Twin stacks on UP Big Steam?

[selector]

I see smoke from what appears to be twin smoke orifices in the smoke stack fairing atop UP 844 in videos. I am seeing things, and if not, would someone please tell me what they know about the arrangement?

Thanks.

-Crandell

[feltonhill]

You're not seeing things. UP 844 and 3985 have twin stacks. 844 also has two exhaust stands in the smokebox, with each stand havng four exhaust nozzles (The Mighty 800, Wm. Kratville, pg82-83). Big Boys were set up the same way. I assume 3985's smokebox is the same. One UP 4-8-4 (832) was experimentally fitted with three stacks..

[Anonymous]

Yeah - double blast-pipes, which, in my opinion add very much to the "mighty" look of an steam engine, very much more so in combination with smoke-deflectors, like UP 844 has them!

But, apart from the advanced look, double blastpipes add to the power and efficiency of a steamer, and André Chapelon, the genius locomotive superintendant of French state railways, was the first to rebuilt older engines this way with oustanding success, in some cases nearly doubling the HP-output of an engine, simply by providing smoother gauges on the way the steam has to pass on it´s way from the boiler to the cylinders and, soon afterwards, double blastpipes as well.
Doing so he radically upgraded the somewhat antique french roster in the 20s and 30s, in the end building new engines this way which were among the best , most powerful and most efficient steam engines anywhere.

No wonder that Otto Jabelmann, road foreman of UP in these times adopted André Chapelon´s ideas on his new engines, the Northerns, Challengers and Big Boys. The engine´s success proved he was right.

[selector]

I thank you both very much.

Perhaps each stand serviced two exhaust ports, the forward serving the front exhaust of both cylinders, and the aft serving the rear? Does that sound plausible?

I posted a link to footage of #844 leaving Greeley in 89 or so on the modeler's forum (the thumbnails show up atop yahoo's first results page if you search "video, Union Pacific #844) a few days back. The twin smoke streams are clearly visible.

If you decide to see for yourselves, it is a hair-raising video lasting 4 minutes, from standing start to 79mph. Click on a thumb, scroll down to the third video on the ensuing page, and download the largest file link, in my case Windows Media.

Wow! Turn up the volume.

Regards to you both.

-Crandell

[feltonhill]

Thanks for the link to the videos. The one where 844 just sort of loafs along for awhile then really gets into it was super!! Who says 80-inch drivers can't accelerate? Great stuff.

[Anonymous]

From what I've read in Kratville's Steam Locos of the UP and elsewhere, the road did a lot of experimenting with front end designs intended to reduce back pressure while keeping the poorer quality coal they used from being sucked out the stack. The Master Mechanics front end was applied to many older locos during the rebuild just prior to the war and featured an oversized single stack that was taller and much larger in diameter.

The double stacks on the later 800s and other UP locos were based on the ideas of a designer named Leonard Botteron, although I'm not sure if he worked for UP, Alco, or ??? The smoke wings were added due to excessive smoke drifting into the cab. Many of the earlier series 800's were also retrofitted with double stacks and the Super 800 was to have 4 stacks according to the Monarchs of the West article in the Classic Trains Steam Glory issue.

[VAPEURCHAPELON]

selector,
where did you post the link with the videos? I can't find.

[selector]

The videos, if they are still posted (available), would be obtained by, in my case using yahoo as the start-page, entering "video,Union Pacific #3985" in the search frame, or the FEF's number. They change from time-to-time, so you may not get what I got back in Feb. They'll appear as thumbnails atop the page that comes up.

The one's I saved to my HD are in the 40 mbite range, so if your IPS can handle that, and your account, I could try to send what I have to you in bundles, and certainly the one on #844.

-Crandell

[Anonymous]

The challangers diverted to the D&RGW were the same design but were changed ti single stacks as I recall. I have no idea why. Sp's latter AC cabforewards had twin stacks but I don't think their Lima built AC-9s did.