# anyone noticed the secret announcement?



## zubi (May 14, 2009)

Double Fairlie from Roundhouse!!! Sure winner, as was the Garratt. Best wishes from Tokyo, Zubi
http://www.roundhouse-eng.com/doublefairlie.htm


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## David_DK (Oct 24, 2008)

Not seen it. Thanks for the update.
But.... 2 boilers?


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## Greg Elmassian (Jan 3, 2008)

So, technically, isn't it a single boiler, with the firebox in the middle, and smokeboxes at each end?

Greg


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## Pete Thornton (Jan 2, 2008)

Greg Elmassian said:


> So, technically, isn't it a single boiler, with the firebox in the middle, and smokeboxes at each end?
> 
> Greg


Not the Roundhouse model, from what I've seen in the test video. I do believe the prototype had one firebox and 2 boilers.


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## Mike Toney (Feb 25, 2009)

And to think that just a couple years ago Rodger L at Roundhouse say "Not gonna happen" when asked to follow up the single Fairley with the double they are gonna do next year. Bet its a hot seller, the Garret has astonded Rodger, he didn't think it would sell due to the high cost, yet they are building as many as they can each run and it sells out. I dont think anybody saw this one coming! Mike the Aspie


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## Greg Elmassian (Jan 3, 2008)

sharp eyes Pete... sure looks like 2 separate ones indeed.

Greg


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## TonyW (Jul 5, 2009)

Pete Thornton said:


> I do believe the prototype had one firebox and 2 boilers.


The full-size ones have one boiler and two fireboxes...









RogerL retired from Roundhouse Engineering last year.


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## zubi (May 14, 2009)

Tony, it is one boiler but only technically, because the locomotive consists of two separate fireboxes, two sets of steam pipes and two smokeboxes and two chimneys, effectively being two boilers connected in between. In fact it looks like the Roundhouse prototype uses two separate boilers connected with some kind of pressure equalising pipe in between. On the prototype the two boilers were indeed connected into one for the same reason... Best wishes from Tokyo, Zubi


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## TonyW (Jul 5, 2009)

zubi said:


> ... it is one boiler but only technically ...


On the full-size locos, which I used to drive, it is one water space and so was always referred to in the singular.


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## zubi (May 14, 2009)

Tony, one water space and one steam space on the prototype, but two boiler-like setups. On the RH model they apparently chose for two water spaces, although what the actual production models will be like remains to be seen. Best wishes from Tokyo, Zubi


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## Lorna (Jun 10, 2008)

Never have been a fan of the doubles but to each their own. Now that Roundhouse has gone this far what is next?

A Kitson-Meyer? or how about the Weird Vulcan Duplex (now that would be fun).


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## JoelB (Jan 3, 2008)

For those who are interested, a new book on the Fairlie locomotives of North Wales was published last year by the Festiniog and Welsh Highland Railways. A bit pricey, but it's no doubt the absolute last word on the subject and loaded with lots of color photos and diagrams.

There were early prototypes of double Fairlies with a single firebox and single, double-ended boiler, but they were poor steamers -- the draft from one end of the boiler tended to pull the fire away from the tubes on the other end! All subsequent double Fairlies used two separate fireboxes as shown in the illustration.

I'd guess that Roundhouse would opt for two separate (but connected) boilers in order to continue to use the tried-and-true single-flue design with poker burners, as on their other locos.


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## Pete Thornton (Jan 2, 2008)

> The full-size ones have one boiler and two fireboxes..


I stand corrected - thank you Tony.


> connected with some kind of pressure equalising pipe in between


Maybe - but my first thought was that it was a long burner tube?


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## Greg Elmassian (Jan 3, 2008)

So the Wikipedia article is wrong Tony?
You state one boiler and 2 fireboxes.

"
*Double Fairlie locomotive*

 

Diagram of a Fairlie locomotive


Fairlie's answer was a double-ended steam locomotive, carrying all its fuel and water aboard the locomotive and with every axle driven. The double-ended part was accomplished by having one double-ended boiler on the locomotive, with one firebox in the centre and a smokebox at each end. The locomotive looked fairly conventional until the observer realised that the locomotive was two-faced, Janus-like. Fairlie was not the first person to devise a double-ended steam locomotive. The "Seraing", built by John Cockerill for the Semmering Trials in 1851 was very similar in design to a double Fairlie.[1]"


https://en.wikipedia.org/wiki/Fairlie_locomotive?




Maybe there are more variations than we think?


Greg


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## rwjenkins (Jan 2, 2008)

zubi said:


> In fact it looks like the Roundhouse prototype uses two separate boilers connected with some kind of pressure equalising pipe in between.


It's hard to get a decent freeze-frame on the video, but it looks to me like there is an upper equalizing pipe for steam and one or two at the bottom for water, which would alleviate the need to monitor the water on both boilers separately. Interestingly though, it looks like each boiler has its own safety valve, and there are two separate gas tanks?


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## Greg Elmassian (Jan 3, 2008)

There's 2 black boxes on one side of the loco, presume one fuel and the other water?

Yeah, would have been nice if they had focused for the foreground pass.

Greg


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## TonyW (Jul 5, 2009)

Greg Elmassian said:


> So the Wikipedia article is wrong Tony?


No ... all explained in the paragraph headed "Firebox".


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## David Fletcher (Jan 2, 2008)

on the original Fairlies, they were originally 2 boilers fed by a single central firebox. The initial engines to this design were poor steamers, as one boiler would draft better than the other, and cold air would get pulled in the stack on one end through to the firebox, the firebox really could not draft properly to both boilers, despite some clever baffles inside. The design was quickly altered to be two fireboxes, effectively two independent boilers. 
I'm very excited about this Roundhouse offering.

David.


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## TonyW (Jul 5, 2009)

David Fletcher said:


> ... effectively two independent boilers.


As they have one water space, one water level, one boiler pressure, and damage due to thermal stressing would result if only one firebox contained a fire, could you explain your use of the word "independent" for me, please?


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## ferroequinologist (May 8, 2016)

Hi Tony W, I think Davids explanation of "independent" is clear as he was talking about fire draughting problems in early designs and for the fire there had to be two separate and independent fireboxes, fire tubes and smoeboxes. For water and steam space it is only one 'vessel' but for fire space it's actually two independent systems like having two boilers for the fire space. If you are talking steam and water space it's one but talking fire space its actually two independent from each other.


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## zubi (May 14, 2009)

Well, boiler is a device to generate steam by heating and boiling water. On Ffestiniog double Fairlie this is done by two independent fireboxes, pipe systems, etc. Effectively making two independent boilers from the point of view of their function. However, the water space is connected and not independent. This is an obvious simple solution to equalize temperature and pressure and provide more or less similar steam supply to both bogies. There are also two independent steam domes too. Best wishes from Tokyo, Zubi


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## Chris Scott (Jan 2, 2008)

Fairlie locomotive
From Wikipedia, the free encyclopedia
https://en.wikipedia.org/wiki/Fairlie_locomotive








Double locomotive Mountaineer. Built in 1866 by J Cross of St Helens. Operated for a short time on the Anglesey Central Railway, and also on the Neath and Brecon Railway. 


Péchot-Bourdon locomotive
The Péchot-Bourdon locomotive was the final development of the Fairlie type. The Péchot-Bourdon was developed by Captain Péchot of the French artillery to operate on 600 mm (1 ft 11 5⁄8 in) gauge railways associated with field artillery and fortresses. The design was chosen with the belief that if one boiler or set of valve gear was damaged by enemy fire, the loco could continue to operate.[citation needed] The primary difference between a Fairlie and the Péchot-Bourdon is that the latter only had one steam dome. Only one design was constructed, a 0-4-4-0. About fifty examples were constructed in 1906, and a further 280 were constructed during World War I, some by the American Baldwin Locomotive Works.








Baldwin-built Péchot-Bourdon locomotive, driver's side







Baldwin-built Péchot-Bourdon locomotive, fireman's side


Fairlies today
Single Fairlie Taliesin (nearest camera)









Operational:
The Ffestiniog Railway in Wales still uses Fairlie patent locomotives to this day; it has three double Fairlies and one single Fairlie in running condition. The most recent double Fairlie locomotives, Earl of Meirioneth and David Lloyd George, were built in 1979 and 1992 respectively in the Ffestiniog's own Boston Lodge works. The veteran Merddin Emrys of 1879 was the first engine to be built at Boston Lodge. The Ffestiniog also owned and operated Taliesin, a single Fairlie, from 1876 to 1927. It was scrapped in 1935 but a replica was built at Boston Lodge in 1999.

The Fairlies on the Ffestiniog Railway were designed to burn coal. Following trials in 1971, in common with most other Ffestiniog engines, they were modified to burn oil. In 2005, Earl of Merioneth was converted to coal having been built as an oil burner.[15] The success of this conversion resulted in Merddin Emrys, the oldest of the FR Fairlies, being converted back to coal burning in 2007.[16]

The oldest Fairlie still in operation is a Mason Bogie preserved at the Henry Ford Museum in Dearborn, Michigan. The 0-6-4 locomotive was built in 1873 and still hauls passengers on a tourist train during the summer season.


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## Ironton (Jan 2, 2008)

The Denver & Rio Grande tried one of these. They dropped it because of the extra maintenance, pulling power, and the fact the engineer/driver and the fireman had trouble communicating since they were on opposite sides of the firebox/boiler.

At least that is what was claimed.


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## Naptowneng (Jun 14, 2010)

Fascinating, Chris. I like that Baldwin-built Péchot-Bourdon locomotive!
Jerry


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## du-bousquetaire (Feb 14, 2011)

The Saxon state railways tried a couple for their steeply graded Kipsdorf line in 75cm gauge made by Hauthorne of Newcastle ca&lled class II K, but the experiment wasn't followed. Not to be confused with their twin locos made by putting back to back two I K 0-6-0 these were called II K Neue. Here is the link: https://de.wikipedia.org/wiki/Sächsische_II_K


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## bille1906 (May 2, 2009)

It looks like they have done the same thing I did to my double Fairlie with crossover tubes on the top and bottom and two butane fired independent boilers 

http://forums.mylargescale.com/18-live-steam/15687-double-fairlie-construction.html

http://forums.mylargescale.com/18-live-steam/17133-double-fairlie-completed.html

http://forums.mylargescale.com/18-live-steam/17802-double-fairlie-video.html


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## du-bousquetaire (Feb 14, 2011)

There is a fine article in the spring 2018 G1MRA Newsletter on how someone is building one of these I think in 1/19th scale for those interested.


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