1)    To improve the quality of suspension, the straight bar of hook should be strictly close to the wells when stationary, If can not do, the number of cells in series should be decreased or the number of cells in unit group should be increased

2)    The number of hooks in each unit can be linked in series is limited in 10.

3)    The construction workers can’t release the cable until the whole of the cable is inserted in the curved hook

 4)  The construction workers are forbid insert the cable into the curved hook in a jump way which make the curved hook bear the weight of cable and body