Bridge Tradeoffs

Now we need to decide which type of bridge we are going to build. 

• The arch bridge won’t work, because it needs ends to push against on the tester, and the tester's support blocks would slide if pushed.

• The suspension bridge won’t work either, because it needs ends to pull against on the tester, and the tester's support blocks would slide if pulled. 

• The cantilever bridge won’t work because it needs weights on each end, and that would make the bridge weigh too much. 

• The beam bridge might work but it’s inefficient. 

• The truss bridge will work. It's more efficient than the beam bridge. 

• Of the different types of truss bridge, we wound up building a "Queen Post" bridge.  We describe the pieces of a Queen Post Bridge in more detail in the next section.