1919.28—Unit proof tests—cranes and gear accessory thereto.
(a)
Except as noted in paragraph (e) of this section, cranes and other hoisting machines, together with gear accessory thereto, shall be tested with a proof load which shall exceed the safe working load as follows:
| Safe working load | Proof load |
|---|---|
| Up to 20 tons | 25 percent in excess. |
| 20-50 tons | 5 tons in excess. |
| Over 50 tons | 10 percent in excess. |
(b)
The proof load shall be lifted and swung as far as possible in both directions. If the jib or boom of the crane has a variable radius, it shall be tested with proof loads, as specified in paragraph (a) of this section, at the maximum and minimum radii. In the case of hydraulic cranes, when due to the limitation of pressure it is impossible to lift a load 25 percent in excess of the safe working load, it will be sufficient to lift the greatest possible load.
(c)
Initial proof tests of new cranes shall be made only with a dead load as specified in paragraph (b) of this section.
(d)
Initial tests of cranes which have been in service, quadrennial tests, or tests associated with replacements or renewals, may be made with spring or hydraulic balances where dead loads are not reasonably available under the following conditions:
(1)
Tests shall be conducted at maximum, minimum, and intermediate radius points, as well as such points in the arc of rotation as meet with the approval of the accredited person.
(2)
An additional test shall be conducted with partial load and shall include all functions and movements contemplated in the use of the crane.
(e)
In cases where shore-type cranes are mounted permanently aboard barges, the requirements of this Subpart E with respect to unit proof tests and examinations shall not apply and the applicable requirements of Subpart H of this part shall be adhered to with respect to unit proof tests and examinations.