The deck erection gantries for the 1490m span Runyang suspension bridge were designed and supplied by Dorman Long Technology to RBG. 2nd Highway Engineering Bureau, the main contractor for the project. The main span of the steel bridge deck was been split unto 47 deck units, each weighing up to 470 metric tonnes. These were fabricated offsite and transported by barge into position under the main cables where they were erected using the deck erection gantries.
The gantries were designed in the UK to British standards. All mechanical components and the control system were manufactured in Europe and shipped to site. The steel structure of the gantries was fabricated in China. Once all components were on site the gantries were assembled, tested and erected within a period of 3 months. The fully assembled gantries, including deck lifting beams, were load tested to 125% of safe working load and function tested on a specially design test frame.
The gantries are a new design, with many new features incorporated including:
Each pair of gantries is capable of erecting deck units at a rate of one per day, but in practice the deck erection programme was dictated by the delivery schedule of the deck units. The gantries were operated by local labour under the supervision of Dorman Long. Erection of all 47 deck units took 12 ½ weeks, the last closure unit being erected on 17th April 2004.
Gantry self erection sequence: