Designer's Report to the Australian Tasar Council
Frank Bethwaite prepared the following report for the ATC meeting
at the recent Australian Tasar Championships.
Gentlemen
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
Designer
December 29, 2008