Page 89 - 360.revista de Alta Velocidad - Nº 5

The role of the ertms users group in the consolidation of the ERTMS technical specification for
baselines 2 and 3

II. The feedback from the commercial experience produced a great number of “Change
Requests”. These were proposals for the improvement of the System Requirement
Specification resulting from the commercial exploitation. Commercial lines in exploitation
had to migrate continuously to get them aligned with the consecutive versions of the
technical specification: SRS 2.0.0 -> SRS 2.2.2 -> SRS 2.3.0 -> SRS 2.3.0 D. This has been the
case of the Spanish Railway Administration, forced to migrate more than 1.000 Km of lines
and hundreds of trains.

III. The feedback from the exploitation of the Madrid – Lérida line showed that the harmonisation
of human factors was an open issue. For the first time, different suppliers of ERTMS On-
board equipment, operated on tracks equipped by different ERTMS suppliers. A comparative
study of the different DMIs, performed by CEDEX, forced the ERTMS Users Group to launch
a new working group on Human Factors. Three different approaches were needed to solve
this open point with experts on human factors, not linked to the technical world (HEROE
Project).

It is worthy to say that the operational interoperability is 50 % of the interoperability, the
other 50% being the technical interoperability. Due to this unexpected issue, the ERTMS
Users Group could not accomplish the operational harmonisation within the period of the
pilot lines. It is only with the launch of the ERTMS Baseline 3, that the DMI specification
becomes harmonised and its specification becomes mandatory. The Human Factors Working
Group, transferred to ERA from the ERTMS Users Group, accomplished the operational
harmonisation.

IV. The handover between the RBCs at the border between Holland and Belgium in the Dutch
High Speed Line South caused a major problem. The trains ought to cross the border in Level
1, disconnecting from the handing over RBCs to solve the problem. This patch, also used
in other countries, had a big impact on the exploitation of the High Speed line due to the
speed limitation in Level 1.

UNISIG came with two proposals for the specification of the RBC handover, asking the
ERTMS Users Group to choose the most convenient one. The election made was the basis for
Subset-098 specification.
V. The starting of the commercial exploitation of the Spanish High Speed Line between Madrid
and Lérida in ERTMS Level 1 was quite problematic due to the lack of reliability of the
Eurobalises. This critical situation was solved thanks to an illegal duplication of fixed balises,
placing contiguously two identical balises. If one balise was failing once every one thousand
of readings, the two contiguous balises had a failure estimated in one every one million of
readings, solving miraculously the problem. It is worthy to mention the role played by Mr.
Jorge Iglesias in solving this crisis that could have strong political consequences.
VI. The Spanish High-Speed network includes the Madrid-Sevilla line, equipped with the German
system LZB. A fleet of hundred high speed trains purchased by RENFE ought to operate on
the ERTMS new lines and also on the Madrid – Sevilla line. This was forcing the Spanish
Administration to request the STM for LZB, as proposed by UNISIG. At the end, major part
of the train fleet was equipped with LZB onboard equipment operating independently from
ERTMS because the LZB STM was not available. Today the use of STMs is optional and only
trains equipped by Bombardier incorporate the LZB STM.
VII. The continuous evolution of the ERTMS Technical Specifications forced the Spanish
Infrastructure Manager ADIF to undertake a continuous migration of their high-speed lines.
Today all lines are aligned to the SRS version 2.3.0 D. New trains purchased by the Spanish
operator RENFE will be equipped with EVCs of Baseline 3, the backwards compatibility
between both consecutive versions is a challenge that will be verified at commercial level
within the following years.

International Congress on High-speed Rail: Technologies and Long Term Impacts - Ciudad Real (Spain) - 25th anniversary Madrid-Sevilla corridor 87