Service Truck Crane Operator Test 1 Flashcards

A service truck crane is operating on a 3° side slope with a rated load chart capacity of 8,000 lb at 10 ft radius on level ground. The operator must pick a load at 10 ft radius. Which action is most appropriate before lifting?

Answer: Derate the load capacity per the manufacturer's slope derating table and confirm the net capacity exceeds the load weight plus rigging

NCCCO and ASME B30.22 require operators to follow the manufacturer's load chart derating procedures when operating on slopes. Side slopes impose lateral forces and shift the tipping axis, so the rated capacity must be reduced according to the OEM's slope derating table. Simply being below a generic 5° threshold does not authorize full-rated lifts; the specific derating for that crane model must be applied and documented.

During a critical lift pre-planning meeting, the rigging foreman proposes using a single-leg wire rope sling in a choker hitch to lift a 4,000 lb steel beam. The sling's catalog vertical hitch rating is 5,200 lb. What is the correct assessment?

Answer: The lift requires a choker hitch efficiency factor of approximately 75–80%, reducing effective capacity to roughly 3,900–4,160 lb, which may not provide adequate margin

A choker hitch reduces a sling's rated capacity to approximately 75–80% of its straight vertical hitch rating due to the angle stress concentration at the choke point. At 75%, the 5,200 lb sling yields only ~3,900 lb effective capacity — less than the 4,000 lb load. At 80% it yields ~4,160 lb, which barely exceeds the load with no real safety margin. The rigging plan should use a basket hitch or a higher-rated sling to maintain adequate capacity.

A service truck crane operator receives a hand signal from the designated signal person: the signal person extends one arm horizontally with fingers pointing up and moves the forearm in a small horizontal circle. What is the correct interpretation and response?

Answer: Use main hoist — engage the primary winch before the next movement signal

Per ASME B30.22 and ANSI/ASSP A10.42 standard hand signals, the signal of one arm extended horizontally with the forefinger pointing up and the forearm rotating in a circle means 'Use Main Hoist.' This signal designates which hoist system to engage before executing a subsequent directional signal. Confusing it with a 'hoist up' signal — which uses a single finger pointing upward with arm raised — is a common and dangerous error.

While performing a pre-shift inspection, the operator discovers that two adjacent outer wires in the same strand of the load line wire rope are broken within a distance of one lay length. Under ASME B30.22, what is the required action?

Answer: Remove the rope from service immediately; it has met a removal-from-service criterion

ASME B30.22 specifies that wire rope must be removed from service if there are six or more randomly distributed broken wires in one rope lay, OR three or more broken wires in one strand in one rope lay. Two broken wires in the same strand within one lay length meets the three-in-one-strand criterion, requiring immediate removal from service. Continuing at reduced capacity or awaiting written authorization are not permitted under this standard.

A service truck crane is rigged with a 2-part line (two parts of rope supporting the load block). The hoist drum has a single-line pull rating of 3,500 lb. Ignoring sheave friction losses, what is the theoretical maximum load the crane can lift in this reeving configuration?

Answer: 7,000 lb — two parts of line multiply the lifting capacity by the number of parts

In a simple block-and-tackle system, the number of rope parts supporting the load block equals the mechanical advantage multiplier. With a 2-part line and a single-line drum pull of 3,500 lb, the theoretical maximum lift capacity is 2 × 3,500 = 7,000 lb (before applying sheave friction derating factors). This is the fundamental reeving calculation operators must perform when determining effective lifting capacity for a given configuration.

An operator is tasked with a blind pick — the load is out of direct sight. The signal person loses radio communication mid-lift with the load at 15 ft elevation and begins using hand signals, but the operator cannot clearly distinguish the signals due to glare and distance. What is the NCCCO-compliant course of action?

Answer: Lower the load to the nearest safe landing immediately and suspend operations until clear communication is re-established

ASME B30.22 and NCCCO operational standards require that crane operations cease immediately when the operator cannot communicate with the signal person or cannot clearly receive signals. The operator must lower the load to a safe landing and suspend the lift until reliable communication is restored. Continuing a blind pick without clear signal communication is a serious safety violation — 'last received instruction' does not authorize continued autonomous operation.