Crane Pick Percent-of-Capacity Checker

Sums the gross load, checks it against chart capacity at the pick and set radii, and tells you whether you're in standard-pick or critical-lift-plan territory. Runs entirely offline; inputs persist in this browser via localStorage.

This is not a lift plan. It is a sanity check for the OAC meeting and the pre-task plan. The load chart for the specific crane in its actual configuration (boom length, counterweight, outrigger position, on-rubber vs. on-outriggers) governs, and the chart's General Notes are part of the chart. Ground bearing, wind, two-crane picks, and personnel platforms are all outside this tool. The qualified lift director makes the call, not the phone.

Gross Load Buildup

Load weight (lb)

From the submittal / shipping papers — verified, not guessed. Include skids and shipping steel if they ride up.

Rigging (slings, shackles, spreader) (lb)

Block / headache ball (lb)

Most charts require deducting the hook block and ball — it hangs on the boom whether you like it or not.

Other deductions (jib erected/stowed, aux line, etc.) (lb)

Per the chart's deduction table for the configuration.

Chart Capacity

Chart capacity at PICK radius (lb) Pick radius (ft) — for the record

Chart capacity at SET radius (lb) — optional Set radius (ft)

If the crane swings the load out to set it, the larger radius almost always governs. Enter both and the tool checks the worst case.

Critical lift threshold (% of capacity)

From the contract specs / owner's safety requirements — not a universal number.

—

Gross load	—
Percent of capacity — pick radius	—
Percent of capacity — set radius	—
Governing condition	—
Margin to chart capacity	—

How the Numbers Are Derived

The math (it's division, done honestly)

Gross load = load + rigging + block/ball + other deductions

% of capacity = gross load / chart capacity at radius × 100

The whole game is in the inputs: an "18,000 lb pump" that is actually 18,000 lb dry, plus a 900 lb spreader, 400 lb of slings and shackles, and a 1,200 lb block, checked at the set radius instead of the pick radius, is a different lift than the one in your head.

What "critical lift" usually triggers

Above the contract's threshold (commonly 75% of chart capacity, or any two-crane pick, or picks over energized lines / occupied facilities), most specs require a written critical lift plan: crane configuration and chart page, rigging diagram with capacities, verified load weight, ground bearing analysis under the outrigger floats, and sign-off by a qualified person before the pick. Below the threshold, standard pre-lift documentation applies. Either way the operator retains stop-work authority.

Common ways this check goes wrong in the field

Reading the chart for the wrong configuration — full counterweight vs. reduced, outriggers full vs. intermediate, over-the-rear vs. 360°.
Radius measured to the wrong point. Radius is from the center of rotation to the hook, not from the outrigger or the tracks — and it grows as the boom deflects under load.
Forgetting the load will swing to a larger radius to reach the set point.
Weights from memory. Get the bill of lading, the submittal, or weigh it.
Wet/soft ground under one float. Percent of capacity is meaningless if an outrigger punches through — matting and ground bearing are their own check.

References

OSHA 29 CFR 1926 Subpart CC — Cranes and Derricks in Construction. https://www.osha.gov/

ASME B30.5 — Mobile and Locomotive Cranes. https://www.asme.org/

The load chart in the cab of the specific crane, including its General Notes — the actual governing document.