This document assists the HEC-2 program user in preparing input for the bridge routines. An understanding of the basic program input requirements was assumed. The program computes the energy loss caused by structures such as bridges and culverts in two parts. One part consists of the losses that occur in reaches immediately upstream and downstream from the bridge where contraction and expansion of the flow is taking place. The second part consists of losses at the structure itself. As an alternative to having the program compute the losses, it is possible to input a loss (or water surface elevation) determined externally from the program. Appendixes contain examples of three different types of computer runs. The HEC-2 Users Manual, available from The Hydrologic Engineering Center provides the input specifications for the program. User Manual editions since August 1979 include this training document as an appendix. (Author).