(1) Unit proof tests of derricks must be carried out at the same times as are specified in WAC 296-304-20003(1) for cranes.

(2) Unit proof load tests and safe working load ratings must be based on the design load ratings at the ranges of boom angles or operating radii. Unit proof loads must exceed the safe working load as follows:

Proof loads must be applied at the designed maximum and minimum boom angles or radii, or, if this is impracticable, as close to these as practicable. The angles or radii of test must be stated in the certificate of test. Proof loads must be swung as far as possible in both directions. The weight of all auxiliary handling devices must be considered a part of the load.

(3) After satisfactory completion of a unit proof load test the derrick and all component parts thereof must be carefully examined in accordance with the requirements of WAC 296-304-20003(4), as far as applicable.