10. The installation method and steps of Gantry Crane (Box Girder)

The gantry crane which belongs to the large-scale equipment, requires high safety and easy to cause heavy casualties must be installed by professional staff or guided by professional. The basic procedure is as following:
  Install the rail
  Assemble the crane structure
  Choose the lifting equipment according to the part weight
  Ground assembly
  Lifting the support legs
  Assemble the main girder in the ground
  Lifting the main girder
  Install the end crossbeam
  Lifting the trolley mechanism
  Assembly the other parts
  Carry the preliminary test

11. Checking methods after installation of Gantry Crane (Box Girder)

After assembly, the geometry dimension, perpendicularity, levelness and deflection must be checked in the following ways:
The wheels span deviation: S<10mm
The main girder deflection: AF=(0.9/1000~1.4/1000)
The diagonal difference of main girder:(D1-D2)≤5mm
The side curvature of main girder: AFP≤S/1200
The trolleys’ gauge difference: Both sides: ±2mm Midpoint: S≤19.5mm
Adjust the wheels (Parallelism, perpendicularity, apposition)

12. Operating requirements and attention of Gantry Crane (Box Girder)

 Adjusting the height of transverse rails of front legs and middle legs  when erecting girder or moving from one pier to keep main girder’s longitudinal slope≤0.5%,transverse slope≤0.5%.   
The normal working wind speed should less than 6 grade when bridge girder launcher works in the open air ; when the wind exceed 6 grade, the bridge girder launcher shouldn’t moving from one pier to next pier, and components should be locked; the machine can’t work in thunderstorm day and must cut off power.  
check the steel rope is broken or not,  the circuitry leaks electricity or not, the brake is reliable or not, and after the reducers get enough lubricating oil and the oil lubricate the open gears, the machine start to work; the safe circle of steel rope on the drum shouldn’t less than 3;checking the surface and fixed parts after every shift of steel rope and making a specific check every 7~11 days;
the brake system of winch is allowed to start again after it checked;
the lifting ,longitudinal traveling and transverse traveling shouldn’t work together; the speed of lifting and translational velocity should be slowly to avoid leaning and side tumbling;
the goods are prohibited to throw out from bridge girder launcher strictly; it is prohibited to lift goods to pass over head strictly;it is prohibited to lift workers by hook or goods strictly;the inflammable goods are prohibited to put on the launching crane strictly;
After the legs move to their places, plug the safe pin to prevent the hydraulic cylinder from bearing force for a long time;
When the tubes of components are fault, the operator should cut off power immediately, and it is checked and repaired by the professional technician; the operator shouldn’t disassemble privately; when checking and repairing the machine , the technician must cut off the power.