarios. It is also important to mention that this group has permitted the possibility of distributing to all the OBUs suppliers, the telegrams of all the lines of ADIF. In this way OBUs suppliers can simulate in their own labs the line before start testing with a train. Many interoperability aspects have been detected during the execution of these tests. The most important issues detected are summarised in the following: a) Specs different understanding (i.e. infill information, maximum number of plain text messages shown at DMI ) b) Adjustment of the release speed to the field c) Reliability of some track components (i.e. eurobalise) d) EVC SW modification to improve time processing in some cases (BG very closed, two much gradient sections in a MA ) e) Unreal Braking curves due to few gradient information or short MAs f) Loss of communication in L2 g) DMI differences. h) Different status of change requests (CRs) implementation. Figure 6. Tests on track. ETCS EVC-Track Integration Tests.
It is also important to mention that this group has permitted the possibility of distributing to all the OBUs suppliers, the telegrams of all the lines of ADIF. This way is very useful because OBUs suppliers can simulate in their own labs the line before start testing with a train in the real track. 8.- Tests performed at CEDEX Rail Interoperability laboratory 8.1.- Background CEDEX involvement in ERTMS started in 1990 with the EMSET project. This project, devoted to show the feasibility of the interoperability concept, was a complete success. At this very early stage of the ERTMS deployment, all the European signaling companies developed prototypes for the key components of the ETCS system, both trainborne or trackside. Most important, there was a common agreement to implement a set of test benches, where these ETCS prototypes could be tested in an independent way, in order to add transparency to the full demonstration process. CEDEX inherited the test tools, and at the end of the EMSET project at 2000, started an update and review process that is still going on. The tools were relocated in two main laboratories (Eurobalise and Eurocabine), both belonging to the Physics and Electronic Department, which was renamed firstly to Rail Interoperability Laboratory and, recently, to Rail Research Laboratory (RRL). From that time, RRL got involved in the european process to elaborate the test specification for Eurobalise and Eurocabine, in such a way that it became the first external partner to UNISIG leading a specification working group. The participation in these forums contributed to gain knowledge and experience around the signaling companies experts. Moreover, all these works were accompanied by several test campaigns in both labs, what helped to check the robustness of the test specification and the utility of the test benches. The first consequence from these works consisted in the CEDEX declaration as the first ERTMS- ETCS Reference Laboratory by the UNISIG companies. With this declaration, UNISIG recognizes CEDEX firstly as a valid laboratory to test Eurobalises and Eurocabines and secondly, as a valid referee to solve interoperability problems. During the last years, CEDEX has maintained these european tasks and has incorporated a growing technical assistance to ADIF (Spanish Infrastructure Manager), RENFE (Main Spanish Operator) and DGF (Spanish Authority) in the Spanish ERTMS Program deployment. In Table VI, tasks performed by CEDEX during the last years are listed. Eurobalise Test Campaign (2002-2004). Eurobalise and BTM tests System Test Specifications (2002-2005). EVC Test Campaign (2003-2005). Harmonization of JRU, DMI, Euroradio and specs interpretation. First european certification of an Eurobalise (2005). First european certification of an Eurocab (2007). System Test Specification upgrade to S.R.S. 2.3.0 (2007- ) Spanish DMI harmonization(2004) Specific JRU SW development (2004- ). All suppliers EVCs tests at lab.(2004-2005). Eurobalise reliability test at Mad-Lleida HSL (2005-2006). Participation and evaluation of S-100, S- 102, S-103, S-104 and S-120 L1 tests (2004- ). Participation and evaluation of S-102 L2 Tests in Madrid-Lleida HSL (2006). Participation and evaluation of HSL Lleida- Tarragona, Cordoba-Malaga, Madrid- Valladolid and Tarragona-Barcelona L1 Tests (2006- ) All suppliers balise tests (2006 ) European activities National activities Table VI. List of activities performed by CEDEX Rail Interoperability Labs in the recent past.
8.2.- Eurobalise Laboratory From the very beginning, the Eurobalise Laboratory has had a deep implication in the European working group devoted to the Air-Gap Interface and Test Specification, hosting several tests campaigns that contributed to get the highly qualified staff currently in charge of the lab. Due to this experience, CEDEX has been able to participate in the solution of the different problems that can arise in the real projects. One of these problems is described below. In 2005, some months before opening the HSL Madrid-Lleida in Level 1, it was detected an interoperability problem between the Eurobalises installed in the track and the ETCS onboard system. The problem had to do with the failure rate in the air-gap communication, since it was too high and affected the normal train operation. CEDEX was requested to support ADIF, RENFE and DGF to find out the origin of the problem. In this regard, from November 2005 up to March 2006 the Eurobalise Lab staff performed some tests in the Madrid-Lleida HSL. Several measurements were done in the track around the balises in order to detect any anomaly in the tele-powering or up-link signals. However, due to the problem randomness, this kind of measurements did not succeed. Finally, CEDEX staff installed a coil under the train antenna to register both the telepowering and uplink signals. This coil was connected to an acquisition system registering at 100 Msamples/s that was placed on the train. After a huge amount of measurements (all the balises in the track were recorded) the main conclusions were the following: When a balise is not received on-board, there is no up-link signal emission. In these cases the telepowering signal emitted by the train was fully compliant with the specifications. The previous result has been registered in 17 not detected balises in different train trips. Most (85%) of the lost balises were fixed balises. The problem was finally solved by means of installing a redundant balise in order to decrease the failure probability, although it is a temporal solution accepted at national level. Figure 7. Eurobalise real track tests. 8.3 Eurocabine Lab The implication of the Eurocabine lab staff in the ERTMS Spanish program deployment started before. In fact, in 2004, as all the ETCS onboard equipments were tested in CEDEX premises during an European test Campaign (Level 1 functionality), a parallel work was also performed, simulating in Lab some real scenarios from the HSL Madrid-Lleida. Thanks to these tests, several results were achieved. First of all, some interoperability problems due to the ETCS information distribution in the balise telegrams were detected and corrected in time. Secondly, it was noticed the differences among DMIs and JRUs from different suppliers. A deep analysis of these differences finished with a Spanish recommendation to harmonize the DMI that was presented to the CENELEC committee in charge of
the DMI specification. Regarding the JRU, CEDEX started a software development in order to decode the download from all the suppliers. This software is commonly used by RENFE and ADIF to analyse the incidences in the train operation. In 2005, also during an European Test Campaign (Level 2 functionality), CEDEX detected a compatibility problem between different versions of the EuroRadio specification. The problem was transmitted to the corresponding UNISIG Working Group and the companies developers were advised to take the necessary corrective actions. Figure 8. EVC Tests at CEDEX Eurocab Laboratory. All the works mentioned up to now were done taking advantage of the presence of the ERTMS/ETCS onboard equipments in CEDEX Eurocabine Laboratory during the European Test Campaigns. However, since 2004, CEDEX has developed a parallel task consisting on the analysis and evaluation of the integration tests between trains and lines before the authorization to enter in commercial operation in ERTMS Level 1. This task, of major importance for the main Spanish Parties (ADIF and RENFE) has contributed a lot to the consolidation of CEDEX as a real independent body. For the year 2008, the main effort from CEDEX will be to support ADIF and RENFE in the ERTMS Level 2 validation of the Spanish HSL.. 9.- Conclusions This paper presents an overview of the situation in Spain regarding the deployment of the new European signaling system (ERTMS) and its implementation in the new High Speed Lines. Due to the ambitious Spanish High Speed Program a big number of new lines are being constructed, and at the same time a big amount of new trains will run over these lines. ERTMS is the signaling system implemented in these lines, as well as in the trains, therefore, real interoperability among practically the whole set of signaling systems suppliers is currently being tested in Spain. Paper shows a summary of the results of these first implementations in commercial lines and it also mention the main problems encountered during this process. The first conclusion is that real interoperability is a fact in Spain. Three L1 lines are currently in commercial exploitation with a high level of punctuality and reliability and with 5 signaling supplying companies (Ansaldo, Thales, Siemens, Invensys and Alstom) involved. L2 will be in operation in the first semester of 2008, and all the tests related L2 are very advanced. The way to reach this stage has been hard due to different interpretation of the SRS by the different suppliers, different DMIs, lack of reliability in some components, and of course the impact of the change requests which are specially important in some cases. Up to now the results are good enough, however it is needed to stabilize the specifications as soon as possible to avoid the impact in countries like Spain where, at the time being, ERTMS/ETCS is a reality. Passengers are traveling at 300 Km/h under this control system and new functionalities must be introduced very carefully and- which is more important- must assure backwards compatibility.