Mind the gap

A company in Tblisi that goes by the name of Georgian Polytechnical Intellect
(sic) has devised a temporary bridge for rivers or rough terrain (WO 98/41692).
The bridge is made from a series of rectangular sheets moulded to form rigid
arches. Each arch has a flat pivoting base at one end which sits on the ground
or in the water. The free end rests against the curved surface of the
neighbouring sheet. The result is a series of overlapping arches, creating a
bridge with a rather bumpy upper surface. This is good enough to walk across,
and can be covered with filler to make it smooth enough for vehicles. The
advantage of the system is that differences in the height of the terrain below
the bridge can be compensated for by simply altering the distance between the
bases.