In 1841, Squire Whipple found a cheaper way to build long iron bridges; more than 100 of his designs later crossed America's canals and growing railroad lines

Picture upstate New York in the early 1800s: a landscape dotted with wooden bridges which are rapidly buckling under the combined weight of barges, wagons, and the burgeoning traffic of the Erie Canal. Step in Squire Whipple, a relatively unassuming graduate of Union College who looked at this national engineering conundrum and set out to solve it with mathematics rather than guesswork.

According to the National Inventors Hall of Fame, the industrious Mr. Whipple went on to patent an iron truss bridge design in 1841 that has seen more than 100 uses across America's waterways and early railroad systems. And for a man whose name evokes the image of a well-tailored three-piece suit, his place in history could not be more forward-thinking: the bridges built to his specifications are cheaper, stronger, and mathematically sound.

A problem the trade had never tried to solve with math


Prior to inventing the Whipple truss, bridge-building in America was the domain of guesswork: carpenters looking at the designs of their predecessors and slowly adapting their attempts until a successful model was made. A native of Hardwick, Massachusetts, who cut his teeth on the various machines put together by his father, young Squire was looking to build bridges for a living, but not just any bridges; he wanted to know, for every piece in his proposed bridge designs, exactly what weight it would bear.

His instincts were rewarded in 1841 when a patent was granted (US Patent #2,064) for his original bowstring design, allowing him to test his theories on a canal bridge near Utica, built into the Erie Canal with his own savings with a budget of approximately $1,000. The design, which saw the use of two metals in a truss construction for the first time, used cheaper cast iron in the arch and stronger wrought iron in the lower "string" of the design to hold up the anticipated weight of the traffic over the banks of the canal. By using the less expensive material in the portions of the bridge that required it, Squire proved that it was possible to build a large-scale structure without breaking the bank in the process, an approach that has since come to define the modern American economy.

The part that made engineers into scientists

In 1847 Squire went one step further, publishing a short treatise on the mechanics of bridge design called A Work on Bridge Building, which, according to a 2002 peer-reviewed technical paper titled “Squire Whipple—Father of Iron Bridges,” published in the Journal of Bridge Engineering, earned Dr. Whipple global recognition as the scientist who first worked out how to calculate the forces within a truss frame, and who went on to share this information with the world. This may well be the most important lesson that the modern reader can take from the career of Squire Whipple: that the process of building things is only one part of the equation.

By publishing his calculations, Squire was able to transform a cottage industry of bridge-building into an international scientific pursuit. STRUCTURE magazine, published by the American Society of Civil Engineers, records that engineer Alfred Boller described Whipple as “the retiring and modest mathematical instrument maker” who, working without precedent or an established engineering curriculum to draw on, arrived at the scientific basis of bridge design largely on his own.

A 19th-century founder who got nothing for his troubles

And so, having created a design methodology that has since been imitated hundreds of times, Squire Whipple found himself in much the same position as many a start-up founder at the turn of the 21st century. Inventionandtech.com, the archive of the former American Heritage magazine on the history of technology, reports that despite his efforts to collect royalties, the enterprising Mr. Whipple was never compensated for his troubles. In his day, the State of New York adopted his "Patent Iron Arch Truss Bridge" as the standard for its canal bridges, but when it came to the money, New York claimed that the work on the bridges was "for the public good." Between 1842 and 1870, hundreds of bridges were built to his design, most of them without Squire receiving a penny in compensation.

Why his bridges still matter

Today, nearly two centuries on from that 1841 patent, few of Squire Whipple’s original bridges remain intact, though some notable reconstructed examples can be found at Union College and throughout New York State. His impact on the built environment of America is immeasurable. Every time an engineer goes to perform a mathematical analysis on a proposed design, they owe a fraction of their thanks to a farmer’s son who made the math work. Not bad for a man few modern Americans would likely recognize.