IRSE NEWS 167 May 11 with Watermark.pdf

IRSE TECHNICAL VISIT
IRSE Visit to Iarnród Éireann, Ireland 25 - 26 February 2011
By Mike Tyrrell and Ian Mitchell
Photos: Mike Tyrell
NOT FOR RE-PRINTING
The party came together for lunch in the Hibernian Hotel at
Mallow on Friday 25 February 2011, some from Dublin and the
majority from Cork. We were welcomed by Peter Cuffe, a long
term member of the IRSE and now the Iarnród Éireann (IÉ) Safety
Chief.
Technical Papers
The first paper was from Pat Judge, the Chief S&T Engineer,
who gave an overview of IÉ signalling and telecommunications.
IÉ has taken advantage of the healthy economy and
European Union grants to implement “Mini-CTC” schemes
modernising signalling on 1000 km of secondary lines in the
West of Ireland over the last ten years. IÉ have secured excellent
value for money in these investments through adopting a
standard set of technology and use of in-house design and
testing resources.
The components of the signalling system comprise:
Centralised Traffic Control from a control centre in Dublin;
Centralised level crossing control from control rooms in
Mallow and Athlone;
SSI with emergency local control grouped at one location on
each line;
Train detection by means of axle counters;
Level crossing control using Programmable Logic Controllers
(PLC);
Synchronous Digital Hierarchy fibre telecommunications
network on railway land linking all locations.
The second paper was by Krassimir Moloney on the use of
standard industrial PLCs for safety critical applications.
For level crossing applications PLCs at the control room and
at the level crossing communicate with one another, and check
the CCTV video feed that the operator sees is live when he
needs to confirm the crossing is clear of road traffic. Another
novel application of PLCs is to generate Automatic Train
Protection codes to be transmitted onto the rails where coded
track circuits have been replaced by axle counters. In this
application the PLC monitors SSI data link messages directly to
deduce signal aspects without needing a relay interface.
Technical Visit: Mallow
After the presentations the party returned to Mallow station and
split into groups for the technical visit. One of the most
impressive features was the level crossing control room, which is
designed to supervise up 96 level crossings, with one operator
provided for every 20 level crossings.
The level crossings are full barrier crossings with automatic
lowering and raising of barriers, and CCTV supervision from the
control room. Home and distant signals on the approaching
railway lines display a proceed aspect to trains when the barriers
are proved down and the operator has confirmed “crossing
©
clear” on a touch screen interface that sits below the CCTV
monitors. Except in station areas, the level crossing is entirely
independent of the signalling – the protecting signals are
operated from the level crossing controller, not the interlocking,
and are not displayed to the signaller at the CTC in Dublin.
In the same building (formerly the station parcels office) there
is a control room for station security monitoring. This is a new
feature provided for the unmanned stations on the recently
reopened Cork-Midleton route. The operator in this room
watches CCTV cameras in stations and car parks, and receives
fault reports from other station equipment such as ticket
machines and lifts.
1
2
6
IRSE NEWS | ISSUE 167 | MAY 2011