Week 6

In week 5 we finally got to start working with Knex.  When making our 2’ bridge we combined all of our ideas together.  We took designs similar to the ones we drew and the ones we created in Westpoint Bridge Design.  Our design was a little bit expensive.  Apparently it only costs $250,000, I think I may cost more but I did not do the estimate.  Our first design started out with a bunch of cubes put together to span 2’.  We tested this design out and there was not enough weight to break it.  After we brought the original bridge back to our station we added a top piece that covered the middle.  This design now looks similar to the one I made in Westpoint Bridge Design but with different trusses. 

            My views of the similarities and differences have not changed at all.  Obviously there are going to be a lot of differences between a Knex bridge and a 20’ real bridge.  The first thing that comes to mind when comparing the two is the materials that are used.  Cement and steel are a lot different then plastic.  The real bridge will be able to hold a larger weight because of the stronger materials that it has.  Another thing is that the Knex really limits what designs you can make.  There are only certain angles that you can make with Knex but on a real bride you can make what ever angle you would like.  In the real world a bridge cannot simply be tested like the Knex to see how much weight it can hold.  Engineers need to be 100% sure that their bridge can hold X weight otherwise lives are being put in danger. 

        -John Watson