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This page looks at setting up the mast (shroud tension and rake, further
below) and shroud control through the mast heeling line.
Catapult's unique shroud control (to assist rigging and allow capsize
recovery) uses a 6 X 1 tackle at the bottom of each shroud (pictured
below) with a single line for both, running across the boat. To heel the
mast, one tackle is slackened while the other is pulled in.
Most boats
are set up with the line running across the boat a
little aft of the dagger-boards.
John Peperell writes on
THE MAST HEELING LINE -FORWARD OR AFT?
Most of us have experienced this – you are doing well on the first beat
and you have the inside slot with the windward mark coming up fast – its
great isn’t it! You put in a neat tack and bu**er – your foot fouls the
heel line & the rig uncleats!! It’s so frustrating – all that hard work
on the beat gone to waste!
Many have gone for another solution – reverse the heel line to run
forward and position the cleats just aft of the forward cross beam. Job
done – perfect solution you might think
(and see photo further below.)
However Jon Montgomery never supported this arrangement - his objection was that the line
was now out of reach if you are in the water aft of the shrouds, as you
likely to be after capsize. In the end Topper kept to JM’s original
design and to help Jon added fair leads inboard (see below)
to minimise accidents.
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This worked
well for me if the shrouds were kept fairly tight but we all
know that a lot more power can be generated if the shrouds are
slack.
With the slack rig set up, I struggled to keep the heel line cleated in
the heat of a race. So last winter I gave the heel system some
more thought and came up with a new arrangement pictured below.
As can be seen with my arrangement the heel line now crosses the
deck forward of the dagger boards and so is much less prone to
accidental tripping.
Also the heeling system can worked from a position aft of
the shrouds and if on capsize you find yourself forward of the
shrouds then my arrangement is also convenient to use.
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Its nice to think that JM might just have
approved of my new heel line arrangement.
Here is a list of the items needed:
12metres mast heel line
2 x HA 182 fairleads & screws
2 x HA 2020 20mm blocks or similar
2 small D shackles
2 small carbine hooks.
Note the forward facing barrel cleats and blocks are not
essential
John Peperell
(Right: The close-up shows the heel line
fair-leads (the two little "drums" top left) inboard of the cam
cleat, giving protection from tripping the cleat.) |
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Left, and top photo:
TENSIONING THE SHROUDS
Both these boats bring the "tail" of the heel line out
from the
blocks to a clam cleat (John on both sides, see top photo, and Alastair on
starboard only, shown.)
This makes it simple to finally tension the shrouds after
setting the mast up with loose
shrouds.
The picture left also shows Alastair's
use of the solution which John describes in the article above, with the heel line led forward rather
than back from the blocks, running across the boat a little
aft of the forward cross-beam.
(See more on this at
Repositioning
the mast heel line )
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SHROUD TENSION: a debate
Everyone agrees that it is essential that the rig is not set up so
tight that mast rotation is restricted, as an un-rotated mast
drastically cuts power and speed until it is noticed and pushed around.
This also needs a smooth mast ball, well-lubricated.
Beyond this, some
are confident that the boat goes best with the shrouds a little
slack (about 6 inches easy movement sideways at shoulder height)
while others argue that only ensuring the mast rotation is the
key.
MAST RAKE
The photo right gives an idea of the 6 degrees of rake most
use, as the designer recommended.
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Alastair comments "I tried varying the rake, by adding a 3cm
shackle to the forestay in strong winds (to add rake to reduce
bow nose-diving) and taking a shackle out in light airs (to
bring the mast upright.)
This is easy with the shroud adjustment shown above,
and I marked the three settings with an indelible pen. Having done all
this, I found I couldn't detect a
real difference in speed in the light winds. (It risks premature stalling
also)
In heavy winds, there is so much going on that seeing a difference may
be lost, and the advantage of less pressure on the bows may be offset by
less responsive tacking. So at the moment I have given this up"
Others may have other ideas on adjusting mast rake, but sticking to the 6
degrees above seems best.
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