“转辙器”用英语怎么说？

火车呜呜地鸣着汽笛, 钢轮擦过铁轨的转辙器时,发出了卡嗒卡嗒的响声.The locomotive whistled , there was the click of steel wheels passing over switches.不含任何弯曲或扭曲轨 、 道岔、转辙器及制动轨, 或有裂口或破底钢轨.Free from bent and twisted rails frog , switches, and guard rails, ...