I have always been interested in bridges growing up and the first design exposure I had was in college in a strength of materials class. The task was to build a truss out of raw sheet metal to hold 100 lbs. I chose a Parker truss to build and found all the tension and compression members. From there I found all the loads on the members using the pin method and then calculated the width of each member. The bridge went together well and held the 100 lbs. Fine. It was a very rewarding project.
Years later I started to notice covered bridges and thought to myself how rewarding a job that must have been to the engineers, designers and builders at the time. I built a post and beam model of a "x-truss" covered bridge just to have over the mantle in my house. I feel it is a nice conversation piece. I then wondered if other people would like to have a covered bridge. I decided instead of a model on a mantle, to have the bridge functional for people. If it had a function, more people might find it more attractive. I decided to model the mailbox bridge after actual bridges. I picked two styles to begin, the Swift River bridge in Conway Village, New Hampshire and the Jackson Honeymoon Bridge in Jackson, New Hampshire. I picked these two because they share a lot of similarities: They both are Paddleford trusses and look very similar except for colors, end caps and side skins. I am a mechanical engineer by trade and always enjoyed working with wood. This project took a lot of research, skill and resources to build.
[For more about Tim's mail boxes, go to the index page and click on Market Place - Ed.]