Single Approach to Isolation (SAI) a.c

SAI Trial Suspended

In light of the impact the Coronavirus (COVID-19) outbreak has had on the nations workforce, including that of the operational running railway, a review of the NR/L3/ELP/25000 trial took place.

To support the increasing demand on the operational railways resources, the decision has been made to temporarily suspend the trial. The suspension of the trial will be effective from 0659 hrs on Friday 20th March 2020.

All planned isolations will revert back to NR/L3/ELP/29987 requirements and all other activities not requiring an isolation, reverting back to Rule Book GE/RT8000 and Task Risk Control Sheet GA21.

It is important to remember that this is a suspension, not a cancellation! Network Rail will continue to monitor the COVID-19 situation in line with Government guidelines, and will further update on when a decision to restart the trial is agreed.

For further information, guidance or feedback; please contact the project team by emailing 

SAI Project Overview

The SAI (a.c.) Project will trial and implement new operating procedures for Overhead Line Equipment (OLE). These procedures are set out in a new standard – NR/L3/ELP/25000 issue 1 “Electrical Safety Measures for Working on the Operational Railway with Overhead Electrification.”  The procedures in the new standard will replace the procedures set out in existing standard NR/L3/ELP/29987, also known as the ‘Green Book’.

The new procedures have significant emphasis on risk assessment and the avoidance of exposure to electrical danger. To support this, the project will introduce enhanced training for all workforce on or near OLE, and new equipment for use when marking out safe working limits. By adopting one set of procedures for use across the whole network, the workforce will have clarity on the procedures they should follow when working on the operational railway with overhead electrification.

The new procedures will be trialled in the Rugby Delivery Unit (DU) area, specifically Ashton, which is just north of Hanslope Junction to Hillmorton of North West and Central Region (NW and C) The trial will commence in Autumn 2019 and first ‘boots on ballast’ Earthed Isolation using the new procedures are due to be undertaken in January 2020. If the trial is successful, the plan is to ‘roll out’ the new procedures nationally from May 2020.


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