Incremental launching is an efficient construction technology used for building steel or composite bridges when there is limited access to the final location of the spans or a short construction time is required (e.g., railway structures). It involves assembling the superstructure in sections or as a whole at the assembly site and then sliding it into its final position. The most commonly used variant is longitudinal launching, although transverse sliding constructions are also encountered.
Typical spans of incrementally launched steel bridges are accomplished using a short launching nose. For larger spans, temporary suspension may be necessary to reduce the deflection of the cantilever.
BBR Poland has successfully applied the longitudinal sliding technology in the construction of numerous bridge structures in Poland and Germany.