Trusses, Trusses Everywhere….Some Truss History
I was out for a walk the other day and as I looked around I noticed how many different examples of trusses that we see in our daily lives. They are all around and uses for this type of structure are numerous. I walked across a trussed bridge, saw a tower for power lines that used trusses, and saw a structure over railroad tracks. It got me thinking about how long the concept of trusses has been around and how people designed and built trussed structures without the use of the design tools and technology that we have at our disposal today.
Trusses have been around for a long time as evidenced by the use of trusses in ancient structures. People figured out how important the triangle was in the design of structures. Matter of fact, when my son was 8 years old he did a science fair project to show how much better the triangle worked in supporting structures. Prior to the 19th century, trusses were designed using the idea of proportions. This can be traced back to the 1st century BC to Vitruvious who wrote a book de Architectura. As society modernized, rational design began to be used in the design of structures and people could evaluate the design by looking at stresses within members. The word truss comes from a French word “trouse” c.1200 meaning a collection of things bound together. A simple definition of the word truss according to dictionary.com is “a structural framework of wood or metal, esp one arranged in triangles, used to support a roof, bridge, etc.”
I am always fascinated to see pictures of structures thousands and hundreds of years old and wonder how people were able to construct and design them with not much more than human horsepower.
Old St. Peters Basilica from the 4th century
York Minster Cathedral 1154-1500
Trussed bridges from the early 20th century
Modern trussed structures
The idea of metal plate connected trusses that we use today began in 1952 in Pompano Beach, FL by A. Carroll Sanford. This idea revolutionized the building industry by allowing for larger clear span capabilities and open room designs. Additionally, this method of manufacturing and erecting these structures proved to be very cost-effective and efficient as compared to previous methods of truss design and construction.
Next time you are out and about, take a look around and see what type of trusses you encounter. You might just be surprised how many are out there! Then come back here, post what you found and share them with us!
Bill Hoover – Design Professional
Gould Design, Inc.