5.7　Overhead/Gantry Crane

5.7.1　Installation，dismantlement，maintenance and overhaul method statements shall be developed for overhead/gantry crane，and shall comply with the requirements as defined in Article 4.2.2 herein.

5.7.2　Crane trolley shall not be rested at the middle of the beam during non-working hours.

5.7.3　The metal structure of an overhead/gantry crane shall be removed from service in case the following defects are observed and cannot be repaired:

a）Crack in main load-bearing member；

b）Plastic deformation in main load-bearing member；

c）Central deflection of main beam reaching 1/700 of its span when the crane trolley is working at the rated load from the middle of main beam.

5.7.4　Lifting mechanism shall be equipped with normally closed brake.

5.7.5　Overhead/Gantry crane shall not be braked in a reverse manner.

5.7.6　Where two or more overhead/gantry cranes are used to lift one workpiece，the lifting load for each overhead/gantry crane shall not exceed 75% of its rated capacity.