How to Write a Lift Plan Somebody Else Can Execute

Why this matters

A lift plan is not a record of what you intend. It is a document a crew who were not in the room have to execute, at a crane, under time pressure, without you. That makes traceability the whole design requirement: every number carries the document it came from, and every abort condition is something a person can measure. A plan whose weight line reads "approx" has quietly handed the most consequential decision on the job back to whoever is standing there when the load will not come off the ground. This procedure builds one plan out to a filled artifact, and the artifact stops halfway through because one field could not be answered honestly, which is the outcome the plan exists to produce.

The fields, and what each one has to carry

Write the plan as a set of named fields rather than prose. Prose lets a missing number hide; a field that says nothing is visibly empty.

Identification. Job, date, machine by serial or unit number, the qualified person who wrote the plan, and a revision number. A plan that changed after the crane position moved has to be re-issued, not annotated.

The load. Description, weight with its source, centre of gravity with its source, overall dimensions, and a note on sail area if the load presents a large face to wind. Attachment points are their own line, with the rating of each and the document it came from, because a lifting lug rating is condition-dependent in exactly the way a sling rating is.

The relationship the plan needs here is the two-point reaction. For a load picked at two points, the reaction at one lug is the total weight multiplied by the distance from the opposite lug to the centre of gravity, divided by the span between the lugs. Equal shares are what that formula gives when the centre of gravity is centred, and only then. Where it is not centred, the load also hangs out of level unless the sling lengths are adjusted to compensate, and once it hangs out of level the angles are no longer equal either.

The rigging. Each sling with its working load limit from its tag, the hitch, the angle from horizontal, the angle factor, and the resulting leg tension. All angles in a plan are stated from horizontal and the plan says so on its face, because half the trade quotes them from the vertical and the two conventions give reciprocal answers. Leg tension is the leg's vertical share divided by the sine of the angle from horizontal, valid while the load hangs free and the legs are symmetric. Hardware gets its own lines with markings. Any below-the-hook device gets its rated load at the spread being used, not the spread on the sticker.

Total suspended weight, itemised. Load, rigging, hardware, device. This is a column of numbers that adds, not a sentence.

The machine and its configuration. Boom type and length, jib erected or stowed, counterweight package, outrigger extension, area of operation. This selects the chart table before any cell is read.

The geometry. Pick radius, set radius, and the governing radius, which is the largest the load will ever occupy including boom deflection and swing-out. The radius card owns that determination; the plan carries its answer plus the terms that produced it, so the next reader can see whether they still apply.

The capacity. Gross chart capacity with the chart page, the deduction list, net capacity, and percent of chart with the convention named in the same line. Total suspended against gross chart is the convention to use, because it is the higher and therefore the conservative of the two readings.

The ground. Critical outrigger reaction from the manufacturer's data, mat size, the effectiveness factor and where it came from, effective area, resulting pressure, and the allowable bearing pressure with its source. Most of those are somebody else's numbers and the plan says whose.

The zones. Exclusion zone under the load, the swing path, and the tail swing behind the machine, all as physical descriptions somebody can cone off. Any power line clearance goes here with the voltage it was based on.

The people. Operator, lift director, qualified rigger, qualified signal person and any spotters, by name, with an alternate for each. The role definitions belong to the rigger and signal person card.

Communication. Primary method, backup method, and the condition that switches between them, decided in advance. Plus the one universal: anyone may give a stop signal and the operator obeys it.

Abort criteria. Measurable, every one. Wind above the manufacturer's limit for this configuration measured at the stated point, loss of both communication methods, any measurable settlement at a float, any load moment indicator alarm, loss of visibility of the load by the signal person.

The sequence, and the sign-off. Numbered steps, including the trial lift: break the load free, hold it a few inches clear, confirm it hangs level and the machine behaves, before anything moves horizontally. Signed by the qualified person who wrote it and the lift director who will run it.

The plan, filled: a fabricated pipe rack module

Load. Fabricated pipe rack module. Weight 9,400 lb, source: fabricator's certified weight ticket. Two rated lifting lugs 18 ft apart, each rated 6,000 lb at 60 degrees from horizontal, source: fabrication drawing. Centre of gravity: see the stop below.

Rigging, on the drawing's centred centre of gravity.

• Vertical share per lug, centred: 9,400 lb / 2 = 4,700 lb
• Sling angle, from horizontal: 60 degrees
• Angle factor per leg, one over sine 60 degrees: 1.155
• Leg tension: 4,700 lb x 1.155 = 5,430 lb per leg
• Sling working load limit, from the tag, single leg vertical: 8,400 lb. Pass
• Inward horizontal at each lug, 4,700 / tangent 60 degrees: 2,713 lb
• Lug rating at 60 degrees, from the drawing: 6,000 lb against 5,430 lb. Pass

Total suspended.

• Module: 9,400 lb
• Hook block, from its marking: 1,200 lb
• Jib, stowed, from the chart deduction table: 1,600 lb
• Slings, shackles, master link: 210 lb
• Total: 12,410 lb

Machine. 100 ft main boom, jib stowed, full counterweight, full outrigger extension, 360 degrees area of operation.

Geometry. Pick radius 22 ft. Set radius planned at 25.5 ft. Governing radius built from the terms the radius card names: 25.5 ft planned, plus 2.0 ft boom deflection under load, plus 1.0 ft swing-out, plus 0.5 ft placement tolerance, which is 29.0 ft governing.

Capacity, first pass. Had the crane been set where the first sketch put it, the governing radius would have been 40 ft, and on the illustrative chart table for this configuration that row reads 12,900 lb gross.

• Percent of chart: 12,410 / 12,900 = 96.2 percent

Capacity, as planned. The crane position was moved in toward the module so the governing radius came out at 29.0 ft, which takes the 30 ft row at 18,000 lb gross.

• Percent of chart: 12,410 / 18,000 = 68.9 percent

Repositioning moved the same lift from 96.2 percent to 68.9 percent with no change to the load, the rigging or the machine. That is the highest-value line in any lift plan and it is only available before the outriggers go down.

Ground. Critical outrigger reaction at 29.0 ft radius, from the manufacturer's reaction data: 58,000 lb, a figure that already contains the machine, counterweight, boom and suspended load. Mat 10 ft by 5 ft, plan area 50.0 ft2. Effectiveness factor from the mat manufacturer, illustrative here: 0.80, giving an effective area of 40.0 ft2.

• Pressure: 58,000 lb / 40.0 ft2 = 1,450 lb/ft2
• Allowable bearing pressure, from the site geotechnical report: 2,000 lb/ft2. Pass

Zones. Exclusion zone coned at the module footprint and the landing area, swing path cleared, and the tail swing marked, because the counterweight sweeps ground nobody watches.

Abort criteria. Wind above the manufacturer's stated limit for 100 ft of boom with this load's face area, measured at the point the manufacturer specifies. Loss of both radio and hand signals. Any float mark movement. Any load moment indicator alarm.

The field that stopped the plan

Centre of gravity. The fabrication drawing shows it centred between the lugs. The module was modified in the yard after that drawing was issued: a small pump skid was added at one end. Nobody re-issued the drawing.

That single unanswered field invalidates the rigging block above, and it is worth showing by how much. Suppose the addition moved the centre of gravity 2 ft toward one lug on the 18 ft span. Using the two-point reaction relationship from the fields section:

• Near lug: 9,400 lb x (9 ft + 2 ft) / 18 ft = 5,744 lb
• Far lug: 9,400 lb x (9 ft - 2 ft) / 18 ft = 3,656 lb
• Check, the two reactions sum to 5,744 + 3,656 = 9,400 lb

The plan's equal-share line said 4,700 lb per lug. The corrected near-lug share is 5,744 lb, which is a re-basing of that figure, not an addition to it. Everything downstream re-runs against the corrected value:

• Near leg tension, held level at 60 degrees: 5,744 lb x 1.155 = 6,634 lb
• Lug rating at 60 degrees, from the drawing: 6,000 lb. Fail

A weight that was certified, a sling well inside its tag and a crane at 68.9 percent of chart, and the lug is over its rating by about 11 percent because of a field nobody filled in. Note also that "held level" is doing work in that line: with an off-centre centre of gravity the module hangs tilted unless the sling lengths are adjusted, and once it tilts the two legs are not at 60 degrees any more, so even the corrected figure is a planning estimate.

So the plan does not get issued. The resolution is not a trial lift to see which way it leans, because the load's first move would then be an uncontrolled tilt with a crew standing near it. It is a re-weigh and a re-established centre of gravity, done on the ground by the fabricator or a qualified person, before the plan closes. Where a load's balance is genuinely unknown, that is the finding, and it changes the job rather than the arithmetic.

The read-back, and the two lines it usually catches

Hand the finished plan to the person who will run it and have them read the numbers back out loud to the operator, at the tailgate, with the machine stationary. Not the whole document; six lines. Configuration, governing radius, gross chart figure, total suspended, percent of chart, and the abort criteria.

Two failures surface almost every time this is done and almost never otherwise. The first is a configuration mismatch: the plan assumes a stowed jib and the jib is erected, or it assumes full outrigger extension and a fence forced an intermediate setting. Either one puts the crew on a different chart table, which is a re-basing of the whole lookup, and the plan goes back to the qualified person.

The second is an unmeasurable abort criterion. "Abort if the wind gets up" survives the drafting and dies at the read-back, because the person who has to call it will ask what number and what they are measuring it with.

One hazard the sequence itself creates. A tag line orients a load; it does not stop one. Nobody wraps a tag line around a hand, a wrist or a body, everyone holding one stands outside the swing path and outside the load's footprint rather than being towed into it, and the line is long enough that holding it does not require standing under the load. Write that into the sequence step rather than assuming it.

References

• 29 CFR 1926 Subpart CC, cranes and derricks in construction, including 1926.1417 on operation within rated capacity and manufacturer procedures, 1926.1419 on when a signal person is required, and 1926.1432 on multiple-crane lifts, which must be planned by a qualified person
• 29 CFR 1926.251, rigging equipment for material handling, including the requirement that slings and fastenings be inspected each day before use by a competent person; 29 CFR 1910.184 is the general-industry counterpart
• 29 CFR 1926.1402, ground conditions, which assigns the ground preparation duty to the controlling entity on a construction site
• ASME B30.5, mobile and locomotive cranes, and ASME B30.9, slings, in the edition adopted by your employer's program, your contract or your authority having jurisdiction
• See related: What Radius Does to a Crane Capacity and Why It Surprises People; What a Critical Lift Is and What Changes When It Is One