Era 1934 to 1970s. In 1934, the D&H converted 30 SS USRA boxcars to carry bulk cement with the addition of roof hatches, wine discharge gate and interior Slope sheets! They were in the #series 17001-17500. The B&O also converted 40 cars numbered 287000-287039. After 1960 these cars were used in company sand service with the D&H operating at least one into 1985. Less couplers.