# UP Challenger - Lempor Exhaust



## Chris Scott (Jan 2, 2008)

Yupp, me and Lempor are back.

Happened across a photo of the UP Challenger showing its Lempor Exhaust (LE). Just talking up LE is not particularly stimulating (let's face it, just so much smoke, and it still may be) but a actual photo of the Challenger has a Lempor Exhaust - very cool.  









http://www.railpictures.net/viewphoto.php?id=196014&nseq=0










They camouflage the distinctive Lempor stack in the smoke box; starting at the top; the Diffuser; next the Mixing Chamber and just below the stack is the multi-pipe thing called the Kordina. More efficient, improved power and uses less fuel - coal/oil & water. I guess if UP thinks a Lempor Exhaust is worth installing in the Challenger, well... can't be all bad.  










As for as prototypically correct, did Aster include the Lempor Exhaust in their Challenger model? Yes, it may or may not impact performance, but still prototypically correct is ....

If Aster did happen to omit the Lempor Exhaustt who's going to be first to retrofit their Challenger? Who's going to be the first to install a Lempor Exhaust in their live steamer; perhaps a T1, or K-36/K-37, etc.?


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## seadawg (Jan 2, 2008)

I'm wondering what it says in chalk "Si no tienes nada....." (If you have nothing....) cant read the rest.

I mean, hey, that's how the Big Boy got its nick name.


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## rbednarik (Jan 2, 2008)

The Lempor work on the Challenger was a fairly recent trial done by UP and was/is not standard equipment. The Challenger's (and FEF's and 4000's) used the UP's own twin stack design from the start, which did not resemble a Lempor.

From what I gathered in talking to John at WRC (who did the contract work) a few years ago the lempor trial exhaust did not win over the existing nozzle stand (at least in the fact that the existing one worked in the eyes of the post Steve Lee management), however the trial was successful. 

The spanish phrase on the smokebox door is from LD Porta and is "Si no tienes nada que hacer no vengas a hacerlo aqui Ing. Porta" 

Translated: 
If you have nothing to do, don't come to do it here. signed Ing Porta

There is no reason why the Aster Challenger cannot be retrofitted with a Lempor or nozzle. A true lempor would require much replumbing of the exhaust to fit the Kordina in place, especially on the front engine.


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## Kovacjr (Jan 2, 2008)

Ryan, sounds like a job for you in your spare time?


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## Chris Scott (Jan 2, 2008)

The Challenger modification was done in 2007-08 but I have not found any report or description of the results. The same comments were on the August, 2008, Trains.com forum. It would be interesting to read it, hopefully it would include diagrams of the installation. 

In the photos (above) the Challenger folks looks to be attempting to fit Lempor Exhaust parts to the existing smokebox with few modifications to maintain the Challenger's external appearance. The same was done to one of the restored Garratts at the WHR. This is the email exchange via the Garratt Yahoo Forum to my question; (As compared to the ACR photos of 2 Lempor Exhaust NG/G16 Garratts.)

------------------------------------------------------------------------------------------------------------
WHR NGG16 Lempor Exhaust

Apr 5 7:29 PM 

Is a Lempor exhaust verboten on WHR's NGG16 fleet? Through all the web pages I could not find a single NGG16 with the distinctive Lempor tapered stack.








Chris Scott
CA


timmiboiinoz
Apr 6 2:28 AM 

Hey Chris
Currently only one of the NG/G16's on the WHR has a Lempor exhaust fitted, number 87. You will not be able to tell it apart from the other 2 as they all carry the same type of chimney.

The ACR Garratt's modified with Lempor exhaust had chimneys designed to be the optimum shape for performance. It is possible (and regularly done) to adapt the inside shape of an existing chimney to suit a "milder" Lempor, thereby retaining the external look of the original loco, a compromise which works well on WHR 87.

Opinion seems divided on how effective it is, however I have found that of the 3, 87 definitely does seem to steam better.

There are some pictures of the Lempor going into 87 here:http://www.whrsoc.org.uk/WHRProject/87.htm

Cheers, Tim

end

Lempor Exhaust as installed during WHR #87 Rebuild;
















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A true Lempor Exhaust system is engineered for the specific locomotive to achieve the performance and efficiency potential. The engineering is complex as alluded to in the above diagram and detailed in, Theory of the Lempor Ejector Description;
http://www.trainweb.org/tusp/lempor/lempor_theory.html
A downloadable .PDF of the same; http://www.martynbane.co.uk/modernsteam/ldp/papers/lempor_theory.pdf

To make the complexity much more clear this tool does the job; THE LEMPOR EJECTOR CALCULATOR; 
The Calculator is an MS Excel workbook written to crunch the math:
http://home.ca.inter.net/~mguy/Lempor%20ejector%20calculator%20beta%201.1.xls

Cannot blame either the WHR or UP wanting to not change the outward appearance of their iconic locomotives. The mixed results and reviews performance of their performance is to be expected. And there is no reason to disagree with them or judge their efforts given a very understandable constraint; history and a very dedicated audience fan base. 

*But the very significant performance and efficiencies to be achieved when properly designed are clearly documented. 
*
*Red Devil:*
The most complete benefits of the Lempor Exhaust is in David Wardale's book the Red Devil where Porta's Theories were put into practice vastly improving the performance of 2 locomotives converted. The book (2 editions) is out of print; expensive in good condition. 

















Book Review of Red Devil 
http://www.railroad.net/forums/viewtopic.php?f=13&t=62695

* 
Further reading;*
6A and the Lempor Puffing Billy Railway modified NA 2-6-2t 6A, Marshall, Don;
http://www.martynbane.co.uk/modernsteam/nday/6aandthelempor.htm









THE PRACTICAL APPLICATION OF 'PORTA TREATMENT'- AN ADVANCED
INTERNAL BOILER WATER TREATMENT SYSTEM - ON STEAM LOCOMOTIVES OF
THE FERROCARRIL AUSTRAL FUEGUINO, REP. ARGENTINA.
http://www.martynbane.co.uk/modernsteam/pt/apppaper.pdf

.
While a Lempor Exhaust is obviously beyond our Gauge 1, etc. scales, it has been installed on 7 1/2 gauge and larger small steam locomotives. However, I believe there are some aspects or ideas for improving our scale locomotive's exhaust and performance. 
.
.
.

.
.


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## Belpaire (Feb 15, 2008)

The Challenger Lempor was a failure unfortunately. One thing a Lempor needs is a chimney of sufficient length to allow for proper expansion. The Challenger doesn't have the height available to perform properly from what I was told.



Chris Scott said:


> While a Lempor Exhaust is obviously beyond our Gauge 1, etc. scales


Are you sure about that? http://www.martynbane.co.uk/modernsteam/nday/45mm/45mm.htm


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## Chris Scott (Jan 2, 2008)

Belpaire said:


> The Challenger Lempor was a failure unfortunately. One thing a Lempor needs is a chimney of sufficient length to allow for proper expansion. The Challenger doesn't have the height available to perform properly from what I was told.
> 
> 
> Are you sure about that? http://www.martynbane.co.uk/modernsteam/nday/45mm/45mm.htm


In the Challenger and the WHR Garratt the length of the stack did seem the most obvious reason for the failure and I felt fairly confident it was. But without evidence, either calculating the Lempor configuration (way beyond my pay grade) or test results, I did not want to speculate. 

The World's Smallest Lempor Exhaust.
That's it! I had a vague memory from the first time I researched Lempor Exhaust there was such a model but much as I searched this time I could not find it. Thank you for digging it up. I had forgotten it has, to a certain degree, a bit of a Rube Goldberg quality. I wondered why he did not just replace the entire stack. However, it does look much better painted. 

It seems if the stack had been replaced the stack and therefore the Kordina could sit lower. The extension to raise the Kordina would not bee needed. 


This was another idea for a modified exhaust for a small steamer (from the Ultimate Steam website);








This idea seemed to me particularly well suited to the exhaust pipes problem with the Accucraft NGG16 Garratt. The two engines' 3mm exhaust pipes are merged into a single 3mm exhaust pipe into the smoke box which causes tremendous back pressure. Correcting this problem is a significant improvement to the Garratt's running.

If anyone is further interested in a Lempor Exhaust for a Garratt you might check out; 
The Rebuild of FCAF's Garratt Locomotive No. 2; the "L. D. Porta"

Ing. L. D. Porta and His New Namesake Locomotive at the FCAF Taken December, 2001 by Shaun McMahon. Porta died at the age of 81, June 10, 2003, 








No. 2 is an 0-4-0+0-4-0 Beyer Garratt type locomotive, designed and manufactured in Argentina in 1994. It is based on the first Garratt type locomotive to be built by Beyer Peacock in Manchester in 1909, the K1. No. 2 is reported to be the first steam locomotive built from scratch in Argentina. No. 2 as built had an estimated weight of 9 tons and was designated KM Class.

At the southern tip of South America, near the city of Ushuaia, Tierra del Feugo, Argentina, a small tourist train operation has become a proving ground for modern steam motive power. This railway is known as the Ferrocarril Austral Fueguino (FCAF).


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## Belpaire (Feb 15, 2008)

Chris Scott said:


> In the Challenger and the WHR Garratt the length of the stack did seem the most obvious reason for the failure and I felt fairly confident it was. But without evidence, either calculating the Lempor configuration (way beyond my pay grade) or test results, I did not want to speculate.
> 
> The World's Smallest Lempor Exhaust.
> That's it! I had a vague memory from the first time I researched Lempor Exhaust there was such a model but much as I searched this time I could not find it. Thank you for digging it up. I had forgotten it has, to a certain degree, a bit of a Rube Goldberg quality. I wondered why he did not just replace the entire stack. However, it does look much better painted.
> ...


Rube Goldberg you say? I'll take that as a compliment. Fabricating and fitting these tiny pieces was no easy feat.

I kept the original stack as I liked the look and it is certainly in keeping with prototype practice to fit the diffuser in the confines of the existing stack, sometimes with a projection above. It also didn't help that I couldn't find tubing to match the existing smokebox, which I would have had to replace.

There was no downside that could be determined to having the nozzles above the line of the tubes, so that is what I did.

I've since added what I believe to be the smallest working feedwater heater to the locomotive.


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## seadawg (Jan 2, 2008)

Belpaire said:


> Rube Goldberg you say? I'll take that as a compliment. Fabricating and fitting these tiny pieces was no easy feat.
> 
> I kept the original stack as I liked the look and it is certainly in keeping with prototype practice to fit the diffuser in the confines of the existing stack, sometimes with a projection above. It also didn't help that I couldn't find tubing to match the existing smokebox, which I would have had to replace.
> 
> ...


So I have toyed with the idea of a feedwater heater, but have done absolutely no research. What is that drain / overflow pipe? Overpressure relief?


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## Chris Scott (Jan 2, 2008)

Belpaire said:


> Rube Goldberg you say? I'll take that as a compliment. Fabricating and fitting these tiny pieces was no easy feat.
> 
> I kept the original stack as I liked the look and it is certainly in keeping with prototype practice to fit the diffuser in the confines of the existing stack, sometimes with a projection above. It also didn't help that I couldn't find tubing to match the existing smokebox, which I would have had to replace.
> 
> ...


Hi Roger,
It's great you're here on MLS. About the Rube Goldberg thing, it was tongue-n-cheek, well maybe a bit too much cheek.

What size pipe did you end up using in your 3-pipe Kordina?

Below photos from the rebuild of FCAF's Garratt Locomotive No. 2; the "L. D. Porta" (photo above). I think No. 2's Lempor configuration would be a excellent fit in Accucraft's NGG16 Garratt and enough room for a 4-pipe Kordina using the larger diameter pipe you used on your 3-pipe Kordina. 

















Feedwater Heater;
I think you'll be keeping that smallest feedwater heater for quite awhile. I met a gentleman at Stavers Steamup this past weekend who had added a feedwater heater to his Big Boy. His name is Chuck, do not know his last name. He lined the smokebox with a coil of copper tubing. 

Occurred to me a locomotive where the boiler is exposed in the cab a tight 2-3 loops of copper pipe around the exposed part of the boiler could work as a feedwater heater.

This is a


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## Nick Jr (Jan 2, 2008)

Chris, anyone who believes anything you say should first check out the thread on Railroad Operations, MOW Caboose . Same Forum. 
And I quote "my postings were not intended to be real". thank you


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## Nick Jr (Jan 2, 2008)

Sorry, I messed up the whole thing, trying to bring his statements from another thread into this one, you will have to look back to see what I am talking about, thank you


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## du-bousquetaire (Feb 14, 2011)

Well at last there are some hardy modelers and model engeneers trying to improve the performance on our small scale steam models. This is real good news, as far as I am concearned it was my main reason to getting involved with live steam in 1975. I wanted to check out some of the teachings of Chapelon on models to see if it worked. This is also why I got to know and become a friend of JV Riemsdijk. He certainly pushed things along quite a bit. It's good to see others are doing research too. I should get on with more advanced things like internal streamlining and feedwater heaters soon as I will be retired and can implement these things, time wise. But congratulations for those hardy who are into it already like Belpair.


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## Belpaire (Feb 15, 2008)

seadawg said:


> So I have toyed with the idea of a feedwater heater, but have done absolutely no research. What is that drain / overflow pipe? Overpressure relief?


The pipe that leads down is the condensate drain. It's nice to see the occasional drip from it so you know the heat from the exhaust steam is going into the feedwater.



Chris Scott said:


> Hi Roger,
> It's great you're here on MLS. About the Rube Goldberg thing, it was tongue-n-cheek, well maybe a bit too much cheek.
> 
> What size pipe did you end up using in your 3-pipe Kordina?
> ...


No offense to the Rube Goldberg comment. I make no claim to the thing being pretty. 

I don't recall the Kordina size but the nozzles were drilled out to 0.0135 dia each.

What you describe on the Big Boy is an economizer, a simpler trick than a waist steam feedwater heater. Mine pulls a small percentage of exhaust steam off before it gets to the nozzles and sends it through a heat exchanger with the feedwater. 

In a bench test, The feedwater temperture was being raised by almost 100° F.


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## Semper Vaporo (Jan 2, 2008)

Chris Scott said:


> Hi Roger,
> {snip}
> 
> Occurred to me a locomotive where the boiler is exposed in the cab a tight 2-3 loops of copper pipe around the exposed part of the boiler could work as a feedwater heater.


You have to be careful where you steal the heat from to heat the feed water. Wrapping coils around the boiler may heat the feed water, but it is also a "boiler cooler" so there is no difference between heating the water on the way to the boiler and heating it after it has entered it.

To be efficient, you lay claim to the residual heat in the exhaust... both the spent steam after it has done all the work you can get out of it, and the gases from the fire that have exited the flues and is about to go up the stack. Using heat that is otherwise lost is efficient, but taking heat from the primary generation point gains nothing.


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## seadawg (Jan 2, 2008)

Chris Scott said:


> Feedwater Heater;
> I think you'll be keeping that smallest feedwater heater for quite awhile. I met a gentleman at Stavers Steamup this past weekend who had added a feedwater heater to his Big Boy. His name is Chuck, do not know his last name. He lined the smokebox with a coil of copper tubing.
> 
> Occurred to me a locomotive where the boiler is exposed in the cab a tight 2-3 loops of copper pipe around the exposed part of the boiler could work as a feedwater heater.


That's Chuck Morton. I just picked up his Berk at Cabin Fever. Than thing is a BEAST of the fire breathing dragon variety! I'll see him in a few weeks at Dr. Rivet's. I will inquire more about his feedwater heater.


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