ABSTRACT
Cables can only transfer load through tension. All cables must have some sag in order to support a load. This is because the resultant force through a cable is in the direction of its axis and because a cable, in theory, cannot transfer loads through shear. Imagine a cable with no sag. The reactions at the cable supports must be in the same direction as the axis of the cable. If a cable has no sag, the direction and therefore the reactions are only in the horizontal or x direction. When forces are summed in the y direction: Σfy = 0 = W, therefore the load W must be 0. A cable must have some sag https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780203583159/43b499e8-36af-4c2c-ba25-59ab9f62f21b/content/Page21-01_B.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/>
