MT Crane/Hoisting Operator cheat sheet

Boom length: the straight-line distance from boom foot pin to boom tip sheave center; affects radius and capacity.

Radius: horizontal distance from center of rotation to center of load; measured with load suspended and boom at working angle.

Counterweight: fixed or removable mass at rear of upperworks; increases capacity but adds tail swing and ground bearing pressure.

Boom angle: angle between boom centerline and horizontal; capacity generally increases as angle increases (radius decreases).

Load moment: product of load weight and radius; used by load moment indicator (LMI) to prevent overload.

Auxiliary head: optional sheave assembly at boom tip for increased line pull or reduced line speed; capacity may differ from main head.

Jib: extension beyond boom tip that reduces capacity and increases radius for a given boom angle.

Outrigger beam: sliding or fixed beam that extends from carrier to increase stability; must be fully extended and pinned per manufacturer.

Telescoping boom sections: sequential sections that extend to increase boom length; capacity charts are specific to boom configuration.

Rated capacity = lowest of structural, stability, or line pull limits for the given configuration, radius, and boom length.

Deduct from gross capacity: weight of all rigging below the boom tip (hook block, slings, spreader beams) to obtain net capacity.

Load moment indicator (LMI) must be calibrated for the specific crane and configuration; never rely on a single chart without verifying radius and boom length.

For pick-and-carry, use the manufacturer's pick-and-carry chart; travel speed, ground conditions, and tire pressure affect capacity.

When operating over the side or front, outrigger configuration changes capacity; use the correct chart for the outrigger setup.

Radius must be measured at the center of the load, not at the boom tip, when the load hangs vertically.

Multiple-part lines: capacity may be limited by the number of parts of line and the line pull; verify reeving against the chart.

Wind area of the load can reduce allowable capacity; consult the manufacturer's wind speed and sail area limits.

Sling tension increases as the horizontal angle decreases: tension = load / (number of legs × sin(angle from horizontal)).

At 30° from horizontal, each leg carries 1.0 × load (for two legs); at 60°, each leg carries 0.577 × load.

Never exceed the sling's rated capacity; capacity is based on vertical pull unless the tag indicates otherwise.

Shackle pins must be fully seated and moused; side loading of shackles reduces capacity and is prohibited unless rated for it.

Spreader beams and lifting beams distribute load and must be rated for the load and configuration; verify proof load test date.

Synthetic slings: inspect for cuts, abrasion, ultraviolet degradation, and chemical damage; remove from service if red warning yarn is visible.

Wire rope slings: check for broken wires, kinks, bird-caging, and corrosion; follow removal criteria (e.g., 10 broken wires in one lay for running rope).

Below-the-hook devices (clamps, magnets, vacuum lifters) must have a current inspection and be rated for the load material and surface condition.

Daily inspection: check engine oil, coolant, hydraulic fluid, tire condition, outrigger pads, and safety devices (LMI, anti-two-block, horn).

Wire rope: inspect for broken wires, wear, corrosion, and diameter reduction; replace when criteria in ASME B30.5 or manufacturer's manual are met.

Hook: check for cracks, deformation, throat opening increase (>15% for many hooks), and wear on the saddle; replace if exceeded.

Sheaves: check for worn grooves, broken flanges, and proper alignment; a worn groove can damage wire rope and reduce capacity.

Brakes: test service, parking, and hoist brakes before lifting; ensure they hold the load without drift.

Anti-two-block device: test that it stops hoisting when the hook block approaches the boom tip; never bypass.

Outrigger pads: ensure adequate size and condition; use pads to distribute load and prevent sinking.

Load moment indicator (LMI): verify calibration, display, and alarm functions; check that the correct configuration is selected.

Ground bearing pressure: outrigger load divided by pad area must be less than the soil's allowable bearing capacity; use mats to reduce pressure.

Outriggers must be fully extended and set on stable, level ground; never block outriggers on cribbing that can shift or crush.

Keep the crane level within manufacturer's tolerance (often 1% or 3°); use a level indicator and adjust with outriggers.

Check for underground hazards (utilities, tanks, voids) before setting outriggers; use a spotter or utility locator.

Maintain clearance from excavations: the slope stability zone depends on soil type; consult a competent person.

Tail swing: the rear of the upperworks can swing beyond the outriggers; barricade the swing radius.

Wind: cease operations when wind speed exceeds manufacturer's limits or when the load's sail area makes control difficult.

Stability: the crane's stability can be reduced by side loads, shock loading, or improper outrigger setup; always operate within the load chart.

Only one designated signal person directs the lift; all signals must be understood by the operator before the lift begins.

Standard hand signals: follow ASME B30.5 or applicable national standard; emergency stop is any signal, shouted, or radio command.

Before lifting, conduct a pre-lift meeting with all personnel to review the lift plan, signals, and responsibilities.

Never lift personnel unless using a man basket designed for that purpose and following the manufacturer's instructions and regulations.

Avoid shock loading: start and stop smoothly; sudden load changes can exceed capacity and cause structural failure.

Do not drag loads sideways; side loading can damage the boom and cause tipping.

Keep personnel clear of the load, rigging, and swing radius; use tag lines to control the load from a safe distance.

If communication is lost, stop operations until communication is restored.

Maintain minimum approach distance (MAD) from power lines: for voltages up to 50 kV, 10 ft (3 m); for higher voltages, add 0.4 in (1 cm) per kV above 50 kV (per OSHA 1926.1408).

Always assume power lines are energized; use a spotter when working near lines and verify voltage with the utility.

If contact occurs: stay in the cab, warn others away, and have the utility de-energize the line; if you must exit, jump clear and shuffle away.

Environmental hazards: lightning, high winds, ice, and poor visibility require stopping operations and securing the crane.

Heat and cold affect hydraulic fluid, wire rope, and steel properties; follow manufacturer's temperature limits.

Confined spaces, overhead obstructions, and other cranes in the area require a lift plan and coordination.

Ground conditions can change with rain or freezing; re-check outrigger stability after weather changes.

Wire rope removal criteria: 6 randomly distributed broken wires in one lay, or 3 broken wires in one strand in one lay (for running ropes).

Wire rope diameter reduction: replace when actual diameter is less than nominal minus the allowable (e.g., 1/64 in for diameters up to 5/16 in).

Corrosion: replace wire rope when corrosion is severe or when diameter loss exceeds limits; internal corrosion can be hidden.

Sheave and drum wear: grooves must not be worn more than manufacturer's limit; worn grooves can cause rope damage.

Hook wear: replace when throat opening increases by more than 15% or when wear exceeds 10% of original dimension.

Brake wear: maintain brake linings and adjust per manufacturer; test brakes regularly under load.

Hydraulic systems: check for leaks, proper fluid level, and filter condition; contaminated fluid can cause component failure.

Record all inspections and maintenance; keep records available for review.

OSHA 29 CFR 1926 Subpart CC governs cranes and derricks in construction; 1910.180 covers crawler locomotive and truck cranes in general industry.

ASME B30.5 covers mobile and locomotive cranes; B30.9 covers slings; B30.10 covers hooks; B30.20 covers below-the-hook lifting devices.

Operator certification: required by OSHA for construction cranes; must be certified by an accredited organization and carry proof.

Operator responsibilities: know the load chart, inspect equipment, follow signals, and stop work if unsafe conditions exist.

Employer responsibilities: provide training, maintain equipment, and ensure a lift plan for critical lifts.

Critical lift: a lift that exceeds 75% of capacity, involves personnel, or has special hazards; requires a documented lift plan.

Signal person qualification: must be trained and evaluated; operator must understand signals.

Recordkeeping: maintain inspection, maintenance, and certification records as required by regulations.