NCCCO Mobile Crane Operator 4 3

Question 1

When operating a mobile crane near energized power lines, what is the minimum required clearance distance for lines rated up to 50 kV under OSHA standards?

Accepted Answer

10 feet

Answer

OSHA 1926.1408 requires a minimum 10-foot clearance from energized power lines rated up to 50 kV.

Question 2

A crane's load chart shows a capacity of 40 tons at a 30-foot radius. If the operator works at a 40-foot radius, what generally happens to the rated capacity?

Accepted Answer

It decreases

Answer

As the load radius increases, the rated lifting capacity decreases due to increased moment (torque) on the crane structure.

Question 3

What is the primary purpose of an anti-two-block (ATB) device on a mobile crane?

Accepted Answer

To prevent the hook block from contacting the boom tip

Answer

An ATB device automatically stops the hoist when the hook block approaches the boom tip sheaves, preventing two-blocking which can cause catastrophic failure.

Question 4

Which document must an operator consult to determine the correct reeving configuration for a specific lift?

Accepted Answer

The crane manufacturer's load chart and operator manual

Answer

The crane manufacturer's load chart and operator manual specify correct reeving based on the load weight and configuration.

Question 5

A mobile crane is set up on outriggers over a suspected underground utility. What should the operator do FIRST?

Accepted Answer

Call 811 to locate buried utilities before setup

Answer

Calling 811 (Dig Safe/Call Before You Dig) to locate utilities before setup is required to prevent striking buried lines during outrigger deployment.

NCCCO (National Commission for the Certification of Crane Operators) Practice Test

NCCCO (National Commission for the Certification of Crane Operators) Practice Test

NCCCO Mobile Crane Operator 4 3