A couple of questions on grain and mill operations as I am starting to concentrate on a new layout plan and building my roster to serve the industries on it.
Grain in the late 60’s was hauled in both covered hoppers and boxcars, would a average milling operation be able to handle both types of cars for unloading?
Flour and other milled grains would be shipped out in different covered hoppers, airslides and such, would it be plausible or probable that the same way freight would bring both loaded and empty cars to the same facility?
If the above question is true, would the loaded cars be ahead of or behind the empties or would it depend on switching conditions at the mill?
Finally, does anyone know of a milling operation that handles both loads in - loads out?
Many times large mill operations had facilities to handle both types of cars. The same local or way freight probably shows up with loaded grain cars and empty Airslides for flour loading and works the entire mill operation. Also, before Airslides, most flour was ‘bagged’ and loaded in empty boxcars for distribution to baking companies. Where the loads/empties are in a consist would depend on the local crews/operations. Milling operatins are usually a loads in/loads out operation as loaded grain cars arrive, and loaded Airslides of flour are shipped out.
I am employed at a soybean processing factory.Back in the 1960’s box and covered hoppers of beans would arrive,but because soybean meal is coarse the same cars were reloaded with bean meal.Cotton seed meal and corn gluten also used non pneumatic cars. It seems like milled grain for animal feed used box cars and normal covered hopper.Some boxcars were lettered “for flour use only” so they would no be contaminated.
Mr B… put “airslide” into a search in Walthers catalogue and you will come up with at least a 50’ Airslide car. A 50’ is a twin covered hopper that could be sealed so that air pressure pomped into the car would turn th flour load fluid and enable it to be pumped out as a (dry) liquid. You should notice that the unloading gates (pipe connections) at the bottom of the hopper bays are different from an ordinary covered hopper.
Airslides are different from “pressuraid”, “pressure differential” (PD) and “centreflow” covered hoppers. (Atlas, Walthers and Athearn respectively). As far as I know they use the highest pressures of covered hoppers except possibly cement cars… which also use air to fluidise the load.
“Normal” covered hoppers unload by gravity… but most are lqabeled that the hatches MUST be opened before unloading … so that a vacuum doesn’t form in the car and cause it to implode.
Don’t know if they still do but Walthers used to do a 40’ single bay airslide covered hopper and a paired 40’ (2 single bays with a fixed coupling… got round the minimum 50’ car rule for a time).
A malting operation would have loads in and out. Barley in and malted barley out.
The order of loads or empties would depend on conditions at the plant, as well as how they move the cars around (gravity, car puller, car mover, tractor, engine, etc.)