26/09/2026

Well, tonight I tried the boiler on the frames and it wasn't too good. It fits ok but as I suspected, the new boiler is again slightly different and it sits too high in the frames, about 0.125" too high.

I discovered this when I tried fitting the cab. It was tilted upwards at the front. At least the profile of the cab seems to fit the boiler fairly well.

When I tried the cab with the old boiler it was fine.

It seems that the new boiler is about 0.125" too high at the firebox end which is causing the problem. It's also too high at the smokebox end but overall it is pretty much level with the top of the frames. I had a look at the drawings and the height of the top of the barrel to the bottom of the inner firebox wrapper should be 4.5625" but on the new boiler it is about 4.625".

I think I can fix this fairly easily (famous last words!) I should be able to lower the smokebox by altering the saddle. The rear of the boiler sits with the bottom of the inner firebox wrapper on the top of the frames. The inner wrapper protrudes below the outer wrapper by about 0.125" so I can lower the firebox by trimming the inner wrapper. This won't affect the boiler at all. It's all more work I don't really need though! Maybe I should have built the new boiler myself after all.

To be continued

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