Buro Happold was commissioned by BAA to design a scheme for the replacement of the bearings on the A23 bridge at Gatwick and carry out an inspection and assessment of 1km of elevated guideway supporting the Inter Terminal Transit System (ITTS). The bridge and viaduct carry light rail trains in both directions between Gatwick’s North and South terminals. The box-like structure of the A23 bridge has two 41m continuous spans, with the transit system supported on out-riggers attached to the steel box.

The premature failure of the bearings had resulted in some vertical movement at one end of the bridge as a train passed over. This in turn caused the tripping mechanism of the train to be activated and it would come to a standstill. Because it is such a busy route, the client requested that during replacement of the bearings the bridge should remain open to rail traffic, so Buro Happold devised a temporary support solution which allowed trains to run normally while work was in progress. We also supervised the fabrication and installation of the new bearings.

The project has been extended to investigate the feasibility of incorporating a third track to allow for future safeguarding of the system.

Date: 2000 - 2010