Bridge Design – The da Vinci Bridge
Leonardo da Vinci (15 April 1452 – 2 May 1519), Wikipedia Link
Although he had no formal academic training, many historians and scholars regard Leonardo as the prime exemplar of the “Universal Genius” or “Renaissance Man”, an individual of “unquenchable curiosity” and “feverishly inventive imagination.” He is widely considered one of the most diversely talented individuals ever to have lived. During his lifetime, Leonardo was also valued as an engineer. With the same rational and analytical approach that moved him to represent the human body and to investigate anatomy, Leonardo studied and designed a bewildering number of machines and devices including the self loading bridge below. Watch Decoding da Vinci on NOVA (PBS) Click Here
The Self Supporting Bridge Design
Da Vinci invented the self supporting bridge sometime between 1485-1487 to be used as an emergency bridge for troops in times of war. This unique design is held together by its own weight without requiring any ties or connections, in fact when a downward force is applied to the structure the braced members are forced to interlock and tighten together through the structural concepts of shear and bending. Da Vinci called it “The Bridge of Safety”. His original design is pictured left.
In its simplest form a self supporting design can be seen in this drawing, top right – of course from the Boy Scouts! (click the image for a larger size) See much more “camp craft” projects – more bridges and pioneering projects CLICK HERE
Some History and Contemporary da Vinci Bridge Construction Examples
The videos below show the construction of a da Vinci Bridge in Germany. Complete construction of the DaVinci bridge on Schloßplatz on February 3, 2016. Eight apprentices from the Zimmerer training center and two masters build the bridge in under 10 minutes. The span of the bridge is 10m, its width is 3.50m and the apex is 1.70m. The Bridge has virtually no fasteners demonstrating the integrity of the design and the total distribution of the load as you can see when the car drives across. As you can see from the Bridge left – the deck can be any design of railing and platform – the load is carried by the woven design below it.
The Video on the Right is a Nova Series “Secrets of Lost Empires” broadcast in 2000
The best resource for da Vinci Bridge design plans is The Rainbow Bridge website by Frank Petersohn. He sells plans for any size bridge for a project for $25. Peruse his website for more details on construction, expanded views, and examples of bridge projects. The largest bridge is a 50 foot span constructed in Quebec – pictured above at the top of the page and also here. The Video Below is a group of boy scouts constructing a “friction” bridge (another term for self loading design). Another great hallmark of these bridges is the “portability” of materials – mostly 2″ x 6″ construction. I would also add that the footings are very important to this design success.