# Gauge 3 ( 2 1/2" track gauge) boiler pressures?



## norman (Jan 6, 2008)

Hello:

Would anyone know what is the boiler steam pressure range for a Gauge 3 ( 2 1/2" track guage ) Pacific locomotive ?

Thank you

Norman


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## xo18thfa (Jan 2, 2008)

That's a very good question. Gauge 3 (2.5” gauge) is almost a "ride-on" scale. 3.5" gauge, the gauge next up, is a "ride-on" gauge. Many Gauge 3 have all the working parts of bigger loco's, especially feed water capability. Many also have regular, coal fired, loco type boilers. I kind of think that Gauge 3 should be treated like a big engine.

If you are buying this engine from someone, have them hydro test it first and certify the boiler. If the boiler is of unknown construction, hydro test it to 60 to 80 PSI and operate it at 40 to 50 PSI like a Gauge 1 engine. Don’t let the boiler run dry.

Do you have a Gauge 3 engine? Please post a photo.

Bob


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## Taperpin (Jan 6, 2008)

Norman ,
Bobs advise is very sound..there are lots of these 2 1/2" being offered on Ebay now, some are very old as they where built in the 30s and 40s inspired by LBSCwritings ..many have rivetted boilers with soft solder caukling, and these now require great caution ..hydro test and dont go over 40 psi for scenic garden use..my own feelings are , buy on the assumption you will reboiler with silver soldered modern construction ..


Gordon.


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## tacfoley (Jan 3, 2008)

I hope that main131 reads this, as he has been a leading light in Gauge 3 in this country for many years, having also been the secretary of the Gauge 3 Society. He will undoubtedly have all the boiler certification documentation to paw. 

tac 
www.ovgrs.org


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## tacfoley (Jan 3, 2008)

Posted By xo18thfa on 08 Feb 2010 08:38 PM 
That's a very good question. Gauge 3 (2.5” gauge) is almost a "ride-on" scale. 3.5" gauge, the gauge next up, is a "ride-on" gauge. Many Gauge 3 have all the working parts of bigger loco's, especially feed water capability. Many also have regular, coal fired, loco type boilers. I kind of think that Gauge 3 should be treated like a big engine.

If you are buying this engine from someone, have them hydro test it first and certify the boiler. If the boiler is of unknown construction, hydro test it to 60 to 80 PSI and operate it at 40 to 50 PSI like a Gauge 1 engine. Don’t let the boiler run dry.

Do you have a Gauge 3 engine? Please post a photo.

Bob






Bob, apropos your comment - the very first loco I built at school was 'Rob Roy' - a 2 1/2" gauge 0-6-0 dock tank - designed by Martin Evans - with Walschaert gear. Running on high level track, it easily pulled two fifteen-year old at a pretty hairy pace. 

tac
www.ovgrs.org


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## xo18thfa (Jan 2, 2008)

Posted By tacfoley on 09 Feb 2010 07:01 AM 
Posted By xo18thfa on 08 Feb 2010 08:38 PM 
That's a very good question. Gauge 3 (2.5” gauge) is almost a "ride-on" scale. 3.5" gauge, the gauge next up, is a "ride-on" gauge. Many Gauge 3 have all the working parts of bigger loco's, especially feed water capability. Many also have regular, coal fired, loco type boilers. I kind of think that Gauge 3 should be treated like a big engine.

If you are buying this engine from someone, have them hydro test it first and certify the boiler. If the boiler is of unknown construction, hydro test it to 60 to 80 PSI and operate it at 40 to 50 PSI like a Gauge 1 engine. Don’t let the boiler run dry.

Do you have a Gauge 3 engine? Please post a photo.

Bob






Bob, apropos your comment - the very first loco I built at school was 'Rob Roy' - a 2 1/2" gauge 0-6-0 dock tank - designed by Martin Evans - with Walschaert gear. Running on high level track, it easily pulled two fifteen-year old at a pretty hairy pace. 

tac
www.ovgrs.org 



Hi Terry: Rob Roy is a standard when it comes to engines in this size. Martin Evans and LBSC both make a big leap in complexity in their designs from Gauge 1 to Gauge 3.


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## norman (Jan 6, 2008)

Hi Bob:

I am having a machinist build a Pacific loco on an existing running gear for which he will build the boiler, etc.

I found a web site of friends models 

http://www.friendsmodels.com/otherdesigns/212gaugelocomotives.html 

The history of Walt Disney and the original owner of friends models becoming friends is really interesting.

I have spoken with Accucraft but they do not see a retail market to produce 2-1/2" or 3-1/2" track gauge models. 
Really too bad as it is difficult to find a skilled machinist who will build a custom model for an affordable price.

The live steam commercial product world seems to be either track Gauge 1 or a jump all the way up to track gauge 7-1/2" or 7-1/4" with nothing in between.

Gauge 2 , track gauge 2" , is totally dead.

Gauge 3, track gauge 2-1/2", is on a "revival" in England.

A Porter of track gauge 3-1/2" was formally produced by O S Engines. 

A Pacific loco in track gauge 3-1/2" weighs around 200 lbs. I can not pick it up. No use to me but has some resale value.

A Pacific loco in Gauge 3, track gauge 2-1/2", weighs around 50 lbs. I can pick it up. Perfect for me but ZERO resale value.

*I wanted to know what would be the 2-1/2" track gauge boiler pressure as I want to order a boiler pressure gauge.* 

*Any advice on how to set up a firebox burner using propane to fire a 2-1/2" track gauge boiler ?*

Norman


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## Spule 4 (Jan 2, 2008)

Norman, the problem is there are differences in design, not just gauge. 

It would be like asking what is the best fuel or the part number for the water pump for a Mercedes and not saying if it was gas or diesel, four banger or V8, W111 or W201, 1965 or 2005, etc. 

I am not to be a smart ass, as we had an early 1900s Drake 3/4" scale 4-4-0 with a pot boiler, while some others of the same design had conventional flue boilers.


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## Engineer Larry (Jun 2, 2009)

Norman,

Here is a link to a construction series of a 2 1/2'' gauge 4-8-4 in the U.K. where the coal fired boiler is shown under steam and blowing off the pop valves at 90 psi.
http://www.baggo.copperstream.co.uk...elen19.htm 

Scroll half way down for the text and pictures.

Most locomotives of a given scale / gauge are all fired at about the same pressure, so your boiler would be in this range also.
Pressure gauges are usually fitted that have a range of twice the working pressure of the boiler, so a 0-200 lb. pressure gauge would be 

fitted. 


(This gentleman is a very prolific builder, and even has part of his website devoted to the design, fabrication and testing of injectors.)

Hope this helps.

Larry


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## tacfoley (Jan 3, 2008)

Mornin', Norman - at the risk of sounding like a PITA, please be a little patient with us over here in UK. The former secretary of the UK's G3 Society, main131, is currently on vacation in Barbados - I'm certain that he will be able to not only answer all your questions, but point you at one of the society's own loco builders to whom you can address your queries directly.

One thing to note - made by Garrett above - and a very important one - is that the building requirements for Gauge 3 - a larger version of Gauge 1 with scenic'ed tracks and layouts, is quite different from 2 1/2' gauge, where passenger-hauling is the aim rather than free-running 'look-at-me' type models. However, I pretty certain that there is as much knowledge and building history in this scale in the USA as there is in the UK, and hopefully there will be one of these mavens looking in on this conversation. If not, then the enormous live-steaming fraternity of the US is there on the end of your mouse.

You've had a good set of responses so far, in particular that for ordering a pressure gauge for your project you would need a 0 -200 psi gauge. As for firing, to it has to be noted that Over here in UK a number of Gauge 3 locos are set up for gas burning as well as coal, ideal as they are driven remotely, often by r/c, but I've never heard of a gas-burning 2 1/2"gauge model, since all those that I have ever seen are sit-behind coal-fired models. I'd guess that there ARE such things, but.................

tac
www.ovgrs.org


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## tacfoley (Jan 3, 2008)

Posted By norman on 14 Feb 2010 06:36 PM 



The live steam commercial product world seems to be either track Gauge 1 or a jump all the way up to track gauge 7-1/2" or 7-1/4" with nothing in between.


Norman





Norman - there are a number of very good reasons why this statement of yours is incorrect. 

Firstly, the market for Gauge 1 live steam models is alive and well because many folks can actually afford to dabble in it. But the cost even the top end of Gauge 1 - the Alleghenies and the Big Boys - disappears into the realms of pocket change when it is compared with a similar loco in 7.5" gauge, especially if you are talking about US/Can prototypes.

Secondly - the market for Gauge 1 is a buyer-led affair - people actually *wan*t to buy a Berkshire, or a Mallard - enough of them to make it a viable commercial success - and 200 -300 locos is the norm here.

This is far from the case with anything larger - build 200 Pennsy K4 in Gauge 3 at $30K each and you'll be left with 195 of them to play with on your own. Build 200 7.5" gauge Berkshires and you might have 199 left on the shelf - at a cost of at least $125,000 each - always supposing that you could find the person or persons who could build them wholesale in the first instance.

Thirdly, even a casual glance at the live-steam scene in the USA and Canada would show you how mistaken you are in your opinion that there is nothing between Gauge 1 and 7.5" - every track that I have ever been to on your side of the pond has multi-gauge trackwork to enable the many fans of 3/4" and 1" scale to run their trains.

There are a number of fine commercial builders stateside who build replicas of Class 1 diesel and smaller non-steam models at reasonable prices - a fully-configured Dash 9 for around $20K or so is typical, but even they are built one at a time, and take a while. Imagine the build-time for a similar scale northern - and amortize that into the $ per hour. That is why there VERY few are commercial builders larger than Gauge 1.

My $0.02.

tac
www.ovgrs.org


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## Spule 4 (Jan 2, 2008)

TAC-

Your reply touches a couple interesting observations I have made.

First, here in the Mid South, the closest club track I know of with 3.5" track is in Cincinnati. There is a track here near by, private owned. Unfortunately, the majority of what is around here is 7.5" track. The other unfortunate thing are the two clubs I have spoken to/attended open events, the club members were LESS than friendly to downright rude. 

Here in the USA unfortunately, there is not much in interest in the smaller scales. Granted, much of it (my guess) is due to ground running not being that practical. But now I am sure I will get 2,374 posts to the contrary!

Second, why could not the two lands of common language elect common gauges? There are some NICE models in 5" gauge from Polly, MaxiTrack, and another one or two I am sure I am forgetting. But here in the US, 4.75" gauge. Ditto on the 7.5/7.25" difference too.

Me? Hoping one day to nab a S/H (I could never be a machinist between my attention span and patience) LBSC 3/4" scale Tich, more for a display/garden model than ride behind.


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## tacfoley (Jan 3, 2008)

Posted By Spule 4 on 15 Feb 2010 09:01 AM 
TAC-

Your reply touches a couple interesting observations I have made.

First, here in the Mid South, the closest club track I know of with 3.5" track is in Cincinnati. There is a track here near by, private owned. Unfortunately, the majority of what is around here is 7.5" track. The other unfortunate thing are the two clubs I have spoken to/attended open events, the club members were LESS than friendly to downright rude. 

Here in the USA unfortunately, there is not much in interest in the smaller scales. Granted, much of it (my guess) is due to ground running not being that practical. But now I am sure I will get 2,374 posts to the contrary!

Second, why could not the two lands of common language elect common gauges? There are some NICE models in 5" gauge from Polly, MaxiTrack, and another one or two I am sure I am forgetting. But here in the US, 4.75" gauge. Ditto on the 7.5/7.25" difference too.




Evenin', Garrett - thanks for the call, much appreciated. The track business is a bit of a conundrum, to tell the truth. Here in UK and the rest of Europe, a great proportion of tracks are actually raised off the ground so that trains of most gauges from 2.5"up to five inch and the smaller 7.25" gauge models can be run with riders straddling the tracks. These layouts are usually accompanied by dual gauge 5" and 7.25" gauge ground level tracks, too. Remember that here in UK even our 7.25 gauge locos can be quite compact, to use a euphemism.

Our own track is 7.25" gauge NG scale section, and we run 1/3rd scale steam and diesel models on it - again these are tiny trains by US standards - look - www.fenlandlightrailway.co.uk

The rudeness is something I have never come across either on this side of the pond, or on your side, and I've visited maybe 20 or 30 live-steamer locations. If you want visitors then you be's friendly, else your railroad, however big or small it is, will certainly wither and perish.

As for common gauges, I'm afraid that you owe YOUR gauges to the usual Yankee ingenuity and the need to rationalise engineering standards in an easy to understand way - I agree with it , BTW. Here in the rest of the world we do not refer to our models by their linear scale, but by the gauge of track they run on - 

3.5" gauge [I can't do fractions on this pc], equates to 3/4" to the foot scale.

5" gauge - equates to your 4.5" track gauge or 1" scale - wrong, I know, but remember that we were first! 

7.25/7.5" gauge equates to your 1.5" to the foot scale. The 1/4" difference seems to begin around about the Twin cities and heads west.

Hope this helps to clear up a few points.

Best

tac
www.ovgrs.org
Secretary - FLR - www.fenlandlightrailway.co.uk 


ge


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## xo18thfa (Jan 2, 2008)

Posted By Engineer Larry on 14 Feb 2010 10:44 PM 

Norman,

Here is a link to a construction series of a 2 1/2'' gauge 4-8-4 in the U.K. where the coal fired boiler is shown under steam and blowing off the pop valves at 90 psi.
http://www.baggo.copperstream.co.uk...elen19.htm 

Scroll half way down for the text and pictures.

Most locomotives of a given scale / gauge are all fired at about the same pressure, so your boiler would be in this range also.
Pressure gauges are usually fitted that have a range of twice the working pressure of the boiler, so a 0-200 lb. pressure gauge would be 

fitted. 


(This gentleman is a very prolific builder, and even has part of his website devoted to the design, fabrication and testing of injectors.)

Hope this helps.

Larry 





Thanks Larry: This is interesting and deserves much study. 

If this engine is set at 90 PSI, I would think a 120 PSI gauge is the way to go. A smart old engineer told me that you don't want the maximum reading to exceed 75% of the gauge. 150 PSI would be even better.


Propane burner. Probably some kind of ceramic type. I was thinking of experimenting with half sized "Marty Burners". The full sized ones work great.


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## Spule 4 (Jan 2, 2008)

Posted By tacfoley on 15 Feb 2010 10:56 AM 
The rudeness is something I have never come across either on this side of the pond, or on your side, and I've visited maybe 20 or 30 live-steamer locations. If you want visitors then you be's friendly, else your railroad, however big or small it is, will certainly wither and perish.

As for common gauges, I'm afraid that you owe YOUR gauges to the usual Yankee ingenuity and the need to rationalise engineering standards in an easy to understand way - I agree with it , BTW. Here in the rest of the world we do not refer to our models by their linear scale, but by the gauge of track they run on - 

3.5" gauge [I can't do fractions on this pc], equates to 3/4" to the foot scale.

5" gauge - equates to your 4.5" track gauge or 1" scale - wrong, I know, but remember that we were first! 

7.25/7.5" gauge equates to your 1.5" to the foot scale. The 1/4" difference seems to begin around about the Twin cities and heads west.

Hope this helps to clear up a few points.

Best

tac
www.ovgrs.org
Secretary - FLR - www.fenlandlightrailway.co.uk 


Tac-

Yes, the opposite end of this was the SEGRS, the live steam members bent over backwards to be friendly, showing off models, etc. They allow others to bring locos, but only have 45mm track so I am out. The two groups I am discussing have had a drop in membership over the years...

As for the other aspect, I guess it goes back to 1.203/SM32, HO/00/EM, O being 1:48, 1:45 or 1:43....


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