Mike: Not to start an argument with you, but...
It is my understanding the rebuilt steel sided San Juan cars were about 3-5 tons heavier than before. I rode the train in early June, 1978 and 476 stuggled terribly with it. We barely made it into Rockwood and actually stalled on 488 hill, but good ol' Uncle Carl Jack got 476 on her feet and walked her over the top. Up in Silverton I had the nerve to ask him if the new steel cars were heavier, his short response was "yes, very".
Later that summer I was back and noticed there was always an extra coach sitting in the yard, indicating they had cut the consist by a car (to 10 cars?). When I rode in '79 and '80 (the "First Annual" and "Second Annual" last D&RGW trains to Silverton") it was slack season and they were running only one 10 car train.