Friday, May 22, 2009

Tall tales

Back to the boring bits with a bump. As you may recall, Warrior's engine chimney has not been the same since its encounter with Osney Bridge last summer (moral: the time to take the chimney off is when you first think of it*).

In all the time we have had the boat, Warrior has never had a flash engine pipe. Initially it was a standard sort of chimney, but at some point cut in two and joined together with a cocoa tin. That took a few hammerings and I think eventually gave way at the join, so we only had half a chimney. Last summer we were running with the stove chimney over the top to give a bit more height, and as the stove chimney is a pretty solid bit of pipe, this was the source of our problems at Osney; unlike the old one with its cocoa tin fail-safe, or indeed a standard thin one, it acted as a lever and actually dented the roof. This isn't (we hope) visible, but it does leave the what's its name that the chimney fits over at a slight angle which is of course magnified if a pipe is put on it.

So, we need to overcome that, plus we want some sort of arrangement to stop that sort of thing happening again. On his new boat, John Shotbolt has quite a complex arrangement of a hinged chimney with a spring to return it to the upright and a wire so that this can all be done without letting go of the tiller. A bit OTT for us, plus since we fitted the engine room vent, running the wire would be very complex. But we have also seen, on Warbler and on Chiswick a simple hinged arrangement that can be lowered manually (but without the need to wrestle it off and worry about where to put it) and in an emergency will lower itself, albeit with a bit of a bang. I can't remember exactly what Warbler's was like, but Chiswick's was simply an intermediate section onto which a standard chimney fitted. They are produced by Tony Redshaw, and are quite expensive.

With all this in mind, Jim has gone down the quay to see Len the Welder who has some suitable pipe. The idea is to make a short lower section that will fit over, or possibly ultimately replace, the current what-do-you-call-it, and in doing so compensate for the angle. Attached to this will be a hinged tall section, with a lip inside to seal it and keep it stable. But - and this is my little refinement - the hinge will have a removable pin or bolt, so that if required the tall section can be replaced with a short one, rather than sitting a normal pipe on top of the hinged section. We even have some strips of brass we can decorate it with, if I could only remember where they were.

*Adapted from a sailing maxim found in a Libby Purvis novel, to give credit where it's due in case anyone recognises it, but applicable to a whole range of situations.

1 comment:

Anonymous said...

The Tony Redshaw 'hinge' is also very poorly made