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mast support

Posted: Sat Nov 12, 2016 10:00 am
by RenJob2016
Dear experts, Are there any drawings or sketches showing the general arrangement of the mast support system for a Westerly Oceanquest AC or Falcon or similar bilge keeled Westerly yacht. In particular does the mast support post, visible in the cabin, sit on the table or pass through the table top and in either case what is beneath the table and down to the hull to provide support.
Any information would be appreciated.

Re: mast support

Posted: Sat Nov 12, 2016 11:20 am
by Jolly Roger
Welcome to the WOA forum.

The mast support would be continuous and the table would be built onto to it. I would expect it to be solid timber. The loading taken by the mast support is high as it is stopping the tension from the rigging and sails pushing downward to the bottom of the hull. The area of the hull underneath the mast would be a substantially thicker layup with reinforcing ribs, both fore and aft, to hold the hull in shape. The rest of the hull shape is kept in shape by bulkheads, so the rigging does not pull the topsides together.

Hopefully this explains in simple terms what is the strength to keep the boat in shape under the huge loadings whilst under sail. If you are thinking you can make any changes, all I can say is do not consider it without consulting the designer as you will probably ruin your boat.

Re: mast support

Posted: Sat Nov 12, 2016 10:21 pm
by mikebuggy
Mast support on earlier Westerlys is a strong wooden post, usually as part of the confluence/corner of the fwd saloon bulkhead and heads or locker bulhead. This is then landed on a strong point or transverse floor in the bilge.
Later Westerlys use a mild steel post, usually taken right through the table to a steel footplate bolted to the top of a strong moulded transverse floor beam. You can usually lift a floor board or hatch under the table to see this. If you cant, you need to make it so. On many boats the steel pole is clad in a nice wood jacket down as far as the table....giving the impression of a wooden post resting on the table. The table is easily dismantlable to see the post. It looks like its glued but it isnt. The top of the post has a large plate which abuts under the raised plinth on deck which the mast heel plate sits on. You should access and prime/paint the foot of the post every 2 years, and the top of the post every 3 or 4 years. At this time check for leaks as the deck fitting bolts are prone to leak. Its rare, but this can also cause the material in the plinth to soften so the mast foot sags. On masthead rigged vessels there is effectively a ring beam running between the cross floor beam, the bonded knees which take the upper shroud chainplates, across the deck through the mast base and down the other side back to the cross floor beam.

Re: mast support

Posted: Sun Nov 13, 2016 2:22 pm
by RenJob2016
many thanks for your prompt response to my question. If anyone has drawings, sketches or photos showing the structure from hull to table top I would still be interested to see them.
Many thanks