Any model three drum boilers out there?

[bryanaverill]

Just curious. Considering the sophisticated all copper model boilers I've seen photos of, a three drum shouldn't pose a particular construction problem. Not sure if a model would have the same circulation as a full size though. Probably not.

Thanks

[crueby]

A friend of mine has one in his rc tugboat driving a two cylinder engine. Fires up pretty quickly.  Don't have any  pictures of it  without the covers on though.

[Jasonb]

There was a detailed build of one a few years back in Model Engineer complete with drawings.

Steam Boat Association (GB) also has designs which would be OK for something like a Stuart 5A or Cygnet if you wanted to put them to work.

[uuu]

KN Harris shows a Yarrow three-drum boiler in his book "Model Boilers & Boilermaking".  With 33 tubes on each side it's likely to have a good circulation.

Wilf

[Michael S.]

I searched my photo archive and found a few pictures of these boilers. These pictures were taken at exhibitions.

Greetings Michael

[bryanaverill]

Thanks Michael.

Those are interesting and attractive models. I'm curious about building a water tube boiler instead of the traditional fire tube vertical. Perhaps a two-drum or a three-drum. I can see it's been done quite well by skilled modelers before. Thanks for the photos.

[Jasonb]

This is the "naked" view of the one that was serialized in Model Engineer

[Mike R]

Here's a 2 drum D type water tube boiler build (not mine!):

https://dboiler.modelengines.info/

[Zephyrin]

note that these 3 drums require careful planning to silver braze without overheating already brazed tubes.
The Yarrow boiler is known to be a very efficient boiler.

[simplyloco]

My Triple will need a high pressure boiler to run as expected, that's why I just bought enough copper bits and pieces to make the Yarrow boiler in Ken Harris's book!
Watch this -or another- space!
John

[crueby]

My Triple will need a high pressure boiler to run as expected, that's why I just bought enough copper bits and pieces to make the Yarrow boiler in Ken Harris's book!
Watch this -or another- space!
John

Looking forward to seeing it come together!!

[bryanaverill]

Some really amazing examples here.

Jasonb. Is the Model Engineer article still available? Year/Month? Seem like a level of complexity I could handle.

Mike R. That is an amazing work. I'll never be at that level, not enough hours in a year. Cool to look at though, an marvel at the high level some folks can achieve.

[Jasonb]

It started in 2009 and ran into 2010 over volumes 203, 204 and 205

May be able to pick up whole volumes from ebay or the dealers, the other option is a digital subscription which will allow you access to the archive that includes those.

I don't think drawings were ever sold separately.

[dudeface]

Would it make sense to build one with just one row of tubes per side, for simplicity and to make it less of a nightmare to solder?

[MJM460]

Hi Miles, I think you will find that it is not practical to design with only one row of tubes each side.

You need to consider the water circulation.  With the two row design, water in the row closest to the fire gets hottest and even partly vapourises, and with the resulting lower density, rises into the top drum, while the outer row, (heated by flue gas which has had the edge of the heat taken out of it), is slightly cooler and hence descends into the lower drums, also called mud drums, to replace the water rising through the inner row.

There are designs with the down-comer rows at the ends, or as a third row, but the idea is similar.

As for how to solder up the nightmare, I will leave that to others more experienced with the soldering than I.

MJM460

[dudeface]

Thanks MJM460.