Gantry crane design calculation

Check a mobile A-frame or column-type gantry crane with real numbers. Enter the load, the hoist and trolley, the beam profile, span and height, the end frames and the castors, then drag the hoist along the beam or use the slider. The calculator gives the allowable load at the most unfavourable trolley position, names the governing check and marks it in orange in the drawing. Free, in the browser, metric or imperial, with print to PDF.




How a gantry crane beam and frame carry the load

The beam spans between two end frames and carries the trolley on its bottom flange. The bending moment is highest with the trolley near mid span: M ≈ φ·q·L²/8 + ψ·F·L/4, where q is the beam self-weight, F the load plus hoist and trolley, and φ, ψ the dead and moving load factors. The castors and legs are most loaded with the trolley at a frame. The wheels also bend the bottom flange locally, which often governs light I-beams before the beam itself.

Gantry crane design calculator: A-frame gantry with the trolley near the left frame, allowable load and utilisation chart
Trolley near the left frame: the most loaded castors govern.
Gantry crane design calculator: the same A-frame gantry with the trolley moved to the right, utilisation along the trolley travel
The same gantry with the trolley at the right frame.

What the free gantry crane calculator checks

  • Beam bending and shear, and the bottom flange under the trolley wheels (prEN 15011)
  • Deflection from the moving load: L/500, L/900, L/1000, or L/600 for the total deflection to EN 1993-6
  • Leg or column buckling, struts and base beam (EN 13001-3-1)
  • Castor loads, push force and stability across the beam
  • Bending moment, shear force and deflection diagrams for any trolley position, with the part beyond each limit in orange
Bending moment, shear force and deflection diagrams of a gantry beam with the allowable moment and the deflection limit exceeded, the exceeded part shown in orange
Overloaded beam: the parts of the diagrams beyond their limit lines are orange.

The method reproduces worked examples from Górecki’s crane textbook and two gantry designs by the author, a 500 kg A-frame and a 2 t column-type gantry.

Free and Pro

Free Pro
A-frame and column end frames, all profiles and values yes yes
Beam, flange, deflection, legs, castors, stability yes yes
EN 13001 limit-state method, lateral–torsional buckling, custom sections – yes
Calculation report, saved projects, comparison of variants – yes

The Pro version is in preparation.

From calculation to production drawings

The calculator sizes the beam, legs and castors; building the gantry needs the full design. papacad.com offers gantry crane CAD projects: 3D assemblies, STEP files, 2D production drawings in DWG and PDF, and a bill of materials, ready for a fabrication workshop. Check your load and profiles here, then use the drawings to cut, weld and assemble the crane.

More for crane design

Your Cart

No products in the cart.