C&O 1309 is neat, and I have owned an HO big boy…but give me the Santa Fe 2-10-4. According to S. Kip Farrington actual road tests showed a remarkable drawbar hp cutve well over 5000 hp and they could really run fast and roll mile long trains of reefers fast. Articulateds have limitations. The Santa Fe engines were relatively underappreciated and starting tractve effort was very conservatively rated at only 93000 lbs.
They would have given C&O 2-10-4 a real run for the money. Also some sources say the T-1was perhaps as good or better than the h8.
Large long rigid wheel base locos have specific advantages and disadvantages compared to articulated locos.
Having only two cylinders and fewer moving parts is actually an advantage, less losses.
The disadvantages start as soon as the track curves…the sharper the curves, the higher the losses in power/TE.
Again, out west different operating conditions allowed large driver long wheel base locos to be more effective. Similar big locos in the east were often restricted to the routes with the easiest curves, and grades that were long and steady, not a lot of changes within the grade.
Example, the B&O had what was likely one of the best 2-10-2 designs in the S1, and their route to Pittsburgh has long steady grades and easy curves, the S1’s were right at home.
BUT, several times they tried them on their lines west route, which goes directly over the Alleghenies - lots of curves, looks like a snake on a map - they put several on the ground and one time they dumped an S1 over on its side trying to use them on that route…
But the EM1’s and EL’s had no trouble…at higher speeds and good tonage…
The driver wheel base of an S1 is 21’, the driver wheel base of an EM1 is only 16.5’ - makes a bid difference on a tight curve…