For a period of launching process leading edge of superstructure is subject to large hogging moment. In this relation, steel launching nose typically about 0.6-0.65 times span length is provided at leading edge to decrease cantilever moment. Occasionally, instead of using launching nose a tower and stay system are designed that serves same purpose

The superstructure continually experiences another sagging and hogging moments in incremental launching. Usually central pre stress is provided in which compressive stress at all points of bridge cross section is equal. In this method, it caters for a possible occurrence of tensile stresses in upper and lower part of cross section when subject to hogging and sagging moment in that order. When whole superstructure is completely started on, continuity pre stressing is performed in which location and design of continuity tendons are based on a bending moments in final completed bridge condition and its provision is supplementary to central pre stress. For very lengthy span bridge, temporary piers are provided to bind the cantilever moment.