Possible Class of Small Ocean Racing Sail boat

[Doug Halsey]

...
The one hard rule from the very beginning of the America's Cup, even though it is raced on a limited, and protected course, is that all entrants must sail their boat to the course, from the origin of the competitor's YC or home port.
...
I haven't followed it in the last few decades, but I believe they still have to be sailed to the race from the challenger's port of origin.

You're kidding, right? You think those foilers are capable of ocean crossings?

I think that stipulation was ditched with the post WWII revival of the cup in 1958 (if not earlier).

 

[Dolfiman]

To limit the sail area is a good starting point in my opinion, and even more I would start from a full defined sailplan, e.g. the one of an existing popular cruising sailboat to have it at a low cost, and doing so to focus the design exercise on what hull(s) for such saiplan.
A rule based on a sum of hull length + etc ... reminds the old Sonder klasse rules, where :
Lwl + Beam + Draft < 9,75 m ; Sails area < 51 m2 : Displacement (all up, without crew) > 1830 kg (+ minimum of thickness for the hull and deck planking : > 16 mm).
International Sonder Class (sonderklasse-yachten.de)
How can we modernise such box rule, some ideas :
** Here the waterline Lwl is a problem, that favors too much the overhangs. But to take the Lhull has the reverse effect, to favor no overhang, the alas current unaesthetic trend also unknowingly supported by the various license and marina taxes based on length overall. If we drop Lwl, same effect, no overhang will be the final optimum. May be one can try something like : Beam + Draft - 0,1 * Loverhangs < ... , i.e. some overhangs can be rewarded by more beam or more draft (the hull length being anyway constrained by the Displacement and the necessary beam).
** To add also a maximum for the draft , for example 1,8 m , or perhaps better to use Draft^2 in the formula to penalise the over draft.
** To add that the keel is made of cast iron or lead or a combination of the two (wing in cast iron + bulb in lead)
** As already suggested, to change the sails area by the sailplan full definition (and weight)
** For the displacement (without crew), to change the minimum thickness by average mass/squared meter of the hull surface and of the deck one. And to add a minimum of mass dedicated for the accomodation + the mass of the selected sailplan.
** And last but not least, the need to fulfill the stability requirements for a classification in a sailing category, for example A2/B6 (2 people for an ocean crossing, 6 people for a coastal cruising/racing at < 200 NM), implying thresholds for the AVS, the STIX, the righting moment energy.

 

[Will Gilmore]

You're kidding, right? You think those foilers are capable of ocean crossings?

I think that stipulation was ditched with the post WWII revival of the cup in 1958 (if not earlier).

The last time I watched the AC, the Aussie's took the cup back to Perth, I'm pretty sure they had to sail their wing keel boat to America to do it. I'm not trying to say it's still a rule, I don't know, but it was a rule for a long time.

I don't pay as much attention to that race as I did when I was younger. They aren't meaningful sailboats to me. I think that's part of the point sharpii2 is trying to make with his mind experiment class.

-Will

 

[Will Gilmore]

Here the waterline Lwl is a problem, that favors too much the overhangs. But to take the Lhull has the reverse effect, to favor no overhang, the alas current unaesthetic trend

Why do you want to penalize a faster design? Aesthetics? You could include a subjective beauty contest element to the race.

-Will

 

[griffinb]

I love the mind-excercise of trying to beat a design rule. But I can't get excited about trying to beat an imaginary, arbitrary rule. Especially when two of the design criteria are to look boring, and be cheap.

Can't we focus on an existing rule, and dream of ways to beat it without worrying about looking boring, or spending too much imaginary money?

 

[gggGuest]

I'm pretty sure they had to sail their wing keel boat to America to do it.

No they didn't. As said above it hasn't been a requirement since WW2.

All this rule text and proposals is all very well, but don't forget that's the easy part. anyone can propose a class and write a rule, I've done it myself. The hard part is the organisation and getting other folk to actually participate. Loads of people will be enthusiastic, comment, encourage, talk, talk, talk, but finding enough people who will actually shell money out is another thing entirely. When it comes to actually doing something real they will all decide to to wait until there's a critical mass. which is of course a catch 22.

 

[Will Gilmore]

No they didn't. As said above it hasn't been a requirement since WW2.

I'm glad to have learned something new. Disappointed that they dropped that rule, though.

 

[Doug Halsey]

I'm glad to have learned something new. Disappointed that they dropped that rule, though.

-Will

The rule was grossly unfair to the challengers! They had to be seaworthy (aka slow) while the defender could be designed for the conditions expected in the race.

 

[griffinb]

We know a conversation has run its course now that we are debating America's Cup rule changes from the 1950s...

 

[Will Gilmore]

Make the race course dictate the rule of sea worthiness. Nassau to Burmuda and back, for instance.

 

[sharpii2]

...
If you aren't going to create a real racing class, and aren't going to build a boat, why do you care that it looks like a normal cruiser, or that it is affordable? Dreams shouldn't be constrained by cruising practicalities or budget.

A good question.

For the answer, I look to my motivation for coming up with this idea.

I think sailboat racing has had a negative influence on sailboat design. When I was in my 20's, powerboats outnumbered sailboats by nearly 10 to 1. Now, it appears the number is closer to 20 to 1.

The main thing that I think racing sailboat design has done is created a trend toward deep draft and tall rigs. This trend has gone on for many decades. IMHO, it has even influenced the races themselves. They are becoming upwind/downwind affairs. This, in turn has encouraged boats that are best on these courses.

The taller rig and deeper keel are best for going upwind. And with only "working sail area" counted, they are best for downwind sailing too.

But a deep draft/tall rig sailboat can be a real nightmare for a cruiser. The deep draft limits anchoring options and even slip ones. The taller rigs are much more vulnerable to damage and are trickier to set up.

My long held suspicion is that the taller rigs get their racing advantages by:
1.) Being able to set up much more sail area than the spars imply (especially downwind), and
2.) Having race courses set up that advantage them.

So I tried to come up with a form of racing that sets a different path. Hence, the hard sail area and draft rule idea. I reasoned that if boats were designed to these limitations, the race courses would soon adjust to them. And differen types of sail would likely be tried (and may even prove better) than the typical Bermuda main with a single jib.

And I am quite aware that boats designed primarily to race are not going to ever be cheap, but I do believe that, with certain strategic limitations, they can be far less expensive.

 

[sharpii2]

To limit the sail area is a good starting point in my opinion, and even more I would start from a full defined sailplan, e.g. the one of an existing popular cruising sailboat to have it at a low cost, and doing so to focus the design exercise on what hull(s) for such saiplan.
A rule based on a sum of hull length + etc ... reminds the old Sonder klasse rules, where :
Lwl + Beam + Draft < 9,75 m ; Sails area < 51 m2 : Displacement (all up, without crew) > 1830 kg (+ minimum of thickness for the hull and deck planking : > 16 mm).
International Sonder Class (sonderklasse-yachten.de)
How can we modernise such box rule, some ideas :
** Here the waterline Lwl is a problem, that favors too much the overhangs. But to take the Lhull has the reverse effect, to favor no overhang, the alas current unaesthetic trend also unknowingly supported by the various license and marina taxes based on length overall. If we drop Lwl, same effect, no overhang will be the final optimum. May be one can try something like : Beam + Draft - 0,1 * Loverhangs < ... , i.e. some overhangs can be rewarded by more beam or more draft (the hull length being anyway constrained by the Displacement and the necessary beam).
** To add also a maximum for the draft , for example 1,8 m , or perhaps better to use Draft^2 in the formula to penalise the over draft.
** To add that the keel is made of cast iron or lead or a combination of the two (wing in cast iron + bulb in lead)
** As already suggested, to change the sails area by the sailplan full definition (and weight)
** For the displacement (without crew), to change the minimum thickness by average mass/squared meter of the hull surface and of the deck one. And to add a minimum of mass dedicated for the accomodation + the mass of the selected sailplan.
** And last but not least, the need to fulfill the stability requirements for a classification in a sailing category, for example A2/B6 (2 people for an ocean crossing, 6 people for a coastal cruising/racing at < 200 NM), implying thresholds for the AVS, the STIX, the righting moment energy.

Long overhangs were a racing innovation. Very short ones were far more typical on working sailboats. And short overhangs do not subtract much from sailing speed. But you are right, overhangs need to be ruled in, or they will be competed out.

One way to rule them in is to count class length as say:

CLASS LENGTH = (2L + LwL)/3

or something like that. This way, making really long overhangs gets quickly punished, but short to moderate ones get somewhat rewarded.

Here's an example:

Class length limit 20 ft.

Boat A:
Lwl = 15 ft. Boat length = 22.5 ft.
Boat B:
Lwl = 18 ft. Boat length = 21 ft.
Boat C:
Lwl = 20 ft. Boat length = 20 ft.

The length gains are paltry compared to the lwl sacrificed to get them.

But consider what it would be like sailing boat C downwind in windy conditions.

There would be a good chance that the bow would dig in and maybe cause a broach.

But boat B would have buoyancy ahead of the lwl, which would have leverage to lift the bow up.

Boat A could well end up hobby horsing or slamming, or both.

In those conditions, I would much rather be on boat B.

This is probably one of the main reasons some Mini class boats have pram like or even scow like bows.