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Edgar Edgar is offline
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First recorded activity by BoatBanter: Jul 2006
Posts: 741
Default Trivial question about entagled lines.


wrote in message
...
This is a trivial question, but it drives me crazy, and maybe somebody
can help me.
For my dinghy/davit system I have 4 triple blocks – two for each side.
All of them are for 3/8 line. Now here is the problem:
Every time when I put the dinghy down and again back the line is
twisted and become entangled. Every time I have to spend time to fix
it – and really drive me crazy.
I use polyester yacht braid.
Thanks in advance
Mada

I suspect it hs something to do with the way you have reeved (roven?)the
line through the blocks as braidline itself has no tendency to twist under
load.
Two triple blocks on each hoist sounds excessive. However if you use these
you have to fix the end of the rope at the top and reeve the line so that
the fall emerges from the centre sheave of the top block This prevents any
tendency for the pull on the fall to twist the whole assembly and for the
same reason said fall must finally emerge also from the centre sheave of the
bottom block If you do not reeve this system correctly the bottom block will
tend to turn over while you are hauling in the slack after launching the
dinghy and I suspect that this is the root of your problem.

It is more usual for boat hoists to have a triple block at the top and a
double block at the bottom since the fall must always emerge from the top
block. Therefore the double block at the lower end has a becket on it onto
which the other end of the rope is spliced and you must then reeve the rope
so that it emerges finally from the centre sheave on the top block, You do
not need swivels on the blocks for a dinghy hoist and if you have swivels
that may also be part of your problem