New Grand Prix Rule

[CDBarry]

It is worth remarking that a while ago one author at a CSYS proposed a claiming rule, much like that in horse racing. Entering a boat in a race, say a $20,000 level, constituted a binding offer to sell it at the designated price. At the end of the race or the series, names of people intersted in buying the boat were dropped into a hat and the name picked got the right to buy the boat.

Might either control costs or get some neat boats for the less wealthy.

On related subject, I still like the square metre rules.

[Robert Lainé]

Stephen,
in the proposed rule there is a Time Correction Factor which is essentially a proven formula. There is no way one can handicap fairly 70ft and 25ft boats in the same race, it has been tried and failed even with sophisticated VPP. Take the case of racing in tidal water, a fast boat may be throught a tidal gateway and gain few hours over the smaller one which did not pass the gate. However for boat of similar rated size but different design a simple formula does work since everyone is racing in the same wheather and tide system.
In the formulation of the proposed rule I set only upper limits to critical dimensions to avoid extrem designs. inside these limits anything is allowed without prejudice. From there on it is open to all sorts of designs. Some will go for lighter and smaller sail area other will go for heavier design, we will see what happen.
The sail area is counted in the rated length formula, so is the actual weight of the boat including its maximum crew weight. As you said, aggregated Crew Weight is the only fair way to go.

[Stephen Ditmore]

I commend the effort, Robert. I think knowledgable people putting together a single straightforward rule is what we need. Some have already done that though in putting together the Whitbred/Volvo/Mount Gay rule, the Transpac 52 & 40, and the various other rules being used (is it ILC or IRC? And then there's CHS, right? I'm not that familliar with the British rules. U.S. Sailing has come out with its own version, Americap, instead of getting on board with one of the European ones, further complicating matters.) Now you're proposing yet another. Why can't we seem to get everyone moving in one direction?

Also, open class racers, maxi/mega owners and now the Volvo 70 class seem to be embracing canating keels. This is among the "extreme" features you seek to ban. If we want to allow different approaches to flourish and compete, shouldn't we be looking for ways to handicap these boats fairly rather than banning them?

Do you agree that canting keels and other forms of movable ballast are largely about increasing SA/Displ? Do you agree that therein might lie the key to integrating them into a handicap rule?

[Robert Lainé]

the reasons for rules proliferation is that each is trying to catch an existing fleet hence the rule is compromised from the beginning... except for the IRC which is a secret formula to keep the freedom to adapt. One day so many people will know that secret formula that it will become a handicap for thoses who do not know it...
Handicaping canting keels is not trivial: it can mean a lot of weight being moved to the "rail", like a big water ballast but 3 meters below. SA/Displacement is one way but whithout the knowledge of the ballast weight how to factor it ? Sandbagging is an old American trick in sailing...
One could allow the keel to swing only such that the ballast does not protude from the side of the hull and then it is more or less equivalent to an equal mass of water ballast or the crew sitting on the rail. That would also prevent designs which become stable upside down if knocked down with the keel far off center. One could then take the rated mass of the boat equal to measured mass minus the crew weight for canting keels design. I explain: in the current rated boat mass there is the actual boat mass + crew mass. The crew mass is normally sitting on the rail to gain righting moment. Taking this crew mass off the rated displacement for swing keel will effectively remove sailing area. Will it be enough ??

[Andy]

Seems like a good idea Robert, but as you say, will the reduced sail area due to the reduced displacement be enough? Perhaps a different method might be to use a formula which takes into account righting moment versus sail area, or righting moment versus heeling moment (i.e. taking into account the vertical centre of effort of the sail plan). The number of crew and their leverage (as a function of Bmax) as well as the influence of canting keels and water ballast could be accounted for in the formula. If we choose to ignore the contribution of the hull to righting moment (keeps BWL measurement out of it) , and rate only the effect of ballast and crew, whilst also imposing minimum stability safety standards for a knockdown situation, might that work? only thing is that by including ballast and excluding hullform righting moment we may end up with very skinny hulls at the waterline...maybe a penalty factor could be worked in as well so that the boats would have to fall between the offshore knockdown and AVS standard on the one hand and a maximum righting moment to heeling moment coefficient on the other. This could ensure that designers include at least a measure of form stability?

Andy

[Robert Lainé]

your arguments on stability make me feel 20 years younger... but not better ! Trying to rate the stability is what drove the IOR and the IMS to nowhere.

[Stephen Ditmore]

I think my view is closer to Robert's than to Andy's - but I'm inclined to simplify it even further. If the rating formula "sees" a boat with a high sail area to displacement ratio it should assume it's getting the stability from somewhere. Sail area is taken as prima facia evidence of stability. Once you've made that assumption, let them sandbag! They'll have to do something to sail to their rating!

Note: this may be too kind to long, narrow, heavy boats with high aspect rigs (as the IACC rule is until you're well into the length penalty zone). When calculating SA/Displ a vertical rig dimention may therefore have to be factored into the numerator and waterline beam may have to be factored into the denominator. Also, though velocity normally scales with the square root of length, it's notable that displacement can be rewritten Cb*L*B*d, and that there could therefore be a cancelling effect if L^0.5 is effectively in the numerator and displacement, and therefore L, is effectively in the denominator. This may need to be taken into account when determining the exponents.

[Andy]

I should point out that what I was trying to get at was a way of allowing boats with or without canting keels etc. to race together. I too feel that robert's ideas of no stability measurements are pretty close to the mark, with sail area and displacement the determining factors. But Robert is proposing to ban canting keels, which I feel may put some owners off. On the other hand, many owners DONT want canting keel boats - who should be catered for? The CBTF MaxZ86's seem to be a good deal faster than the water ballasted boat, which would whip a standard configuration boat (were there such a thing) on most days...I dont think everyone will be pleased whatever the outcome (c'est la vie). And then the cost of the canting mechanism is an issue...its a tough call all around. Maybe hydraulics could be banned for boats under 50 feet, and minimum keel chords imposed to allow cheaper, fabricated fins. As long as the systems are safe, I feel they could ultimately reduce costs by reducing the crew requirements, something which could be factored into the rating formula as a reduced crew weight limit.

Andy

[Andy]

Re-reading the earlier posts, I had forgotten that Robert had suggested 2 separate fleets for canting and non canting keeled boats...makes sense! Has anyone any thoughts on construction? I think its important to make the construction accessible to the backyard builders for the smaller sizes of boat, whilst the bigger boats can make much better use of carbon and nomex, etc.?