If a structure is going to be strong it needs support struts, the square bellow did not take much effort to break:

Now if you add an extra strut…

…it becomes much stronger, this is called triangulation. The bridge structure I’ve chosen are a selection of methods of using triangulation.

Now for the bridge structures, I’m going to test a Pratt truss, a Howe truss, a Warren truss with vertical supports and an inverted Warren truss with vertical supports.

First the Pratt truss:

This structure took 250g before collapsing, It’s not looking good for my bridge building as it appears it is one of the glue joints that gave way…

Now the How truss:

This structure took 250g before collapsing, definitely a structural collapse this time.

On to the Warren:

Collapse happened after 260g

And Finally the inverted Warren:

The structure made it to 250g before collapsing in a heap.

So now I have my strongest structure; a Warren Truss :) Onward to bridge building!