Re: Real boiler pressure and its impact on t.e. and operations

More....

Tractive effort is starting power. Getting a train up to speed and keeping it there is horsepower. Horsepower requires the ability to maintain steam pressure and water level at a constant rate over a long period.

To address, Tom M's comment on tire thickness. Thinner tires make a noticeable difference in pulling power. When we first ran 489 in the 1980's she had real thin tires and would out pull everything on the road. Later when we put new tires on her, I measured the old worn tires and found them to be 39 5/8" in dia. Her tractive effort worked out to over 40,000 lbs.

On the other side of the coin, when we got 497, she had brand new tires that had been fitted by the D&S. In order to get more tire life, she had been fitted with tires 1" thicker that stock, giving her 46" drivers giving her 35,830 lbs of TE. She was the weakest of the bunch.