Eyebar

In structural engineering and construction, an eyebar is a straight bar, usually of metal, with a hole ("eye") at each end for fixing to other components.

In the center of this end will be a hole which will receive a cylindrical pin, which may have provision to accept one or more nuts or bolts.

If of round cross section the bar will typically be end-forged to create a head, which is then flatted by additional forging.

This field reaming ensures that stresses will be uniformly distributed among the several bars forming the truss element or the chain link.

Corrosion resistant treatment in the form of grease, white or red lead oil paste, or other water-excluding material may be added at the time of the assembly.Eyebars are used in portions of pin-jointed trusses where it can be established by engineering procedures that the bar will not be imposed with any stress other than tension under all expected conditions.

However, more modern low-redundancy chain link suspension spans fell into general disfavor as a result of the collapse of the Silver Bridge in 1967, which led to the deaths of 46 people.

(The current method of suspension bridge design is to use multiple strands of drawn wire to form substantial cables.

Oxygen gas is funneled past an electrode creates an arc, which can be channeled down into steel allowing the metal to be cut.

As a result, the steel pins in the eyes become loose and lose tension, which in turn compromises the integrity of the structure.

Researchers like Dewey Walls Jr. of the Union Pacific Railroad have compiled resources on how to review, identify compromised locations and how to properly repair the area.