WEST POINT BRIDGE DESIGNER 2016 LOWEST COSTING BRIDGE HOW TO
If you do not know how to start designing your own bridge, I would recommend the Warren, or the Pratt or Howe trusses. I think the Warren is a very solid choice when designing a model bridge. In fact, you can get a learning kit using a Warren Truss from my store. I have also used for some popsicle stick bridges. I have definitely used the Warren truss design for many balsa and basswood bridges. Unfortunately, not many Warren bridges are made anymore. Thus, engineers must calculate how strong to make each member of the bridge and build accordingly. Thus, if you want your school project bridge to be able to hold more weight then try to spread out the force across the top of the bridge.įor a real life Warren Truss bridge, the forces often will be very localized and not spread out along the bridge. The top and bottom chord are under larger forces, even though the total load is the same. When the load is concentrated on the middle of the bridge, pretty much all the forces are larger. Interestingly, there is a significant difference. Therefore, you can take the numbers as a percentage of the total load. The second shows a localized load in the center of the bridge. The first shows the load being applied across the entire top of the bridge. Here are two diagrams showing how the forces are spread out when the warren truss is under a load. This happens especially to the members near the center of the bridge. Interestingly, as a load (such as a car or train) moves across the bridge sometimes the forces for a member switch from compression to tension. The equilateral triangles minimize the forces to only compression and tension. This is opposed to the Neville Truss which used isosceles triangles. The Warren Truss uses equilateral triangles to spread out the loads on the bridge. Examples of it can be found everywhere in the world. Regardless, the Warren Truss has been around a while and has been very popular. His patent was more about the methodology of building rather than a “design”. James Warren patented a design in 1848 (in England), which many attribute the name “Warren Truss”. It’s exact history and origination is a little muddled, however. The Warren Truss is a very common design for both real and model bridges.