The CATS system provides a flexible, automated solution to assist with testing and commissioning railway interlockings. It can simulate signalling equipment and routes to allow for advanced function and principles testing without requiring track possessions. This reduces personnel needs, testing time, and risks associated with commissioning. CATS has been used successfully on various projects in the UK to test interlockings and geographical sets.

1. CATSComputer Aided Testing System

2. CATSComputer Aided Testing System
The Technologies division of Balfour Beatty Rail is a market leader in the provision of
signalling products and services to the global rail industry.
With significant expertise in the testing of signalling interlockings, the Computer Aided
Testing System (CATS) has been developed specifically to meet the varied requirements
of the signalling testing and commissioning process.
Developed specifically by signal engineers, CATS offers a flexible, automated solution
to the signalling tester to assist in the testing and commissioning of interlockings.
Testing support is also available as a service using experienced signalling works testers
(Modules 2, 3, 4 & 5) and signalling maintenance testers to assist the available testing
resource.

3. CATS offers a number of project benefits at all stages of the testing process:
• Personnel requirements can be reduced - for example, principles testing can be undertaken
by one principles tester
• Assists the signalling test and reduces the risk associated with commissioning
• Increased safety
• Improved testing records for auditing purproses
• Reduces the time taken for the testing of interlockings
• All signalling equipment can be simulated without possessions
• The entire interlocking can be functionally tested before the commissioning
• Improved method for fault finding
• Cost effective solution
CATS offers a number of key features:
• The hardware is connected to the incoming and out going cable links or plug couplers
• Compact and easily installed, using Windows-based software
• Once CATS has been connected the interlockings are ‘set to work’ and basic route setting
is undertaken by in-house IRSE-licensed testers
• Up to 4,200 channels can be configured acting as inputs or outputs
• Interfaces with any type of mechanical, relay or eletronic interlocking
• Full user training included
• Design and configuration is undertaken offsite by fully trained and IRSE-licensed engineers
Benefits and Features

4. • Trackside simulation/panel simulation
• Geographical set testing - Westpac/GEC
• Free wired interlockings
• Level crossings
• Lever frame simulation
• TDM testing
• Other customer specific requirements
Typical Uses of CATS
The abolition of the Rochdale signal box, in preparation for the Manchester Metrolink
extension, required a new RRI to be installed with control from a new NX panel at Castleton.
CATS was used on the replacement RRI project to enable the advance function and
principles testings of the interlocking. A CATS trackside simulator was provided in
conjunction with a panel simulator incorporating a simulated PBI located in the REB.
All principles testing was undertaken from the REB and once the test team was satisfied
with identified issues, the TDM was connected to the new NX panel. A brief principles test
was then undertaken in preparation for the final commissioning.
During the weekend of the commissioning only trackside correspondence and fringe
principles testing was required, thus reducing testing time and the risk of the project
overrunning.
Project Rochdale Re-signalling
Client Network Rail
Type RRI
Size Large
Location Rochdale
Date 2011
Case Studies

5. Case Studies
CATS was deployed to aid the testing of the replacement interfaced SMARTLOCK
interlocking as part of the SAIR project. CATS was installed in the new REBs and
configured as a trackside and level crossing simulator with remote communications to
enable the tester to operate the trackside simulator from the controlling signal box.
This enabled the tester to set routes via the panel simulator and to simulate trains and
fault conditions through the CATS system and the SMARTLOCK interlocking.
All through testing was completed ahead of schedule by utilising the functionality
of CATS. Rehearsals were also undertaken and to facilitate this, CATS was simply
disconnected in readiness and reconnected for modification testing.
Project Southampton Area Interlocking
Renewals (SAIR)
Client Signalling Solutions for Network Rail
Type Interfaced SMARTLOCK 400
Size Four VIXLs
Location Eastleigh ASC and remote REBs
Date 2010 - 2011
Projects Silver Migration Alleviation
Client Babcock for Network Rail
Type Westpac Mk3a geographical sets
Size Circa 3,000 sets
Location Routiner testing undertaken
at Babcock Depot
Date 2006 - 2012
CATS routiner testing was undertaken for every new replacement Westpac set being
installed on the West Coast Mainline.
Pre-written automatic test routines were run through the geographical set to
functionally test every circuit path and plug pin within the geographical set.
This gave the test and project team the confidence that the geographical set was both
wired and functioned correctly prior to commissioning.

6. Contact:
Balfour Beatty Rail Ltd
Quarnmill House, Stores Road,
Derby DE21 4XF
Tel: +44 (0) 1332 225130
Fax: +44 (0) 1332 225131
info.bbrt.uk@bbrail.com
www.bbrail.co.uk
Copyright © 2012 Balfour Beatty Rail Ltd
All rights reserved. No part of this publication may be reproduced
without the written permission of Balfour Beatty Rail Ltd.
CATS