A Practical Treatise on Suspension Bridges; Their Design, Construction and Erection

📘 This historic book may have numerous typos and missing text. Purchasers can download a free scanned copy of the original book (without typos) from the publisher. Not indexed. Not illustrated. 1922 Excerpt: ... direction are relieved of load. 14. Anchoring of the Cables.--Parallel wire cables are anchored by making the end of each strand in the form of a sling. With the wrapping omitted at the end of the cable, the free wires loop around a half-round, flanged casting called a strand shoe (Fig. 36), and then pass back into the strand. Large cables are divided for this purpose into 7, 19 or 37 strands; and such cables accordingly have 7, 19, or 37 strand shoes at each end. Steel pins pass through these shoes for connection to the anchorage eyebars (Fig. 32). The strand shoes are grouped into a number of horizontal rows (generally 2 or 4), and the anchor chain divides into an equal number of branches to effect the connection (Fig. 32). About 10 feet forward of the shoe, the two halves of a strand are combined into one; and all strands, before leaving the masonry, are squeezed into a round cable. The shoes have slotted pin-holes which are provided with shim-blocks (Fig. 36) to permit regulation of the individual strands before combining into a cable. Bending the wires around the shoe produces bending stresses exceeding the elastic limit; but the resulting stretching of the outer fibers redistributes the stress over the cross-section of the wire; with properly ductile steel wire, the strength at the loop is not materially impaired. If the wire is very hard, or if the cable consists of wire ropes, a larger radius of curvature must be provided or some other form of connection must be used. For wire ropes a larger shoe is used, with the end of the rope fastening into a socket after bending around the shoe. The sling construction is avoided by setting the ends of the strands or ropes directly into steel sockets. After inserting the rope into the expanding bore of the sock...