A2-HOWARD

I designed my bridge as a straight truss bridge with one level.  The most common shape I used is the triangle because it is considered the strongest shape and can hold a large amount of weight.  My goal was to use the minimum number of members in order to make it cost efficient.  I found that a more simple design is usually more effective in West Point Bridge Designer so I used that knowledge in designing my Knex bridge.  I decided to use one level because adding a second level caused a large increase in cost and was not necessary.  I also made the bridge out of smaller pieces instead of a few large ones because it is stronger and the cost is not much different. 

My original design for a bridge was made in WPBD.  It was a similar shape however the angles were slightly different making the length of the members different.  I had to take into account that Knex can only be joined in increments of 45 degrees.  My design also changed in that originally I had many more joints to add support but this made the price much higher.  I decided to use a simple design that was low in price.  My design still includes all triangles however there are less of them. 

From designing this bridge, I learned that the cost is very important.  It is very hard to design a safe bridge and keep the cost relatively low.  I also learned that you have to work with what is provided.  It was challenging to come up with a unique design while limited to 45 degree connections and predetermined sizes of members.   

                     Figure 1: Elevation

                     Figure 2: Plan

   Figure 3: Bill of Materials and Cost