Redesign Trevithic Model Dredger Engine
Further to my previous post I played around with the drawing of the boiler flat end. I have come up with some changes, which will bring the design closer to the original Trevithick design, as far as can be ascertained.
I have already made the cutouts and drilled the holes, so I have compromised somewhat with the changes.
Not a great photo of a computer screenshot.
On the left is the end plate with the cut outs and drilled holes as at present. The black holes are the ones which I would have to fill, presumably with copper or bronze thread, silver soldered into place.
On the right are the:
1. modified inspection hatch, covering the rectangular hole. I would likely change the shape a bit closer to a circular shape than drawn here.
2. The chimney secured to the flat plate with a flange and studs with square nuts
3. The firebox flange a simple disk silver soldered to the end plate, a fire door roughly elliptical in shape with older style hinges and latch and catch, and an open ash pan. Actually, I will check the ashpan situation to ask my expert boiler friends whether these were open as in the London Science Museum engine, or whether it would have had a grille of some kind.