逆轉機
逆轉機是動力鐵路車輛上用於設定行駛方向，通常位於駕駛室內透過操縱桿進行操作的控制裝置。除了前進、倒退，類似變速箱，也有用於使傳動系統脫離動力的空檔。
搭載逆轉機的車輛能以同樣動力向前、後方行駛，為此也多在兩端配有相應燈光。依據車輛設計不同，行駛方向僅有著駕駛室能見度及冷卻性能有機會受到影響。
Reversers should never be operated when vehicles are in motion, to avoid catastrophic damage to the powertrain. For the same reason, to operate the reverser, throttle and dynamic brakes need to be disengaged.
Many vehicles only have one set of controls, facing a particular direction. To drive these vehicles in the opposite direction comfortably, it helps to use the universal control stand, or a locomotive remote controller, if supported.