Although the arch bridge is almost as old as the bridge they are not generally used for modern military bridging, even non equipment bridging. Developed in conjunction with Queens University Belfast, the Flexi Arch bridge system from Macrete uses precast concrete sections to dramatically improve installation time.
Arches are strong, robust and look good but they are labour intensive and expensive because they need formwork in order to centre the bridge and strong abutments to transfer the loads.
By using the flatpack precast Flexi Arch with their precast voussoirs a durable and long life bridge without corrodible reinforcement can be built.
Once the foundations have been built the arch is lifted in, spandrel walls attached and concrete fill poured. The road surface and cladding can then be finished. Typical build times for a 15m arch are less than a day. The maximum span is limited by transport and crane lifting capacity but they are already developing a double radius arch for rail profiles.
Perhaps not of enormous relevance to the military bridge builder but interesting nonetheless and good to know bridge building innovation is still alive and well in the UK.