12-28-2009, 06:51 AM
Gary S Wrote:I see what you mean, Dave.
My industry produces a product which is shipped in covered hoppers. I have a fleet of 20 private cars which serves my weekly needs, but occasionally I need more cars. So my industry would order empties from the serving railroad? And what if they don't have any empties? What happens then?
All covered hoppers are not created equal. It depends on what type of hoppers and what type of product. If its any product other than grain, fertilizer, soda ash, potash, sand, cement or something else that can be put in a generic gravity unloaded covered hopper (such as plastic pellets or flour) then the railroad may not own cars suitable for your load.
If you use all your cars and they don't have cars, then you stop shipping until your empties come back.
To figure how many cars you need, take the transit time to the average destination, double it, add two or three days for unloading and multiply by the number of cars per day you load. Figure on a car moving at about 15 mph and taking 16-24 hours at every yard it goes through. So if your average shipment takes 7 days to get to the customer and you load 5 cars a day, that would mean you would need 7 + 7 + 3 time 5 cars or 85 cars. That assumes no cars break and your customers unload on arrival. Obviously you don't need that many cars on a model railroad, but that gives you an idea on your fleet size.