Where the Union Pacific 4-8-8-4 "Big Boys" compound Mallets or where they simple expansion locomotives?
Nick
steam_marc wrote:Big Boys were simple articulated locomotives. Steam was supplied to all 4 cylinders, unlike a mallet where steam is sent through the rear cylinders to the front cylinders.
not pickin nits but............steam is supplied to all cylinders at boiler pressure as apposed a compound which uses exhaust steam from one set to the other at reduced pressure hence the larger dia. cyl.
To Steam_Marc and J. Edgar;
Thanks to both of you for answering my question on the U.P. "Bog Boys". I appreciate you taking the time to do so.
I think all of the later US articulateds intended for main-line service are simple, as opposed to compound, with the notable exception of the N&W Y6, Y6a, and Y6b 2-8-8-2's.
J. Edger wrote;reason being IMHO is that compound articulateds are only good to a certain speed...usualy low 15 to 25
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BigJim wrote: J. Edger wrote;reason being IMHO is that compound articulateds are only good to a certain speed...usualy low 15 to 25OH NO! Not again!This is one of the great myths of the railroading world that just seems to pop up from time to time. At least the N&W knew how to get some speed of 'em!
sigh.....i did say "usually"...i know they are more then capable of faster speeds....but you must admit generaly speaking they were planned and designed for slower drag service....once simple articulateds became available with proper design changes to make them stable and boilers capable of suppling steam the need for "slow speed compound articulateds" wasnt there across the board......sure certain RR's coughn&wcough kept building them but maybe thats cuz they werent to bright
wsherrick wrote:I guess the French didn't know that compounds were supposed to be slow since they had them running in excess of 80 MPH.
show me a ARTICULATED French compound doing 80.....id like to see it....just cuz i havent seen one....English compunds such as Webbs of the 1860's regularly ran expresses over 80
J. Edgar wrote: wsherrick wrote:I guess the French didn't know that compounds were supposed to be slow since they had them running in excess of 80 MPH. show me a ARTICULATED French compound doing 80.....id like to see it....just cuz i havent seen one....English compunds such as Webbs of the 1860's regularly ran expresses over 80
Of course there are no French Articulated Compounds doing 80Mph. I used the French example to show that the compound principal wasn't strictly limited to drag freights and slow speeds. The N&W Railroad, having a more intelligent motive power policy than most other railroads, continued to develop the compound mallet into an efficient machine that regularly ran at speeds above 50 MPH. The max horsepower rating for a Y6b was reached around 25 MPH which is a lot faster than the earlier compounds maxed out. This was the ideal speed because these engines could use their maximum power in the speed ranges they normally operated at.
The N&W Railroad, having a more intelligent motive power policy than most other railroads, continued to develop the compound mallet into an efficient machine that regularly ran at speeds above 50 MPH.
why is everone pickin on me......I fully understand that N&W's motive power philosiphy before Saunders was big steam power...this is a proven fact.....i also hope i showed that i understand that compounding wasnt for slow speed drag freight service....meaning Webbs English compounds as well as the few in this country pre 1910.....my only point is.....during the drag freight era...WW1 to the Superpower age... compound articulateds were built for heavy haul slow speed service...case in point would be UP's 2 classes of "challenger" types...the Blue Moose Compounds which gave way to the passenger speed simple articulateds....and i say this next only because history says that i should..... "the intelligent motive power policy" still gave way diesels didnt it??.....that part makes me choke account i am a diehard steam man to the core.....
back to the point of the original post....comparing a Bigboy to a compound articulated from an earlier era is apples and oranges....1 was built for speed and power...the other for the most part was stictly power
and i was attempting a lil bit of humor...sad as it may have been...
Hi J. Edgar,
Not to pick on you also, but the UP engines were called BULL MOOSE, not Blue Moose, and they were a 2-8-8-0 type, not a Challenger type. All of UP's Challengers were simple articulateds. The Bull Moose were originally Compounds and were later simpled.
Doug
May your flanges always stay BETWEEN the rails
wsherrick wrote: J. Edgar wrote: wsherrick wrote:I guess the French didn't know that compounds were supposed to be slow since they had them running in excess of 80 MPH. show me a ARTICULATED French compound doing 80.....id like to see it....just cuz i havent seen one....English compunds such as Webbs of the 1860's regularly ran expresses over 80Of course there are no French Articulated Compounds doing 80Mph. I used the French example to show that the compound principal wasn't strictly limited to drag freights and slow speeds. The N&W Railroad, having a more intelligent motive power policy than most other railroads, continued to develop the compound mallet into an efficient machine that regularly ran at speeds above 50 MPH. The max horsepower rating for a Y6b was reached around 25 MPH which is a lot faster than the earlier compounds maxed out. This was the ideal speed because these engines could use their maximum power in the speed ranges they normally operated at.
It wasn't just the French. There were plenty of American compounds that routinely exceeded 80 MPH. As just one example The Reading used Vauclain Compound Atlantics on the Camden to Atlantic City run. At times they exceeded 100. That certainly was not drag service.
JonathanS wrote: wsherrick wrote: J. Edgar wrote: wsherrick wrote:I guess the French didn't know that compounds were supposed to be slow since they had them running in excess of 80 MPH. show me a ARTICULATED French compound doing 80.....id like to see it....just cuz i havent seen one....English compunds such as Webbs of the 1860's regularly ran expresses over 80Of course there are no French Articulated Compounds doing 80Mph. I used the French example to show that the compound principal wasn't strictly limited to drag freights and slow speeds. The N&W Railroad, having a more intelligent motive power policy than most other railroads, continued to develop the compound mallet into an efficient machine that regularly ran at speeds above 50 MPH. The max horsepower rating for a Y6b was reached around 25 MPH which is a lot faster than the earlier compounds maxed out. This was the ideal speed because these engines could use their maximum power in the speed ranges they normally operated at.It wasn't just the French. There were plenty of American compounds that routinely exceeded 80 MPH. As just one example The Reading used Vauclain Compound Atlantics on the Camden to Atlantic City run. At times they exceeded 100. That certainly was not drag service.
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