scope:

Introduction 

This task covers the management of sites with inherently higher or unusual derailment risk in track, through effective identification and mitigation. Despite incremental improvements in the standards, derailments still occur where a number of design conditions exist, for instance on non-standard layouts or tight radius curves where the failure mechanism is not evident or unusually rapid. This TWI will assist identification of locations with higher or unusual risk of derailment in track system and provide a framework to assist the risk assessment and identify mitigations.

 The standard NR/L2/TRK/001 specifies the minimum requirements for the inspection and repair of plain line track and switches. This task details:

o The identification of high or unusual derailment risk locations and many of the aggravating factors for inclusion in the Delivery Unit Track Risk Register (TRR).

o Creation of a supporting plan for identification, risk assessment and mitigation (including enhanced inspection and/or failure mode elimination).

Out of Scope:

o This TWI applies to the identification of inherent design features and factors that make faults less evident and combine to increase or heightened derailment risk. This TWI does not address other track assets that may appear on Track Risk Register (TRR) for instance items appearing due to asset condition, life expired assets or the failure of other supporting systems.