I have oft wondered what methods the folks at Wilkins Rogers Milling used over the years to offload/load grain and other materials at their mill. I have seen photos showing boxcars but never covered hoppers, until now. Most of the time there are various boxcars sitting at the loading dock. Some showing grain doors indicating bulk loadings and others without, indicating bagged loadings. Both are reasonable. But I’d never seen a covered hopper of any kind there in the older photos I have, which is not too many good ones.
Perusing the DDoT DC archives page (which is great!) I stumbled on some photos from the flooding in Georgetown during Hurricane Agnes in late June, 1972. In one image, showing the mill, sitting on the siding at Wilkins Rogers are four cars; three boxcars (one, oddly enough, from the UP, apparently!) and one cylindrical covered hopper!
I can’t make out any reporting marks and I’m not an expert on these sorts of cars, but it seems there is an air hose connected to one end, draped up to a valve, most likely, which would be assisting in the unloading of whatever grain was inside. *EDIT- Matt R. says: Probably an ACF 3500 CuFt covered hopper. Atlas makes the model. Dates to early 60’s. Many different owners as well as ACF’s own lease fleet.
General American developed the “Airslide” covered hopper, which used air and a special membrane to move materials out of the car chutes with ease. These types of cars are new for me, as I haven’t really studied them. A quick search turned up a site with some great history and back story on these cars. As it seems they started showing up in 1954, I can include them on my layout, which really is delightful. It seems that Con-Cor produced a model of this car, which is close to what I would use. More research is in order.