Yes, you are correct. I did mean the exhaust nozzles. They both have in fact already been reduced once by Mike, to reduce the fierceness of the blast, which had caused the previous high temps, and blistered paint!. This weekend, with the red coals flying, the casing temperature was reading 286F. So I guess I am getting up there again, and you may be correct about the load.
My track has some tight radii and "S" bends, plus 7 coaches at 50lbs+, engine at 28lbs,
and a thick coating of white hot anthracite certainly makes the blast pipes bark.. Whereas on a large plain oval track, with the same load and constant momentum, the blast is much quieter. As to be expected.
I have concerns about fitting a mesh screen after firing up, what is the melting point of facial skin!??. I guess I have to learn when to back off!.
Have a great day.
Best Regards,
Tony D.
a At 12:17 PM 3/31/03 -0800, Geoff Spenceley wrote:
Tony,
Any discussion of coal, blowers and exhaust nozzles is always worth discussion. Firstly, I would hazard a guess that cinders (in pieces of eight?) from the chimney would be more likely be a problem with the smaller scales. You write blower, do you mean the exhaust nozzle too, or just the blower?
I have a few problems with cinders on the 3/4" scale but only one occurrence of any significance was a few years ago with an OS Porter, the cinders caught my hair on fire and started a small grass fire--the engine was working hard and the nozzle blast caused the cinders to fly from the stack. It was great!
The stainless steel mesh may work might work but I wouldn't bother--even the prototypes ( according to Steam World) would blow out cinders when working hard. It's probably those heavy J&M coaches you haul with the Duchess. On the other hand is the exhaust nozzle the right size--should it be enlarged--or reduced?
One suggestion, if you can stand the departure from realism, would be to have a spark arrester you can insert in the chimney after steam is up, like a piece of stainless steel tube with a SS screen--the tube could be a tight fit--but would that interfere with the draught--( slurp)? Well time to experiment! You can Americanize a small pwrt of the Duchesss!
In closing, I say: Let the sparks fly, or, "Let the FIRE Fall" as we said in Yosemite yesteryear when the fire was dropped from Glacier Point!
Geoff
Hi Geoff, > Of course, they were "pieces of eight". Just using a little poetic >licence relative to the correct lapping method you described. > > Question:- If I start getting 1/8" size red hot coals being thrown out >of the "chimney", of the Duchess, does this mean the blower draught is a >little strong!?. (Joke, but true). > I now think I may need to place a piece of stainless steel mesh inside >the bottom of the petticoat, primarily to keep such sparkies inside the >smokebox, but it also needs to sit below the suction fan nozzle at fire-up. >However, the mesh may also affect the path of the blower jet and disperse >it before it enters the petticoat, thereby minimising its intended affect. > Have you experienced a similar problem from your "large scale", >Britannia?, or are you waiting to set your real estate on fire yet first?. > Any thoughts?. > Regards, > Tony D. > >At 03:06 PM 3/28/03 -0800, Geoff Spenceley wrote: >>"Ello Tony, >> >>Trust you to be a "smart alec"--I thought they were pieces of eight!! Well, >>you have the Duchess and the Britannia, so you must know! >> >>Cheers, >> >>Geoff. >> >>
