Algodoo

@frogman786: I assumed that "NO modifying the template scene" and "if its self constructing it must start in the box" meant that a self constructing bridge has to start in the box on the right. Since you allowed TC42 to move the box, that sets a precedent that I plan to take advantage of, as seen in the uploaded scene. I don't see where this breaks any rules if the box is allowed to be moved. This design accomplishes the task without any hinges and is 73% lighter than, and twice as fast as, the TC42 design. Also, on my computer, the TC42 bridge falls in the ditch 10/10 times. I can improve the situation by setting sim.frequency to 500, but I would consider that a scene change. I will also upload a solution that does not attach to the box, just in case you decide to make some last minute rule changes.