Record Air Bridge Movement

The British Airports Authority's plans to upgrade London's Gatwick airport called for a passenger bridge to be built over an aircraft taxiway between a terminal and an aircraft loading pier. This is only the second time a taxiway has been bridged, the first was in Denver, Colorado.

To minimise disruption to the UK's second busiest airport, the construction programme called for the air bridge structure - 810 feet long by 98 feet wide by 49 feet high (247 x 30 x 15 m), weighing 3168 tons (2874 tonnes) - to be pre-fabricated off-site. It was then transported to site and lifted into position overnight, when the aircraft taxiways could be closed.

The contract for the construction of the air bridge was awarded to Watson Steel, which sub-contracted the transport and lifting portion of the project to Fagioli PSC.

The initial phase of the work included the on-site assembly of the Fagioli PSC lifting system, comprising standard Fagioli PSC Towerlift masts and strand jacks. This was assembled over a two-week period and a test lift of 3600 tons (3266 tonnes) was made.

Due to the limited time available for the transport and lifting operations it was necessary to transport both the longest section of the air bridge, at 548 feet (167 m), and the supporting gantry together. This meant a total payload of 2174 tons (1972 tonnes), which required a total of 120 axle lines of Fagioli PSC self propelled modular transporter (SPMT), which together made a total convoy weight of 3748 tons (3400 tonnes). The transport arrangement used to move the bridge together with the lifting towers to the final location comprised two sets of 60 axle lines of SPMT.

Final positioning of the bridge was required to within +/-1 inch (25 mm) at each end. Access to the final position required a 90 degree turn, with very little clearance at each end to fit between the terminal connection piers. Any minor discrepancies in steering between the two transporter groups could create enormous torsion forces over the 548 foot (167 m) distance, so a tubular restraint system was designed and installed between each trailer group and the bridge.

Due to the bridge being already fully glazed and painted, the convoy needed to be continually monitored and maintained to within +/- 2 inches (50 mm) over its length and width to minimise any stresses over the 0.62 mile journey from the construction site to final destination.