NCCCO Telescoping Boom and Jib Configuration 2

Question 1

When a telescoping boom section is positioned at an intermediate (mid-travel) extension — not fully extended or retracted — the operator should:

Accepted Answer

Consult the manufacturer's manual, as intermediate positions may not be load-rated

Answer

Many manufacturers only rate capacities at specific fully-extended or fully-retracted boom positions; intermediate positions may lack structural pin engagement and are often not rated for lifting.

Question 2

Which type of jib attachment allows the operator to adjust the jib angle while the crane is under load during operations?

Accepted Answer

Luffing jib

Answer

A luffing jib has its own luffing mechanism that allows the operator to raise or lower the jib tip while a load is suspended, unlike fixed or swingaway jibs which must be pinned before the lift.

Question 3

When is it generally permissible to telescope a hydraulic boom while a load is suspended from the hook?

Accepted Answer

Only when the manufacturer's documentation specifically permits power telescoping under load

Answer

Some cranes are designed for power telescoping under load, but this must be explicitly permitted and detailed in the manufacturer's documentation, as capacity changes dynamically.

Question 4

When the telescoping boom is extended, the crane's center of gravity shifts in which direction?

Accepted Answer

Toward the front of the crane, reducing tipping stability

Answer

Extending the boom moves mass forward and outward, shifting the crane's center of gravity toward the load side and reducing the margin against tipping.

Question 5

After completing operations, a swingaway jib should be:

Accepted Answer

Secured alongside the main boom in the travel position per manufacturer instructions

Answer

The manufacturer specifies an approved travel/stow position for the swingaway jib to prevent damage during transport and maintain safe travel dimensions.

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

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

NCCCO Telescoping Boom and Jib Configuration 2