Fixing boiler cleading to firebox

[Peter VennParticipant @petervenn53369]

I am building Don Youngs O2 and I’m thinking about the boiler lagging and cleading. Whilst the boiler bands hold it onto the barrel of the boiler, I’m wondering how it is fixed to the fire box? It presumably goes down the side of the fire box and can’t be seen due to the position of the side tanks, but even so it must need fixing in some way at the bottom end?

I know this is probably a bit of a beginners question, but I simply don’t know the answer and wonder who can tell me?

Peter Venn

[WearyParticipant @weary]

Maybe worth looking at this topic on Model Engineering Clearing House which covers construction of a 5″ gauge O2, and if necessary contacting ‘springcrocus’ (who is a fairly regular visitor) and/or posting your question on that site.

Phil

[BazParticipant @baz89810]

This is one of the things that never gets covered in all the “ words and music” of construction articles, Polly locos tucked the firebox wrapper between boiler and frames, not easy or very elegant, some people drill into the foundation ring and tap 8 or 10BA, wouldn’t recommend doing it without consulting a boiler inspector as some will fail the boiler due to local weakening. Personally I would joggle the wrapper and attach it to the frames with a couple of small screws.

[norm nortonParticipant @normnorton75434]

I cannot refer to the O2 design specifically, but will answer generally for how models might be assembled. The firebox wrapper will typically be a ‘U’ shaped piece that fits fairly closely to the firebox, on top of a thin insulation.

There is generally a transition moulding, or shoulder, between the firebox and the boiler barrel wrappers and this might be quite a thick section of brass or copper beaten to shape. This transition section will be held under the boiler wrapper, and might be screwed to it, it therefore makes quite a firm mounting for the front of the firebox wrapper that can now be screwed to the shoulders.

The rear of the firebox wrapper needs to be mounted to a backhead clothing plate, which itself will be bolted in a few places to blind bushes in the backhead, even if these are only the firedoor mounts. The problem comes when there is no backhead covering and then the firebox wrapper has an ugly and unrestrained rear end. It might be only the cab that holds the wrapper in place.

If held properly at the front and rear as described, the bottom of the wrapper does not need fixing to the firebox.

[Nigel Graham 2Participant @nigelgraham2]

I don’t know the specific locomotive but the cladding is often held to the backhead by a rolled angle of thin sheet material, commonly of wide root-radius. Using bushes in the boilder itself would need those installing as part of the boiler’s own construction.

The bottom edges along the firebox sides could be restrained by tucking them behind simple strips screwed to the frames or to the expansion-brackets that hold the boiler to the frames, or by fitting the sheet with small lugs screwed to the frames.

[duncan webster 1Participant @duncanwebster1]

<p style=”text-align: left;”>I tucked it behind small angles fastened to the footplate</p>

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