International 14 Mailing List
Re: Rigs (fwd)

14

From: Andy Loukes (aloukes@argogroup.com)
Date: Thu 16 Sep 1999 - 09:15:48 BST

Here is some interesting stuff from Tim Willets. It seems that we are led
by fashion more than technology quite a lot of the time.

I did check whether it was ok to forward to the list...

I'll put this on the web site in the articles section. If anyone wants to
send interesting articles I'd be happy to collect them together.

By the way I do have a job, it's just a bit boring at the moment ;-) 

-- 
Andy Loukes

System Administrator                          http://www.argogroup.com
Argo Interactive                              tel:+44 (0)1243 815 815
7 Dukes Court, Chichester, PO19 2FX           fax:+44 (0)1243 815 805

<p>---------- Forwarded message ----------
Date: Wed, 15 Sep 1999 09:06:38 +1300
From: Tim Willetts <twcc&cc@xtra.co.nz>
To: Andy Loukes <aloukes@argogroup.com>
Subject: Re: Rigs

Andy

My name is Tim Willetts and we are the rig builder you talk about in
your recent website posting.
I can't help feel very dissapointed in the constant bias in a lot of the
recent reports on the subject of rigs.
We are very proud of the product we produce, which to be fair has
totally dominated both the last two World Championships, as well as
numerous National and Regional championships.
Let us not forget that Charles Stanley was actually dead heat tied with
Geddes (and the CST rig) at the end of the last worlds, separated on
countback in favour of CST. But our rigs were on Irwin,Berkowitz,
Stanley in the top 5.
At the previous Worlds we had 15 of the top 20.

There is of course a great deal to be said for the CST rig. It is very
well built, and provides a new and innovative approach to the rig
dilemma, that all rig builders face.
Everyone knows the CST rig is very fast in Moderate winds of around
15-20 knots. It is very easy to use in that range of wind also.

In terms of its main difference from a TW rig.
It is dimension. We run a much bigger diameter tube (with a thinner
wall),below the hounds, to produce a rig offering far greater control
than a CST rig.
At the most recent Worlds, it is no surprise that the CST rig struggled
in the Lightest air races (although the wind never actually got that
light), whereas  those races were won by TW rigs.
This is simply because with the CST rig, applying more Mainsheet tension
to increase Leach tension (and Power), simply bends the mast too much
and flattens out the sail.

In any class of boat, a softer rig will be fast once the wind comes up,
but its a question of being able to get a good range from each rig.

In the case of our rigs, we get good results in Light air, but it is in
the really windy stuff that our rigs out-perform all others (Certainly
this was very evident in San Fran where it was windier than in
Melbourne). The extra Dimension of the rig, means greater rig tension is
carried (better control over jib shape).
But in a strong breeze there is an important difference. As the Tube
size of our rig is bigger, our tapered section becomes more gust
responsive than the CST equivalent (there mast bends more evenly over
its length than ours does in Strong winds).

In your report you described the CST as more automatic. But I believe
you are totally wrong on that. It is not remotely automatic in Light air
or in really strong winds (but certainly is in Medium conditions).

The TW rig has always been a little finicky to set up, and is not what
I'd call a totally automatic rig, but it does offer the total range of
conditions in which it will perform well. It may have been labelled
"stiff" on many occassions, but never by those who use it, and know it
best. It is NOT a stiff rig. (There are plenty of examples around of
those).
Many sailors will find the cST rig both faster and easier to use than a
TW rig in Medium conditions, but that is not to say that a well set up
TW rig, in the best hands, is not just about as fast.

We are of course very interested to see how the rigs develop from here
as well. I don't doubt the CST rig will be very easily and quickly
improved from where it is now.
Our TW rig on the other hand though is now a 7 year old design, and
while there are not any real advances on that rig out there yet (in all
wind conditions), we do feel a great deal of pressure to improve it.
The other rigs are getting a lot better, and most definitely the huge
advantage we had in San Fran, is certainly being reduced a great deal.

Mostly I believe we did lose some market share in the UK simply because
we couldn't keep up with the demand, and had trouble also with the
Airfreight delivery.
we are also perceived as very expensive, although no one here is getting
rich on 14' rigs. we just put in more time on the finishing detail on
ouyr spars.

As far as the discussions on Rotating masts are concerned. We have
already designed that mast for a NZ14. The systems to make then work are
available to anyone who looks at a Tornado rig.
The Engineering is no problem at all, although in our case in 14's the
Spinnaker does add a few extra problems, and leads to a higher
hounds/bigger topmast than otherwise would be the case.
Keeping the weight down on a Wing section is critical to its
performance, and our rig design was within 1 kg in weight of our regular
section mast. The technology is defintely there to do it, but obstacle
one is very definitely the cost.
As a guide a round tube with a track on is the cheapest possible
construction.
The Wing is one of the most expensive.
In our case, a round section costs 950 pounds.
The Wing section costs 1700 pounds. (Almost double the price).

The second problem has never been touched on ,in the email discussions.
Most certainly the Wing section develops around 10% more power in any
given wind (we had a 280mm wing), and is equivalent to around 220 sf of
sail area.
All of which is fine in Light to medium, but the REAL problem is in a
stronger wind.
On the Cats, when they become overpowered they grossly over-rotate the
mast which effectively depowers the rig somewhat.
However our Stay base conspires against that idea (it is a lot narrower
than a Tornado).
So the only option to depower is to under-rotate the rig.
That is very effective in terms of depowering, but unfortunately it
increases drag in the form of additional heeling force.

The only effective solution is to reef the rig, smaller main and jib.
(You see the big Cats reef a great deal).
While this actually speeds the boats up a lot, it is very difficult in
the 14' to always have the right rig on.

In a one-man Trapeze skiff class i sail, we have a good % of the top end
of the fleet using a Rotating mini-wing section that works really well,
is only slightly dearer than a round section, and still offers a good
improve on  Light air power.

Best regards

Tim Willetts

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