Crane Safety and Pre-Operation Inspection Flashcards

During a pre-operation inspection, you discover that the load line wire rope has a section where 6 randomly distributed broken wires appear within one rope lay length. The rope diameter is 1-1/8 inch. According to ASME B30.2, what is the correct course of action?

Answer: Remove the rope from service immediately, as 6 broken wires in one lay length meets the removal criterion

ASME B30.2 requires removal from service when 6 randomly distributed broken wires are found in one rope lay length, OR 3 broken wires in one strand in one lay length. Six broken wires in one lay length meets the removal threshold exactly — not 'more than 6.' There is no provision to continue at reduced capacity when a removal criterion is met.

A mobile crane is set up on a job site where the outrigger pads are resting on compacted gravel fill that was placed 3 weeks ago over a utility trench. The soil bearing capacity report shows 3,000 psf for native soil, but no data exists for the fill. What is the MOST appropriate action before beginning lifts?

Answer: Require a geotechnical assessment of the fill compaction before any lifts are performed

Ground bearing capacity for recently placed fill over a utility trench is unpredictable — compaction may be inconsistent, and the trench void creates a differential settlement risk. OSHA 1926.1402 and crane manufacturer requirements mandate that ground conditions be verified as capable of supporting the crane before operations. A geotechnical assessment is required; doubling pad size without knowing the actual bearing capacity is not an engineered solution.

While performing a pre-operation inspection on a lattice boom crawler crane, you observe that two lacing members on a boom section are bent but not cracked, and the boom chord shows no visible deformation. The crane is needed immediately for a critical lift. What should you do?

Answer: Remove the boom section from service and replace it; do not operate until a qualified engineer assesses the damage

Any structural deformation of boom members — including lacing members — must be evaluated by a qualified engineer before the crane is returned to service. ASME B30.5 and manufacturer guidance prohibit field-straightening of structural steel members with heat or mechanical force, and there is no OSHA or ASME provision to continue operation at reduced capacity when structural members are bent. The time pressure of a 'critical lift' does not override this requirement.

A hydraulic telescoping boom crane's load chart shows a 40-ton capacity at 30 feet radius with the boom at 70° angle on outriggers fully extended. The operator notes that outrigger float position indicators show all four floats are extended but one float's pressure gauge reads significantly lower than the other three. What does this condition most likely indicate, and what is the correct response?

Answer: A hydraulic leak or cylinder bypass in that outrigger circuit; operations must cease until the outrigger is inspected and repaired

A significantly lower pressure reading on one outrigger float compared to the others indicates a potential hydraulic fault — such as an internal cylinder bypass, seal failure, or a leak — that could cause that outrigger to creep or collapse under load. ASME B30.5 and crane manufacturer manuals require that outrigger systems be in proper working condition before operations. Simply re-extending outriggers does not diagnose or correct a hydraulic fault; the system must be inspected by a qualified person.

During pre-operation inspection of a tower crane, the operator discovers that the last entry in the crane's maintenance log is dated 14 months ago, but the crane has been in continuous use. The required OSHA periodic inspection interval for tower cranes is:

Answer: Every 12 months, meaning the crane is overdue and must be taken out of service until a periodic inspection is completed and documented

Under OSHA 1926.1412(f), periodic inspections for cranes and derricks in construction — including tower cranes — must be performed at intervals not exceeding 12 months. A 14-month gap means the crane is out of compliance. The crane must be removed from service and a periodic inspection completed and documented by a qualified person before it may be returned to service. Tower cranes do not have a special extended inspection interval under OSHA.

An operator is about to use a crane equipped with an Anti-Two-Block (ATB) device. During the pre-operation function test, the ATB device triggers correctly and disables hoist-up and boom-down functions. However, the operator notices the ATB does NOT disable the boom-up function. Is this a deficiency requiring removal from service?

Answer: No — boom-up moves the headache ball away from the boom tip, so it cannot cause a two-block condition and need not be disabled

A two-block condition occurs when the load block or hook rises into contact with the boom tip or the lowest rope sheave. Booming UP moves the boom tip away from the block, which increases the distance and cannot cause two-blocking. Therefore, the ATB system is not required to disable boom-up. The critical functions the ATB must prevent are those that close the gap between the block and the boom tip: hoist-up and boom-down (which lowers the tip toward the block). The ATB behavior described is correct and does not constitute a deficiency.