This posting may be only a testament to my ignorance (and perhaps is information already well-known to forum members) but I learned something about pontoons reading Muffling's Memoirs recently. I had always assumed, unthinkingly, that pontoon-bridges and pontoons were made from wood, boats, wooden boxes, or something like that. Apparently they were also made of copper, and even of canvas.
Muffling described a bridge of canvas pontoons. He said they were used "with great advantage" during the 1813 campaign. 12-pdr batteries had crossed such bridges. Being so light, though, "even a small quantity of floating ice would have destroyed the bridge."
In a footnote on page 406 he describes the canvas pontoons:
"A pontoon train of this sort consists of frames of the same form as a copper pontoon, which are to be laid down separately. Round these frames, strong canvas, soaked in pitch, is nailed in such a manner that the whole takes the form of an usual pontoon. The canvas resists the water. A carriage is necessary for each pontoon; but these carriages are so light they can be driven on all kinds of roads. If the canvas is easily damaged, it has the advantage of being easily repaired, which is a long process with copper pontoons."
Did all armies use copper pontoons? Canvas? Any other materials?