Craftsman Excavator Operator flashcards

32 cards. Read the term and the definition here. The deck at the top of this page is optional.

Hierarchy of controls

Ranking of risk controls from most to least effective: elimination, substitution, engineering controls, administrative controls, then PPE. Excavator examples include remote demolition instead of cab operation and water spray instead of respirators.

Three-point contact rule

When mounting or dismounting a machine, keep three points of contact with the steps and handrails at all times: two hands and one foot, or two feet and one hand. Never carry tools while climbing.

Noise action level

The exposure level, commonly 85 dB(A) as an eight-hour time-weighted average, at which hearing protection, audiometric testing, and noise controls are required in most jurisdictions.

Spill response order

Stop the source, contain the spill with absorbent or bunding, protect drains and watercourses, then report per the site plan. Never wash fuel or hydraulic fluid into drainage.

Swing radius exclusion zone

The area swept by the counterweight and attachment during slew. Ground personnel must stay outside it, and it is barricaded when the operator's visibility is restricted.

Open-centre hydraulic system

A circuit using fixed-displacement pumps where oil bypasses to the tank at neutral. Flow is constant regardless of demand, so excess flow generates heat and wastes fuel.

Load-sensing hydraulic system

A closed-centre circuit with variable-displacement pumps that adjust flow to match demand. It reduces heat generation and fuel consumption compared with fixed-displacement open-centre systems.

Counterweight function

A mass at the rear of the upper structure that balances the attachment and load. Rated lift capacity falls as load radius increases and when lifting over the side rather than over the idler or sprocket.

Counter-rotation (spot turn)

A turn in place achieved with independent track drives by running one track forward and the other in reverse. Avoid it on steep or slippery ground where track slip is likely.

Swing parking brake

A normally spring-applied brake in the swing circuit that holds the upper structure when the machine is stopped or parked. It is released hydraulically when swing is operated.

Track tension check

Measure the sag of the track span between the idler and first roller on level ground, typically 10 to 30 mm. Too tight wears pins and bushings; too loose causes derailment.

Hot radiator cap rule

Never open a pressurized radiator cap while the engine is hot. Coolant can flash to steam and cause severe burns. Wait until the system is cold before checking or topping up.

Warm-up procedure

Idle the engine at low speed for several minutes and cycle the hydraulic functions slowly before applying full load. Cold oil is viscous and can cavitate the pump.

Air cleaner servicing

Clean or replace the paper element according to the restriction indicator. Never wash a paper element in solvent, and never run the engine with the element removed.

Defect tagging

A machine with a defect affecting safe operation is tagged out and taken out of service until repaired. The defect is recorded on the daily inspection sheet.

Stop hand signal

A raised hand with the palm facing the operator, or any emergency signal from anyone on site. The operator must stop immediately whenever a stop signal is given.

Raise boom signal

The signaler extends the arm upward with the palm facing up and moves the hand upward. The operator acknowledges and raises the boom slowly until the signal changes.

Designated signaler

One person assigned to communicate with the operator during a lift or blind operation. The operator stops work if the signaler is out of sight or the signal is unclear.

Excavator blind spots

Areas around the machine, particularly the counterweight and right side, that the operator cannot see from the seat. Mirrors, cameras, or a spotter are used when reversing or slewing near people.

Safe travel posture

Keep the bucket low, about 200 to 400 mm above ground, and the boom over the idler end when climbing. Travel straight up or down slopes, never across the face.

Digging cycle

Position the bucket, curl it while crowding the arm, then lift with the boom. The arm cylinder provides the main digging force; the boom is used mainly for lifting.

Bucket misuse

Using the bucket as a hammer, dropping it to break ground, or pushing loads sideways with the boom or arm. These actions damage the attachment and can tip the machine.

Parking procedure

Park on level ground, lower the attachment to the ground, engage the safety lock and travel lock, stop the engine, and remove the key before leaving the machine.

Spoil pile setback

Spoil and materials are kept at least 1 m, or the distance required by the jurisdiction, from the trench edge. Spoil over the trench line adds surcharge load and can cause collapse.

Trench protection trigger

At depths defined by regulation, commonly 1.2 to 1.5 m, trenches require sloping, benching, shoring, or a trench box. Protection is inspected daily and after rain.

Potholing

Trial excavation with hand tools or vacuum equipment to confirm the exact position of underground services before machine digging. Any unmarked line is treated as live.

Rated lift capacity

The maximum load at a given radius and height, read from the load chart. Capacity falls sharply as radius increases, and lifts near the limit require a lift plan.

Slope working position

The machine sits level on a stable bench, never on an undercut edge. On slopes the boom is kept on the uphill side and the bucket close to the ground as a brace.

Confined space entry

Entry into pits, tanks, or deep excavations requires atmospheric testing for oxygen, flammable gas, and toxic gas, plus a permit, an attendant, and rescue arrangements.

Power line approach distance

The minimum distance a machine or its load may approach an energized line, set by voltage in the jurisdiction's rules. A spotter and de-energization are used where possible.

Hydraulic overheating causes

Common causes are low oil level, blocked cooler fins, a loose fan belt, a mis-set relief valve, or holding a function against relief for long periods. Check each in order.

Track derailment recovery

Relieve track tension, lift the machine with the bucket to realign the track, then re-tension. Investigate worn sprockets, misalignment, or incorrect tension to prevent recurrence.