STUART No1 and a 6" boiler ?

Some time ago I bought a vertical multi tube 6" boiler with super heat, that had been assembled to a very high standard with every bell and whistle, including a hand pump,injector and even a weir feed water pump and later a Stuart No1 engine !

They have sat on the shelf for too long and now I want to play with them. Opinions seem to differ as to wether the boiler will drive this engine ! Some say nay, but recently one well known person stated that in his opinion it would quite happily drive the bigger Stuart 5a, and proved it on the tube !

I want it to work hard be it powering a dymano, saw bench or since it has reversing gear most likely a vehicle of some sort that might even take me to the pub !

WILL IT WORK ? or do I make do with the pestige Hi dome on the kitchen work surface !

Your opinions gentleman please ! Noel.

Simple thing to do is compare it to a single cylinder traction engine with a similar size bore and stroke. That puts you into the 3" engines which typically have 7-8" diameter boilers and a larger grate area than your 6" vertical.

A dynamo needs to be run at speed and even with pullies your No1 will need to be reving fast and therefor you will need a large volume of steam. No1 was typically worked at 1000-1500rpm. Running simply for display is another matter and it will happily tick over with no load on a lot less steam at a lower pressure

Also take a look at the steam plants being used on small steam launches that use No1 or No5 engines and you will get an idea of the size you need for a working engine.probably about a 10" dia vertical. Like this one powering a 5A

Edited By JasonB on 21/11/2021 13:54:01

Thankyou for the reply Jason, you confirm what I had always been led to believe. An interesting point in the video was the venting of the exhaust from the stern rather than use a condenser or take it up the funnel to draw the fire and therefore improve the steaming rate. Any comment on this point ? I would have thought that lifting the fire was unlikely ? Noel.

I think it has the option for both, when he first pulls away there is nothing coming out the back, it is only just after he puts his hat on, adjusts a valve and then looks behind that you can see the steam coming out the back.

Assume that he only uses the blast when it's needed rather than draw too much air through the fire and risk blowing the safeties.