Chiswick Bridge, Stonework, cathodic protection, marine works, english heritage, stone parapet strengthening,

CHISWICK BRIDGE

OVERVIEW

OVERVIEW

Topbond were employed to carry out concrete repairs to the Grade I listed structure as part of a wider refurbishment project. Concrete repairs were required to the soffit of all arches and inside the structure within the voided cells under the road.

Confined spaces access within the voided cells and difficult access in and out of the cells made removal of existing failed concrete as well as placing of new concrete particularly difficult. Repairs to the soffit of the arches required tidal working from a barge below with MEWPs but large areas of concrete removal required an innovative removal method that wouldn’t involve hydro demolition as the risk of water run off into the Thames was too high.

THE CHALLENGE

THE SOLUTION

For access within the cells hydro demolition was employed and spray concrete repairs, meaning most of the large equipment and materials could be kept outside of the cells with hoses trailing inside. To remove the extensive amounts of debris from inside the cells a vacuum excavator was preferred, dramatically reducing the amount of manual labour and therefore the number of personnel and time spent inside the confined space. For the soffit repairs a P.A.M (positioner, actuator, manipulator) was installed on a MEWP on the barge. This robotic demolition equipment meant productivity could be maximised, with no HAV impact on the operator and no alkaline run off into the Thames from Hydro demolition.