A 2 bay hopper is 34? feet or so. What are the lengths of 3 bay and 4 bay hoppers?
Bob,
It ‘All depends’ - Most open hoppers are designed to ‘load out’ with a specific capacity of product. I have seen 3 & 4 bay open hpppers that are about the same length(about 40+ feet). As far as coal capacity, you can figure about 70-75 tons capacity for a 3 bay, and 100+ tons capacity for a 4 bay car. That extra bay may be for faster unloading. Another factor is if the car is designed for gravel service, you find that gravel is more ‘dense’ than coal - thus a shorter car may carry the same capacity.
This plays the same with ‘covered’ hoppers as well The shipper is looking for cubic capacity. They do not want a car that will ‘cube out’ before a full load is reached.
Jim
Not necessarily true, old Post WWI 4 bays that the PRR and B&O had were only 70 Ton Capacity. Also the later 3 bay Hoppers ie. PRR H43 were 100 Ton Cars. It all depended on cubic capacity, wheel bearings and wheel sizes. After a number of the 70 Ton Cars were built, wheel bearings were rerated resulting in a capacity change to 77 Tons.
Rick