ACF Flexi-Flo Covered Hopper

Prototype Information

Built between August 1964 and June 1966 the American Car & Foundry (ACF) 3500 cu. ft. covered hopper was an early innovator in pressure differential unloading and a marketing masterclass thanks to the “Flexi Flo” tag coined by the car’s biggest customer, the New York Central railroad.

Other than seven cars built for Shippers Car Line (SHPX), a subsidiary of ACF, the NYC was the only purchaser of the PD3500. They made up for it in quantities, with a total of 220 cars rolling off the Milton, Pennsylvania, production line over three subtly different batches.

Through the Penn Central years, plenty made it through with their full NYC paint continuing to be exposed to the elements with nothing more than reporting mark and number patches. The Conrail era meant many cars were repatched again, making them rolling billboards in north-eastern railroad history! Many others were fully repainted, with Conrail applying at least three different schemes.

By the 1980s and 1990s, most remaining cars would be transferred to Conrail’s Merchants Despatch Transportation Co. (MDTX) subsidiary, and then the later sale of cars to NAHX (for Lafarge), gaining new full paint schemes and being seen throughout North America. By the 2000s, patchouts were the norm with a plethora of different reporting marks popping up and no part of the USA or Canada was off limits to seeing these unique cars continue to earn their keep.