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Wessex Minor Works - TCaids

Project Outline:

So far S&T Cover have replaced, relocated and installed at new sites a total of 567 TCaid Units, improving the performance of 60 Track Circuits, utilising a new TCAID-MK2 unit that has modern components and has been developed and approved for use on the infrastructure within the Wessex Route. These works were necessary due to obsolescence of the components in the originally installed TCaid units, they had become unserviceable and strategic spares were in short supply, so the units required replacing. The works included ‘like for like’ replacement of the old redundant MK1 units with the new functionally equivalent MK2 type units, including any missing disc-boxes / stakes / trestles and leads and rail connections that were installed as required. Also new installation, pre-test and commissioning was completed of TCAID-MK2 Units on the Wessex Region on lines that never previously had TCAIDS installed, but had suffered from track circuit reliability issues during the leaf fall season, of these, five of the Track Circuits identified were of the HVI (High Voltage Impulse) type, these were trial sites.

SMTH and G11O Testing was used to control the testing activities.

Project Summary

  • 228 MK1 TCaid Units renewed with MK2 TCaid Units.

  • 220 MK2 TCaid Units relocated to standard.

  • 84 MK2 TCaid units installed and tested at new locations.

  • 35 MK2 TCaid units installed at 5 HVI Track Circuits as trial sites.

  • SMTH and G11O Testing.


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