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From 'Bemastung und Takelung' it appears that dimensions in the rigging of the tall sailing
ships are within certain limits. A lower yard of 30 m was considered to be a maximum
size.
Bigger then that was not manageable anymore, not for the crew and not for the materials used.
If a yard has an upper limit in seize, so has the brace winch. In the examples I made the same
winch is used on different ships. Those examples show that the winch fits on a ship of 80 m as
well as on a ship of 109 m, so the winch covers a reasonable range.
In the booklet, there is a chapter on how to use the spreadsheet, followed by two examples of
calculations on a five mast bark of 3650 brt and a full rigged ship of 1947 brt, both distracted
from Middendorf.
After finishing the 'study' of the brace winch and the spreadsheet, there might be a useful
application for it. I encountered quite some difficulty to find the proper
adjustment of the winch. Adjusting the winch in real live is even a tougher job, as I have seen on the 'Cisne Branco'. First
one has
to brace
around the yard, minding not to break anything, then one has to decide what adjustments
has to be
made. Accordingly one has to ease of the braces, give slack on the windings on the drums to be
able to move the discs that hold the bars. After putting everything back in place
one has to brace
around again to see what has changed. Not likely it will be perfect, so one has to start over
again and that for all three shafts.
Piet Meereboer
It
seemed to me that calculating the length of the braces was a rather precise job, it could not
be done accurate enough. I don't know if Capt. Jarvis had that problem. He developed the winches
and had them built at his own expense, on the ships he was sailing on. So likely he measured the
length of the braces directly on board.
But he too had to make the calculations on the winch, the same way I did and that is an achievement
that commands respect.
For me it was a true struggle to penetrate a device that already exists for more then 100 years.
Jarvis however had an idea and had to design a device from scratch and he didn't have a
calculator to work with !
These items, including the spreadsheet, are available on request only, with a statement
where it will be used for.
With the spreadsheet it should be possible to come close to the right adjustments,
before even having rove the winch with the braces.
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4535 EJ Terneuzen
The Netherlands
