Atlas Master Line HO 20006392 ACF 5250 Covered Hopper, General American #60423Atlas Master Line HO 20006392 ACF 5250 Covered Hopper, General American #60423 Part Number: 843069186380 Description Atlas Master Line HO 20006392 ACF 5250 Covered Hopper, General American #60423 Introduced in 1961 by ACF to haul sand, clay, salt, grain and bulk plastics, the Cylindrical Hopper was the first commercially successful tank type covered hopper car design. A few of the more than 4,000 cars of this type built through 1966 can still be seen