Estimate beam demands from load, span, and geometry. Check tension, compression, stress, and deflection clearly. Use practical outputs before formal engineering review and approval.
Overall page flow stays single column. The input controls use a responsive 3-column, 2-column, and 1-column form layout.
This calculator models a symmetrical spreader beam with a center lifting point and two lower pick points. It also checks a two-leg top sling case for added beam compression.
Gross Load = Lifted Load + Beam Self Weight
Design Load, W = Gross Load × Dynamic Factor
Maximum Moment, M = W × L / 4
Allowable Stress = Yield Strength / Safety Factor
Required Section Modulus, S = M / Allowable Stress
Deflection Limit = L / (Deflection Ratio)
Required Inertia, I = W × L³ / (48 × E × Deflection Limit)
Bottom Sling Tension = W / (2 × cos(bottom angle from vertical))
Two-Leg Top Sling Tension = W / (2 × sin(top angle from horizontal))
Beam Compression from Two-Leg Top Sling = Top Leg Tension × cos(top angle)
The quick trial check uses entered section properties to estimate bending stress, compression stress, combined stress, and deflection. It does not replace detailed checks for lateral stability, local flange/web effects, welded lug design, or connection eccentricity.
Illustrative scenarios only. Use them to benchmark your own inputs.
| Scenario | Load (kN) | Span (m) | Design Load (kN) | Moment (kN·m) | Req. Sx (cm³) | Req. Ix (cm⁴) | Bottom Sling Tension (kN) | Status |
|---|---|---|---|---|---|---|---|---|
| HVAC skid lift | 90.00 | 3.00 | 108.10 | 81.08 | 541.58 | 4,560.47 | 54.26 | PASS |
| Generator module | 160.00 | 4.50 | 201.60 | 226.80 | 1,515.02 | 21,262.50 | 101.79 | PASS |
| Precast panel spread | 210.00 | 5.00 | 275.00 | 343.75 | 1,617.08 | 35,807.29 | 139.62 | PASS |
| Pipe rack module | 300.00 | 6.00 | 378.00 | 567.00 | 2,667.30 | 85,050.00 | 193.22 | PASS |
It estimates major actions for a symmetrical spreader beam with two lower pick points. Outputs include design load, sling tension, maximum moment, required section modulus, required inertia, and a quick trial-section check for stress and deflection.
No. It is a screening and planning tool. Final designs must verify lugs, welds, local flange and web limits, stability, buckling, torsion, fabrication tolerances, and all project-specific rigging requirements.
As the sling moves away from vertical, less of its force acts vertically. Each sling therefore needs more total tension to support the same share of the load.
Each top sling leg pulls inward as well as upward. That inward component introduces axial compression in the beam, which can raise combined stress and affect member selection.
Enter the strong-axis section modulus, strong-axis inertia, and gross area of your trial beam section. These values are commonly taken from manufacturer tables or steel section manuals.
Loads are in kN, span is in meters, stress is in MPa, modulus is in GPa, section modulus is in cm³, inertia is in cm⁴, and area is in cm².
That depends on company practice, beam service expectations, and project rules. Many users adopt a ratio such as L/450, L/500, or L/600 for planning checks, then confirm with design standards.
A beam can satisfy bending while failing deflection, compression, or detailed connection checks. That is why the calculator reports several checks and still recommends engineering review before lifting.
Important Note: All the Calculators listed in this site are for educational purpose only and we do not guarentee the accuracy of results. Please do consult with other sources as well.