TRANSPORT FOR Wales and Amey Keolis Infrastructure Ltd (AKIL) made the first physical track alteration in the £750 million Core Valley Lines upgrade on the weekend of 31 October and 1 November, when the track was lowered beneath a bridge on the Aberdare line.
The track, at Mountain Ash, was lowered by up to 280mm for clearance for future 25kV overhead line equipment (OLE). OLE beneath bridges on the CVL will not be energised, allowing safe operation with smaller overhead clearances than would otherwise be the case. Trains will automatically switch to battery power at each bridge. This method is expected to save considerable expense and disruption from rebuilding of bridges.
Explaining why track was lowered at Mountain Ash, TfW said: ‘In order to install Permanently Earthed Sections (PES) of OLE, in some circumstances the soffit height between railhead and structure needs to be increased. The decision as to install a PES or another type of intervention, such as significant track lower or jack/build a new bridge, is determined by undertaking a whole-life costing of all options.
‘On this occasion, which may be similar to others, undertaking a minimal track lower was far more cost efficient than any other…
