The Royal Engineer BR-90 family of bridges are built from a range of seven modular panels of advanced aluminium alloy, interchangeable through the various bridge types, to form two interconnecting trackways with a 4 metre overall bridge width and a 1 metre girder depth.
Close Support Bridge - It consists of three tank-launched bridges capable of being carried on a tank bridgelayer and a tank bridge transporter (TBT) truck.
There are three basic tank launched bridges (also known as Close Support or Assault Bridges): numbers 10,11 and 12.
General Support Bridge - This system utilises the Automated Bridge Launching Equipment (ABLE) which is capable of launching bridges up to 44 metres in length. The ABLE vehicle launches a lightweight rail across a gap where the bridge is then built.
The bridge is assembled and winched across the gap supported by the rail, with sections added until the gap is crossed. Once the bridge has crossed the gap the ABLE launch rail is recovered. A standard ABLE system set consists of an ABLE vehicle and two TBTs carrying a 32 metre bridge set. A 32 metre bridge can be built by ten men in about 25 minutes.
Spanning Systems - There are two basic spanning systems. The long span system allows for lengthening a 32 metre span to 44 metre using ABLE and the two span system which allows 2 x 32 metre bridge sets to be constructed by ABLE and secured in the middle by piers or floating pontoons, crossing a gap of up to 60 metres.