Hello Martin

Without wishing to dampen your enthusiasm I have to say that building your own boiler can be fraught with problems and potential danger especially if you haven't built one before or have limited experience with model steam plant.

I would strongly advise anyone to purchase a commercially built and fully tested boiler rather than risk the explosive results of an inadvertent error.

Paul

Ssshhhhhh, don't let the green brigade hear this, coal !!!!!!

Think of your addition to 'global warming', plus, since Maggie decimated our coal industry, you would have to import your fuel, the taxes are going up every year.

Martin,

This is a mature design field, and the obvious thing to do is to make use of existing knowledge and use proven plans and techniques rather than design your own from scratch. But it's a rare skill in the boating hobby. May I suggest that the live steam railway people are the ones to contact? They will have extensive experience of coal firing and associated boiler/firebed design and building practice.

They will also know where to get the small coal granules and little shovels, etc…

Edited By Dodgy Geezer on 17/04/2016 16:36:00

I can't say that coal firing looks easy – **LINK** 

The fact that you can't readily alter the heat levels may not be a problem on a train carrying a stoker, but will add complexity to an unmanned boat…

Edited By Dodgy Geezer on 17/04/2016 18:15:38

Hello Martin

I apologise as I didn't realise you had experience with silver solder as your posting gives the impression that you didn't know what to do.

Paul

Found this coal-fired open launch from San Diego on youtube.

**LINK**

Having spent many years working with industrial coal, why not? just do the research and work to the correct standards.

I have a book called Model Boilers and Boilermaking by KN Harris which deals specifically with marine boilers and there are a couple of drawings of vertical coal fired boilers in there. One is a single flu and the other multi fire tube. It tells you all you need to know about boiler making I think.

I built a 3'' gas fired boiler having had no experience other than extensive reading and it worked well. It had a main vertical fire tube with about four cross tubes.The main trick, as you will no doubt know, is having the equipment to provide sufficient heat- a largish nozzle on your torch and a hearth. I used firebricks.

I only ever saw one coal fired boat which was built by one of the chaps at Cheddar Models- I think his name was Iain Holland- and it was wonderful. He was an expert- but I doubt he was born one!

I don't think building the boiler will be the difficulty, but steaming a small boiler with solid fuel may be tricky and as others have said, it's out on the water and would need regular tending. But what fun- and I wish you luck.

All the best,

Ian

I think I have seen a post on this topic before, when the responses were mostly along the lines of:

yes you can coal fire a boat boiler, but you need a big fire grate area ( or something) to get the same amount of heat that a smaller gas fired grate produces.

As you can see, I'm not au-fait with boiler terminology, but I think the gist of the old post was that a boat boiler would need a larger grate size, a larger chimney to create the necessary draw for a coal fired grate, and add the problem of feeding the fire when afloat makes the coal fired boat boiler a no go ( on practical levels rather than possible levels)

Chris

Martin,

Id be very interested to see how you go on.

I was thinking about building a relatively simple steam launch for my next project and the last thing I would do is to buy a boiler and engine (I am lucky enough to have acquired most of the tools to scratch build).

I have been looking at gas firing but haven't settled on the engine and boiler design yet. However, I believe that nearly all of the published designs are relatively old and will need to be adapted/ modified.

Philh

I am not a 'steam' modeller although I do take an interest in the subject and what I have read gives me the impression that an effective gas burner is a key factor in building a hassle free steam boat model. Richard Simpson has written about this in his Boiler Room series in the magazine – can't recall which issue though!

There is also an interesting article on burners by Martin Ranson in our Features section:

http://www.modelboats.co.uk/news/article/more-gas-tanks-burners/599

Colin

Edited By Colin Bishop, Website Editor on 18/04/2016 11:28:58