Influences ofLocomotive Dynam ic Brake on Brake Operation and Lim iting Grade

Brake processes were analyzed under different locomotives, trains, brake operation procedures, and limiting grades. W ith application ofdynamic brake, release times increase from 110 s to 172 and 234 s for trains hauled by aDF8B or an SS7 locomotive, respectively, at a down slope of 12‰grade, and from 68 s to 138 and 225 s for trains hauled by double DF8B or double SS7 locomotives, respectively, at a down slope of 18‰grade. Combining air and dynamic brake also decreases the times ofairbrakes and the temperature raise on the thread surfaces, which increases the safety of trains and relaxes the constrainton limiting grades in railway design.