Yarrow Water Tube Boiler Casing

[artemis]

Ron,
So is that grate area the area of the openings where the combustion air gets through or the area of the grates all together?
I'm fairly green when it comes to launch steam but I've never noticed any dampers on the wood fired boats around Puget Sound. My ash door and fire door are very good fits and I can go from a roaring fire all the way to holding steady pressure with the engine stopped in about a second by closing everything up.
I like the performance of blowers but I'm so miserly about makeup water that I haven't fitted one. Soon enough, I suppose.
Mike

Total area that the fire burns on including "holes" for combustion air. I fitted a damper on Artemis and used it when I burned wood. Regulated the steam pressure wonderfully. Remember gramma had one on her kitchen stove as well as one of the draft to the firebox. She sure baked good bread and pies with that stove!

[Mike Rometer]

Dear Pete ,

I think some Burrell traction engines also had the double sliding doors you describe . I believe they're called butterfly doors .
The only steamboat I know of which has them is PENDLEBURY , not sure who owns her now but I think Roger Mallinson made them . They work very well .
I'll almost certainly be seeing Roger in the next few days and I'll try to remember to ask him .

Regards Edward .

I could suggest that is not stricktly a "butterfly door". Those are more usually two halves that are hinged some distance above, or below, the opening, so that as a pedal/lever is pressed they 'fly' open sideways, and return on release. The biggest advantage of these sort of doors is that they don't flap about with motion, as hinged doors usually manage to flap shut, just as you throw the fuel at the hole! There are many types in use, I prefer 'sliding' for the reason given, and they will stay open, or partly, if required, to give 'top air' to the fire.