NCCCO Tower Crane Operator Test 1 3

Question 1

What is the purpose of the moment limiting device (MLD) on a hammerhead tower crane?

Accepted Answer

To automatically reduce trolley travel speed as the crane approaches rated load moment, and cut off functions when rated moment is reached at any radius

Answer

The moment limiting device monitors the load moment (load times radius) continuously and cuts off crane functions, particularly trolley travel out and hoisting, when the combination of load weight and radius would exceed the rated moment for the crane's current configuration.

Question 2

What is the procedure for performing a 'no-load' check before the first lift of the day on a tower crane?

Accepted Answer

Raise the empty hook block to a moderate height and test each crane motion function to verify proper operation before any loaded lifts are made

Answer

A no-load functional check tests all crane motions (hoisting, slewing, trolley travel) with the empty hook to verify all systems respond correctly before a load is applied, catching any malfunctions in a low-consequence situation.

Question 3

What is the correct procedure when a tower crane load indicator shows the lift is near maximum rated capacity?

Accepted Answer

Slow all crane movements, increase caution, avoid simultaneous multi-axis motions, and verify the actual load weight before proceeding with the planned lift

Answer

Near-capacity lifts require extra caution: slowed movements to reduce dynamic loads, single-axis motion to minimize combined stresses, and verification that the indicated load weight matches documented load weight before proceeding.

Question 4

What should a tower crane operator do if they experience a sudden uncontrolled slewing movement while operating?

Accepted Answer

Gently apply slewing counter-motion to slow the rotation while simultaneously lowering the load toward the ground, and then stop crane operations to investigate the cause

Answer

Uncontrolled slewing requires gentle braking with counter-slew while lowering the load, avoiding abrupt stops that could snap wire rope, then ceasing operations to identify the mechanical cause before resuming.

Question 5

Why must a tower crane operator monitor the load's behavior immediately after picking it up from the ground?

Accepted Answer

Observing the load just after pickup allows the operator to identify load shift, rigging imbalance, or unexpected weight before committing to the full lift path

Answer

Lifting the load just clear of the ground and holding it briefly allows identification of rigging problems, unexpected weight, or load imbalance before the load is moved over workers or structures during the full lift path.

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

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

NCCCO Tower Crane Operator Test 1 3