NCCCO Service Truck Crane cheat sheet

Firm level support is required within the outrigger/stabilizer footprint; the crane manufacturer's chart assumes the machine is level to within 1% (about 0.5 degrees) unless the chart states otherwise.

Outrigger float (pad) size matters: required pad area = total float load divided by allowable ground bearing pressure; doubling pad area halves the pressure applied to the soil.

Distributed load under a float spreads at roughly a 45-degree (1:1) angle through granular fill; at depth d below a pad of width B, the loaded width is approximately B + 2d.

Keep the swing radius barricaded: the crane's tail swing and counterweight can extend well beyond the boom side; the swing area is a struck-by and pinch zone for ground personnel.

Check for underground utilities, vaults, septic tanks, and recently backfilled trenches before setting stabilizers; a void under one float causes tipping, not just settling.

Maintain the manufacturer's minimum clearance from energized power lines for the highest point of the boom, load line, and load; when that cannot be met, use a spotter and a documented plan.

Wind acts on the load's sail area and the boom; the load chart capacity applies to freely suspended loads, so tag lines and wind-induced side loads reduce usable capacity.

Level the crane with the manufacturer's bubble level, not the operator's judgment; a small out-of-level condition can swing the load radius and reduce capacity significantly.

Barricade and mark the counterweight swing path when working near walls, excavations, or traffic; counterweight radius is fixed by the machine, not by boom length.

Net capacity = chart capacity for the actual radius, boom length, and configuration, minus deductions for all lifting attachments not already accounted for (jib, auxiliary head, hook block, slings, and the load).

Radius is measured horizontally from the center of rotation to the center of the hook (or load) with the boom under load; booming out or the boom flexing under load increases the true radius.

Deductions for a jib or stowed attachment are taken from the main boom chart value, not added to the load weight; always use the chart notes for the exact configuration.

Two-crane (tandem) lifts: each crane must be rated for at least its share of the load, and the load share depends on hook height and geometry - the crane whose line is more vertical carries more.

Standard hand signals: raise/lower boom, raise/lower load, swing, stop, emergency stop, extend/retract boom, and dog everything; one designated signalperson directs the operator.

Before any lift, verify the load weight from shipping papers or a scale; the load chart is a maximum, and unknown weight is a stop-work condition.

Shock loading from rapid hoist starts, sudden stops, or dragging a load can exceed the rated capacity even when the static load is within the chart.

When the load is out of the operator's view, use a signalperson or radio communication; loss of communication means stop the operation until contact is restored.

Side loading the boom (dragging, pulling, or swinging a load that is hung up) loads the boom in a direction it was not designed for and is prohibited without manufacturer approval.

The load moment indicator (LMI) or rated capacity limiter compares actual load moment to the programmed chart and warns or locks out before the rated capacity is exceeded; it does not replace the operator's chart.

The anti-two-block device prevents the hook block from contacting the boom tip; it must be functional and never bypassed, and it is tested during the daily inspection.

Boom angle and boom length together determine radius on a lattice or telescopic boom: radius = boom length x cosine of boom angle (plus offset from the rotation center).

Boom deflection and machine flexing add to the geometric radius under load; the chart radius is the actual working radius, so measure it with the load in place when in doubt.

Wire rope inspection criteria include broken wires, kinks, bird-caging, corrosion, and diameter reduction; removal criteria come from the manufacturer and applicable standards, not operator preference.

The counterweight and carbody provide the resisting moment; stability is governed by the load moment versus the machine's resisting moment, which is why the chart is configuration-specific.

Daily (pre-shift) inspection covers wire rope, hooks, latches, outriggers, levels, LMI, anti-two-block, alarms, and hydraulic leaks; documented deficiencies must be corrected before use.

A hook latch must be present and functional; a hook with a missing or sprung latch, cracks, or excessive throat opening is removed from service.

Periodic inspections are more thorough than daily ones and are performed at intervals set by the manufacturer and standards; the inspection record travels with the machine.

Read the chart for the exact boom length, boom angle (or radius), outrigger configuration (full, partial, or on-tires), counterweight, and jib stowed or erected.

Capacity decreases as radius increases; on most charts the capacity is limited by strength at short radius and by stability (tipping) at long radius, and the chart does not tell you which.

Interpolate between charted radii only if the manufacturer permits it; otherwise use the next longer (lower capacity) charted radius.

Deductions listed in the chart notes (jib, auxiliary boom head, hook block, and stowed attachments) are subtracted from the chart value before comparing to the load weight.

The load chart applies to a freely suspended load with the machine level on firm support; on-tire or pick-and-carry ratings are separate charts with lower capacities and often require tire pressure and travel-path limits.

Area of operation (over the side, over the front, over the rear) may have different ratings; note which quadrant the chart row applies to before lifting.

Boom angle is read from the boom angle indicator, and radius is read from the boom's radius indicator or measured; both must agree with the chart entry used.

When the chart gives a maximum load for a range of boom angles, use the lowest capacity in that range for planning; never assume the best case within a band.

The chart's structural and stability limits are configuration-specific: changing counterweight, outrigger spread, or boom mode (e.g., telescoping under load) changes which chart applies.