AIC Tools & Equipment Operation 4

Question 1

Which excavator is best suited to digging trenches below the level where the machine sits?

Accepted Answer

Backhoe (hoe)

Answer

A backhoe pulls its bucket toward the machine, so it digs efficiently below its own track level.

Question 2

Which machine works best for excavating soft, wet material below grade at a long reach, such as dredging a canal?

Accepted Answer

Dragline

Answer

A dragline casts its bucket far out and drags it back, which suits wet material at long reach.

Question 3

A clamshell bucket is most appropriate for which task?

Accepted Answer

Vertical excavation such as shafts and cofferdams

Answer

A clamshell drops straight down and digs vertically, which makes it ideal for shafts and confined pits.

Question 4

Under OSHA 1926.652, at what trench depth is a protective system required (unless the trench is entirely in stable rock)?

Accepted Answer

5 feet

Answer

Trenches 5 feet or deeper need sloping, shoring, or shielding unless they are in stable rock.

Question 5

Under OSHA, how far back from the edge of an excavation must spoil piles and equipment be kept, at minimum?

Accepted Answer

2 feet

Answer

OSHA 1926.651(j)(2) requires materials and equipment to be at least 2 feet from the excavation edge.

AIC - American Institute of Constructors Certification Practice Test