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Thursday, 16 February 2012

Exhausting!

Unlike conventional steam locomotives, which have their boilers laid horizontally, Sentinel 7109 has its boiler the right way up (vertical) so that steam and smoke exhaust straight up and out of the top, in this case through a hole in the cab roof.
Roof top Chimneys
7109's original roof was clearly showing signs of rampant air-conditioning, nice in Summer but neither structurally nor aesthetically pleasing all the year round.
Air-conditioned original cab roof
A new 3mm thick mild steel cab roof was obtained some years ago and has been waiting its turn for attention.
It's substantial, 3mm thick and takes 4 people to lift it
Another day spent being 'jiggen' by a shake-saw cut the hole for the chimneys.
27" squarish chimney aperture
(the newly-restored, pristine S&D PMV is in the background)
The new baffle plate to support the boiler's superheater has now been cast, machined and fitted. A length of ceramic rope is needed to provide a seal between the assembly and main boiler superstructure. When this has arrived, the superheater assembly will be able to be lowered into place and fastened down - hopefully never to be removed again before steaming.

Then the roof can be put in place.

2 comments:

  1. Had something rectangular been placed over the hole in the original roof? There seems to be some discolouring.

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    1. This has been the subject of some debate. Norman reported seeing something that may have fitted around the hole but I've never found it. The first picture in the article is not clear enough to help; I'll put another one on a posting and see what you think. Finding good pictures of the top of locomotive cabs is not easy; people don't seem to specialise in that sort of photo!

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