Bridges presentation
Figure 12 Whipple Truss Bridge (1867), Normanskill
Farm, Albany, New York (USA), remains in service to
this day, restricting only buses and trucks, thus
testifying to the efficacy of Whipple's design. All
members are original, their sizes determined by the
forces they carried, deduced from scientific analysis.
Smithsonian Institution
The first practical design solution was obtained independently in the USA by Squire Whipple in
1847, and in Russia by D I Jourawski in 1850. Whipple had been working on the problem since
before 1841, when he patented and built his all-iron bowstring truss bridge, which proved
exceptionally suitable for short highway and canal spans. His book on stress analysis, A Work on
Bridge Building, is recognized as the USA's contribution to structural mechanics for the period. His
major breakthrough was the realization that truss members could be analysed as a system of forces
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