10.8.2 Pre-use Inspection/Thorough Examination

The installation of jib cranes calls for a thorough examination to be made by a Competent Person before they can be taken into service. Although electrical and mechanical equipment will have been tested in accordance with appropriate Standards at the crane or equipment manufacturer’s works, it will usually be necessary for the Competent Person to conduct load tests as a part of the thorough examination. The purpose of this testing is to determine whether the crane is in accordance with standard and specification requirements, correctly installed and to ensure that it is safe to operate.

In addition to the crane structure and fixings, the thorough examination will extend to the lifting appliance and power feed system. Deflection, dynamic and overload (proof load) tests should be carried out in accordance with standard to which it was made. The proof load should be at least 1.25 times the SWL.

The manufacturer is required to specify the maximum permissible deflection to be used and compared with measured deflections obtained in the test. A deviation greater than +/-10% indicates an issue with the installation that needs to be resolved. However, it should be noted that deflections are not the governing criteria for the design and safe operation of slewing jib cranes.

Whilst the maximum allowable deflection must not be exceeded, the vertical deflection of the jib arm must be such that it ensures sufficient stiffness so that:

  1. The trolley on the jib arm will not run out of control when under load.

  2. The slope of the jib arm is not too great so that there is difficulty in travelling the trolley up the gradient.

  3. The jib arm will not slew on its own.

  4. The lifting appliance, and therefore the load, can be accurately positioned.

On satisfactory completion of all tests and the thorough examination, the Competent Person should issue the necessary report of thorough examination, which will include details of the tests he has made. In many cases the lifting appliance will be detachable from the jib arm and may have differing proof testing requirements. If so, a separate report or individually itemised report should be issued for the jib crane, trolley and lifting appliance. This should be retained with the qualified engineer’s written approval and cross referred to the equipment’s historical records. (See 10.7 LEGAL REQUIREMENTS)