We have been borrowing a bridge from another pack for several years. This year, our Webelos2 group (actually 2 dads) built a bridge for our own pack, based on the design of the one we've been borrowing. It doesn't collapse, but it stores small.
I don't have a digital image, so I'll have to draw and describe it.
------------
| |
------------
These pieces are the supports - really just 2x4's on end. We actually took the end pieces and put them on a slant. One side is red and the other is blue. The red side has the Boy Scout insignia, the blue side has the C