Page 16 - Wire Rope News & Sling Technology - October2019
P. 16

The History of the


                           Wire Rope’s Invention


                      and the Decisive, but Unfortunately Transitory,
                                        Role of French Engineers

                                       by Jean Marc Teissier and Don Sayenga
                                                    Part One:
              History Begins in France, with Suspension Bridges

         Wire rope was invented to replace fiber rope, or chain, in many applications, including
         the construction of suspension bridges, and hoisting of heavy objects with machines.
         Fiber ropes were produced using natural fibers, mainly hemp and sisal. The use of
         fiber ropes dates from before the age of antiquity (3000 BC). The use of chains, which
         is much more recent, followed the progress of the iron/steel making techniques.


              he first chain suspension bridges   dre III Bridge was later erected in the   ened his  position.  The Tournon  Sus-
              were built at the very beginning   same place.                   pension Bridge opened to the public in
         Tof  the  19th century.  They  were   Claude Navier published in 1823  a   August 22, 1825.
         designed and built by American engi-  book Rapport et Mémoire sur les ponts   Independently  of  the  Tournon
         neers (James Finely) or English engi-  suspendus, which was re-published in   Bridge,  Swiss  authorities  were  man-
         neers  (Thomas  Telford).  These  first   1830 with  additional information  re-
         constructions  were mainly based on   lated to the Invalides Bridge. This book
         empirical approaches.              has been used as a reference for the de-
           Claude Navier was a “polytech-   sign of suspension bridges. Although it
         nicien”* engineer, most known for his   was written for chain suspension, the
         mathematical works,  especially those   exposed theories were fully applicable
         applied  to  fluid  mechanics  (Navier-  for  wire rope suspension  bridges.  In
         Stokes equations). He was also a civil   fact, today  the equation for the equi-
         engineer “des Ponts et Chaussées,” and   librium of weighing wire is still named
         worked on the construction of the first   the equation of catenary, or “équation
         Invalides Bridge in Paris.         de la chaînette” in French.
           This  chain  suspension  bridge was   Parallel wire cable was invented at   Rope with parallel wires (Marc Seguin).
         intended to be an  example of optimi-  that time. The invention of parallel
         zation,  as  opposed to  the  same  type   wire cable is usually credited to Marc   aging the project of the Saint Antoine
         of bridges built in England and in the   Seguin, but the story is a bit more   Bridge in Geneva. Marc Seguin sub-
         US. Claude Navier, an expert in math-  complicated.                   mitted  a  bid,  but  the  contract  was
         ematics, developed a global theory on   Marc Seguin began working on the   finally  awarded  to  Guillaume  Henri
         the matter of suspension bridges. As a   Tournon Bridge project in 1820. In 1822   Dufour. The Saint Antoine Suspension
         result of the accuracy of his theoreti-  he built a prototype  over the Cance   Bridge opened to the public on August
         cal approach,  the safety factors  were   River. The construction of the Tournon   1, 1823. Factually this is the first wire
         reduced. Unfortunately, there were not   Bridge was delayed because the project   cable  suspension  bridge  in  history.
         enough margins of error. In September   was changed from a pedestrian bridge   Credit  for  the  invention  of  parallel
         1826, when the bridge was fully erect-  to a bridge for vehicles,  and because   wire cable is usually given to Marc Se-
         ed, an underground water pipe on one   Seguin was busy with other projects.   guin because, not only was his project
         bank broke, compromising the founda-  Navier considered parallel wire   ready before Dufour’s project, but also
         tion of one of the piles. The bridge be-  cable to be a competitor of chain. But       continued on page 18
         gan to crack.  It was  dismantled even   by 1824, the problems faced by Navier   All photos and illustrations courtesy of Jean Marc
         before its grand opening. The Alexan-  with  the Invalides Bridge, had weak-  Teissier unless otherwise noted.













         Multi strand rope (Julius Albert) – theoretical section (left), and replica by Roland Verreet (right).
         16     Wire Rope News & Sling Technology   October 2019
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