L68B3 Mast Section Precautions in preparation, process and completion of jacking and jointing of tower crane
1. Preparation before lifting tower crane
a. According to the requirements of the heightening tower, prepare the standard sections to be added and arrange them in a row along the direction of the boom.
b. The jacking and jointing operators shall enter their posts manually according to their responsibilities.
c. Check whether the hydraulic system works normally, the hydraulic oil pressure shall meet the requirements, and the piston rod shall extend and retract smoothly without jamming.
d. Check the condition of lifting balance beam and hanging plate.
e. Adjust the clearance between the guide wheel of jacking jacket and the main chord of tower body to meet the specified requirements.
f. According to the specification, lift one standard section to be added to the imported balance beam, then lift another standard section, move the luffing trolley to find balance, and lock the slewing mechanism.
2. Precautions during lifting of tower crane
a. In the process of jacking, special personnel shall be responsible for the command, take care of the power supply, operate the hydraulic pump, hold the jacking beam, pull the claw and install the standard section. All staff should concentrate, follow the command and stick to their posts.
b. Lifting operation cannot be carried out at night. When jacking operation must be carried out under special circumstances, sufficient lighting must be provided.
c. When the wind speed exceeds level 4 or the wind speed specified in the instruction manual, jacking operation is strictly prohibited. In the process of jacking, in case of strong wind, the jacking operation shall be stopped immediately.
d. In the process of jacking, it is forbidden to rotate the jib and mobile trolley.
e. In the process of jacking, in case of jamming or other faults, the machine must be stopped immediately for inspection. If the faults are not eliminated, the jacking shall not be continued.
f. The operator must concentrate and concentrate on the operation, and shall not extend the probe into the range of the guide wheel to avoid the sudden movement of the standard joint.
g. Pay attention to check that the cable relaxation length meets the requirements, and strictly prevent the cable from being pulled, jammed and squeezed during the movement.
h. The newly introduced standard joint must be firmly connected with the upper and lower tower bodies before the next jacking and joint adding operation can be continued.
3. Precautions after lifting of tower crane
a. Check and tighten the height bolts between the upper and lower tower bodies.
b. Check whether the operating handle of the hydraulic system has been set to the zero position.
c. Check and cut off the power supply of the hydraulic jacking system.
d. Remove the standard section on the lifting steel for balancing and contact the locking state of the return mechanism.
