When a gap to be bridged is too wide to be economically crossed by
a single span structure, it is necessary to provide intermediate
piers and install a multi-span bridge.
The positioning of intermediate piers is often dictated by the
local geology and topography of the site. Otherwise, the
positioning and quantity of piers depends upon the most economic
balance between the cost of the piers and the cost of the bridge
construction appropriate to the varying span lengths.
It is a design feature of CB200 Bridging(CB200 Bailey Bridge) that in addition to simple spans, it may also be erected to form
multi-span structures. This can be done in two ways; either with
continuous bridge trusses supported or as a series of
broken-spans linked at each intermediate pier by span junction
equipment. It should be noted that both of these options provide a
continuous road deck for the traffic.