Standing Rigging Wire Size Calculator

Inputs

View results
Working/design load used for this rigging member.
lbf
Required breaking strength multiplier. Use class, designer, rigger or manufacturer requirements.
Minimum breaking strength from the exact wire and terminal manufacturer.
lbf
Nominal wire diameter.
in
Approximate straight wire span used for elastic stretch.
ft
Effective axial modulus for the wire construction. Stainless wire rope is commonly below solid-bar stiffness.
Mpsi
Approximate fraction of solid round area occupied by metal in the strand construction.
Initial dockside tension as a percent of selected wire breaking strength.
% MBS

Results

Default result
Edit inputs
Required breaking strength
4,000lbf
Pass

Also computed

Selected safety factorPass5

Strength utilizationPass0.8x

Required breaking strength divided by selected wire breaking strength.

Breaking-strength margin1,000lbf

Initial tension load750lbf

Estimated metallic area0.03682in²

Elastic stretch at initial tension0.2661in

Method notes 3 notes
  • Required breaking strength = design load * target safety factor.
  • Elastic stretch uses delta = F*L/(E*A), with A estimated from nominal wire diameter and metallic area factor.
  • Standing rigging is safety-critical. Final wire size, terminal choice, swage/mechanical fittings, fatigue, corrosion, toggles, chainplates, mast geometry and inspection intervals require a qualified rigger, surveyor, designer and applicable rules.

Powered by MachineCalcs ↗