Autoracks. B&O's "Wagontop" Cars. A typical 40-foot flatcar is loaded with a 2,150-horsepower Electro-Motive model 645 prime mover bound for a towboat belonging to the Nashville Bridge Company in 1972. According to Mike Schafer's book, " Freight Train Cars ," some rocks weighed as heavy as 60-65 tons and the railroad employed timber-planked