Question 1

Under 1919.73(a), when must unit proof tests of derricks be carried out?

Accepted Answer

Under §1919.73(a) unit proof tests of derricks must be carried out at the same times specified for cranes in §1919.71(a)). These test intervals are set by the crane inspection and testing schedule referenced in §1919.71(a)). Always document the test date and link it to the crane/derrick schedule required by §1919.71. (See §1919.73(a)).)

Question 2

Under 1919.73(b), how much higher must the proof load be than the safe working load for derricks rated up to 20 tons?

Accepted Answer

Under §1919.73(b) the proof load for derricks with a safe working load up to 20 tons must be 25 percent in excess of the safe working load. Example: a derrick with a 20 ton safe working load would require a 25% greater proof load (20 tons × 1.25 = 25 tons) unless a more conservative approach is used. (See §1919.73(b)).)

Question 3

Under 1919.73(b), what is the proof load requirement for derricks with safe working loads between 20 and 50 tons?

Accepted Answer

Under §1919.73(b) the proof load for derricks with safe working loads from 20 to 50 tons must be 5 tons in excess of the safe working load. Example: a derrick rated 30 tons SWL must be tested with a 35 ton proof load. (See §1919.73(b)).)

Question 4

Under 1919.73(b), what is the proof load requirement for derricks with safe working loads over 50 tons?

Accepted Answer

Under §1919.73(b) the proof load for derricks with safe working loads over 50 tons must be 10 percent in excess of the safe working load. Example: a derrick with a 60 ton SWL requires a 66 ton proof load (60 tons × 1.10 = 66 tons). (See §1919.73(b)).)

Question 5

Under 1919.73(b), at which boom angles or operating radii must proof loads be applied during a unit proof test?

Accepted Answer

Under §1919.73(b) proof loads must be applied at the derrick's designed maximum and minimum boom angles or operating radii, or if that is impracticable, as close to those extremes as practicable. The specific angles or radii used for the test must be stated in the certificate of test. If you cannot reach the absolute maximum or minimum, document how close the test positions were to the design extremes. (See §1919.73(b)).)

Question 6

Under 1919.73(b), what should you do if it is impracticable to apply proof loads at the designed maximum and minimum boom angles or radii?

Accepted Answer

Under §1919.73(b) if it is impracticable to test exactly at the designed maximum or minimum boom angles or radii, you must apply the proof loads as close to those extremes as practicable and state the angles or radii tested on the certificate of test. Document why testing at the exact extremes was impracticable and record the actual angles or radii used. Ensure the certificate of test lists the tested angles/radii so the test record is clear and auditable. (See §1919.73(b)).)

Question 7

Under 1919.73(b), must the weight of auxiliary handling devices be included in the proof load?

Accepted Answer

Under §1919.73(b) the weight of all auxiliary handling devices must be considered part of the load when determining and applying the proof load. Include hooks, jibs, blocks, slings, spreaders, or any other attached handling equipment in the total test weight. Account for auxiliary weights in both calculation and physical setup to ensure the proof load meets the required excess over the safe working load. (See §1919.73(b)).)

Question 8

Under 1919.73(b), must proof loads be swung during the unit proof test, and if so, how?

Accepted Answer

Under §1919.73(b) proof loads must be swung as far as possible in both directions during the unit proof test. Swinging the load checks stability, rigging behavior, and mechanical function under dynamic positioning. Record how far the load was swung and include any limitations in the certificate of test. (See §1919.73(b)).)

Question 9

Under 1919.73(c), what inspection is required after a satisfactory unit proof load test?

Accepted Answer

Under §1919.73(c) after a satisfactory unit proof load test the derrick and all component parts must be carefully examined in accordance with the requirements of §1919.71(d)), as far as applicable. This means conducting the post test examination items and any detailed inspections prescribed in §1919.71(d)). Document findings, repairs, and any items that require corrective action following the examination. (See §1919.73(c)) and §1919.71(d)).)

Question 10

Under 1919.73(b), what information must be stated in the certificate of test after proof loading?

Accepted Answer

Under §1919.73(b) the certificate of test must state the boom angles or operating radii at which the proof loads were applied. The certificate should also record the proof load value used, the dates, and any limits on swinging or positioning encountered during the test. Keep the certificate with maintenance/testing records so inspectors can verify compliance with the test positions and magnitudes. (See §1919.73(b)).)

Question 11

Who must determine and approve the competent person to perform derrick proof load tests and post-test examinations?

Accepted Answer

The employer must assign or approve the competent person who performs derrick proof load tests and post-test examinations; OSHA recognizes that the employer is responsible for designating a competent person qualified to identify hazards and take corrective action.https://www.osha.gov/laws-regs/standardinterpretations/1977-04-26

A "competent person" is defined as someone capable of identifying hazards and authorized to take prompt corrective measures; the employer must ensure the person is qualified for the specific derrick testing and inspection tasks.
Document the person's qualifications and authorization as part of the testing record.

(See the OSHA interpretation on competent person designation at https://www.osha.gov/laws-regs/standardinterpretations/1977-04-26 and 1919.)

Question 12

Under 1919.73(a) and 1919.71(a), can derrick proof testing follow the same schedule as cranes?

Accepted Answer

Yes. Under §1919.73(a) derrick unit proof tests must be carried out at the same times specified for cranes in §1919.71(a)). Follow the inspection and testing intervals established in §1919.71(a)), and keep records showing the derrick tests matched those intervals. (See §1919.73(a)) and §1919.71(a)).)

Question 13

If a proof load test reveals defects, what actions are required under 1919.73(c) and related provisions?

Accepted Answer

After a proof load test reveals defects, you must carefully examine the derrick and its components per 1919.71(d) and take any corrective actions required by those inspection and maintenance provisions.

Perform the detailed examinations and document findings as prescribed in 1919.71(d).
Repair or remove from service any parts that do not meet acceptance criteria before returning the derrick to operation; keep records of repairs and re-tests.

(See 1919.73(c) and 1919.71(d).)

Question 14

Under 1919.73(b), how should you handle the 20-ton boundary between the "Up to 20 tons" and "20 - 50 tons" proof load categories?

Accepted Answer

Section §1919.73(b)) lists "Up to 20 tons" (25% excess) and "20 50 tons" (5 tons excess); because the wording creates an overlap at 20 tons, the safest approach is to apply the more conservative requirement (the larger proof load) and document that decision. For a 20 ton safe working load, applying the 25% excess yields a 25 ton proof load (more conservative than adding 5 tons to get 25 tons in this particular case they are equal); however, when a boundary is unclear for other values, choose and document the safer option. If uncertain, document the basis for your choice or consult OSHA compliance assistance for clarification. (See §1919.73(b)).)

Question 15

Under 1919.73, what parts of the derrick are covered by the term "unit proof load test" and post-test examination?

Accepted Answer

Under §1919.73 the "unit proof load test" covers the derrick and all component parts thereof; after the test the derrick and all component parts must be carefully examined as required by §1919.71(d)). Components to consider include the boom, hoists, blocks, sheaves, hooks, wire rope, fittings, auxiliary handling devices, and structural connections. Include any auxiliary handling equipment in the test weight and in the post test inspection. (See §1919.73(b)) and §1919.73(c)).)

Derrick proof load testing

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