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Project title

A single Automatic Warning System (AWS) receiver for DC and Non-DC operation (T309)

  • Project number:

  • Topic:

    Control, Command and Signalling
  • Status:


Project Summary

This project assessed the feasibility of a single Automatic Warning System (AWS) receiver for vehicles operating on DC and non-DC lines. Currently, different receivers are required.

Project Abstract

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Due to the extraneous electromagnetic fields that can be created on DC electrified lines, a less sensitive Automatic Warning System (AWS) receiver is used on trains that are constrained to these lines. Dual voltage electric trains utilise two receivers for operation on AC and DC electrified lines with automatic switching between the two receivers depending on the power supply. However, diesel trains operating over DC and non-DC lines have a single standard type receiver. Lloyd's Register Rail (LRR) were engaged to establish if a single receiver is viable that can operate effectively on both DC and non-DC lines. The research is now complete and has been discussed with the AWS Working Group, a sub-group of the Vehicle/Train Control System Interface Committee. LRR has shown that cross-track DC feeder cables can create magnetic fields of similar strength to standard AWS magnets. They conclude that a single receiver is possible but not without more sophistication and the working group see difficulties with this. They recommend that the theoretical approach taken by LRR in this research project should be supplemented by practical field measurements.

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