I discovered an article on the Kalmbach web site that ostensibly lists the Baldwin-calculated drawbar horsepower curves from several 4-8-4s including the Frisco's 4500 class. Based on the plotted curve, the 4500s produced a maximum horsepower of about 4200 HP, which is considerably less than the 5600 HP listed by Stagner, who cites the Frisco as his source. http://ctr.trains.com/~/media/Files/PDF/4-8-4 Locomotives/5-Later Baldwin 4-8-4 DBHP.pdf http://ctr.trains.com/en/Railroad Reference/Locomotives/2011/11/Calculated drawbar horsepower curves for 4-8-4s.aspx
That is interesting, because David P Morgan is his book Steam's Finest Hour lists the 4500s max horsepower at 5600 between 47 and 65 mph.
