NCCCO - National Commission for the Certification of Crane Operators Tower Crane Operator Test 1

Question 1

When a tower crane is climbing (jumping) to gain additional height, who is responsible for supervising and directing the climbing procedure?

Accepted Answer

A qualified and competent person designated by the crane manufacturer or erector

Answer

Climbing operations must be supervised by a qualified and competent person with specific knowledge of that crane's climbing system, as specified by the manufacturer. This ensures the procedure follows engineered sequences to prevent structural failure.

Question 2

What does the anti-two-block (ATB) device on a tower crane prevent?

Accepted Answer

The hook block from colliding with the boom tip or head machinery

Answer

The anti-two-block device detects when the hook block approaches the head machinery (or boom tip) and stops the hoist before a two-block condition occurs, which could part the hoist rope and drop the load.

Question 3

On a hammerhead (top-slewing) tower crane, where is the counterweight located?

Accepted Answer

On the opposite end of the jib from the hook, mounted on the counter-jib

Answer

The counterweight is mounted on the counter-jib (back mast), which extends in the opposite direction from the load-carrying jib. This balances the crane and reduces the bending moment on the mast.

Question 4

A tower crane operator receives a signal from a signal person to stop and hold a load. The operator notices the load has begun to drift due to wind. What is the correct action?

Accepted Answer

Hold the load in position and communicate with the signal person before taking further action

Answer

When a stop signal is given, the operator must hold position. Any change in condition — such as wind-induced drift — must be communicated with the signal person so the team can assess the situation and issue appropriate instructions before any further movement.

Question 5

What is the primary purpose of the load moment indicator (LMI) on a tower crane?

Accepted Answer

To alert the operator when the combination of load and radius approaches or exceeds the crane's rated capacity

Answer

The LMI monitors the combination of load weight and working radius (the moment) and provides a warning — and in many cases an automatic cutout — before the rated load moment is exceeded, helping prevent structural overload.

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

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

NCCCO - National Commission for the Certification of Crane Operators Tower Crane Operator Test 1