Dorman Long Technology are the designers and suppliers of an innovative 2 x 870 tonne capacity bridge deck erection gantry for the Temburong Bridge Project in Brunei, to main contractor Daelim-Swee. The gantry is used to simultaneously erect two 50m long 870 tonne precast concrete bridge deck girders, and it is believed to be the first ever bridge erection gantry of this type. It will be used to erect all bridge deck girders on a 13.65 km long marine viaduct across the Brunei Bay that will link the regions of Brunei Muara and Temburong. The gantry erected the first pair of bridge girders in January 2017 and is expected to be in operation on the project for 2 years. The gantry is designed to erect viaduct sections that are up to four decks wide in some sections at an erection rate of one bridge span every 2 shifts.
This new type of gantry provides a fast and economic solution for the erection of twin box marine viaducts, and removes the need for over deck delivery from a transfer gantry or from a casting yard at the end of the bridge. The casting yard can therefore be located anywhere in the region with water frontage and the viaduct can be constructed in separate sections without the need to provide a continuous line for over deck delivery.
The gantry uses DLT strand jacks for lifting for improved safety and to reduced gantry weight when compared to a conventional winch system. Our strand jacks incorporate a stroke synchronised slow bleed lowering system, allowing the two bridge girders to be carefully lowered onto the bearings for a smooth and balance load transfer, Transverse movement of the deck beams after lifting and forward launching of the gantry are achieved using DLT pinned climbing jacks. The gantry has three legs and uses an innovative launch sequence to avoid placing heavy loads on the deck beams away from the piers when the gantry moves forward into the next span. The gantry hydraulic systems are centrally monitored and controlled using our DL-P40 computer control system.
Video of the erection of the second pair of bridge girders (Video courtesy of Daelim-Swee).....