Planning a boom truck lift

R 03 mWhat a lift plan is for

A boom truck's capacity is not one number. It changes with radius, boom length, the quadrant the load is in and how the outriggers are set, which is why Alberta's s.63(1) requires the truck to carry load charts showing rated capacity at all permitted boom angles and radii¹. A lift plan pins the job to one place on that chart.

At its simplest, the plan is the operator's check before each lift. It becomes a document when the lift is heavy, near a line, over people or shared between cranes. Either way it answers the same questions:

Under Alberta's s.64, only a competent worker authorized by the employer may run a lifting device, and that worker must on request show knowledge of load charts and the hoisting signal code¹.

R 06 mWhen Alberta requires a lift calculation

Alberta's rule is one sentence: the employer must ensure a lift calculation is completed for any lift exceeding 75% of a crane's rated capacity¹. Two points of reading:

• Which machines. Section 68.1 says "crane", the Code's broad word for equipment designed to lift, lower and move loads horizontally¹. It does not say "mobile crane", which the Code defines as a crane other than a boom truck and which s.88 uses to adopt CAN/CSA Z150-98¹. Plan on the basis that it reaches a boom truck lift, and check your employer's procedures.
• Rated capacity where. The figure that counts is the chart capacity at the lift's radius and configuration, not the truck's headline rating.

The Code does not say what the calculation contains. A useful one records the load and rigging weight, the radius at pick and set, the configuration (boom length, outriggers, quadrant), the chart capacity there, any deductions, and the percentage of the chart used.

Example: two provinces, one lift

Example inputs, not from a real chart: a 1,800 kg load with 120 kg of rigging, so 1,920 kg on the hook, set at 12 m on a truck whose chart gives 2,400 kg at 12 m over the rear, with a 20 m maximum permitted radius.

• 1,920 ÷ 2,400 = 80% of the chart. In Alberta that is over 75%, so a lift calculation is required.
• In BC, 80% is under the 90% critical-lift line, so it is not a critical lift on that test.
• If the chart gave 2,100 kg at 12 m, the lift would use about 91% at a radius more than half of 20 m: a critical lift in BC.

R 09 mBC's critical lifts

BC defines a critical lift, then requires a written plan for it. For boom trucks, the definition includes a lift over 90% of rated capacity at a load radius more than 50% of the maximum permitted radius, and any lift over or between energized high-voltage conductors³. The full list also covers³:

• a tandem lift with any one crane over 75% of its rated capacity, or more than two cranes;
• lifting a person in a work platform attached to a crane;
• a load whose centre of gravity, or a sling leg's length, changes during the lift;
• a lift from a floating base over 90% of rated capacity, and lifting a submerged load.

For every critical lift, a written plan must be at the site during the lift. It covers rigging details, wind speed limits, maximum hoist line speed, maximum travel speed where it applies, load distribution, and whether signallers are needed and where they stand. Immediately before the lift, a pre-job meeting goes through the plan with everyone involved; the supervisor documents it, and it is repeated whenever the people or the equipment change³.

Two more BC rules feed the plan. A boom truck rated 10 tonnes (11 tons) or more needs a load weight indicator or a system that stops it lifting beyond rated capacity³. And a boom angle indicator, plus a radius or boom extension indicator, is required wherever rated capacity depends on those values³.

R 12 mKnowing the weight of the load

Every margin in a lift plan is a percentage of a weight. BC requires the weight of each load to be determined and communicated to the operator and the rigger; where it cannot be determined accurately, the crane needs a load weight indicator or an overload prevention system³. Alberta makes the employer give the operator, the rigger and the person in charge of the lift the information they need to determine it¹.

Count everything below the boom tip. IHSA notes that a hoist's rated load does not allow for hook blocks, hooks, slings or equalizer beams, so their weight is added to the load².

Where the weight comes from

• The bill of lading, delivery slip or packing list.
• The manufacturer's data plate or drawing, for units such as rooftop equipment, tanks and transformers.
• Shop or engineering drawings, for precast, steel and trusses.
• For bundles, the count times the unit weight.
• A weigh scale, when nothing else is reliable.

Ask what is inside. A tank with liquid in it weighs more than its empty weight, and a load whose centre of gravity moves during the lift is a critical lift in BC³.

R 15 mMargins and duty cycles

The chart is a limit, not a target. IHSA recommends choosing a crane with at least a 5% working margin over the capacity each lift needs². For duty-cycle work such as placing concrete, manufacturers typically require chart ratings to be reduced, usually by 20%, or supply a separate chart².

Example, from the lift above: 1,920 kg plus a 5% margin needs at least 2,016 kg of chart capacity at the radius. On repetitive bucket work, the 20% reduction raises that to about 2,520 kg.

Three things eat the margin before the lift starts:

• Radius error. Boom angle indicators can be off by as much as 2° and should not be relied on for critical lifts; a measured radius is better². Radius also grows under load as the boom deflects².
• Out of level. In IHSA's example for one crane, 1° out of level cost 10% of chart capacity with a short boom and 30% with a long one².
• The quadrant. Capacity is normally greatest over the rear, less over the side, and may be nil over the front².

The boom truck size estimator applies the margin and the duty-cycle reduction to your numbers. More in how to read a load chart.

R 18 mPower lines and signallers

An overhead line within reach of the boom adds people as well as distances to the plan:

• Alberta. Within 7 m of a line, the employer must determine the voltage and set the limit of approach before work¹.
• British Columbia. A lift over or between energized high-voltage conductors is a critical lift, like a lift over 90% of capacity at long radius³. If the distance cannot be kept, the owner's written assurance is required; where the lines cannot be isolated, rerouted or guarded, a safety watcher with a positive stop signal is designated⁴.
• Ontario. Where a crane could encroach, the constructor sets written procedures⁵, and a competent worker is designated as signaller, in full view of the operator and with a clear view of the conductor⁵.
• Manitoba. Within 3 m of a line, the employer notifies the electrical authority, gets written instructions and, when instructed, assigns a signal person⁶.
• Newfoundland and Labrador. The voltage and clearance come in writing from the utility; without them, 5.5 m must be kept⁷.

Signals matter away from lines too. In BC, an operator who cannot see the boom, load line, hook and load through the whole lift acts only on the directions of a qualified signaller who can, and must stop on a stop signal from anyone³. Distances by province are in how close a boom truck may work to a power line.

R 21 mWho signs off

No single rule names one signature. The duties are spread out, and the plan says who holds each:

For heavy lifts, a non-Canadian reference sets a ground trigger: Queensland's code calls for geotechnical certification before lifts such as bridge beams of 10 t or more, or loads of 50 t or more⁹. See outriggers and ground bearing pressure.

On an operated rental the operator comes with the truck, while the site belongs to the customer's employer or constructor. Settle in writing, before the day, who prepares the plan, who supplies the weight and the ground information, and who is in charge of the lift. And respect the stop: an operator who will not lift while in doubt is doing what Alberta's Code requires¹.

R 24 mWhat to give a supplier so they can plan the lift

A supplier quotes the job, and the quote is only as good as the brief. The quote request on BoomTrucks.ca asks for what a lift plan needs:

In the notes, add access and overhead clearance for the truck, the set-up space and its distance from edges, whether the load passes over people, site hours, and who will direct the lift.

Request a quote; it only goes to a company with your consent. With your consent, your request goes to one company that rents, sells or finances boom trucks in your area. That company may pay BoomTrucks.ca for the referral. Start with the quote request, or size the lift first with the size estimator.