Hanneys Crossing

This was a project in two halves. Hanneys Crossing was a bridge deck replacement for the Great Western Electrification scheme due to the existing clearance under an unclassified road being insufficient for the line to be electrified.

The main Contractor BAM Nuttall approach Crouch Waterfall to provide a temporary works scheme to enable access to the bridge, requiring the design of a temporary haul road and temporary bridge. The haul road was not only designed to include drainage layer to allow surface water to flow and prevent pooling but also to spread the load from site traffic and a mobile crane thus reducing ground bearing pressure. The temporary bridge utilised a proprietary bridge deck and precast concrete abutments with approach ramps consisting of compacted granular fill to oversail the existing bridge which was too weak to take the imposed load of the crane.

The other half of this project involved temporary works during sequencing of the demolition without damaging the existing abutments. RM Penny were appointed by BAM Nuttall to undertake the demolition and in turn approached CW to design the temporary works. To enable lifting the bridge deck out in one unit CW designed a lightweight ramp using timber mats, baulk timbers and expanded polystyrene (EPS) blocks which the excavators used to access the bridge deck. Demolition was undertaken in a long possession on Christmas day 2015.