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Fort Wayne Historical Society to get NKP Mike
http://www.rypn.org/forums/viewtopic.php?f=1&t=40004
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Author:  J3a-614 [ Wed Jun 21, 2017 12:37 pm ]
Post subject:  Re: Fort Wayne Historical Society to get NKP Mike

The 765 would have a combustion chamber the 2-8-2 lacks. This is an extension of the firebox into the barrel to provide more combustion room. Its presence is indicated by more staybolts forward of the firebox proper, as can be seen in this photo of C&O 2789, Alco 1947--and one of the few preserved steam engines with a welded boiler.

https://i.ytimg.com/vi/gthnTdOX6mg/maxresdefault.jpg

Author:  Les Beckman [ Wed Jun 21, 2017 1:01 pm ]
Post subject:  Re: Fort Wayne Historical Society to get NKP Mike

J3a-614 has brought C&O 2789 into this discussion as an example, and his photo of the Kanawha was a bit jarring to me. After many years, the 2-8-4 at North Judson finally got her sand dome put back on, as in the photo below.


Les

Attachments:
Cold finally hits at HVRM 12-19-15 004.JPG
Cold finally hits at HVRM 12-19-15 004.JPG [ 334.29 KiB | Viewed 2913 times ]

Author:  rlsteam [ Wed Jun 21, 2017 1:02 pm ]
Post subject:  Re: Fort Wayne Historical Society to get NKP Mike

I knew someone would have the answer! In diagrams of combustion chambers I have seen, the gases are diverted "backward" over the arch and into the chamber before passing through the flues. But maybe I misunderstand what I am seeing.

Author:  TrainDetainer [ Wed Jun 21, 2017 3:43 pm ]
Post subject:  Re: Fort Wayne Historical Society to get NKP Mike

RL -

You are correct about the brick arch diverting the fire gas for a longer burn (also spreads heat out over the length of the crown sheet better), but your terminology just needs a little tune-up. The firebox, while technically/literally a combustion chamber, isn't what's called a combustion chamber in steam locomotive part description. It's simply the firebox. The part actually known as the combustion chamber is the more or less cylindrical extension of the firebox that extends from above the throat sheet into the rear course of the boiler barrel, and as the name suggests its purpose is additional time/space for the fire gas to complete combustion and release heat, with the added benefit of even more primary heating surface before the fire is broken up entering the flues/tubes. The combustion chamber often has a cross section that continues the same top arch as the crown sheet.

As the others have alluded to, the additional crown and open combustion area adds greatly to super power boiler steam production. The biggest example off the top of my head are the Big Boy boilers. With those huge boilers, the flues are only 22' long (what you might call the boiler proper) but the firebox and combustion chamber are 28' 1" from flue sheet to top of backhead - well over half the length of the whole boiler - and the combustion chamber alone is 9' 4" long.

Author:  rlsteam [ Wed Jun 21, 2017 9:52 pm ]
Post subject:  Re: Fort Wayne Historical Society to get NKP Mike

Thanks for the clarification!

Author:  Howard P. [ Wed Jun 21, 2017 10:54 pm ]
Post subject:  Re: Fort Wayne Historical Society to get NKP Mike

One other important difference is the superheater type; the 2-8-4 has Type E multiple-pass superheater units, producing much higher degree of superheat in the steam. This allows much more expansive working of the steam produced in that larger firebox and combustion chamber. The earlier 2-8-2 has Type A units, which are a single-pass design.

The E units (yes, seems strange to use this term when talking about a steam locomotive!!) were more maintenance-intensive than the A units, but were worth it for the extra performance and horsepower.

Howard P.

Author:  Stationary Engineer [ Thu Jun 22, 2017 9:41 pm ]
Post subject:  Re: Fort Wayne Historical Society to get NKP Mike

I haven't seen many pictures of a welded locomotive boiler. It was good that they preserved the 2789.

Baldwin's Ralph Johnson recommended 18 or 19 foot tube length for coal burners and 20 feet for oil burners. Increasing gas flow resistance vs. ever declining heat transfer for each additional foot of tube length. One of the reasons the Van Sweringen Berkshires were such good engines, I think, is because they had 18 foot tubes.

Few railroads, other then the UP, PRR and N&W seemed to appreciate the advantages of a longer combustion chamber and shorter tube length. The N&W shortened the tubes on the Y6b from 24 to 20 feet and lengthened the combustion chamber from 42 to 84 inches compared to the previous Y's. They retrofitted the rest of Y6's and one Y5.

Tom Hamilton

Author:  Cody Muse [ Fri Jun 23, 2017 12:15 pm ]
Post subject:  Re: Fort Wayne Historical Society to get NKP Mike

If I'm not mistaken 611 has a longer combustion chamber as well.

Cody Muse

Author:  dinwitty [ Sun Jun 25, 2017 11:09 pm ]
Post subject:  Re: Fort Wayne Historical Society to get NKP Mike

I've watched this thread for a while, having been in 765's firebox I know whats there. As far as I care the whole interior is your combustion chamber, the firebox sides gather heat as well as the flues, but 765 has these 2 "flubes" that reach into the firebox to get to the hottest flames. This has been a long developed concept, I have seen earlier engines having simple tubes reaching into the firebox, I don't know what 624 has but I bet its very similar to the berk with an earlier design. This is part of the berks "superpower".

And 765 does not get its steam from the steam dome, it has an intake near the cab where the hottest steam is. Then it goes thru the superheaters. The image above is clear where the "boiler" actually starts at the end of the staybolts.

Author:  tom moungovan [ Mon Jun 26, 2017 6:48 am ]
Post subject:  Re: Fort Wayne Historical Society to get NKP Mike

Regarding the comments on longer combustion chambers on C&O locomotives, I couldn't help but take notice of the length on 2-6-6-2 1309, now being restored in WV for the Western Maryland Scenic.

She was built with a 90" combustion chamber. That's longer than the 68" on an SP AC-7 Cab Forward, the 64" on an F-3 2-10-2 and the 80" on a GS-3 4-8-4. They did not short themselves in this category.

Author:  Richard Glueck [ Mon Jun 26, 2017 9:13 am ]
Post subject:  Re: Fort Wayne Historical Society to get NKP Mike

All interesting information, however the subject is the preservation of Nickel Plate #624.

Author:  dinwitty [ Tue Jun 27, 2017 9:58 pm ]
Post subject:  Re: Fort Wayne Historical Society to get NKP Mike

Someone asked about 624's combustion chamber and you got more than your money's worth... 8-P 8-D


cheers

Author:  Alexander D. Mitchell IV [ Fri Sep 29, 2017 1:47 pm ]
Post subject:  Re: Fort Wayne Historical Society to get NKP Mike

Update:

Cranes are on site at Hammond today dismantling 624 into truck-sized sections.

https://www.facebook.com/fortwaynerailr ... 2448987883

Image

Author:  Steve A W [ Mon Oct 16, 2017 7:47 pm ]
Post subject:  Re: Fort Wayne Historical Society to get NKP Mike

I saw a couple of three axle trucks on a semi truck heading
south on In49 in Chesterton In. this afternoon.
Are these from the tender of 624?

Steve A W


Author:  filmteknik [ Mon Oct 16, 2017 11:35 pm ]
Post subject:  Re: Fort Wayne Historical Society to get NKP Mike

Perhaps they are finally getting the rest. I would have thought crane expense would have had them load it all on a number of trucks but in fact that initial move was only the boiler. On Oct. 2 they posted on Facebook "The rest of the move happens this week" but it did not happen. It was all still there on Friday Oct. 13. I was starting to get worried about illegal scrappers.

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