The old Stuart 500 boiler was what they suggested as a minimum for teh S50 and that was a 64mm dia x 203mm horizontal. To give a bit more scope teh 501 would be a better bet at 73mm dia x 203mm long,

You maight also want to look at something along the lines of the GLR vertical boiler which can be had in several kit forms

Here's a photo of a vintage boiler, it is 12" tall, probably a Stuart Turner design, the engine is an early(1930ish) ST 10V.    Ian S C

Edited By Ian S C on 01/06/2016 10:45:53

The "Standard" boiler kit from GLR is basically just a collection of materials and plans/manual for you to do all the work of making the actual boiler.

Size can depend on a number of things – steam usage, the bigger the capacity and speed of an engine the more steam it will consume. – Display or working, if just running the engine it won't use as much steam as if it were working powering something – Water Feed, some boilers that don't have provision for water feed will just run until empty (or preferably run out of fuel) so a larger boiler gives a longer run – Ease of use, a larger boiler can be easier to fire and get a consistant boiling rate.

Gas is probably the most practical, spirit or fuel tablets OK for small boilers, coal and charcoal a bit more fiddly but more like the real thing.

Once you have decided on a size the thickness of tube wall, endplates etc is usually governed by the pressure you intend to run the boiler at.

J

The boiler in my photo is coal fired, although in the bottom right of the photo you can see the wood box. I think the bits of wood about 10 mm square X 50 mm long would be OK for starting, maybe soaked in kero/paraffin. The above boiler is not in condition to steam, but it is on display in my mates museum about 100 meters down the street. Ian S C

Hi

If you are interested there is a book available from Tee Publishing **LINK** it feature boiler designs for 3.5" x 6", 4" x 7" & 4.25" x 8" Vertical Boilers and 3" x 6.5", 2.125" x 6" Horizontal Boilers

There are also designs on HMEM in the download section by SandyC who I believe made boilers for a living. 3" vertical page 1 here **LINK** there is also a horizontal design. You will have to look through the whole download area because the pages are scattered about.

regards

Steve

I made the vertical boiler in Tubal Cain's simple model steam engines, part 2, but added an inch or two to the height.

Produces enough steam to run small engines. Looks very like Ians.

Neil

Rod

The attached photo shows the boiler I use to steam my Stuart 10V. It was described by Tubal Cain in the Feb '77 issue of ME. It's a 3" dia. water tube boiler (see attached plan). At 10 psi the stop valve is barely open to steam the 10V at a reasonable speed ( opened up the engine races way too fast). In the introduction to the article he states that this boiler should produce 8500 cu. in' /hr of steam at 60 psi, (enough for an engine of 5/8 to 3/4" bore) and 2-3 times that amount at 10 psi.

John Purdy

Mick

The pictures also seem to have gone missing from my album. I've put them back, but here they are.

John

Strange they were showing earler

I probably looked about 6.30pm and they were in your post from just before six