A temporary gantry has been installed at the Forth Bridge to allow engineers to safely access the structure’s southern suspended span.
The gantry, which will enable the bridge’s maintenance team to carry our repairs to steel troughing sections, was raised into place from a barge. The design of the gantry allows the team to make repairs from below, eliminating the need to disrupt train services. It is expected to remain in place, 46 metres (150 feet) above the Forth, for the next two years.
Jamie Mclaren, Network Rail Asset Engineer said:
“Network Rail completed a major restoration of the Forth Bridge in 2011 but the focus for that work was on the super structure which supports the bridge rather than bridge deck which carries the track.
“This work will focus on repairs to the trough deck area of the suspended span. This section of the bridge is underneath the running lines and is part of a wider maintenance programme to fix similar defects across the whole length of the Forth Bridge over the next few years.
“Steelwork repairs to these areas will address historic deterioration of the steel deck caused by various changes in track profile and heavy freight traffic which no longer runs across the bridge.”
Colin Hardie, Construction Superintendent for Balfour Beatty said:
“The gantry itself is large structure, so getting it out onto the water then raised up to deck level was a major logistical challenge.
“Now it’s in place, we can move it gradually along the underside of the suspended span as steel repairs are completed.”
Balfour Beatty was the lead contractor during a ten year restoration of the Forth Bridge, completed in 2011. The restoration focussed on the critical structural elements of the bridge, with the focus on steel repairs as well as blasting and painting.
Network Rail currently spends approximately £1M per year or regular inspections, maintenance and repairs at the Forth Bridge.