From: Clive Watts [[email protected]]
Sent: 10 december 2002 05:47
To: Carter Jackson; Ali Meller; 505world-List
Subject: CST 505 Carbon Spars - info for the AGM

Att 505 Sailors 

We've invested many hours producing a prototype 505 Mast which is currently being showed off at the Worlds in Perth. Please follow this link to have a look the details and price. 
 

https://www.cstcomposites.com/2013/07/31/505-class-new-boom/
 

https://www.cstcomposites.com/2002/12/03/new-505-carbon-rig/

We think that the carbon spars for the 505 are a great and constructive development for any development class - We've been doing this for 7 years now and on the dinghy side of our business we've had a number of world championships under our belt in the 18 skiffs, International 14's and Contenders. 

Contrary to what a few people have said on this forum - it is our opinion that the carbon spars have been a real plus for the 18 skiffs. It was only a couple of years ago that sailors were regularly changing their glass fibre tips 2 -3 times a year and Aluminium base panels (metal had fatigued/yielded). Some skiff sailors were metal spinning up to ten different tips a season to chase the stiffness they were after. In the 18's today more of the aluminium base sections break than the carbon tips (2nd rigs) and in the no1 rigs none of our full carbon 18 masts have ever failed in two years. John Winning's Yandoo, RMW Marine from the UK, all the European Skiff Pro Tour 18's are still running around with their original carbon rigs from 3 years ago. 

Ask anyone in the I14 fleet if carbon rigs are really bad - this is a full on development class with 130 boats at the Worlds in Melbourne 99, 115 boats at the Beer Worlds.

The equation is simple if you want reliability in a carbon spar - set a conservative minimum weight and a minimum diameter so expensive satellite technology carbon does not come into the class. For the first couple of years put weight correctors on the carbon masts and set a CG point. This is exactly what happens now with the AUD 22000 carbon prepreg honeycomb boats that need 20 kgs of lead to bring them up to class weight.

What 50% of the fleet have just spent on new sails at the current Worlds will buy a new carbon rig which will last pretty well indefinitely. Next worlds every one will have new sails again!

We of course are somewhat biased as carbon spars are our business but I think you will find that if longevity and reliability are put into the equation then a carbon mast is a lower cost overall and better proposition than an aluminium spar. 

Its easy selling a product you believe in!

Rgds

Clive Watts
Managing Director
Composite Spars & Tube
P: +61 2 9668 8488
F: +61 2 9668 8499
POB 651, Caringbah, NSW, 1495, Australia
78-80 Tasman Street, Kurnell, NSW, 2231, Australia
www.cst-marine.com

From: Kimball Morrison
Sent: 10 december 2002 12:12
To: 505world-List
Subject: RE: CST 505 Carbon Spars - believe it.

Dear all,

How nice of Ali to keep us all so enviously well informed, exactly how wonderful the sailing is down there. Thank you Ali. I hope you are all having fun.

Next, thanks must go to Clive Watts at CST for building a prototype carbon mast for the 505. I've got nothing but praise for his masts and have had one on my International 14 for the last three years. They are on many other 14s around the world. I'm not sure the last time one broke, if ever, from failure of the actual tubing. 

As an example, a couple of years ago the upper shrouds broke on one boat twin wiring with the kite up in a steep chop. Now remember this is not just a LLS, but something quite a big bigger strung from the mast tip. The mast banana-ed over the front of the boat, the crew dropped the kite and they sailed home. The only damage to the spar was the sail track had unstuck from the aft edge of the mast and needed re-gluing..... That mast is still competitive today.

Don't vote for carbon because of any perceived performance benefit, don't vote against carbon because of fears of disadvantaging many older boats. Vote in favour of carbon because over a few years the fleet will change over to a material which is much more robust and in the long run will keep costs down.

Happy sailing,
Kimball

(ex GBR 8429)

From: Nigel Lott
Sent: 4 february 2003 12:36
To: 505world-List
Subject: 505world: Carbon masts.

I have repaired the mast step on both Kyrwoods I have owned, and noted that
many other 'steps on boats in our local fleet and at a couple of nationals
were suffering varying degrees of failure (cracks in joints and worse).
Even in one relatively new carbon/vinyl ester Kyrwood.

If carbon masts were to be allowed fewer masts might be broken due to
shallow water but boats, especially the older ones, are likely to suffer
greater structural damage from bottom strikes? Perhaps the carbon mast
committee should quantify the increase in buckling and bending strengths
from a Cumulus/M2/Goldspar to a 'typical' carbon mast so we can see what the
potential increase in maximum load is going to be. I'm sure it is possible
to design and construct a mast step which will not fail when you slam a wave
into a 505 held firm by the step, but I'm not confident that even the newest
boats, to varying degrees, will withstand that load without at least local
failure(s).

Unless of course we do a fair bit more work on our boats!

Nigel
ex AUS6483. 7982 and 8xxx.