NCCCO Ground Bearing Pressure and Outrigger Setup 5

Question 1

When a crane is set up on a slope, which outrigger typically carries the greatest load?

Accepted Answer

The downhill outrigger on the low side

Answer

The downhill (low-side) outrigger carries the highest reaction load because the crane's center of gravity shifts toward the lower side on a slope.

Question 2

What is 'mat bearing pressure' in the context of crane setup?

Accepted Answer

The distributed ground pressure beneath a timber or steel mat used to support outriggers or crawlers

Answer

Mat bearing pressure is the load per unit area transmitted to the ground through a mat system used to spread crane outrigger or crawler loads.

Question 3

A crane manufacturer requires outrigger pads to be used whenever the crane is set up on outriggers. An operator decides to skip pads on a paved parking lot. This is:

Accepted Answer

Unacceptable; manufacturer requirements must be followed regardless of surface type

Answer

Manufacturer requirements for outrigger pads are mandatory; pavement does not exempt operators from following setup specifications.

Question 4

When outrigger beams are extended and the floats are down, what must be confirmed before beginning a lift?

Accepted Answer

That the crane is level within manufacturer's specified tolerance

Answer

The crane must be level within the manufacturer's tolerance (typically ±1%) before lifting, as unlevel conditions shift loads and reduce stability.

Question 5

Which of the following best describes 'outrigger reaction force'?

Accepted Answer

The downward force transmitted from the crane to the ground through each outrigger

Answer

Outrigger reaction force is the vertical downward load each outrigger transmits to the supporting surface, determined by the crane's weight, boom configuration, and lifted load.

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

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

NCCCO Ground Bearing Pressure and Outrigger Setup 5