Leaving out articulateds, duplexes, 3 cylinders, compounds, experimentals, who had the biggest, heaviest, most TE, most HP conventional 2 cylinder steam loco’s?
Were the Santa-Fe 2-10-4’s tops in any of these categories, or were some others bigger?
Don’t forget about the PRR’s M class or the I class units either.
Biggest-- zat mean longest? Engine only? For engine and tender I’ll guess SFe 4-8-4s with the 16-wheel tender.
Heaviest-- offhand guess PRR 2-10-4.
Highest nominal tractive effort (no booster): likely the IC 2-10-2.
Highest power: nobody knows which 2-10-4.
How about the 2-12-4’s?
The Santa Fe 5001 class might win the first two categories, most TE without booster would go to B&LE’s 600 series 2-10-4s. Horsepower would be much harder as most of the contenders were never tested either properly or at all. SP and UP’s 4-10-2s were 3-cylinder locomotives as were UP’s 4-12-2s.
Asketh selector:
“What about the 2-12-4s?” Does he mean UP’s 4-12-2s?
There weren’t any 2-12-4s, and the 4-12-2s had three cylinders, rendering them inelgible for this thread . . .
Old Timer
For relative size to what they could pull, the GN O-8 Mikes (2-8-2) could (and did) pull whoppers of trains and SP’s Mogul type “Valley Mallets” (2-6-0) could pull a train approaching the size of what an AC class articulated could pull in the Sacramento and San Juaquine Valley’s.
Okee doke! Thanks for your answer, Old Timer.
The PRR 2-10-4 was a copy of the C&O 2-10-4, but without rear truck booster, so the C&O version could start a heavier train. The PRR 2-10-4 was built during WWII, and they were forced to use an existing design.
What about CP 8000, a T4a 2-10-4? That was the largest canadian locomotive, but did it have multiple cylinders? I think it could pull as much as 2 normal CP Selkirks.
You might also want to check out the PRR Q-2 a 4-4-6-4 rigid frame conventional engine and the PRR/C&O 2-10-4 design. The Q2 doesn’t exactly meet your specifications but it was a beast and doesn’t belong in either category.
The Pennsy J-1’s were actually heavier than the Santa Fe 5011 class by about 20 tons (locomotive only) , IIRC. In terms of outright horsepower, there was an article in Trains quite a while back that stated that a Santa Fe 5011 class could take the same train over the road faster than a 4 unit F-7 set under conditions where the grade profile didn’t favor the diesel’s greater low speed tractive effort. Seems to me I remember that the Santa Fe 2-10-4’s were good for about 5600 DBHP.
Andre
The winner is going to be a 2-10-4; it would be interesting to have the comments of the guys on PRR’s Sandusky line who ran both the Santa Fe 5011s and the PRR J1s. Other than that kind of testimony, this will be another of those fascinating controversies that we’ll never settle.
And aren’t we ignoring the KCS 2-10-4s? Didn’t they share the ATSF 310-pound boiler pressure?
If you have to choose between the C&O/PRR and the ATSF/KCS engines, the nod for potential horsepower will have to go to the one with the highest boiler pressure.
Old Timer
If you mean calculated TE, the B&LE engines don’t match the IC 2-10-2s, unless their pressure/dimensions changed. Were they always 31 x 32 cyl, pressure 250, drivers 64?
Here are some figures to toss around -
IC 2-10-2 - TE 104,484 lbs with K factor of 0.90; 98,679 lbs with K factor of 0.85
ATSF 5011 - TE 93,000 lbs with K factor of 0.73; 108,960 with K factor of 0.85
C&O T1 - TE 93,350 + 15,275 booster = 108,625 with K factor of 0.85
PRR J1 - TE 93,750 + 15,000 booster = 108,750 with K factor of 0.85
B&LE H1f - TE 96,700 + 13,000 booster = 109,900 with K factor of 0.80; 102,106 + 13,100 = 115,206 with K factor of 0.85
KCS - TE 93,300 with K factor of 0.85 (27 x 34 cylinders)
ATSF 5011 class would lead if calculated TE was the criterion at K=0.85 (108,960 engine only, no booster). IIRC, something in this vicinity was confirmed during tests on ATSF (see Lloyd Stagner’s article in Aug 1975 Trains mag.). Made them a bit grumpy at low speeds.
As far as DBHP goes, I’m staying out of that for time being. Be advised that most DBHP figures for the PRR J1 are locomotive DBHP based on Altoona Test Plant records. This is not the same as DBHP at the rear of the tender.
I’m just going by the table in 10/48 Trains, which shows pressure 275, cyl 30 x 32, drivers 64 1/2 for the 2800 class. Did they not use that pressure in service?
Yup, that’s always the question-- what do you assume for a limited-cutoff engine. Not 0.85, in any case?