Steve Nichols <aussieswift@xxxxxxxxxxxx> wrote: Date: Thu, 17 Aug 2006
13:28:44 +1000 (EST)
From: Steve Nichols <aussieswift@xxxxxxxxxxxx>
Subject: Re: Class Rules Opinions please
To: Greg Ryan <greg@xxxxxxxxxxxxx>
Greg,
I didn't get the data that you sent re the mast.
In factThe 59er I sail has almost an identical size rig to the Swift Solo and
was designed to be appropriate for relatively small righting moment - the 59er
was conceived as a 2 man hiking boat. This rig may be closer to the Bethwaite
version of what they think would be appropriate for the Swift Solo. I am going
to play with the spinnaker on the Swift for fun.
During the shake down process for rigging the Swift Solo I've had a few
realisations. One of these has been that most Bethwaite gear whilst ok for its
designed purpose - relatively low cost strict one design boats is not suitable
for the Swift Solo application. Most of their gear is designed down to a price
and not up to a standard. The "carbon" mast on the 59er and the "carbon" spin
pole on the 49er are actually fibreglass and weigh and flex more than their
carbon equivalents. I could continue this list with other components. That is
not to say they are doing a bad job but I believe they will occupy a different
section of the market from us. I could have easiliy decided to drop the 59er
rig on top of the Swift Solo but I don't think that is the right spirit for our
class. The sailmaker we have selected - Dave Alexander has made world
championship winning I14 sails in conjunction with CST as the mast maker. He is
happy to work with us on our application and is confident
that he can produce a good product.
Greg Ryan <greg@xxxxxxxxxxxxx> wrote:
Hi Steve, I didn?t get a reply from you regarding the mast data I
sent or the Australian Member National Authority and ISSA Council delegate. In
the mean time, and possibly of interest, we have been measuring the 29er over
here. As you know the 29er hull is very close in size and weight and shape to
the Swift. The 29er jib IS the same size as ours, but our mast and main is
bigger. The 29er XX carbon mast is said to have the same (or very close)
overall mast dimensions as ours, of course the standing rig will be different
so I have been waiting to get hands on the 29erXX rig to check the dimensions
and compare the Pride/Bethwaite designed spinns. Maybe this is something you
can work out. In any case it might be a simple option, but not necessarily any
cheaper, IF it is sized close enough. Worth looking at anyway? (Some picture
comparisons are up on Al?s flicker site).
On advisory rulings in general;
In general, if anyone is looking for benediction on what they consider a
variation that might need prior approval of the technical committee (whose
authority comes from part A 3.8 and 3.9 Management Rule and Part B Rules
4.4-Restricted Features and Materials and 4.5-Advisory Rulings, see below) then
you should make a detailed drawing with explanations and email or send it to
the Class Secretary. The Secretary will pass the drawings on to the chairman
of the technical committee (appointed each year by the Class Council or EC) to
examine it correspond with you about it and finally recommend action to the EC
which will issue an advisory ruling to you through the chairman of the TC (who
will also direct the class measurers in the application of the advisory
ruling). If you or the EC and or council consider Class Rules need to be
changed to accommodate such a design variation, then a proposal (seconded by
two other owners) should be submitted to the Secretary before March in
the year the member owners would vote on the issue. The EC will arrange a
(email/web) vote prior to the AGM and a simple 2/3 majority of votes received
from eligible owners will accept the proposal. It will normally come into
effect at the AGM which is held after the Gold Championships (next in the
northern part of NA around the US mid summer 2007 timeframe, and yes, this year
competing boats WILL be measured).
4.4 Restricted Features and Materials
To ensure the objects of the class are not prejudiced, where a person
proposes to build a Swift Solo which:
1. Incorporates a design feature of the hull not expressly specified in the
template drawings plans and construction manual; or (?) not currently in use in
Swift Solos already racing, the owner must seek the approval of the Technical
Committee of the ISSA before constructing the Swift Solo.
4.5 Advisory Rulings.
Builders intending to construct boats for measurement under these Rules are
advised to submit details to the ISSA, or its approved representative, of any
feature which may impinge upon the spirit or letter of these rules. Upon
submission of full drawings and explanations, a confidential advisory ruling
may be obtained without obligation.
On a more specific note regarding your prod receiver design,
The guidelines our Vice President Robert Harper foreshadowed are reasonable I
think. Keeping in mind when designing the pole spar that the pole and the
forestay fitting are ?included? in both the swing test and the weight test, so
I don?t see a strong incentive to make them much lighter, and therefore in real
need of receiving tube support out in front of the boat. No poles have broken
in the class so far. However, I don?t think the feeling in the class is to
stand in the way of improvements in rig, especially if you can make a case for
reliability and efficiency issues. Moreover, I don?t think the class would be
in favor of maintaining the status quo simply to provide a convenient lifting
or pivot point for the boat, but there would likely be a negative response from
the TC and current EC to a proposal for penetrating the deck and flotation
space at the bow in any way. Without preempting the TC?s or EC?s decision on
the matter, the relevant rule might be
5.12.3b Hull Dimensions
Length overall shall be measured with the hull?s designed waterline
horizontal, between perpendiculars at the AMP and the forward most protrusion
of the hull. This measurement shall be a minimum of 4.363m (171 3/4 inches) and
a maximum of 4.375m (172 1/4 inches).
So the length of the hull and protrusions is set at 14.35 feet. It could be
possible that if you make a good argument that the prod is a part of a
?forestay fitting? rather than a part of the hull (and this may hinge on
attachment method) then rule 5.12.3b might not apply, as a fitting might not be
considered as part of the hull. The usual rules for position of forestay
attachment etc will apply to that fitting. The mechanical problem I see with
that is that the pole is a long lever - on the bolts of the forestay fitting.
It better be attached aft and securely to the deck.
Alternatively you might make the outermost part of the receiving tube at
position 4.375m and extend the structure inwards, attached to the deck. As the
designers building guidelines now stand, the pole guide and forestay fitting
complex is not all that far in front of the pole collar. A receiving tube
extending back that far or most of the way might accomplish the objective? The
attachment of the pole is not a controlled measurement point, per se, in so far
as it does not frustrate the rules or alter the nature of the design. Hence
the reason for inclusion of rule B.4.5
Good sailing..
Greg Ryan
ISSA President.
----- Original Message -----
From: Steve Nichols
To: Swiftsolo
Sent: Wednesday, August 16, 2006 3:32 AM
Subject: Class Rules Opinions please
Guys,
I've been talking to Clive at CST re masts for Swifts over here. We are also
going to get the other spars from him ie spinnaker pole and boom.
Clive is very keen to change our pole launching system so the spin pole
retracts into a receiving sleeve a la I14 style. This has a couple of
advantages - smoother launches and no issues with point loads on the pole. The
question I have is that reading the class rules it specifies that the pole must
retract to 700mm of the stem. We would like the receiving pole to go out to
this dimension - this further minimises any bending that may occur.
What are peoples opinions? Is this breaching the rules or not?
Also what actual length are the poles in use and diameter?
Cheers,
Steve
nb the 14s allow this but it is specifically catered for in their rules
Class rule extract
a. The Spinnaker Pole shall be retractable to within 700mm (27 5/8 inches) of
the stem. The length from the AMP to the outer most extremity of the spar, when
the spar is fully extended shall not exceed 6.095m (240 inches).
Check out my Swift Solo build progress on
www.aussieswift.livesaildie.com
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