Pandrol-Vortek AWS Renewals

The challenge

Following the discovery of 4 faulty AWS (Automatic Warning System) magnets during the course of Alstom’s VIC 3 resignalling project, a common manufacturing defect was identified with a machined feature on the units’ covers leading to water ingress and subsequent magnet failures.

Originally installed between 2022 and the early part of 2023, the 63 magnets identified required immediate replacement, reinstatement and testing in order to return the AWS units to full compliance and ensure correct functionality of Network Rail’s asset management system.

The solution

Working directly for Network Rail’s Southern Works Delivery team, Amaro was instructed to replace the relevant AWS Pandrol-Vortok Series 2 powered magnets, collecting the repaired units prior to the shift and delivering them to the site via the use of skates or track trollies (except during line blocks without isolation).

Due to the need for wheels free testing, not to mention the extremely high volumes of traffic in the area, a significant amount of pre-planning and third-party integration was required prior to any site works taking place. From the booking of possessions to the organising of line blocks, our team worked diligently to remove as much risk as possible, coordinating their activities with other stakeholders and working around ongoing maintenance in order to guarantee the absolute minimum of disruption to both programme and budget.

Once on site, and following a detailed briefing and confirmation that the appropriate SSOW had been established, the Amaro COSS would contact the signaller in order to take the necessary line blocks and, once authorised, the PIC and COSS would then take the blockage as per Network Rail standards.

Prior to any works taking place, the following steps were taken:

1. The SMTH would inform the signaller of their intention to work in the area, letting them know exactly what equipment would be affected and providing their contact details.
2. All relevant signalling equipment would be tested in association with the signaller to guarantee that the required signal aspects and/or points movements could actually be achieved for testing purposes.

With all pre-installation steps now complete, the replacement AWS units were installed in accordance with NR/L3/SIG/11303/2U05, with all installation and testing being carried out by Amaro’s in-house installers and SMTH licence holders in line with SMTH test plans AW02 and SMS 024.

Once testing was successfully completed, operatives would contact the signaller to ensure that no other signalling equipment within the vicinity was showing as occupied for track sections or points out of correspondence.

The outcome

Works are still ongoing on this project and, at the time of writing, there are 29 AWS magnets out of the original 63 still left to replace. With each unit replaced, however, both system reliability and passenger safety are improved significantly.