1. Load limiting device.

If any of the following problems occurs, the tower crane shall be judged to be unqualified:

(1) no weight limiter installed or not sensitive.

(2) no torque limiter installed or not sensitive.

2. Travel limit device.

If any of the following problems occurs, the tower crane shall be judged to be unqualified:

(1) the lifting height limiter is not installed or is not sensitive.

(2) amplitude limiter is not installed or is not sensitive.

(3) travelling tower crane is not equipped with travelling limit or is not sensitive.

3. Protection device.

(1) there is no buffer and stop device installed at the end of the track travel of walking and trolley luffing or it does not meet the requirements of the specification.

(2) tower cranes with a height of more than 50m are not equipped with anemometer or are not sensitive.

(3) the height on the top of the tower crane is greater than 30m and higher than the surrounding buildings. Or, the above three problems should be judged tower crane inspection unqualified.

4. Hook, pulley, reel and wire rope.

(1) the hook is not installed with wire rope anti-decoupling device or does not meet the specification requirements.

(2) the hook is worn and deformed to the scrapping standard.

(3) pulley and drum wear to scrap standards.

(4) steel wire rope wear, deformation, corrosion to scrap standards.

(5) the specification, fixation and serious winding of the steel wire rope do not meet the product specification and specification requirements.

5. Multi-tower operation.

(1) no special construction plan has been formulated for multi-tower operation or the construction plan has not been approved.

(2) the minimum erection distance between any two tower cranes does not meet the specification requirements.

6. Installation, dismantling, acceptance and use.

(1) the installation and disassembly unit has not obtained the professional contracting qualification and the safety production license.

(2) no special plan for installation and disassembly has been formulated.

(3) the scheme has not been examined and approved.

(4) installation and demolition personnel, drivers and commanders do not have their licenses.