An open 8 Footer for adults?

[Richard Woods]

I hadn't read this thread until now

I learnt to sail on an 8ft6in Poole AB and at the time (early 1960's) there were many adults sailing it. More seaworthy and a bit quicker than an Optimist. So I have a soft spot for small sailing dinghies

Surely the simplest rule would be to say that everything must fit inside a 8ft x 4ft x 15in box? And that the design (or boat if a one off) must be proven to get from trailer/car roof to sailing in 15 minutes by one person. That meets the intent of the class in the simplest way

But if those were the rules then I would try a "clam shell" design, very low freeboard scow that hinged at midships, something like a Fireball when opened out.

If you don't like that idea and want to stay with set dimensions then 55kgs is massively heavy for an 8ft boat. My 8ft Crayfish yacht tender can weigh around 30lbs (15kgs say) built from 2 1/2 sheets of 3mm plywood. Plenty strong enough for 3 adults to sail/motor

I see no point in going to 10-12ft when there are so many existing designs in that range, Byte, Streaker, Spiral, Splash, Moth etc, never mind the Mirror dinghy

Richard Woods of Woods Designs

www.small-boat-designs.com

 

[WhiteDwarf]

Mik, Richard,

Greatly appreciate the input of two experienced designers.

The youTube seems to confirm that the PDR too, will plane, and I hope some will attend our regatta. Hopefully Huey will lay in sufficient wind to prove the point.

I absolutely agree that rules should largely follow the regatta, not preclude potentially interesting designs before it. The only rules that we envisage are length (and possibly a minimum weight) but I can't imagine that anybody will want to invest in a carbon fibre freak for this particular event, but it might be great if they did, we might all learn a bit.

My own thoughts turn to an eight foot version of an Int'l (scow) moth called Twora (or something like that) beautifully made in cold moulded ply, and for the time incredibly light. She came across to the worlds at Lymington (1973?) and in windy conditions left us all for dead, not withstanding a sharp chop in the Solent. How wide to make it before complications of twin centreboards etc...?

 

[woodeneye]

I tend to agree with Boatmik about not framing any rules at this stage other than setting an initial length limit of 8', primarily for fear of producing an unexciting boat for adults to sail. Somebody mentioned 6.5sqm as a suggestion of a sail area limit. Wow, that would certainly limit the possibilities as I was thinking of a single sail of more like 8 SqM! (but certainly not limited to this even, as this is Australia, not the USA or GBR!) The exciting thing with a sail boat this size is that you could keep the rules very simple so as not to limit design at all as it is very unlikely to become an expensive class. In other words, create a development class, but with cost restrictors (such as no carbon, no kevlar, no professionally made foils, no lifting foils, no solid wing masts, dacron sails etc) but leave all other dimensions apart from length, open for designers to play with. Safety is also easily regulated by stipulating at least two buoyancy tanks that must perform to a measurable standard.

Boatmik posted a video of the PDRacer scow sailing in a strong breeze. I have seen other videos showing remarkable performance from these little boats which has changed my mind about what small sail boats should look like. When I first saw them, my immediate concerns were how these blunt ended things could possibly go upwind in waves? In fact, they work very well, just look at the video! The best way to think of them is as a scow with two bows. Like most scows, they are simply sailed upwind with a slight heel, so slamming into waves is actually very minimal. Boatmik's video shows that the PDR/OzRacer type boats can very easily power a large adult to acceptable planing speeds, and it looks to me like quite a nice boat to sail.

 

[WhiteDwarf]

Wooden,

Sail area is an extremely tricky factor. May I respectfully point out that the Spiral, for example, is 12.5ft long and sets 6.5 sq m off(65 sq ft) of sail. It is definitely no slouch in a breeze. The 11 foot .int'l Moth sets 8 sq m and it is definitely an extreme class.

On an 8 footer, even if you can balance the capsize moment of the rig, you could encounter instability fore and aft. This might be managed with a lug rig set up for rapid reefing and resetting, perhaps Boatmik will be able to comment from his experience.

 

[woodeneye]

Wooden,

Sail area is an extremely tricky factor. May I respectfully point out that the Spiral, for example, is 12.5ft long and sets 6.5 sq m off(65 sq ft) of sail. It is definitely no slouch in a breeze. The 11 foot .int'l Moth sets 8 sq m and it is definitely an extreme class.

On an 8 footer, even if you can balance the capsize moment of the rig, you could encounter instability fore and aft. This might be managed with a lug rig set up for rapid reefing and resetting, perhaps Boatmik will be able to comment from his experience.

Tricky only if you're talking about tippy boats with a pointy end, like the Spiral and most other "conventional" boats, yes. But if you're talking about boats with lots of stability, not so tricky. Have you looked at the video that Boatmik posted? If so, you witnessed a demonstration of the stability of an 8 footer with 8sqm of sail in a good breeze and waves This is why I'd be reluctant to set parameters as there are definitely possibilities for something pretty exciting with this format.

Boatmik, your cue...

PS. One of my boats has a balanced lug rig, one is a Laser (not unlike the Spiral), and the other is a ......Moth

 

[Richard Woods]

Mik, Richard,

My own thoughts turn to an eight foot version of an Int'l (scow) moth called Twora (or something like that) beautifully made in cold moulded ply, and for the time incredibly light. She came across to the worlds at Lymington (1973?) and in windy conditions left us all for dead, not withstanding a sharp chop in the Solent. How wide to make it before complications of twin centreboards etc...?

I think you mean 1977 at Hayling Island.

Yes I was also thinking of a 8ft scow Moth myself, my folding Fireball was just to indicate you have to be careful when making rules. A major part of a racing yacht designers job is "bending" rules.

So how about a swivelling seat rather than wings or a real IC style sliding seat. Off wind in waves would be the big problem. 8sqm is too big, 6.5 sounds more reasonable

is this the sort of thing envisaged?

http://www.youtube.com/watch?v=QMH2X5SUGNk

I assume the potential market is not just older sailors

Richard Woods of Woods Designs

www.small-boat-designs.com

 

[woodeneye]

I think you mean 1977 at Hayling Island.

Yes I was also thinking of a 8ft scow Moth myself, my folding Fireball was just to indicate you have to be careful when making rules. A major part of a racing yacht designers job is "bending" rules.

So how about a swivelling seat rather than wings or a real IC style sliding seat. Off wind in waves would be the big problem. 8sqm is too big, 6.5 sounds more reasonable

is this the sort of thing envisaged?

http://www.youtube.com/watch?v=QMH2X5SUGNk

I assume the potential market is not just older sailors

Richard Woods of Woods Designs

www.small-boat-designs.com

Hi Richard

You do realise that that the little 7'7" skiff in that video has a sail area of 11.5 sq m (main and jib)? The 8 sqm of the OzRacer is quite modest by comparison.

The brief from CRSC is for an 8 footer for adult sailors as they are losing adult graduates from their LTS programs for lack of a suitable boat capable of being stored in a garage. A boat with wings and a very long mast may be problematic from the storage and car-topping aspect, but not insurmountable.

By the way, car-topping regulations restrict the width to a maximum of 150mm wider than the car's mirrors, so fixed wings would need to be quite small.

 

[tspeer]

You might want to look into the International 3 Meter Trimaran. Bigger than 8 ft, but the disassembled boat wouldn't take up that much more space. They were popular in the Pacific Northwest for a while.

If you want the ultimate in apartment-friendly boats, take a look at the Oru kayak. It's not a sailboat, but it is bigger than 8 ft and fits in a closet.

 

[Richard Woods]

Hi Richard

By the way, car-topping regulations restrict the width to a maximum of 150mm wider than the car's mirrors, so fixed wings would need to be quite small.

just fit wide mirrors

yes I did know the little skiff had a big sail area. That is in part why I asked if that is the sort of boat you envisage?

One of the problems with small boats is that humans don't get smaller to compensate. So the boom has to be relatively high to get under it. so it might make sense to have a wishbone boom, which also does away with the kicking strap.

No reason why you cannot have a two part mast, the Laser does, so does the Tasar, never mind it being an option on Hobie cats. That's why I said have a rule that requires everything to fit in a dimensioned box. If clever designers can fit detachable wings, a bowsprit, etc then why not? Unless you want a new version of the PDR.

There is an existing 10ft (3m) class in Italy.

I don't think you should limit sails to dacron only, lots of similar size boats use plastic sails as they are cheap.

What about a nesting dinghy like Russell Brown's beautiful boat?

Richard Woods

 

[woodeneye]

just fit wide mirrors

yes I did know the little skiff had a big sail area. That is in part why I asked if that is the sort of boat you envisage?

One of the problems with small boats is that humans don't get smaller to compensate. So the boom has to be relatively high to get under it. so it might make sense to have a wishbone boom, which also does away with the kicking strap.

No reason why you cannot have a two part mast, the Laser does, so does the Tasar, never mind it being an option on Hobie cats. That's why I said have a rule that requires everything to fit in a dimensioned box. If clever designers can fit detachable wings, a bowsprit, etc then why not? Unless you want a new version of the PDR.

There is an existing 10ft (3m) class in Italy.

I don't think you should limit sails to dacron only, lots of similar size boats use plastic sails as they are cheap.

What about a nesting dinghy like Russell Brown's beautiful boat?

Richard Woods

Hehe, fitting wide mirrors doesn't work as the regs discount them. I went through all of those issues with the Moth and once had a lengthy discussion with a very friendly cop on the side of the freeway who gave me advice to look up the regulations, but he did a great job in summarising them. I think he just wanted to have a close look at the Moth.

I don't really have a vision of anything, except that it needs to fit the requirements. So far in this discussion, about the only boat that does currently fit the requirement is the OzRacer/PDR. I think it's now up to you designers to come up with something that works and bring a prototype along to the regatta. Personally, I would have no objection to jointed masts, plastic or laminated sails, bowsprits or hiking wings, high booms or low booms (although I don't understand your reasoning that the boom has to be "high". If you design something with a low boom, simply add "Duck" to the name!). Just bear in mind that attachments and folding boats etc are complications that mean extra rigging/unrigging time to the unloading and packing up, and they also have to be transported and stored. I'm just thinking of the wings on my Moth. They are removable but it's a real PITA and the frame takes up quite a bit of storage room because they are curved. Most unit garages are quite small and won't even accommodate a large car let alone lots of boat bits that intrude into the space.

Russell Brown's nesting dinghy is very nice, but I think it's still too big when nested.

Perhaps some measurements from someone who has access to a typical unit garage would be handy? The available space once a medium sized car is accommodated so that you don't have to exit the car via the tailgate.

 

[Richard Woods]

I think he just wanted to have a close look at the Moth.....

I don't understand your reasoning that the boom has to be "high". If you design something with a low boom, simply add "Duck" to the name!

I was once stopped for the same reason with my Moth on the roof

The boom on an 11ft scow Moth is only about 15in above the cockpit floor. Scale that down to 8ft and I think many people would struggle to get under, especially if there was also a kicking strap to shorten the fore/aft gap

I write this from my house in BC Canada, it has a double garage (a major reason why we bought it in the first place). In 7 years the car has been in the garage 3 weeks. The rest of the time it has been full of boat(s). Cars are much better left outside where they belong. They rust less that way

More seriously. My brother cannot keep his Laser cartopped in his communal garage, it has a low barrier to prevent motorhomes parking there. That's very common, if not standard. So surely the first thing to check is not the floor area, but the standard entrance door height and compare that to a car

Richard Woods

 

[sharpii2]

I suggest that Sail Area be somewhat limited by weight.

A heavy person, not necessarily fat, has quite a disadvantage when on a planing sailboat of limited length.

The lighter boats will all plane and his will be stuck in a furrow.

With SA limited to weight, the heavy person's boat will have an advantage in lighter winds, when none of the boats will plane, and the lighter person will have the advantage in winds strong enough to plane in.

It's no fun when people of certain body weight and proportions always win.

Just a thought.

 

[WhiteDwarf]

sharpii,

I can do no better than refer you to your own mantra...

"I am highly suspicious of the terms 'perfect' and 'best'. I favour the terms 'inadequate', 'adequate', and 'better', instead, with the first of these closest to being an absolute"

We are seeking a space to improve the breed, surely a process which will never be completed.

 

[woodeneye]

I suggest that Sail Area be somewhat limited by weight.

A heavy person, not necessarily fat, has quite a disadvantage when on a planing sailboat of limited length.

The lighter boats will all plane and his will be stuck in a furrow.

With SA limited to weight, the heavy person's boat will have an advantage in lighter winds, when none of the boats will plane, and the lighter person will have the advantage in winds strong enough to plane in.

It's no fun when people of certain body weight and proportions always win.

Just a thought.

That's certainly something for the Club to keep in mind and it's a great suggestion. However, I'm not sure about the practicality of it as it does introduce a complication that will make administration very difficult or perhaps impossible. I'm trying to think of a class where such a rule is in place. Lasers do have 3 different official rigs (and a couple of established unofficial rigs), but these are all self regulating. For example you rarely see 50kg sailors sailing a Laser Standard, nor do you see 90kg sailors in 4.7s and there are no rules precluding anyone from competing in any category by reason of their weight.

If someone turns up to a regatta or club race and they are just under the weight, do they have to stand on a scale before the race and do you disqualify them because they don't have the correct rig? Bathroom scales are not calibrated, so it means the club has to invest in a proper weighing device.

Another way to go is to introduce corrector weights on the hull, but again, that's yet another complication requiring lots of administration.

I've just remembered one class that has crew weight restrictions. The International Star.

 

[CT 249]

Somebody mentioned 6.5sqm as a suggestion of a sail area limit. Wow, that would certainly limit the possibilities as I was thinking of a single sail of more like 8 SqM! (but certainly not limited to this even, as this is Australia, not the USA or GBR!)

A British dinghy designer pointed out to me some time ago that UK dinghies often have more sail area than comparable Australian dinghies. This is partly hidden by the fact that some of them (N12, MR) have older rulesets that under-rate the real sail area. Compare a N12 to a NS14, Merlin Rocket to MG14, Solo/Phantom to Sabre/Impulse, UK Cherub to Aus Cherub, the significant numbers of singlehanded boats with spinnakers, etc. And the Sharpie has a tiny rig (much smaller than US and UK 3 person classes of the same era) but is one of our biggest classes.

Obviously the skiffs have big rigs, but it seems that there's no general Aussie tendency to big rigs.