Crane Safety and Pre-Operation Inspection Flashcards

During a pre-operation inspection, you discover that a wire rope has a broken wire located within one rope lay length of an end fitting (such as a swaged socket). ASME B30.2 requires removal from service if which condition exists?

Answer: Any broken wire within one lay length of an end fitting

Per ASME B30.2, any broken wire within one rope lay length of an end fitting is cause for immediate removal from service. End fittings are stress concentration points, and even a single broken wire in that zone indicates dangerous fatigue that can lead to catastrophic failure. This is a stricter standard than the general rule applied to the running portion of the rope.

A crawler crane is being set up on a job site where the soil bearing capacity is rated at 2,500 psf. The crane manufacturer's specification lists a maximum ground bearing pressure of 4,200 psf under the crawler pads. What is the MOST correct course of action before beginning operations?

Answer: Install crane mats or cribbing to reduce and redistribute the ground bearing pressure to within soil capacity

When the crane's ground bearing pressure exceeds the site's soil bearing capacity, crane mats or engineered cribbing must be used to spread the load over a larger area until the pressure per square foot is within safe limits. Simply reducing load chart capacity or changing boom angles does not address the fundamental soil overload risk. An engineer should verify the mat sizing calculation.

During pre-operation inspection of a hydraulic telescoping boom crane, the operator notices that the boom extension/retraction function operates normally but the boom nose sheave groove shows a wear pattern offset to one side. This MOST likely indicates:

Answer: Misalignment between the boom nose and the hook block, which can cause rope fleeting angles to exceed allowable limits

Offset wear on a boom nose sheave groove is a classic indicator of excessive fleet angle — the angle between the rope centerline and the sheave groove centerline. Misalignment between boom nose and hook block causes rope to bear on one flange of the sheave rather than riding centered in the groove. This accelerates both rope and sheave wear and can cause rope rollout. The maximum allowable fleet angle is typically 1.5° for most crane reeving.

OSHA 29 CFR 1926.1413 requires that the following be checked before each shift. Which item from the list below is specifically categorized as a 'monthly' inspection item under this standard, NOT a shift inspection requirement?

Answer: Wire rope reeving for compliance with the manufacturer's specifications

Under OSHA 29 CFR 1926.1413(a), wire rope reeving for compliance with the manufacturer's specifications is listed as a monthly inspection item, not a daily/shift item. Daily shift inspections cover items like hooks, control mechanisms, electrical apparatus, and safety devices. Operators must distinguish between frequent (shift/daily), periodic (monthly/annual), and as-needed inspections to remain in compliance.

An operator is performing a pre-operation inspection and finds that the load line drum has two wrapping layers of wire rope with one full wrap remaining on the drum at maximum hook travel. The crane manufacturer's specification requires a minimum of three full wraps at all times. What action is required?

Answer: The crane must be taken out of service immediately; the minimum wrap requirement is a structural safety requirement

Minimum drum wraps (typically 2–3 per manufacturer specification) are not advisory — they are mandatory structural and friction requirements. The wraps anchor the rope to the drum via friction generated by the remaining layers; insufficient wraps can cause the rope to slip or pull free under load. When the minimum wrap requirement cannot be met at maximum hook travel, the crane must be removed from service until the rope length is corrected. Operators cannot self-authorize reduced limits.

During pre-operation inspection of an overhead bridge crane, the operator finds that the upper limit switch (ULS) stops hook travel at the correct position when tested at slow speed, but fails to activate when the hook approaches at normal operating speed (high speed). What is the CORRECT interpretation of this finding?

Answer: The ULS has failed and the crane must be removed from service immediately, as the device must function at all operating speeds

Upper limit switches must function reliably across all operating speeds to prevent two-blocking, which can cause catastrophic wire rope or hook block failure. A ULS that only functions at slow speed is a failed device — it will not protect against the most dangerous scenario, where an inattentive operator runs the block to the boom tip at full speed. ASME B30.2 and OSHA both require that safety devices be operable; a device that functions only under limited conditions does not meet the standard and requires the crane to be taken out of service.