Posted by Jock on November 12, 2005 at 19:47:06 from 81.190.44.215 user Jock.
In Reply to: Re: Iron centreboards posted by John Nichols on November 12, 2005 at 18:37:44:
There's a danger in trying to use university level science to explain the behaviour of wooden boats. I was involved at the birth of a project which eventually led to the building of a working replica of a 16 C. wooden submarine. If all the recommendations of the scientist assigned to the project had been faithfully followed by the boatbuilder there might have been one h*ll of a disaster.
Having got that of my chest, "Swallow" might well have been built of elm planks on oak frames. She would have had a wrought iron rubbing band from the top of her stem along the bottom of her keel to her stern. She's an old boat, having had a previous career as a working boat on the sea. Her timber would be more porous than that of a relatively new boat like "Amazon" and in the moist climate of the Lake District would hold a great deal of moisture. So in comparing the buoyancy of "Swallow" with her ballast removed, and "Amazon" with her iron centreboard you can end up with an apprarently paradoxical result.
Course, if we build a replica "Swallow" and also a relica "Amazon" we could carry out a all sorts of interesting research!