BRITISH CONTRACTORS last week began using four unique self erecting cable mounted gantries to lift deck sections for a Chinese suspension bridge which has the world's third longest main span.
The first 470t steel deck unit was lifted into position by the gantries last week, the second is expected this week.
Engineers from Dorman Long Technology have designed the gantries for the £330M Runyang suspension bridge, which has a 1,490m main span.
The bridge crosses the Yangtze river at Zhenjiang, 250km west of Shanghai.
'The gantries can self-erect and dismantle from the main cables at any point along the bridge, ' said Dorman Long managing director David Dyer.
The 140t gantries were raised into position using strand jacks attached to the main suspension cable.
The gantries were then attached to the cables so the strand jacks could be reused to haul them into position ready to lift deck sections. All systems are fully computer controlled.
Pairs of gantries are used to raise each 3m deep orthotropic deck section into position.
The 47 deck units are due to be lifted in a rapid 52 day programme.
Main contractor for the works is RBG 2nd Highway Engineering Bureau and client is Jiangsu Provincial communications Department.