I rounded off the numbers for the sake of convenience.
What you did was to calculate the weight for 4 cars and divide it by the number of axles for 3 cars.
The point I was trying to make is that the D types were harder on track and roadbed.
I thought your point was that the costs associated with the increased wear that the D-types infliced on the roadbed more than compensated for their reduced maintenance cost.
Do you disagree?
I agree that the D-types had marginally higher axle loading than their contemporary (1924-1928) fleet. The loading was no where near as high as you suggested.
Your point?
I do not have sufficient data to determine whether or not the D-type's low maintenance cost was offset by increased maintenance of way cost. Your argument, that it might have been true, is based on incorrect numbers.
Do you ever do anything besides nitpick numbers?
Numbers are the easiest thing to verify. There can be little cogency for any agument, if it flunks this simple test.
You have to be the biggest bore in town.
There is a great folklore regarding operational decisions over the last 125 years. There have been a many rationalizations to cover up bad managerial decisions. Simple statements cannot always be accepted at face value.
The relentless pursuit for finding truth in these pronouncements can indeed be lonely and boring. :-)