[modeleng] Re: Juliet boiler question

Hi there Phill,

I haven't driven a Juliet, but I learnt to drive on a loco with a similar 
sized boiler (though maybe a fraction bigger).

I'm not sure I would like to have lost an extra 1/4 of an inch of useable 
steam space from the water gauge (which I think is what you're proposing), 
the chance of drying out on top of the crown-sheet...etc.

Would suggest that unless you've tried driving something similar, it isn't 
a good idea to be redesigning the boiler (Norwich and District Society has 
an unofficial rule that they don't even like you building a boiler till 
you've had some experience of driving a loco, for this and other reasons).

If you really must redesign the boiler to meet with Australian codes (can 
I ask - at what size of boiler do they cease to apply - ie 5/8" flanges on 
a hornby 00 gauge boiler would be rediculous) - then I'd be worried that 
with crown stays in place (assuming they are of the girder type) that the 
crown or the girder stays would foul the regulator tube and mechanism.

Also, you really want a slight rise in your tubes going from firebox to 
smokebox - are you sure you aren't going to end up with them sloping 
downwards?

Yours,


Rich.

On Sat, 23 May 2009, Phill Smith wrote:

> G'Day Gents,
>
> Sorry to bother you all with my questions. Again.....
>
> I have just been going through the boiler design as per the book, and
> redrawing it to meet our boiler code. To fit the tubes into the boiler with
> the correct size ligaments between the tubes, (and keeping the same number
> and sizes of tubes) I found that the crown plate will rise 222 thou'. Can
> anyone see any problems with this happening?
>
> The problems I can see are as follows;
>
> Bottom cock on water gauge lifting same amount and hence reducing gauge
> glass length.
> Less safety margin for beginners to play with in the water level.
> Distance between longitudal stays and firetubes reduced. (though they can be
> moved a bit as well, maybe)
>
> Anyone else see any other problems? (Especially you Alan, as you have built
> one!!!!)
>
> Cheers,
>
> Phill.
>
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