Author Topic: Boiler suppliers and other bits suitable for (small) G3 live steam  (Read 1854 times)

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Offline cabbage


You have used my own words to attack me and used them out of context. Again with the Mathematics you voiced opinion rather than facts, what you have never done is ask why I have made those comments….

1: As a host I have a duty of care to my guests. Some of my most enthusiastic guests (for no fault of their own) often have mental ages below 10…

I consider myself fortunate to be chosen for Wednesday afternoon treats for a few pupils from St
Andrews Special School during the summer. A pupil plus ECO will sit on the grass and drink orange squash with ice cubes and eat sandwiches and chocolate cake. Due to “excitable bladder” I limit the number of guest to five plus five ECOs. Down’s Syndrome and other intellectual problems do not preclude the enjoyment of watching trains.

2: In my first year of GTG I barred steam engines completely. It is my personally belief that the 3BAR litre rule cannot be .…

I admit this! I had no idea how a steam loco would react on my track since they were an unknown quantity. My track was never designed to take steam locos but high speed running of Diesel and Electric traction of no more than a 2-D0-2 bogie with no larger wheels than 50mm. As to how a 75mm driver would handle the 3metre radius gauge widened curves I did not know. The late Dave Lowe brought his Brit “02” and we did some cautious testing. We found that it WAS possible to get “02” around the tight corner -but only in reverse. Having proved the largest commercial steam loco was tenable and would not leap off the corners etc -I lifted the  interdict

3: The insurance company simply insist that your equipment is safe. Certification ensures that!

To quote you
“With an off the shelf (relatively cheap) batch built certificated boiler,” If you read the text all I am insisting on are certified boilers. If you were to present me with a boiler lacking a serial number, a TUV or CE mark and no paperwork then I feel that I have a duty to certify it as safe -regardless of volume or working pressure before I let it run on my tracks.

4: I note this morning that the Australian Rails in The Garden Group state it is likely they will move away from their current codes for Sub Miniature boilers.

Yes I know they are, I have seen a copy of the new regs… You really wouldn’t like them as it also includes classification of boiler testing required by gauge of track, boiler diameter and 8 types of boiler and YES G3 track is outside the limits for simple testing. By all means go and check!!!

I see that you have started using SCENIC in capitals as if this is supposed to indicate that I am referring to locomotives used for tractive purposes. All (bar one) of the steam locomotives that have been on my tracks have been SCENIC. The one non SCENIC locomotive (a Green Arrow) which belonged to the late Dave Lowe and we found it could not take any of the curves. The loco remained under my son’s baby grand until the next owner collected it.

5: Turning to your mathematics, I'm afraid I'm reminded of the aerodynamics of a bumblebee.

Interestingly enough so did the inventor of the Ekranoplans of the Soviet Union. The simple fact is that the thrust from the wings is used to provide air flow over the body of the bee. The shape of the bee provides a lifting body. This also explains why the engines of an Ekranoplan are at the nose end…

6: However, if you now accept that size alone does not make a boiler safe or unsafe.

I have never said that. Again I repeat, “Those Are Your Words Not Mine”.

7: Show people how easy it can be to get involved with G3 steaming, and maybe their second loco will indeed be a Pacific with big boiler, cavernous cylinders and buckets of spare steam.

Southern Magyar is my first steam loco. It is based on the “very easy” beginners LBSC design called “Southern Maid”. The boiler has been altered from coal firing to gas firing, and the boiler design from Stephenson to that of Brotan, (which would be more prototypically correct for a MAV or KKStb loco of the Austro Hungarian Empire period). The boiler is smaller and shorter than it should be -but is disguised under a large wrapper. The cylinder size is smaller too. It was designed to pull 3 double bogie coaches (Berne Gauge) for about 45 minutes. Since Brotans produce “wetter” steam than the Stephensons it also has two large superheaters and a “Clench” steam drier. When the loco is complete and running to my satisfaction I will take it out to GTGs. I would EXPECT the host to look at it sideways and insist on the documentation. As this is something I would do myself.

Could it pull me? To be honest I don’t think so. This has nothing to do with my lack of waist but more to do with my design aspects for it.  I had a small boy who used to delight in having his tricycle pulled along the garden path by my SM32 “Lady Anne”. So I will leave it up to you to decide if it is SCENIC or simply a well designed powerful little loco?

I also have some ideas for running G1 equipment on G3. But I warn you Jaime -you will foam at the mouth, because the original by line of the entries on this forum was;

“Everything I build was real -Unfortunately...”

Offline jamiepage


The "Three BAR Litre" rule is I believe useless at our scale.

Your words.

Is there within your contribution now a re-appraisal of that opinion?

If not, there really is no point carrying on a discussion.

ps Because the empirical data (a bumblebee does fly) disproved then accepted theory, the theoreticians had to work out why. Lift producing fuselages- think Thunderbird 2- were the result. Empirics drove the theory.
It's not an unusual process, is it? It starts with observing something , then trying to understand why and how.
Much healthier than first calculating something won't work, then ignoring all evidence that it does.

pps Ekranoplans  exploit ground effect. Most 'cruise' engines were actually positioned somewhere aerodynamically neutral, not in the nose. And ideally high enough to escape water spray.
Some designs did have additional engines positioned toward the nose; their efflux was used for general thrust, but importantly was (or could be) deflected to augment airflow below the Lift- producing stub wings; this extra flow of air increased the ground effect 'cushion'.
This is the primary purpose of the cluster of forward positioned engines on some designs.
Indeed, they were perhaps most used during take off, where the efflux had a ready yet constrained  path between wing and sea. There would have been no way to direct air under the fuselage (until airborne).
The stub wings were able to generate the required amount of lift to support weight, but only within ground effect. Ground effect reduces Induced Drag to the extent that their short stubby wings had L/D ratios normally only achieved with long thin wings (eg as sailplanes).
But only within ground effect- try climbing, drag increased and it would settle back to equilibrium.
Some also had a proportion of engine efflux  ducted below the fuselage to form a sort of hovercraft- like cushion of higher pressure air, but that wasn't specifically exploiting a 'Lift producing fuselage' in any meaningful sense either.

It would take a deliberately poor design to produce absolutely no Lift at all from a fuselage, but all in all, the Ekranoplans  really don't owe too much to the bumblebee.

ppps I think you are referring to the current Aussie code and latest amendments, the one to which the garden gaugers are wanting to move away from. As they say, they want to come up with their own code, which 'shouldn't be too dissimilar to those recently issued by G1MRA and 16mm Assoc. .

Offline jamiepage


Sorry, I'm not as clear as I thought-
 Are you now accepting both parts of this?

However, if you now accept that size alone does not make a boiler safe or unsafe, and if you have accepted  the 'new' code which no longer mandates an annual visit to an Inspector such as yourself,  then there is no more to be said.

I assumed you had, but am not so sure about the second bit now.

If you have, then it's just

The "Three BAR Litre" rule is I believe useless at our scale.

which remains in dispute.  (Apart from Aussie Rules, bumblebees and Ekranoplans)

Offline cabbage

First of all let me produce Exhibit “A”, which are copies of the Australian Association of Live Steamers Volumes 1.0 Part 3 for 2006 and Volume 2.0 Part 3 for 2017.  These were mailed to me 02-09-17 by Mr Phil Gant with his covering letter...

Having no other guide I built the boiler for Southern Magyar to an old copy of the 2006 specifications sent to me by family in Cairns.

From the 2006 1.0 Code -Page 1

Item 1.1.1 This Code is intended to serve those hobbyists who design build  and / or operate miniature steam boilers of 77mm (3”) external diameter or less, have a volume of one litre or less and operate at a pressure of 520kPA (75PSI) or less.

Item 1.1.4 These models for reasons of power or practicality, are generally incapable of hauling passengers. In the case of steam locomotives, boilers covered by this Code are those that are normally fitted to models with a track gauge not exceeding 45mm.

YES I do know I broke 1.1.4 sentence 2(!)

Exhibit “B”. This is the original article and design brief for Design14 from KN.Harris’s book “Model Boiler and Boilermaking”. This is I believe, as I have seen PDFs on the internet, to be out of copyright and may be downloaded for perusal.

The total length is 240mm and the diameter 77mm. A “Project” boiler is typically about 205mm with a diameter of 50mm.

You ask “Is there within your contribution now a re-appraisal of that opinion?”

The answer has to be no.

This is because the 3BAR litre rule is too small to provide either enough water, or steam at a usable pressure to be useful. The Australian 5BAR litre rule however is a very useable rule for G3 (13.5mm) scale work. I follow the facts and figures. I do not use opinion in any design that I make. The 3BAR litre rule will work well for any G1 (10mm) scale or SM32/45 scale loco of that I have no doubt -as I have designed a few for friends. As I have said before, once you pass from G1 (10mm) to G3 (13.5mm) it would seem that you pass the limits for small model boiler work and have to use techniques from the larger scales.

You want to use G1 (10mm) scale boilers and fit them to G3 (13.5mm) scale locos -I have no problem with that. I assume you are happy with the fact that it will be underpowered and overstressed. But what you have to remember is that you are using a G1 (10mm) scale boiler then the 3BAR litre is applicable. If you apply the 3BAR litre rule to a G3 (13.5mm) scale boiler then you must accept low pressures, (meaning more fuel is used to boil water), short running times, (less enjoyment after having to raise steam)  and lack of power, (see MW’s prior entry on the subject of Venture).

Here I state for the record.

The mathematical calculations I have performed show to my satisfaction that the 3BAR litre rule is far too low to be successfully applied to a G3 (13.5mm) scale boiler, although it will work satisfactory with Gauge 1 (10mm) scale and SM32/45 scale boilers. If the rule was increased to 5BAR litre then this would be perfectly workable at G3 (13.5mm) scale.

Once I have been through the BI course in Peterborough I will examine, test, and certify as required by the Orange Book.

Offline jamiepage

That's good, I hadn't misdirected you then.

To correct your misunderstanding, your comment

Yes I know they are, I have seen a copy of the new regs… You really wouldn’t like them as it also includes classification of boiler testing required by gauge of track, boiler diameter and 8 types of boiler and YES G3 track is outside the limits for simple testing. By all means go and check!!!

does not refer to the 'new' regs for Small Boilers.
First, they  don't exist yet. (As I explained).
You are showing the current codes which the (some?) garden gaugers want to get away from. Why? Because in their opinion, they have become 'unnecessarily erroneous and bureaucratic', and they consider them too reflective of inappropriate influence from the 'larger ride- on scales'
Sounds familier, no?
They hope to produce their own codes for 'Sub Miniature Boilers', and they anticipate their new code will not be too dissimilar to those recently introduced here by G1MRA and 16mm Assoc.

Perhaps also we can put Ekranoplan's aerodynamics aside by accepting the engines weren't put on the front because of bumblebees? Because they really weren't.

Turning now to the important stuff, however-

Small Boilers for G3.

You state

The mathematical calculations I have performed show to my satisfaction that the 3BAR litre rule is far too low to be successfully applied to a G3 (13.5mm) scale boiler, although it will work satisfactory with Gauge 1 (10mm) scale and SM32/45 scale boilers. If the rule was increased to 5BAR litre then this would be perfectly workable at G3 (13.5mm) scale.

Whatever your calculations, I find the logic behind your conclusion and your utter refusal to accept evidence to the contrary completely unfathomable, so I really cannot see any point in continuing the conversation.

Perhaps it's enough however, that you do not believe Small Boilers to be unsafe, and that you would be content with the 'new' code which will not require annual visits to an Inspector.

Offline jamiepage

Yes, I'll do it, thanks.

Offline John Candy

Jamie and Ralph.

I am not sure this wrangling is of very much interest to the majority of forum members or that it will have any effect upon the the application of the "Orange Book" directives (which appear to satisfy demands in relation to <3 Bar-litre issues).

The primary purpose of this forum is to help members construct and operate model trains. : This thread which started out with useful comments is now straying into an esoteric argument involving material from another hemisphere.

I am not going to use the "red pencil" but allow forum members to vote using the "LIKE" button.

If members feel the thread should be TERMINATED, CLICK THE "LIKE" BUTTON ON THIS MESSAGE.


Mike's suggestion of the new button has found a new use already!

My fellow Members, ask not what your Society can do for you, ask what you can do for your Society.

Offline Andy B

Before I vote for termination or otherwise, can I make another suggestion / plea?
There are some positive and useful parts of this thread, which are pertinent to its title and have shown endorsement of the ideas and means of achieving 'small boilered' G3 locos  - which I believe would be good to keep and hopefully be expanded on further.
Can these parts either be put into a new thread, or the protagonists of the inputs which have deviated away from these agree to have the moderator use his 'red pencil' to remove them from this thread?

I am very disappointed that, once again, it has come to this. It is little wonder that people are put off using forums, given the nature of some recent posts.


Offline jamiepage

You're right Andy, it's all rather depressing.
And once again, I'm the common denominator amongst all the locked threads unfortunately, so I'll step away from the keyboard.
I think this malarkey takes social skills I just don't have!

Offline John Candy

There are useful parts of this thread .... it has become a "can't see the wood for the trees" situation.

Stick at the keyboard .... it is just an unfortunate coincidence that your threads have been controversial!
Perhaps you would care to extract the useful bits from your messages and create a new thread, "Application of Smaller Boilers in G3" (or similar)?

My fellow Members, ask not what your Society can do for you, ask what you can do for your Society.

Offline jamiepage

The only things I've said which might have some relevance (apart from the aerodynamics of Ekranoplans) is

1. The 'new' Small Boiler code is welcome and can be used to help encourage growth of activity.

2. Within the Small Boiler world, simple proven G1 designs already exist and boilers can be made and certified by Society Inspectors, or purchased cheaply, fully certificated, from professional manufacturers.

3. These boilers can often fit well into G3 scale models of small prototypes.

4. Numerous prototypes could be fitted with <3 bar litre boilers and turn in adequately scale performance.

5. These same small models could also 'pick and mix' other off the shelf G1 items such as cylinder blocks etc

6. Published  designs for a large G1 loco can often be adapted to use for a small G3 loco. Certainly the important working bits.

7. 16mm designs, boilers, parts etc,  have to some extent evolved along different lines, which opens up another source of the necessaries.

8. Using these items could encourage new blood into G3. Once in, they may want to build bigger and enjoy the additional complexity of bigger boilers etc

9. It's not either/ or. If someone wants to start with a Pacific, then that's excellent as well. Find a set of drawings or use a large boiler design.

10. G3 needs to move on from its 'legacy' of ride on activity and focus on scenic railwaying.

Offline AshleyW

come on, i ran a kingscale 14xx at ralphs with no boiler cert on an open day without any questions??

Offline jamiepage

Which reminds me.
I've just checked a set of the published 14XX G3 drawings.

They show a 2in. dia. boiler, 8in. overall length- just about exactly the same as my example yesterday for a GWR Standard boiler.

 Therefore, well within the <3 bar litre limit.