Red Seal HEO cheat sheet

Hierarchy of controls, most to least effective: elimination, substitution, engineering controls, administrative controls, personal protective equipment.

Ground disturbance within 1 m (3 ft) of a buried utility line must be done by hand excavation or non-destructive methods; mechanical digging is limited to the tolerance zone boundary.

Excavations 1.2 m (4 ft) or deeper require a means of escape within 7.5 m (25 ft) of lateral travel for workers, such as a ladder or ramp.

Spoil piles and equipment must be kept at least 1 m (3 ft) back from the excavation edge; the spoil side adds surcharge load to the trench wall.

A competent person must inspect excavations, trenches, and adjacent structures at the start of each shift, after rain, and after any event that could affect stability.

Soil classification for protective systems: Type A (cohesive, unconfined compressive strength 1.5 tsf or greater), Type B (0.5-1.5 tsf), Type C (less than 0.5 tsf or submerged/loose granular).

Confined space entry requires a hazard assessment, atmospheric testing (oxygen 19.5-23.5%, LEL under 10%, H2S under 10 ppm), an attendant, and a rescue plan before entry.

Spill response order: stop the source, protect drains and watercourses with berms or socks, contain, notify the supervisor and regulator as required, then arrange disposal.

Hearing protection is required when exposure exceeds 85 dBA over an 8-hour equivalent; noise above 105 dBA requires dual protection and engineering review.

Excavator cycle: position, lower blade/stabilizers, boom-and-stick to the bucket, curl, lift, swing, dump, swing back; keep the bucket low and the load close to the machine while swinging.

Tracked excavators travel with the idlers forward for best stability and climb capability; the travel motor is at the rear, so the sprocket end trails.

Dozer production is governed by blade load, push distance, and rolling resistance; slot dozing and downhill pushing raise production by reducing resistance and rehandling.

A dozer blade cuts best when the cutting edge is angled slightly down and the load rolls in front of the blade; a stalled track spin means the blade is over-loaded.

Loader bucket fill factor improves with a level floor, a low approach speed, and a breakout curl at the pile; carrying a loaded bucket at ground level maximizes stability.

Wheel loaders articulate at the center; the rear frame swings, so the tail swing radius must be checked before turning near walls, banks, or pedestrians.

Backhoe stabilizers must be fully deployed with the rear wheels clear of the ground before digging; the loader bucket is lowered as a front counterweight.

Never swing or travel a load over personnel, utility trenches, or the cab of another machine; keep the bucket or blade at or below waist height when moving.

Operating on side slopes: excavators work with the boom uphill where possible; dozers and loaders stay within the manufacturer's slope limit, typically 20 degrees or less for loaders.

Cut-and-fill balance: total cut volume should equal total fill volume plus swell minus shrinkage; haul distance decides whether material is wasted, borrowed, or moved on site.

Swell factor example: bank volume x (1 + swell) = loose volume; a 0.85 load factor means 1 loose m3 yields 0.85 bank m3.

Compaction is measured as a percentage of maximum dry density from a standard or modified Proctor test; typical specification is 95-98% for structural fill.

Moisture content must be near optimum (typically within plus or minus 2% of OMC) or density cannot be achieved with the available compactive effort.

Lifts are typically 150-300 mm (6-12 in) loose for a smooth-drum roller; thicker lifts leave loose material at the bottom that later settles.

Trench backfill: bedding first, then lift-placed and compacted backfill in layers, with compaction testing at specified intervals before the next lift.

Grading to a subgrade: establish grade stakes or a laser/GPS reference, cut to the design elevation, then proof-roll and trim before placing base material.

Dozer and grader finish passes should be made at low speed with a light blade load; a full blade rounds off high spots and fills low spots incorrectly.

Slope stakes and batter boards define cut and fill depths; a 2:1 slope is 1 vertical to 2 horizontal, so a 2 m rise needs 4 m of horizontal run.

Walk-around inspection order: fluids and leaks, belts and hoses, tires or tracks and undercarriage, cutting edges and teeth, guards, lights, horn, backup alarm, fire extinguisher, and seat belt.

Daily checks include engine oil, coolant, hydraulic oil, fuel/water separator, air filter restriction indicator, battery condition, and grease points per the lube chart.

Track tension is correct when there is roughly 10-20 mm (0.4-0.8 in) of sag at the midpoint between the idler and the first carrier roller, measured per the manual.

Undercarriage wear limits: sprocket teeth worn to a sharp point, bushing wear beyond the turn limit, or a track shoe height worn to the pin boss means replacement or turning.

Hydraulic oil is checked with the machine level, the attachment on the ground, and the oil warm; a milky or foamy appearance indicates water or air ingress.

Coolant is checked cold only; opening a hot pressurized radiator cap causes steam burns. Use a 50/50 glycol mix unless the manual specifies otherwise.

Grease every fitting at the interval in the maintenance chart; over-greasing a sealed bearing can rupture the seal, so pump until fresh grease appears and stop.

Record hour-meter readings at each service; preventive maintenance intervals are keyed to hours, not calendar time, and records support warranty claims.

A pre-start inspection finding of a cracked weld, leaking hose, or damaged ROPS/FOPS structure means the machine stays out of service until repaired.

Locate request must be placed before ground disturbance with the required notice period; the locate ticket is valid for a limited window and must be renewed if it expires.

Tolerance zone: the band on each side of the marked utility, commonly 1 m (3 ft) in the horizontal plane, where hand excavation or vacuum excavation is required.

Color code for utility markings: red electric, yellow gas/oil/steam, orange communications, blue potable water, green sewer/drain, purple reclaimed water, white proposed excavation, pink temporary survey.

Benchmark is a fixed elevation reference; a temporary benchmark (TBM) is set on site and tied to a permanent datum before grading begins.

Cut and fill sheets show existing and design elevations; the difference between them is the depth of cut or fill at each station.

Stationing is measured along the baseline in 100-unit stations (station 1+00 is 100 units from the start), with offsets measured left or right of the baseline.

A laser level or GPS grade control must be checked against a known benchmark before use; a mis-set receiver produces systematic grade error across the whole site.

Silt fence, straw bales, and sediment traps are installed before any clearing or grubbing, and stabilized construction entrances are placed before hauling starts.

Clearing limits are marked with flagging or stakes; grubbing removes roots and organic material to the depth specified, and topsoil is stripped and stockpiled separately.

Sling tension formula for a two-leg bridle: tension per leg = (load / 2) / cos(angle from vertical); wider sling angles increase leg tension.

Working load limit (WLL) is the maximum load a rigging component may lift; the assembly WLL is set by the weakest component, not the strongest.

Sling angle factor: at 30 degrees from horizontal the multiplier is about 2.0, at 45 degrees about 1.4, at 60 degrees about 1.15, applied to the load per leg.

Never exceed the load chart for the boom length, radius, and counterweight configuration; the chart already accounts for the machine's stability and structural limits.

Excavator lifting requires a certified lifting point, a load chart for lifting, and a check valve or hose-burst protection on the boom and stick cylinders.

Tag lines control rotation and swing of a suspended load; personnel stay outside the fall zone and never stand under a suspended load.

Quick couplers and attachments must be fully engaged with the locking pin or wedge installed and visually verified before lifting or digging.

Shackle pins are fully seated and moused or wired; hooks need a functioning safety latch, and damaged slings (cuts, broken wires, heat damage) are removed from service.

Rigging hardware is inspected before each use and periodically by a competent person; sling tags must be legible, and unmarked slings are not used.

Load securement minimum: one tiedown per 3 m (10 ft) of article length, with at least two tiedowns for any article longer than 1.5 m (5 ft) or heavier than 500 kg (1,100 lb).

Aggregate WLL of the tiedown system must be at least 50% of the cargo weight; each tiedown must be rated and marked.

A tiedown is not counted if it is attached to the same point on the vehicle as another tiedown for the same article; anchor points must be independent.

Working load limit of a chain binder assembly is limited by its weakest link; Grade 70 transport chain is the standard for load securement.

Load the machine centered over the trailer axles, low, and with the attachment lowered and pinned; the machine's center of gravity should sit forward of the trailer's rear axle group.

Travel with the boom or blade lowered, the parking brake set, the transmission in the manufacturer-specified transport position, and the seat belt secured.

Trailer ramps must be aligned, dry, and rated for the machine's weight; approach straight, keep the machine centered, and use a spotter.

Check the load after the first few kilometers and again at intervals; tie-downs stretch and settle, and re-tensioning is required.

Height, width, and weight limits vary by jurisdiction; oversize permits are required before moving a machine that exceeds legal dimensions or axle loads.

Standard hand signals for excavator operation: raise/lower boom, swing, stop, and emergency stop are given by one designated signal person only.

Radio protocol: identify the machine and the operator, state the message, and confirm receipt; the spotter's instructions override other signals except an emergency stop from anyone.

Daily inspection forms, hour-meter logs, fuel and fluid records, and maintenance work orders are legal and warranty records and must be accurate and timely.

A field-level hazard assessment or pre-job briefing documents the tasks, hazards, controls, and participants before work starts and is reviewed when conditions change.

Incident reporting includes the time, location, equipment, personnel, sequence of events, injuries, and immediate actions; preserve the scene and evidence.

Near-miss reporting is used to correct hazards before injury; a near miss is documented the same way as an incident.

Utility locate tickets, permits, and dig permits are kept on site and match the work being done; an expired or mismatched ticket stops the dig.

Shift handover covers machine condition, open work, hazards, and any defects reported; verbal handover is backed by a written note in the log.

Diesel no-start troubleshooting order: battery and connections, fuel supply and filters, air in the fuel system, then compression and injection timing.

Hydraulic system pressure is measured at test ports with a gauge rated above system pressure; low pressure causes slow cycle times and weak breakout force.

A hydraulic cylinder that drifts under load indicates internal leakage past the piston seal or a faulty holding valve, not necessarily a pump problem.

Overheating causes: low coolant, plugged radiator fins, faulty thermostat, loose fan belt, or a failed water pump; check the simple causes first.

Black exhaust smoke indicates incomplete combustion (over-fueling or air restriction); blue smoke indicates oil burning; white smoke indicates unburned fuel or coolant ingress.

Track and tire wear patterns diagnose alignment: uneven edge wear points to misalignment or incorrect toe-in; center wear points to over-inflation.

Electrical faults: check fuses, grounds, and battery terminals first; a voltage drop test across a connection locates high resistance better than a resistance reading.

Minor repairs permitted by the operator are those in the manual's operator maintenance section; anything involving pressure, structural welding, or ROPS requires qualified service.

After any repair, function-test the machine at low load and check for leaks before returning it to full production.