Girder

A girt is a vertically aligned girder placed to resist shear loads.

[2] The Warren type girder replaces the solid web with an open latticework truss between the flanges.

This arrangement combines strength with economy of materials, minimizing weight and thereby reducing loads and expense.

Patented in 1848 by its designers James Warren and Willoughby Theobald Monzani, its structure consists of longitudinal members joined only by angled cross-members, forming alternately inverted equilateral triangle-shaped spaces along its length, ensuring that no individual strut, beam, or tie is subject to bending or torsional straining forces, but only to tension or compression.

It is an improvement[citation needed] over the Neville truss, which uses a spacing configuration of isosceles triangles.