Tools & Equipment Operation Flashcards

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

Answer: Backhoe (hoe)

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

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

Answer: Dragline

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

A clamshell bucket is most appropriate for which task?

Answer: Vertical excavation such as shafts and cofferdams

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

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

Answer: 5 feet

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

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

Answer: 2 feet

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

In trenches 4 feet or deeper, OSHA requires a means of egress (such as a ladder) within how much lateral travel distance?

Answer: 25 feet

A ladder, stairway, or ramp must be within 25 feet of lateral travel for workers in trenches 4 feet or deeper.

Which compactor is most effective on granular soils such as sand and gravel?

Answer: Vibratory smooth-drum roller

Vibration rearranges granular particles into a denser packing, so vibratory smooth drums work best on sands and gravels.