BOILER PRIMING

[wsmcycle]

Thanks John
What size coal chunks are you burning please?
Is there a picture somewhere showing this arrangement?
Do you also induce with steam in the stack?

[TahoeSteam]

Was there a system to stop the flow of the fan whilst in reverse, preventing sucking hot coals out and depositing them in the boat?

[johngriffiths]

coal size commonly known here as doubles, about 1" x 2" or slightly larger 1 1/2" x 3", firebox 12" diameter, Centrifugal fan so going into reverse is not a problem. I don't have a blower. Important to have a well sealed firedoor and ashpan to base/bottom. Fan axis parallel to engine crank, it vents into a steel tube complete with butterfly valve then to manifold bolted to 4" x 1 1/2" hole (remember cutting it but size may not be correct) in bottom of the ash pan. Valve necessary because some coals are very hot indeed.
The ash pan bottom is a water cooled mild steel box using water bypassed from the outfall from the inboard surface condenser. Inboard because the air pump is an Edwards and they don't have much in the way of lifting capacity and depend on condensate flowing in. I used to use cast firebars but the local foundries are no more so the current set are welded steel from 40 x 10 stock.
No pics because the boat is currently under a 30' X 15' sheet to keep the rain off.

JohnG

PS 40 x 10 is approx 1 1/2" x 3/8" and if I were making another (3rd), set I would taper the sides