2006 Advice on Hull Weight

Advice on Hull Weight from Frank and Julian

22nd December 2006

To:   World Tasar Council
Tasar Licensees and Agents
Tasar Owners
Paul Patterson, Xtreme Sailing Products

From: Frank Bethwaite
Julian Bethwaite

Re Tasar One-design, Robustness and Certainty.

It is self-evident that in blending into the one-design Tasar the advanced dynamics of the NS14 and Nova development classes and the then-new foam sandwich structural technology Ian Bruce and I created in 1975 an unusually light, strongly-built dinghy of outstanding performance. A population of owners who enjoy a high quality of product together with a high quality of performance have been attracted to the class and have cooperated world-wide to manage the class well.

The certainty of product quality implicit in the one-design principle has lead to continuing demand for thirty years.

"One design" in practice means "As stable as you can keep the concept in the light of experience with the product, external changes in material availability and internal changes in preference within the class".
"Experience with the product" lead early to increasing the skin thickness to improve abrasion resistance, then the addition of substantial under-deck reinforcement to improve both basic strength and fatigue resistance. Weight of the rigged hull increased from 140 to 154 pounds (64 to 70kg).
"Internal class changes in preference" lead to the world-wide adoption of fiberglass centerboards and rudder blades about 1990, with substantial increase in cost, and to the adoption of mylar sails of improved performance in 2005, with substantial reduction in cost.
"External changes in material availability" lead -
1. First to the availability about 1984 of light (125g/sq m) matte, which enabled us to reduce the fully rigged weight from 70 to 64kg for a robust hull with all reinforcement still in place.
2. More recently aggressive pursuit of economies of scale due to globalisation has seen concentration by manufacturers on fewer product options with elimination of previously available product. The light matte is now no longer produced anywhere in the world.

The class' response to 1 has been to introduce a phased reduction in RACING weight, in which newer lighter boats carry ballast so the older heavier boats can remain competitive. This has lead to a mindset in the class the effect of which is to expect new hulls to finish, rigged, at no more than 64kg.
The designer (me) and builder's response to 2 is to accept that to build a robust boat with the materials available now and for the foreseeable future will result in a minimum rigged weight of 68kg. 64kg is no longer achievable with a reserve of appropriate robustness.

Over recent months I have become increasingly concerned as these two trends in opposite directions have increased tensions and uncertainty.

Put bluntly, customers have asked my agents or licensees for new hulls "but only if they finish at 64kg or less".
My agents and licensees have leaned on the laminator who has responded by cutting the margin of robustness.
These boats, when assembled and rigged with established good practice, are giving their usual good service. As designer, I point out in passing that a boat not assembled according to design is not a Tasar.
But a limit has been reached with the emergence of the problems referred to by Julian.

My response is to take what action is now appropriate to restore certainty.

1. I have consulted with the laminator (Paul Patterson) who advises -
• That 125g matte is simply no longer available.
• That supply of 230g matte is assured in the sense that there is no plan to discontinue its production.
• That his preferred bonding adhesive is a Canadian product which is formulated to be slightly flexible, and is also slightly heavier that the Australian "Probond Superlight".
• That when using these materials, a practical and repeatable weight for a bonded hull and deck and thwart, without fittings other than the "under the thwart" saddles and cleats for the swing straps, is - 60kg

2. The weight of the added hull fit-out fittings is a little less than 6kg.

3. The weight of the new deck laminate which will incorporate the previously approved alterations to the deck should be unchanged, but it would be wise either to allow 1 kg heavier as a contingency now, or alternatively to structure any rule change (if necessary) as "Subject to confirmation when decks from the new mould are available for weighing."

Accordingly -

4. I advise the class that, because of the change in materials availability noted above, the delivered weight for a new Tasar hull, rigged as per manual ready for racing, w.e.f 1st Jan, 2007 will be not more than 68kg.

5. I ask the laminator to furnish me with a quarterly advice advising the numbers and weights of Tasars produced.

6. I will speak with each of my licensees and agents to encourage them to support the changes outlined above and advise their customers.

Frank Bethwaite

From Julian Bethwaite

I think everyone needs to take a step back and have a little reality check.

Tasar is 30 years old, its a remarkable boat and the recent advancements that have been made re sails and the look are all very satisfying and have lead to a surge in interest. All good stuff.

We are presently investing heavily in new moulds, with alterations as approved by all of you to the way we land the thwart and mount the chain-plates, plus we have started preliminary work on an all new Carbon mast.

All that is positive.

There are some issues and the weight of the boat is one. If we built the 29er at 60kgs, which given that it is smaller than a Tasar in surface areas, would be relatively easy, we would have sold 1/2 the number we have today. Not because they would be weak, we would in fact come down to about Tasar laminate to do that. Because the perception world wide is it would be too light.

The Tasar is a light boat, and pushing builders lighter and lighter because of a perceived perception was always going to come a cropper somewhere.

So it has! As one person said to me a few days ago "it is not the fact you make a mistake, its inevitable, its how you deal with it and how you get out of it that matters". As a class, this area of the rules has been rubbery, it needs to be re-defined and all doubt removed to restore confidence as fast as possible. Again this is a perception thing.

The other issue is cost. The Tasar is not a cheap boat to build! The previous Australian Boat Builder went bust, the guy who brought it off him went bust also, sell boats at the price you wanted to pay. The Melbourne group who looked at buying us out, baulked so this is not something that people are actively seeking to get involved with.

The advent of a new US builder is great news, the question is whether he can afford to build the boats at the price you wish to pay.

Lets face it, the reason Kit As are so popular, the new sails, we started sourcing foils from Asia and all of a sudden we had a rash of orders and these new boats is all because the price is attractive.

I remember Takao saying once that a batch of boats he got off us, due to currency fluctuation meant he sold them at a loss. He can't keep do that for very long.

The price of a Tasar is very price in-elastic!

Hence the move to Asian building

Whether you like it or not, it is probably the only viable production alternative that we have to ensure the class's survival.

What I am very concerned about is that the Tasar does not do a B14 and just price itself out of existence.

I'm not 100% sure of the number but Xtreme have built 24-25 Tasars, 18 of those boats are simply not a issue and are being sailed across the world without any major issue. There are 5 which Takao is meeting with Paul tomorrow about and there is one in UK under dispute between Tim and Mandy. I think that the work that Martin Sly, Takao, ourselves and Mandy and Geoff Stock have done to bring this new supply source on line, which will end up being the life line of the class, should be commended.

There are always teething problem, in this case exacerbated by the weight issue. And there will be warranty. It is critical in this interim period that we keep all of these costs to a minimum because they will be passed on in the course of business and will come back to the cost effectiveness of the whole project.

So we need as builders and as the class to get on with this new look and do it with a single voice and a high level of certainty.

We need to ensure that the world knows where we are going and why.

Just as a final point, and I will use an example that Takao may be aware of. Recently we had a spate of 29er Center Boards breaking in Holland. Given we have over 1200 foils out there and this had never happened before, it was perplexing. I used a partner who is a Naval Architect to model the 29er foil through to destruction in a infinite analysis program. If any of you are interested, I can send you a video. The board by the way can stand 357kgs tip load before it fails, but we have now instigated a fix that ups that to well over 600kgs. Bit of an over kill, but the point is I use a connection to reduce the cost of analysis or getting a second opinion which meant that the cost of the boat went up about $2 rather than $50-60 if I had done the whole thing outside my sphere of influence. This was November this year.

It was in this context that I suggest that Geoff Stock had access to un-paralleled technical advice via Greens.

Julian Bethwaite