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Back in 1970 I rode behind (then) #8444 on a trip from Denver to Laramie it was an incredible excursion. All these decades I have been wondering about her steam whistle. I have never seen any steam coming from the whistle. Is this correct? Would super heated steam not condense?  Thanks.

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Jeff B. Haertlein posted:

Back in 1970 I rode behind (then) #8444 on a trip from Denver to Laramie it was an incredible excursion. All these decades I have been wondering about her steam whistle. I have never seen any steam coming from the whistle. Is this correct?

Depends on the weather, as when it's hot and DRY, there is very little steam vapor cloud from her whistle, especially since it is supplied with superheated, i.e. VERY hot & dry, steam.

Would super heated steam not condense? 

Again, it depends on the weather. If it is cool and moist outside, then you will see vapor from the exhaust and whistle.

Thanks.

 

It’s actually more likely due to her whistle being directly next to the smoke stack... just as an example NKP 765 is powered with superheated steam yet when she blows her whistle you can see it very clearly.  The power and thrust coming out of 844’s smoke stack is a more likely reason on why you won’t see 844’s whistle steam, because it is sucked into the smoke stack’s exhaust. Pictures are attached to prove my point.  One is a picture of on top of 844 showing how the steam from the whistle is going to be directed right into the smoke stack exhaust... the other is a photo from when the locomotive wasn’t moving and you can clearly see steam coming from where the whistle was.... that being said, it is most definitely not because of super heated steam.

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Evan Cihlar posted:

It’s actually more likely due to her whistle being directly next to the smoke stack... just as an example NKP 765 is powered with superheated steam

Don't think so, as the whistle on all NKP Berks is mounted directly to the side of the steam dome, thus prior to the superheater header. Steam supply for the whistle on the "big three" UP steam locomotives, i.e. the 4000s, 3900, and 800s, comes off the superheater header, on the superheat side.

yet when she blows her whistle you can see it very clearly.  The power and thrust coming out of 844’s smoke stack is a more likely reason on why you won’t see 844’s whistle steam, because it is sucked into the smoke stack’s exhaust. Pictures are attached to prove my point.  One is a picture of on top of 844 showing how the steam from the whistle is going to be directed right into the smoke stack exhaust... the other is a photo from when the locomotive wasn’t moving and you can clearly see steam coming from where the whistle was.... that being said, it is most definitely not because of super heated steam.

Nope. It all depends on the weather/temperature conditions. Very hot and dry, not much if any vapor. Cool/cold and damp, you can hardly see forward through the vapor cloud. The same thing applies the UP 3985, and SP 4449, both use superheated steam.  I spent some 17 years as a contract Fireman on the UP Steam Team, on both 8444/844 and 3985, plus more than 40 years on SP 4449.

 

Jeff B. Haertlein posted:

Oh, OK. I recall when I was on that excursion, 8444 engineer blew the whistle, and quite a bit of condensate (water) burbbled  the whistle.

Yes, that usually happens before the superheater units are fully hot and dry. Also the same reason the Engineer opens the cylinder cocks prior to moving and when first departing town. All that condensation has to go someplace.

Hot Water posted:
Evan Cihlar posted:

Interesting how the whistle is fed directly off of the superheater.

Actually, the steam supply comes off the superheater header, which also supplies the turret in front of the cab. Such is fairly typical on steam locomotives equipped with the American multiple valve frontend throttle system.

Very interesting... never would have guessed that.

Evan Cihlar posted:
Hot Water posted:
Evan Cihlar posted:

Interesting how the whistle is fed directly off of the superheater.

Actually, the steam supply comes off the superheater header, which also supplies the turret in front of the cab. Such is fairly typical on steam locomotives equipped with the American multiple valve frontend throttle system.

Very interesting... never would have guessed that.

Well, you are pretty young, and havn't worked on, and/or learned about, too many steam locomotives.

Last edited by Hot Water
J 611 posted:

To my ear for whatever reason I think whistles sound better when not run off superheated steam.

Although I tend to agree, especially for those various chime whistles, those big deep "steamboat" type Hancock whistles do seem to sound better on superheated steam. N&W J Class locomotives are the obvious exception, as they reportedly use saturated steam supply for their whistles.

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