Redesign Trevithic Model Dredger Engine

by John

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.


Even painted, this just would not look right.