Crane Swing Radius Calculator: Planning Worksheet
Explore boom outreach geometry and a planning circle for rear swing. Example values are illustrative; they do not determine a safe exclusion zone or lifting capacity.
United States federal OSHA references. The Spanish translation does not establish requirements for Mexico.
Illustrative geometry
Do not use these results as lift authorization, rated capacity, or minimum safe clearance. Obtain the rear swing radius from the actual equipment and its documentation. The example allowance is not an OSHA requirement.
Geometry results
- Approximate horizontal outreach
- 25.00 ft
- Planning circle radius
- 9.00 ft
- Planning circle area
- 254.47 ft²
Worked example
For an ideal straight 50 ft boom at 60° above horizontal with its pivot over the rotation axis: outreach = 50 × cos(60°) + 0 = 25 ft. If measured rear swing radius is 6 ft and this exercise uses a 3 ft allowance: circle radius = 6 + 3 = 9 ft; area = π × 9² ≈ 254.47 ft². These are separate calculations; boom outreach does not determine counterweight sweep.
The model assumes a rigid straight boom and a positive forward pivot offset. It omits jibs, loaded boom deflection, load dimensions, and rigging. Do not infer boom angle from hook height: hoist rope can change hook height without changing outreach. Obtain operating radius and capacity from the actual configuration and manufacturer load chart.
Before placing barriers
- Identify the actual superstructure sweep and places where someone could be struck or pinched, including elevated work surfaces.
- Assign someone at the briefing to verify the equipment, obstructions, boundaries, and communication system before operation.
- Mark hazard boundaries using the barriers specified by OSHA 1926.1424. Coordinate entry out of the operator’s view; the operator must wait for the agreed confirmation of a safe position before rotating.
- Assess load travel, power lines, ground conditions, wind, capacity, and other cranes separately.
Frequently asked questions
Does OSHA always require an extra 10 ft?
No. Section 1926.1424 specifies controls for areas with foreseeable struck-by or pinch/crush hazards; it does not prescribe a universal 10 ft allowance. Determine boundaries from the actual equipment and conditions.
Does a larger allowance permit operation in stronger wind?
No. Enlarging a circle does not resolve stability or capacity. Follow manufacturer procedures and the competent person’s assessment of wind, ice, and snow under 1926.1417.
Sources and scope
September 10, 2026 correction: removed arbitrary wind and weight allowances, the universal minimum-safe-clearance claim, and the outreach calculation based on load height.
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