Service Truck Crane Operator Test 1 Flashcards

A service truck crane is rated at 4,000 lbs capacity at a 10-foot radius. The load chart shows a 40% capacity reduction at 16 feet. If the operator must lift a 2,200 lb load at 16 feet, what is the minimum acceptable rated capacity at that radius, and is this lift permissible?

Answer: Minimum rated capacity must be at least 3,143 lbs at 16 feet; the lift is permissible only if the crane meets this rating

ASME B30.22 requires that the load not exceed 75% of the tipping load, meaning the rated capacity already includes this safety factor. To determine the minimum rated capacity, divide the load by 0.70 (the remaining capacity fraction after a 30% derating for rigging and other factors is applied): 2,200 ÷ 0.70 ≈ 3,143 lbs. The crane's rated capacity at 16 feet must equal or exceed this value for the lift to be permissible.

During a pick at maximum radius on a service truck crane, the operator notices the outrigger pad on the load side has slightly sunk into soft asphalt. The load is currently suspended mid-air. What is the CORRECT immediate action?

Answer: Immediately lower the load to the ground as quickly as safely possible without moving the boom laterally

When an outrigger begins sinking during a suspended load operation, the safest immediate action is to lower the load vertically to the ground without introducing additional dynamic forces from lateral boom swing. Swinging the load (option A) introduces centrifugal force and shifts the load moment, potentially accelerating the tip. Increasing hydraulic pressure (option C) does not address the ground failure and could worsen it. Holding in place (option D) allows continued settlement. ASME B30.22 requires immediate cessation of the lift if ground conditions become unsafe.

According to ASME B30.22, which condition SPECIFICALLY exempts a service truck crane operator from requiring a load line load limiting device?

Answer: When the crane's maximum rated capacity at any radius does not exceed 2,500 lbs

ASME B30.22 specifies that cranes with a maximum rated capacity at any radius of 2,500 lbs or less are exempt from the requirement for a load line load limiting device. This threshold reflects the standard's risk-based approach to equipment requirements. The anti-two-block device (option D) is a separate safety requirement and does not substitute for a load limiting device on cranes above the 2,500 lb threshold.

A service truck crane operator is lifting a transformer with a rated capacity plate showing 3,800 lbs. The rigging consists of two wire rope sling legs at a 60-degree included angle from vertical. Each sling has a vertical rated capacity of 2,600 lbs. What is the sling capacity at this angle, and is the rigging adequate?

Answer: Effective sling capacity is 3,007 lbs total; rigging is inadequate

At a 60-degree included angle from vertical (30 degrees from horizontal), the sling angle factor is approximately cos(60°) = 0.5. Each sling's effective capacity is reduced to 2,600 × 0.5 = 1,300 lbs. With two sling legs, total capacity = 2 × 1,300 = 2,600 lbs... However, with a 60-degree included angle from vertical (meaning 30° from the vertical axis), the tension factor is 1/cos(30°) ≈ 1.155. Each sling carries 3,800/2 = 1,900 lbs of load force, but actual sling tension is 1,900 × 1.155 = 2,195 lbs per leg. Total rigging capacity = 2 × (2,600 ÷ 1.155) ≈ 2 × 2,251 = 4,502 lbs effective; the load of 3,800 lbs is within this, so rigging IS adequate. Wait — let me reconsider the answer choices. The 60-degree included angle means each leg is 30 degrees from vertical. The sling angle factor = cos(30°) ≈ 0.866. Each sling capacity = 2,600 × 0.866 = 2,252 lbs. Total = 4,503 lbs. The load is 3,800 lbs, so rigging IS adequate. Answer A is correct.

A service truck crane operator completes a lift and stows the boom. After stowing, the operator notices the boom tip has a slight upward deflection and the hydraulic system shows no obvious leak. What is the MOST likely cause and required action?

Answer: Internal cylinder bypass (drift) in the boom hoist circuit; the crane must be taken out of service and inspected before further use

Upward deflection of a stowed boom tip with no external leak indicates internal bypass (drift) within the hydraulic cylinder — fluid is bypassing the piston seals internally, allowing unintended movement. This is a critical deficiency because the same bypass that permits drift while stowed can allow uncontrolled boom descent under load. Per ASME B30.22 and manufacturer requirements, any unintended movement of the boom or load line when controls are in neutral requires the crane to be removed from service until inspected and repaired. Thermal expansion (option C) affects all components uniformly and dissipates quickly; it does not cause sustained deflection.

Under OSHA 1910.180 and ASME B30.22, when must a service truck crane undergo a comprehensive (annual) inspection by a qualified inspector, even if it has passed all monthly and pre-shift inspections?

Answer: At intervals not exceeding 12 months, or more frequently if the crane is used in severe service conditions as defined by the manufacturer

ASME B30.22 and OSHA 1910.180 both require periodic (comprehensive) inspections at intervals not exceeding 12 months. Critically, the standard also mandates more frequent comprehensive inspections when the crane operates in 'severe service' — defined by the manufacturer and including environments with high cycle rates, corrosive atmospheres, or extreme temperature exposure. The 12-month interval is a maximum, not a fixed schedule. Hour-based triggers (option C) may supplement but do not replace the calendar-based requirement; site relocation (option D) is not independently a trigger for comprehensive inspection.