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CABLE SPINNING

Support cables are an essential part of any suspension bridge design as they bear the load of the decks and traffic. Four spools, each containing 60 miles of steel wire and mounted on axles, were set up on the cable anchorages at the tops of the towers. Each wheel had two grooves and the wire was unreeled from two spools simultaneously, placing four wires in the cable on each trip of the spinning wheel. Guide wires were carefully laid into position, with the workers making constant adjustments so that all the wires were laid to the same sag, thereby sharing the load equally. When 472 wires were laid, they were bound with metal bands forming one strand. Thirty-seven strands were compressed by powerful compacting machines into one 28 ¾ - inch suspension cable. Repairs to the cable wires are impossible once the cable has been completed.
 

 
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Design & Construction | Cable Spinning
Autos & Trains | Charles H. Purcell | Celebration

Introduction | Related Links | Acknowledgements

Copyright © 1999 UC Berkeley Library
Data owner: R. Brandt
Updated 12/9/99