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Union Pacific - Big Boy 4014

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RBSN

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Hello everyone,


How many of these amazing loco's are still operational? And do the UK or Europe have something as big or heavy duty as the 4014?

I'm amazed by the engineering behind it and would like to learn more.

:)
 
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ac6000cw

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How many of these amazing loco's are still operational?

None (yet) - 4014 will be the first since they were retired from normal service.

And do the UK or Europe have something as big or heavy duty as the 4014?

No - it wouldn't fit through the bridges/tunnels etc. (the Big Boys are too large to run everywhere on the US rail system as well, as far as I know).
 

Taunton

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No - it wouldn't fit through the bridges/tunnels etc. (the Big Boys are too large to run everywhere on the US rail system as well, as far as I know).
However, they were built by Alco, in Schenectady (near Albany), upstate New York, so had to make their delivery run on the New York Central and Chicago & North Western to get to Omaha in Nebraska. I don't recollect any gauge issues, the big problem with these locos is curves, particularly reverse curve crossovers.
 

ac6000cw

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However, they were built by Alco, in Schenectady (near Albany), upstate New York, so had to make their delivery run on the New York Central and Chicago & North Western to get to Omaha in Nebraska. I don't recollect any gauge issues, the big problem with these locos is curves, particularly reverse curve crossovers.

Good point - I was aware of the crossover curve problem, but had forgotten they were built 'back East' :)
 

Taunton

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The front eight-wheel set of driving wheels in the 4-8-8-4 configuration is effectively on a bogie, mounted on slides, with flexible steam pipes to the cylinders (must be a challenge for the fitters at 300 psi keeping these steam tight). I did once see a photograph of one, taken along the loco side, with it stationary on a crossover, and the displacement of the front "engine" as they were termed was quite considerable. Do I recall correctly that some of the driving wheels were flangeless.

I understand they only had one throttle, and one of their issues was that one of the engines might slip while the other was still driving, which would cause all sorts of pressure imbalances in the steam piping.
 

55z

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It is due out for the Union Pacific celebrations in 2018.
 

ianhr

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Hello everyone,


How many of these amazing loco's are still operational? And do the UK or Europe have something as big or heavy duty as the 4014?

I'm amazed by the engineering behind it and would like to learn more.

:)

I think the largest steam loco constructed in Europe would probably be the Soviet AA20-1 which was a 4-14-4! I gather it was not a success, whereas the UP Big Boys were arguably very successful for their rather specialised purpose.
 

ac6000cw

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I think the largest steam loco constructed in Europe would probably be the Soviet AA20-1 which was a 4-14-4! I gather it was not a success, whereas the UP Big Boys were arguably very successful for their rather specialised purpose.

UP also had some 4-12-2 locos which were reasonably successful hauling trains across the 'flatlands', but I think they felt that was as far as a practical rigid-wheelbase loco could be pushed in design terms.

Most of the 'mountain' railroads went down the Mallet-style articulated route eventually - usually using single expansion instead of true Mallet compounding (due to simpler maintenance), but the Norfolk & Western always used compounding for better fuel economy.
 

SWTH

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I understand they only had one throttle, and one of their issues was that one of the engines might slip while the other was still driving, which would cause all sorts of pressure imbalances in the steam piping.

Most multi-cylinder articulated locomotives only have one regulator for both engines - double Fairlies are the only design to have separate regulators for each end. If I remember correctly Beyer Peacock offered twin regulators as an option on Garratts, but I don't think any were built with them.
 
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