Author Topic: Pattern of hull strengthening timbers?  (Read 54 times)

petel

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Pattern of hull strengthening timbers?
« on: July 02, 2018, 10:52:49 PM »
Hello all

I know this question is a long shot, but here we go;  I have a Winklebrig but with a difference - she's a steam launch!  I have only recently acquired the boat and am currently renovating the hull as I've found a lot of wet timbers under the floors.

The boat uses the Winklebrig hull and has timber decks and coamings etc. (so does not have the fibreglass decks or internals).  My question is regarding the timbers bonded to the hull in the form of ribs and stringers etc.  Has anyone any sketches, drawings or photographs of the internal hull strengthening as the boats were built?

I am trying to work out what might have been original and what was added later.  There are a few stress cracks to deal with and I suspect they have been caused by the removal of timbers during the conversion.  I am planning to renew everything with Douglas Fir bonded in with epoxy, filleted and taped but can't decided where the timbers need to go at the moment!

Pete

dave_cawston

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Re: Pattern of hull strengthening timbers?
« Reply #1 on: July 03, 2018, 03:17:43 PM »
Hi Pete,

This is the strangest post I have seen on the forum and the most interesting.  What have you got?  Some photos showing the outside and inside of the hull would be most useful.  I am assuming you have a converted dayboat hull as opposed to a cruiser hull.  I can only speak about cruisers and there are no structural stringers or ribs on the cruiser, apart from the ribs which appear to be a thin layer of GRP laid up over rolled newspaper and to which the internal pine cabin linings are fixed.

Please post some photos, how to do that can be found in the Forum Information in Admin Matters.

Dave

petel

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Re: Pattern of hull strengthening timbers?
« Reply #2 on: July 03, 2018, 11:21:44 PM »
Dave

The boat is quite well know in steam boat circles - Chimera II.  There is another steam launch called 'Esmeralda' based on a similar hull.  You can see both boats on the Steam Boat Association website.  Search youtube for 'steam outboard competition' and you will see her in action.

The boat is in good order with the exception of the rotten under floor timbers.  The hull appears to be conventional glass fibre of 4mm to 8mm thickness.  Unfortunately I have had to remove most of the interior woodwork to get access to the bits that I need to replace....quite a big job now!  The hull is very flexible where the timbers have rotted or become detached, hence my thinking that there would have been some timber in the original hull build.  I also suspect that the extra weight of the steam plant and rollers on the trailer may have added to the stresses on the hull.

Pete

petel

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Re: Pattern of hull strengthening timbers?
« Reply #3 on: July 05, 2018, 09:45:13 PM »
After a bit more research I tend to agree with Dave's idea that this was based on a dayboat hull (I did not know that there were two versions until now!).

Having found a couple of pictures the dayboat on the web it appears to have an open floor made up of wooden slats;  can anyone help me find out what is under the dayboat floor?

I am assuming that it is a series of ribs across the boat - if that is the case, how many are there, what is the spacing and what width / depth of timbers are use?  This will help a lot in re-designing the timbers for the re-build.  Any information or photos would be really useful,

Thanks

Pete