The engineering behind the film
A floating bridge carries its load differently from a bridge supported by piers. As a heavy vehicle moves onto its pontoons, they settle deeper into the water. The additional displaced water provides the buoyant support, while the roadway still has to carry the concentrated load from the vehicle's tracks.
The Improved Ribbon Bridge brings these ideas together in sections that can travel on trucks and unfold on the water. Connecting the sections creates a roadway, but that is only part of the job. River current pushes sideways, and the floating crossing has to meet fixed ground at each bank.
This film uses military training and bridge footage to explain buoyancy, load distribution and boat support. It also looks at how bridge sections can form a ferry when a complete crossing is not available.
