Re: 346 on a 4% grade

A typical NG car is about 12 tons empty. If you had a gon filled with coal to capacity (25 ton load) that would make for a 37 ton car. With a tonnage rating of 92 tons. a C-19 could drag 2 of them, plus the caboose. If a car was full of lumber, the capacity would have been limited by volume, not wieght, so a load would wiegh less. So the answer is 2-3 loaded cars.

Going down is an entirely different matter as the air brakes do the work. Capacity is limited to the amount of air that can be created by the air compressors. With a pair of 9 1/2" pumps, I'd say about 25 loads.

Speed uphill would be in the 8-10 mph range. Downhill, about the same. Speed is your enemy when decending steep grades with heavy trains.