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WTCA >Agendas>2007 Designer's Report

Designer’s Report to Tasar World Council Meeting, Phuket, July 2007

Summary
The Tasar class is emerging as a well managed, well supported, affordable class with a boat which lies at about the highest performance level that can be handled by the great majority of present sailors.

This realization has important consequences for future class promotion, class growth and class longevity.

Logic
The idea of a “class” in which all boats should be built to the same plan and so sail at equal speed seems to date from the “Patiki class” 18 ft Youth Trainer designed by Arch Logan for the Parnell Yacht Club in Auckland, NZ in 1898. From this start “Class racing” has been adopted almost universally world-wide.

The desire to eliminate real or perceived small differences between nominally identical boats lead to the concept of “Producer- control One Design” with Ian Bruce’s Laser in 1969.

The Tasar, developed from the NS14 and Nova classes between 1972 and 1975 in cooperation with Ian Bruce followed the same thinking.

At that point both constructors and sailors breathed a huge sigh of relief with the belief that “That’s it. These boats are truly identical. In the future we will not change anything, ever.”

But the management of a one-design class jointly by the class’ officers and the designer over a long period of time is turning out to be a more complex exercise than originally imagined, because, over longer periods of time, different sorts of differences begin to appear.

• Some of these affect speed. In the case of uncored “fiberglass” boats the skin softens with use and time and as it softens the boat sails more slowly. The only cure for this is repeated upgrading to a new hull.

• Some affect price and availability. In the case of the Tasar the progressive increase in cost of Dacron sailcloth and reduction in cost of Mylar has been responded to and handled by the class and the designer in a copy-book manner.

o At some time in the future the progressive increase in the cost and availability of alloy and the reduction in the cost of carbon will probably call for a similar decision to change to carbon spars at half the weight. The Tasar’s alloy rig is the industry benchmark for aerodynamic efficiency. To see what a carbon rig might look like I have experimented with likely mast profiles which would offer the same mix of mechanical and aerodynamic efficiency.

• Some affect design. Over the past four decades the average weight of particularly the American and the Australian adolescent and adult has increased significantly. In the case of designs which are very weight sensitive and in which only sailors of a particular weight can win this factor is profoundly adverse. In the case of the Tasar the hull shape is fortunately relatively weight-tolerant, and I used the recent opportunity of Mylar sail re-design to increase the sail area from 123 square feet to 128 sq ft, so the Tasar is well positioned to remain an attractive choice for the fit but slightly heavier adult of the future.

The object of this note is to draw the class’ attention to three further factors, one only recently identified, which are likely in the future to enable the Tasar class to grow more strongly than might otherwise be imagined.

The first is that the Tasat class is well managed. The class is coherent with good communication and the class’ management is strong and adaptable. Nothing could better exemplify this than these championships which were organized with unusual speed at relatively short notice and represent brilliant thinking “outside the square”.

The second is that the class is strongly supported and promoted by its constructors and their agents and dealers. New Tasars of high quality together with spare parts are quickly available globally at affordable prices. A significant statistic is that the ISAF recently invited constructors to display, at Hyeres, such boats as they wished to be considered for a proposed new fast Women’s two-hander Olympic dinghy class. We put up the 29erXX. Whatever its technical properties may be, a key statistic is that the price of the 29erXX is about half that of any of the other 4 contenders. The Tasar is similarly built and priced. My point is that most of the other classes which ten or twenty years ago attracted similar sailors have not survived nearly as well, so a flow of sailors from declining classes into this more vital and affordable class is likely.

The third factor is new. For the last three/four years I have been working with the sailing simulator to find out what best can be taught on the simulator, and how best to teach it. Access to the simulator has been like having a microscope where previously the view was through frosted glass. The key lesson has been the realization that the great majority of sailors - I would say 90% to 95% - sail with a handling technique which I now call the “Natural” handling technique.

This “Natural” handling technique is so universally adopted because –

• It is simple to learn, because

o It is consistent, and

o It calls for no conscious coordination.

• With it a sailor can sail yachts, catamarans and unballasted dinghies up to about Tasar and scow Moth performance level almost as fast as a sailor who uses fast handling technique, but can do this only in winds up to the design wind.

However, we can now see the disadvantages, which are that the Natural technique sailor –

• Cannot handle with confidence in any wind any of the faster boats such as the apparent wind skiffs or the skiff Moth or the foil Moth.

• Cannot sail fast in any boat in winds stronger than the design wind.

This leads to the new realization that the Tasar is about the fastest boat that the great majority of present sailors can handle with confidence and enjoyment.

Conclusion

The Tasar class is well positioned to grow and thrive for about another generation, because –

• It is well managed by its members.

• It is well supported by its constructors and distributors.

• The Tasar is almost uniquely positioned as the fastest dinghy which can be handled with confidence and enjoyment by a “Natural” sailor. This is a new realization.

The three factors above constitute a powerful promotional platform for the Tasar class.

Frank Bethwaite,
Designer.

Appendix 1 - Summary of “Natural” and “Fast” Handling Techniques.

Natural Handling

1. In the Tack, Gybe and Mark Rounding turning manoeuvres, the helm turns to the new heading, then trims sail, then hikes. Often he/she changes hands during the turn.
I call this “Sequential Execution”.

2. In straight line sailing, the helm adopts “best VMG” mode at all times.

3. In straight line sailing upwind, the helm steers to the wind, trims sail, and hikes as necessary. In stronger winds he tends to clutch the sheet immobile and uses only the rudder to luff for equilibrium in roll. In stronger gusts he luffs higher.

4. In straight line sailing when reaching downwind, the helm steers to the mark, trims sail and hikes as necessary. In stronger winds he luffs for equilibrium. In stronger gusts he luffs higher.

I call this “Luff for everything”.

Fast Handling

5. In the tack, gybe and mark rounding turning manoeuvres, the helm turns the boat to the new heading at the rate of turn which will lose least speed as compared with a rival who does not tack etc. During the turn, he/she will trim sail and move body as necessary to be at full hike in acceleration mode as soon as the boat steadies on its new heading. Only when the boat is accelerating strongly will the helm change hands.
I call this “Synchronised Coordination”.

6. In straight line sailing the helm sails in two modes –

a) In Acceleration Mode when not at Target Speed.

b) In Best VMG Mode when at target speed.

I call this “Two mode sailing”.

7. In straight line sailing upwind, the helm steers to the wind, trims sail, and hikes as necessary. In stronger winds he continues to steer to the wind, and eases and recovers sheet as necessary both to maintain target speed and maintain equilibrium in roll.

I call this “Simultaneous Independent Coordination”.

8. In straight line sailing downwind (reaching), the helm steers to the mark, trims sail and hikes as necessary. In stronger winds he bears away (turns downwind) for equilibrium in roll, then uses “steer for balance” for continuous control of roll at speed, and for as long as the wind remains strong he continuously “snakes” down in the gusts and up in the lighter moments to probe for and sail at the stability limit. In this way he accelerates to and maintains maximum speed.
I call these three related skills “Steer for Balance”.

The Practical Differences (other than in light air)

9. As between 1 and 5, if we take the tack as the example –

a) The Fast sailor slows for 4.5 seconds while turning, starts accelerating in acceleration mode at 4.5 seconds, regains target speed at 9 seconds, then shifts to Max VMG mode. Loss to non-tacker about 2 lengths or 4 seconds.

b) The Natural sailor slows for 5 seconds while turning, continues to slow while changing hands, trimming sail and hiking, starts accelerating at say 10 seconds, regains target speed at about 20 seconds if using acceleration mode, more usually at 25 to 30 seconds if using best VMG mode (which gives slow acceleration. Loss to non tacker between 4 and 6 lengths.

10. As between 2 and 6,

a) The fast sailor sails at Target Speed for almost all of the time,

b) The Natural sailor accelerates more slowly and so sails at the same target speed but for less of the time.

11. As between 3 and 7,

a) The fast sailor maintains best boat speed for maximum VMG.

b) The natural sailor loses speed while luffed. In the extreme, the natural sailor slows to the point where he loses steerage way and suffers loss of control.

12. As between 4 and 8,

a) in the gusts the fast sailor bears away to sail fast more downwind, so tends to stay in the gust for the life of the gust, In the lulls he luffs to maintain apparent wind and speed and so sails faster more crosswind as he regains the rhumb line. In this way can access the next gust sooner.

b) The natural sailor luffs for equilibrium, and so sails fast across the gust with poor VMG, away from the mark and usually out of the side of the gust. In the lull he bears away and so sails more slowly more downwind as he regains the rhumb line

The difference between 12a and 12b in both speed, and in control in stronger winds is huge, with everything in favour of the helm who coordinates the three “Steer for balance” techniques skillfully.

Summary

• “Natural” handling technique is based on hopeful optimism.

It expresses the hope that the simplest handling technique will also turn out to be the fastest.

Regrettably, this is not true.

• “Fast” handling technique is based on measured certainty.

It expresses the certainty that efficient handling delivers faster sailing.

As a bonus, it delivers sure control in stronger winds, confidence, and enjoyment.

Frank Bethwaite
Designer

Updated 2007-06-22

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