2009 Designers Report

Designer's Report to the Australian Tasar Council

Frank Bethwaite prepared the following report for the ATC meeting at the recent Australian Tasar Championships.


Herewith my designer's report.

Five points -

1. All best wishes for a good regatta.

2. Thanks again to the Melbourne group who had the vision to see that a re-imaged Tasar could enjoy a second product life cycle.

3. I reiterate and emphasise the point I first made in Phuket - The Tasar happens to be the fastest popular boat that can be sailed by a natural sailor. (Higher Performance Sailing Ch 24 et seq)

So my suggestion to the class is that its promotional message could well become something like - Easy to sail - Rewarding to sail well.

4. Carbon rig for the Tasar.
The cost situation is developing along the lines of the Mylar sails, where the cost of dacron was going up and the cost of Mylar was coming down. I think we changed sail material at about the right time.
With respect to spars -

A The cost of alloy must increase with pollution surcharge
B The cost of carbon is reducing.
C With new moulding technology it is now possible to mould aerodynamically efficient wingmast shapes and to do a better job on the desired flexibility than the alloy design.
D With respect to performance, the initial recent work on the 49er rig is described in Higher Performance Sailing Ch 22.

The subsequent performance measurements on the fully developed new rig are surprising -
The standard rig sails to windward in 12 to 15 kts of wind at 14k at 048 degrees.
The new rig sails at 14 kts at 041 degrees

When the class wants this let us know. It would take about 2 to 3 years to develop.
(I explained to Martyn by 'phone prior to the meeting that the change to a more automatic rig on the Tasar could not be expected to confer this sort of performance increase because nobody is suggesting changing the sail shape, but that there would certainly be some performance increase plus the handling advantage of a rig of half the weight.)

5. One from left field - We are developing a strap-on kit to put the 49er on foils (talk to Graham Hanna)
The Tasar, with its compact. efficient. tight-leech rig, may just become one of the fastest foilers in the years ahead.
(I explained to Martyn that the 49er has too much sail to be really fast. On calculation 42 knots in a 20kt wind looks the fastest possible. This assumes that all the sails above about ten feet are at zero coeff of lift. But it has adequate sail for tremendous fun and spectacular speed in the 10 to 20 knot wind speed range.
The Tasar, heeled to windward with its smaller rig and one on trapeze looks much more like a Skeeta.)

Have a good regatta.

Frank Bethwaite
December 29, 2008