We could lift prefabricated girder with one450T gantry crane or two. As for 900t box girder, two elevators could be used.As for box girder of 450t or less, the elevator could be used independently. Itis attached with outrigger propelling, crown block and crown block hoistingequipments so that full directional and mechanized operation will beaccomplished. It can be principally used to hoist the precast girder from theprecast girder platform to storing girder platform. After the precast girder'smaintenance, it will be hoisted from the storing girder platform to transporting girder vehicle. It canaccomplish the assembly and dismantling of bridge girder erecting machine.
According to differentworking conditions, there are 450t gantry crane for girder filed and for overline.Performance and parameters：
Rated hoisting capacity: 450t
Portal frame span: 32m or 38m (over line)
Hoisting height: 10m or 28m (over line)
Run speed: 0-10 m/min
Transverse moving speed: 0-3 m/min 0-6 m/min
Rising and falling speed: 0-0.5 m/min 0-1.0 m/min
Run slope: 1.5%
The entire machine weight: 300t(single-elevator)