1. The door frame have single main type and double girder type two kinds of for the user choice for reasonable use of material, the main variable cross-section of the optimization design.

2. The door frame with rigid legs have simple columnar type and double pillar. 

3. On a pair of main car hook, the two main girder are set, but may be alone and lateral movement 0-2m. 

4. There is main, under the car of hook, in two main girder below center. 

5. Under the car, each other across the homework. 

6. All the lifting mechanism and operation organization adopts inverter. 

7. A rigid legs side, at the top of the main girder have arms maintenance, to complete the crane car maintenance work. 

8.In order to prevent the storm, with safe and reliable clip rail, such as the journal, chain wind device