How Steam Locomotives Work

Steam locomotives ruled railroads through the 1940s. From the beginnings of railroading in the early 1800s until the coming of diesels in the 1940s, steam locomotives led almost every freight and passenger train in North America. From their diminutive beginnings, steam engines developed into large, powerful locomotives that could lead mile-long freight trains at 60 mph or lug thousands of tons of coal up mountain grades. With their moving rods and valve gear, steam locomotives have long cap...