Proceedings 2002/2003 - IRSE

74 CTRL SIGNALLING AND COMMUNICATIONS
the KVB system currently applied to lineside signals
in France.
SAFETY ASSURANCE IN DESIGN AND
APPROVALS
All railway systems have been specified and
developed in accordance with the relevant requirements
of the recent European norms on reliability,
availability, maintainability and safety, ie EN50126
(general requirements) EN50128 (software assurance)
and EN50129 (signalling). Contractors have
therefore demonstrated safety in design installation
and commissioning by means of a structured
safety case. In the case of signalling this safety
case has evolved through the stages defined in
EN50129.
GENERIC PRODUCT SAFETY CASE
The safety justification of the products to be
adopted (using the principle of “Cross Acceptance”
where applicable).
GENERIC APPLICATION SAFETY CASE
The safety justification of the design of the
product as modified to comply with CTRL requirements.
APPLICATION-SPECIFIC SAFETY CASE
The safety case for the system as installed.
APPLICATION SPECIFIC SAFETY CASE: POST-
COMMISSIONING ADDENDUM
The safety case updated to take account of test
results and any subsequent modifications.
These safety cases are reviewed and accepted by
an independent panel (the CTRL System Review
Panel). This panel comprises a range of railway
experts who ensure that each safety case is
subjected to a rigorous and thorough review. The
design, installation and testing of the systems is also
subject to review by the Contracting Entity’s Notified
Body as part of the Conformity Verification process
mandated by the EU Directive on Interoperability
and the TSIs.
Prior to the Railways (Interoperability)(High-Speed)
Regulations 2002 coming into force, the emerging
designs were presented to HMRI as part of the
process of consultation under the Railways and
other Transport Systems (Approval of Works, Plant &
Equipment) Regulations 1994.
THE SIGNALLING SYSTEM ON CTRL
On CTRL the signalling system is based on the
Interlocking and Train Control System (ITCS), a
computer-based system able to perform all the
signalling functions on a new high-speed line.
BACKGROUND HISTORY
In 1993, SNCF commissioned the TVM430 system
(Track-to-Train Transmission) on the North Europe
High Speed Line. This system, developed with CSEE
Transport, has since been installed on the Paris
Bypass and Lyon Bypass high-speed lines, as well
as in the Channel Tunnel and in Belgium. It is
currently being installed In Korea.
The TVM430 system provides cab-signalling
functions on all these lines. Depending on the trackside
signalling status, the system determines the
running instructions to be given to the train (speed
indication and data for the on-board ATP system).
The experience gained has shown that the use of
such computerised systems:
• allows easier implementation;
• makes the testing phase easier, both before
commissioning and for managing modifications;
• allows connection of computerised maintenance
aid equipment.
SNCF with CSEE Transport have therefore
integrated the interlocking and cab-signalling
functions (TVM430) within the same system, to
develop a computerised system able to manage all
the signalling functions of a High Speed Line. This
system, called SEI (Système d’Enclenchement
Intégré), has been implemented on the new
Mediterranean High Speed Line.
For CTRL, the same system has been chosen but
with the name ITCS.
FUNCTIONAL DESCRIPTION
The ITCS is responsible for the following
functions:
• receiving controls from the Rail Control Centre
(RCC);
• sending monitoring data to the RCC;
• train detection;
• calculation of interlocking functions (route
setting, point controls, route proving…);
• acquisition of data having an impact on the
signalling, such as electrical sub-sections for
automatic overhead line equipment (OHLE)
protection and hot axle box detection;
• calculation of the TVM 430 type message to be
transmitted to the train;
• data transmission to and from an adjacent ITCS.
In addition to the system itself, the following tools,
necessary throughout its life cycle, have been
developed:
• a production line to configure an ITCS for a
particular area depending on operational
requirements and signalling principles, and to
modify it later;
• a test tool to validate the data capture for the
first implementation as well as for each modification;
• maintenance aid equipment.
Track circuits and the track-to-train transmission
limit the spacing of ITCS to a maximum distance of
15km, as for the TVM 430 system. This is due to the
fact that track circuit transmitters and receivers are
concentrated within the ITCS to allow them to be
oriented in accordance with the direction of running.
The maximum length over which a track circuit can
be fed is 7.5 km, so if the distance between two
adjacent interlocking areas is greater than 15 km, an
intermediate signalling room is required.