12. Operating requirements and attention of THQ900t bridge girder launcher for tunnels

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. 

13. The maintenance time and item of THQ900t bridge girder launcher for tunnels

 After construction are finished everyday, the workers must check the following content: if the level of main longitudinal girder meets the requirements or not; the connection of bolts and pins are firm or not; the electrical wires are broken and extruded; hydraulic system is regular or not; the track joints are plain and smooth or not;  the connection of position limiter of crane and trolley are firm or not; the rail clamping device is in the working position or not; bed timber is plain and stable and the size of gauge is right or not etc.     
 The welding lines are checked every month ::upper and down chords of main girder , web plate, vertical welding lines of legs  and the welding lines of connecting frame etc. The operators should stop working when the welding lines are broken or fatigue crack.  When the users find the crack by eyes, but they can’t make sure the dangerous degree, so they should use the welding inspection instrument to test and then adopt reasonable steps to deal with.
 About the painting of structure which should be painted again every two years. The users should clean the primary surface by steel brush and pay attention to the welding lines before the structure are painted.
 The lifting mechanism, traveling mechanism of crane and trolley, reducer of motor and steel rope of winch are lubricated and maintained according the rules of specification.

14. The disassembly and site-transferring steps of THQ900t bridge girder launcher for tunnels

The machine is disassembled according to the following steps after the erection construction is finished. 
cylinder jacks up to make the whole machine go up 250—300mm。
2.0m sleepers are paved to nearby middle and rear legs respectively.
take back the cylinder of legs and the put on the transporter.
two lifting trolley are lifted and then put on the transporter by the special  gantry.
disassembling front, middle and rear legs and front and rear connecting frame.    
disassembling the coupling pin from back to front , each beam is carried in order and then the disassembly is finished.
when disassembling and carrying the parts, brutal work and violent  collision are  prohibited, special hook and lifting tools are used for lifting. Connecting bolts and pins are put in order after they disassembled to avoid disordering and losing; the disassembly and assembly of connecting plates must be in order, and they must be marked clearly before they disassembled and assembled.