Steam Loco's built for Passenger Service

Compare the total main line mileage of SP + UP + SFe with the total main line mileage of PRR + NYC + B&O + C&O + N&W … which do you think will have a higher percentage of curves 10 degrees and sharper?

PRR NY-Chicago and NY-St Louis-- maybe none? (Oops-- the Fort Wayne bridge out of Pittsburgh, that was definitely 10+. Any others?)

NYC ditto-- maybe none?

B&O-- probably had a few here and there.

C&O-- people say that curve at Hawk’s Nest was the sharpest main line curve, and it’s just under 10 degrees. Think they’re wrong?

N&W-- now there you’ve got a chance.

Just one example since I’m short on time.

In 1869 the orginal UP mainline was said to have no sharper curve than 6 degrees.

The B&O lines west over the allegheny summit is full of curves that are 9 degrees, the same 9 degrees that put a B&O 2-10-2 on its side. I have road that line, its not a few sharp curves, it is all curves, mostly sharp ones.

Sheldon

Omaha to Ogden… yeah, could be.

Cumberland to Grafton is respectably curvy, nothing record-breaking-- maybe 10-12 curves of 10 degrees or sharper. Cumberland to Pittsburgh… does it have any 10-deg curves?

No, I would think not. 6 degrees is probably the sharpest there, heck maybe only 4 degrees. Hence the 2-10-2’s with 70" drivers, truely a unique application.

Details aside, fact remains, curves restrict tonage just like grades, and limit speeds. Lines like Cumberland to Grafton are continious curves, sharp in places, not in others. Steam locos with shorter rigid wheelbases lost less TE and maintained higher average speeds than what could have been done with longer locos under the same conditions. The EM’s and EL’s that worked that line had rigid wheel bases less than 16’, made them pretty nimble. Andre will say many locos in the west where the same, true. But again, as designs evolved eastern locos stayed with shorter wheelbases, western ones grew with drivers sizes and/or axle counts.

In the west, the tight spots, no mater how tight, are connected by long, straight, often relatively flat ground that needed to be covered at speed, hence a different approach to loco design and application. They could slow down for the tight spots, even if they where sometimes tighter than the “average” in the east, as long as they could fly out on the open range.

In the east, no open range, more important to make steady speed under all conditions. Fact - USRA/N&W Y3 locos used out west during WWII where a failure, not enough top speed for the open range. Was it the ATSF that broke a couple frames trying to run them too fast? Same loco on the N&W slugged coal at 30 mph up hill, down hill, through curvy passes with great success until the 1950’s.

On the C&O, with better curves, the 2-6-6-6’s still did better than the 2-8-4’s and 2-10-4’s. Same story, different details.

Sheldon