Simplex Boiler

[ozzie46]

I have been able to scrounge up some 4" ID copper pipe for the Simplex boiler but the plans call for 4 1/2 " ID.

Will a 4" ID boiler produce the needed power for the cyl? The cyls are 1 1/2" dia bore by 2 1/8" stroke.

Will I need A smaller bore and are there any other things I need to be aware of?


Ron

[drjohn]

Hi Ron

That 1/2" reduction equates to about a 12% reduction in volume plus of course a significant loss of firebox width.

If I were you, I'd hold out to get the right size - after all the work involved in making the loco, it would be a shame if it couldn't generate enough steam.

Just my own opinion. Others may tell you differently.

DJ

[ozzie46]

Thanks DrJ, as it will be a while before I actually build the boiler I may be able to find some. That stuff is like gold here in the States.

Ron

[baggo]

Hi Ron,

You could roll it up from flat sheet and just fit a butt strap along the join underneath the barrel. You could then make the barrel and firebox outer wrapper in one piece and avoid having to extend the sides of the firebox wrapper which you have to do when making it from tube. Gets rid of those horrible butt straps on the firebox sides and might be cheaper as well.

John

[alanstepney]

Apart from the actual reduction in size as mentioned by drjohn, you would also have the task of rearranging the boiler flues, of which you would only be able to fit fewer.

You can buy that size over this side of the "pond" although shipping it is an expense, so it might be worth looking out for someone who travels the atlantic who could transport it for you.

[ozzie46]

Thanks John, I thought about slitting lenght ways and putting in a 1" strip but that would mean having two butt joints and I'm not sure of the effect on strength there.

Alan, thats one of the things I was afraid of and as I'm not a designer by any stretch of the imagination I would not know how to go about it.

I don't know any one who travels a broad so no joy there either.

Thanks Alan

Ron