The Tison floating footbridge is an unusual structure requiring a combination of maritime and structural engineering. It is designed with a floating central support enabling the saving of a large quantity of steel by halving its span. Floats are provided on the bank so that if the river is in spate, the footbridge lifts and does not form an obstacle. The two spans are isostatic with a central caisson with variable inertia.
Among the technical difficulties, we can cite the design of telescopic tubes which deploy in the event of spate to hold the footbridge and which take up the torsion generated by the drag of the floats and excentric crowd loads. To ensure parallel alignment, the telescopic tubes driven 6m into the ground are inserted into guide tubes that are poured-in-place in piles.