NCCER Crane Crane Components, Configurations & Terminology

Question 1

What does the term 'parts of line' describe on a crane?

Accepted Answer

The number of wire rope lines supporting the load block

Answer

Parts of line is the number of hoist rope lines reeved between the boom tip sheaves and the load block. More parts of line raise lifting capacity but slow line speed.

Question 2

What is the main function of a crane's counterweight?

Accepted Answer

To offset the load moment and increase stability

Answer

The counterweight sits at the rear of the upperworks. It balances the overturning moment the load and boom create, which increases the crane's stability-based capacity.

Question 3

What is the main structural difference between a lattice boom and a telescopic boom?

Accepted Answer

Lattice booms are built from pinned truss sections, while telescopic booms extend nested sections hydraulically

Answer

Lattice booms are assembled from open truss sections pinned together, so changing length means adding or removing sections. Telescopic booms have nested box sections that extend and retract with hydraulics.

Question 4

What does 'luffing' mean in crane operations?

Accepted Answer

Raising or lowering the boom angle

Answer

Luffing is changing the boom or jib angle, which also changes the load radius. Swinging is rotating the upperworks.

Question 5

What is an 'overhaul ball' (headache ball) used for?

Accepted Answer

To provide weight so a single-part line pays out freely without a load

Answer

An overhaul ball is a weighted hook on a single-part line. Its weight lets the line lower (overhaul) through the sheaves when there is no load on the hook.

(NCCER Crane) National Center for Construction Education and Research Crane Certification Practice Test

(NCCER Crane) National Center for Construction Education and Research Crane Certification Practice Test

NCCER Crane Crane Components, Configurations & Terminology