Re: Steam locomotive horsepower...

Calculated HP of various classes of locomotives.

T-12
5 mph - 148
15 mph - 348
25 mph - 355

C-16
5 mph - 240
15 mph - 456
25 mph - 413

C-17, 18, 19 160 psi
5 mph - 266
15 mph - 514
25 mph - 458

RGS T-19
5 mph - 276
15 mph - 583
25 mph - 546

K-27
5 mph - 386
15 mph - 801
25 mph - 742

K-28
5 mph - 397
15 mph - 868
25 mph - 864

K-36
5 mph - 522
15 mph - 1140
25 mph - 1135

K-37
5 mph - 535
15 mph - 1169
25 mph - 1164

The superheated K-27, 28, 36 and 37 classes may have had higher HP output since the Baldwin reference pre-dates common application of the superheater. My son Paul, helped build a small spreadsheet to run the calculations.