Page 16 - Wire Rope News & Sling Technology - October2019

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