New Schematics Show Phase 2 Design

Schematics published today show the design of additional strengthening works being carried out on the Forth Road Bridge in order to allow HGVs back on the bridge.

Phase One of the repairs was completed in December, when steel ‘splints’ were welded onto the truss end links, allowing non-HGV traffic to use the bridge again, and ensuring the previous failure could not re-occur at other truss end link locations.

Phase Two will see a new steel bracket attached to the south face of the north east main tower leg, from which the top of the deck truss will be supported via steel “strand jacks”. This will effectively provide an additional cable hanger adjacent to the main tower.

Design and programming of Phase Two is now complete and work on site is expected to begin within the next few days. Assuming fair weather and no further defects are discovered, work is planned to be complete by mid-February. This will allow HGVs to use the bridge again.

State of the art structural monitoring systems are also being installed on all eight truss end links to provide as much data as possible about the behaviour of the bridge. The technology includes strain gauges, displacement transducers, tilt meters and temperature gauges.

Phase Three of the repair will involve complete replacement of the truss end links at a future date, with the truss supported from the new tower bracket. This can be done without the need for daytime closures.