functionality of "elephant ears?"

There will be better explanations than mine, but as far as I knew, they were fitted to steam locomotives to help force the air to keep the smoke to the top and center of the locomotive, to keep excess smoke from getting into the crew's eyes.

Garrett76 posted:

What exactly was the purpose of the elephant ears on steam locomotives and how well did they work?  I'm assuming there is some sort of intended aerodynamic effect of the air moving around the forms to create a pressure of vacuum spot.  Can anyone explain the functionality and effectiveness?

Thanks!

If you look carefully at the tops of the "elephant ear" (properly called 'wind wings' on the Union Pacific), they are curved inwards, on each of the ears. Thus, at train speeds over 60+ MPH, an upward wind draft occurs, lifting the exhaust smoke/gasses higher above the passenger train.  Various European steam locomotives had all sorts of smoke lifter designs, which tended to work pretty well at higher speeds.

Eddie Marra posted:

There will be better explanations than mine, but as far as I knew, they were fitted to steam locomotives to help force the air to keep the smoke to the top and center of the locomotive, to keep excess smoke from getting into the crew's eyes.

Although the "ears" did tend to help crew visibility, the primary reason was to keep the exhaust smoke/gasses as far above the passenger train "slip stream vacuum" as possible so as NOT to be sucked into the passenger car ventilation and air conditioning systems, during high sped operations. 

If there is no serious cross wind, I can attest that the "Wind Wings" on UP 844 work very well. Although not readily visible to the uninitiated, the "smoke lifting" arrangement on the Southern Pacific semi-streamlined GS Class Daylight locomotives, which was designed by the SP Mechanical Dept. and the Lima Locomotive Works Engineers, also works quite well at higher speeds.

Hot Water posted:

Eddie Marra posted:

There will be better explanations than mine, but as far as I knew, they were fitted to steam locomotives to help force the air to keep the smoke to the top and center of the locomotive, to keep excess smoke from getting into the crew's eyes.

Although the "ears" did tend to help crew visibility, the primary reason was to keep the exhaust smoke/gasses as far above the passenger train "slip stream vacuum" as possible so as NOT to be sucked into the passenger car ventilation and air conditioning systems, during high sped operations. 

If there is no serious cross wind, I can attest that the "Wind Wings" on UP 844 work very well. Although not readily visible to the uninitiated, the "smoke lifting" arrangement on the Southern Pacific semi-streamlined GS Class Daylight locomotives, which was designed by the SP Mechanical Dept. and the Lima Locomotive Works Engineers, also works quite well at higher speeds.

Thank you for that explanation, as I had an idea of what they were for, just not more specific an answer.  I remember in the UK, after Flying Scotsman was restored this last time, those were fitted to the locomotive (so she would look like she did in the last years of mainline service, 1963 or so).  There they call them "smoke deflectors", but I grew up with my dad showing me the Marklin or the UP 4-8-4 he had in HO and always calling them "elephant ears".

Here's an interesting one - a Canadian 2-6-0 with elephant ears, built for export to China but the order was cancelled. I doubt it got up to smoke-deflecting speed in its paper mill job.

http://www.trainweb.org/oldtim...os/logging/steam.htm

The NKP Hudsons had them too.

banjoflyer posted:

The deflectors also look way better than this early attempt to do the same thing:

How'd you like to wear these when the smoke gets real bad in a tunnel...

(The word "host" above should be "hose" I think.)

Here's the article where the above is discussed.

Mark

 

 

Nothing about what you posted has anything to do with what the original poster asked about, i.e. "elephant ears". The information you provided is for operations within tunnels.

They even had a variety of smoke deflectors for diesels.i

Tommy posted:

They even had a variety of smoke deflectors for diesels.i

That looks like a gas turbine/electric locomotive, which would definitely be throwing some heat out that exhaust.

At about the 15 minute mark in this video the narrator indicated the deflectors were mainly about reducing turbulence around the cab. Multiple images of engines running at speed seem to indicate they weren't much more effective at keeping smoke high and centered than engines without them.

Pete

banjoflyer posted:

The deflectors also look way better than this early attempt to do the same thing:

How'd you like to wear these when the smoke gets real bad in a tunnel...

(The word "host" above should be "hose" I think.)

Here's the article where the above is discussed.

Mark

 

 

I'm the original poster and this is relevant and interesting.  Thanks!

Garrett76 posted:

I'm the original poster and this is relevant and interesting.  Thanks!

 Interesting, yes. However, not "relevant" since you originally inquired about elephant ears, and their functionality & effectiveness.

Not identical test subjects or speeds but it does appear UP 844's smoke seems to run a bit higher over the boiler than the "non elephant ear(ed)" NKP 765 where the smoke skims right over the top of the locomotive.

Hot Water posted:

Garrett76 posted:

I'm the original poster and this is relevant and interesting.  Thanks!

 Interesting, yes. However, not "relevant" since you originally inquired about elephant ears, and their functionality & effectiveness.

 

relevant as it deals with smoke and its effects on crew and passengers.  and interesting.