ABSTRACT
This paper examines the practical strategies required when implementing modern automatic train control systems on existing complex, high density metro systems, drawing upon Thales’ experience in providing SelTrac across the globe and on the London Underground in particular. Thales is successfully delivering resignalling on the London Underground by focusing on the needs of the client’s service operations and maintenance departments, understanding the true requirements of the operators, both train drivers and signalling staff, and then ensuring these requirements are captured and delivered though a robust systems engineering approach thus providing a solid foundation for the design activities.
As the railways have to keep operating throughout the implementation of the new systems, strategies, such as overlaying the new system onto the existing infrastructure in a shadow operating mode, developing a migration strategy that prioritises the needs of the operator over those of the signal engineers and providing efficient changeover switching between the old and new signalling, have been developed to minimise the disruption to the operating railway and to allow comprehensive testing and reliability proving in parallel to the old signalling continuing to protect the existing services.
The final stage of the resignalling is also dealt with, through close working with the operators, to ensure operational readiness across the client’s organisation for the new systems. This ensures the necessary post commissioning support mechanisms, such as maintenance and reliability growth, are in place sufficiently early for operational service. The paper concludes that complex signalling systems can only be implemented onto operational railways by a combined client and supplier ‘One-Team’ approach with a close working relationship at all levels and appropriate contractual arrangements.
Keywords: Resignalling, Metro, SelTrac, Radio.
