My 10 year old and I rode the bike path alongside the tracks tonight. Looking at markings on the side of each covered hopper, I noticed that the empty weight of the cars varied quite a bit. Most cars were 263,000# loaded weight. The empty weight varied from around 59,000# to 62,000#. If I pay to have a grain car moved from S.D. to Duluth, MN.,do I pay freight on 263,000#? or on the weight of the grain only-somewhere between 201,000# and 204,000#? For efficiency, wouldn’t a railroad want lighter cars?There would be something like 1% to 1 1/2% more dead weight if a shipper got all “heavy” cars. Do railroads and shippers try to order lighter cars?
I used to work for a freight car manufacturer, as well as a railroad, and car weight is a real consideration. Every pound of “Tare” weight, the weight of the car, you drag around reduces the revenue freight you can load. And the railroad gets paid for moving the freight in the car.
But it’s a trade off. Light weight costs more. Aluminum costs more than steel. In service where cars have high utilization and carry heavy stuff, like unit coal trains, aluminum will pay for itself. If it’s a plastics car, cars that are frequently used for storage of their commodity, it won’t. The car builder’s challenge is to balance the ecnomics of construction costs vs. weight.