sail area vs ballast

this may be an apples and oranges comparison. the term was "garbage scow," not racing scow. yes, boats that plane break the displacement rules and are the fastest sailboats. that isn't what we're talking about.

and multihulls aren't a recent advent. polynesians have been sailing them for millennia [i think]. a long time anyway.

moreover, we run into a problem when we assume that a boat built to a one-design class is inferior. it depends on the parameters of that class. a racing scow is faster than, say, a 12 meter under optimum conditions, but it would be a handful under certain wave formations. i have an enterprise dinghy that is built to strict one-design standards but it is a superlative sailboat for dinghy cruising and racing, if you like 13', unballasted boats. but it is true that some real abominations have been created in adherence to a rating rule, many of them lightweight, planing racers.

finally, stephen didn't write that quote. i did, and the point is that light weight isn't everything for displacement craft. shape is very important, as well. 12 meter boats occasionally surf but they never plane so the comparison doesn't apply. the idea of heavy ballast and lotsa sail has to do with the motion of the boat, i think. now, that is an interestng comparison and i suspect there are two very different schools of thought.

 

You make a very important point. Light and heavy displacement boats are designed differently. A narrow beam boat of light displacement will be unsafe and tender. A wide beam heavy boat will pound the fillings off your teeth. Displacement, or any other characteristic, has to be considered in relation to the rest of the design. A very important factor is the expectations of the owner. His requirements will determine design by a higher percentage than anything else.

 

good points, gonzo. so for most of history, heavy and narrow was the design criteria. only recently have we decided that light and wide is viable. i think alot of the reason is availability of ightweight materials [like plywood] but what would the sailing characterist differences be?

i've owned a number of the light/wide models but never sailed the heavy/narrow variety. there must be advantages to the latter; i've read old tymers write about how beautifully the older designs sailed. is it the "motion of the ocean" that made them attractive?

 

I suspect the ability of narrow heavy vessels to "punch through waves" might have something to do with it. I remember sailing a Wianno Sr. after a summer of sailing O'Day Day Sailers. The feeling was like a locomotive that gets going slowly, but once in motion is hard to stop. The difference was especially striking to windward. Steering tricks to keep the boat going fast in waves were completely unnecessary.

 

tell me more. i'm not finding many people who have sailed these type boats. i know i haven't.

in my unballasted dinghys, i add rocks to the sole in order to make the boat hunker down on her lines and behave. although slower, they are more enjoyable to sail that way, imho.

but i'm not too sure they're that much slower since ballast allows the boat to carry more sail. any thoughts on that relationship?

 

I've sailed a variety of types and I dislike the motion of the old heavy beamy boats BUT it's a very personal choice and has a lot to do with your conception of sailing and the type you like.

Some boats -

Alden "Malabar" schooner - only sailed once, smooth but very ponderous in motion and helm.

Standard 59' ketch. The same, but the one sail was 1080 miles. Not for me. Full ends bounced a lot, but slowly. Helm like a bus. If you don't enjoy the sailing, take a plane as far as I reckon, and this wasn't fun sailing. Also long-keelers can't steer around bad waves so you have to sit there and get hit in gales.

Swanson (AUS) 42' heavy long keel double ender on 1080 nm race - full bow and double ends meant it hobbyhorsed over a considerable distance, the weight made the motion slow but yechhhhh. Like the Malabar & 59, it was too slow on the helm for me. I'd rather be on the rail of a lightweight than the helm or bunk of a heavyweight like this. Comfortable in 60 knots but we had to endure lots more than the racing boats which finished earlier. Would rather have taken my own fairly lightweight 28' I think....

Cole 43 (1968 ocean racer, like an "Intrepid" era 12 metre in its narrow 10' beam and shape) - 2 x 630 nm Sydney-Hobart races + many other races to 480 nm.

Low initial stability made it sail at a high angle of heel (compared to new boats) but stable when low c of G took over, very fine bow often took green water but never seriously and it allowd the boat to drive through waves rather than slowly bounce over them like the previous 3 boats. A nice combination of directional stability but responsive enough to the helm. Stunning to look at (makes classic Swans look like Catalinas), very nice all round- but that heel made living down below a bit of a pain. A great reputation for seaworthiness (including singlehanded non-stop round the world) BUT at least 2 have rolled 360 degrees in Hobarts, what does that mean; I don't know. Nice - if you want a classic get a beautiful fast-ish one like this.Mmmm.

S & S Modified Finnisterre (very beamy & heavy 1950s-60s racer), day racing + overnighter. Full-ish bow made spray, bounced a bit. Heavy, hard to manouevre but hugely succesful racer. Like other old boats,I think the amplitude of the motion was greater but the movement was slower. It's a personal choice about what you prefer AFAIK and I get annoyed with those who prefer the old boats and assume they have the only valid preference for motion characteristics. I'd rather a faster bounce over a smaller amplitude.


IOR boats (most sizes) and Young 88/Farr 1020 style of NZ cruiser-racer (several thousand miles of racing to 380 miles); moderately quick motion but (because of fine bows that cut through waves and good weight concentration) over a fairly small amplitude (ie bow doesn;t go up and down too far each wave). These boats stopped if they dropped off waves and slammed, so helmsmen paid attention to easing them over waves which made for a more comfortable ride. Responsive to steer but IOR boats were interesting downwind. A bit tender.

Nice boats; not as fast as a new boat but if you want speed, don't get a monohull yacht. Good for the $$$$$.

30' 2,400 kg IMS / IRC racer and a couple of larger, similar boats to 80'.
Experience - 1 630 nm Sydnedy-Hobart, day and overnight races

BANG! CRASH! Light, light ends, much higher righting moment than previous style, no IOR rating bump in bows (when heeled, the IOR bump often presented a seakindly Vee to the waves). The whole boat seems to be picked up by the heavy keel and thrown into the oncoming waves with a smash. Unlike IOR or light older cruiser racer types, the IMS boats (perhaps due to the high righting moment and better foils) are faster when they slam over the waves - so the crew just have to endure it &n hopes the boat's strong enough. The amplitude is low (light ends so less inertia) but the speed of motion is very high. Very rough ride (thrown out of bunk regularly in Sydney-Hobart, hard life on the bow, moral is don't be a combination bowman/helm/watch captain) but lovely on the helm. Fast, if any leadmine is fast. Carbon makes for really noisy boats and scary sheet loads on 52-80 footers.

Classic 12 metre (1963? vinrtage) Only one day race. Mmmmmm. I want one. Never realised how well the spoon shaped bow works in a narrow boat where the entry angles are fine. Sliced beautifully. Wouldn't be so nice offshore in a swell, tho'. Being on bow, calling the boat to the line alongside Intrepid, Courageous, Columbia etc was just too wonderful, as was looking down the boat from the bow after gybes etc.

John Spencer (NZ) 28 to 73. 1968-1970 lightweights (28' is 2,100 kg). Finer stern, fuller bow than modern boats, like an S&S of the day but much lighter. Vee shape. Beautiful motion due to balanced ends (moderate amplitude of pitch) and moderate weight concentration (moderate speed of pitch). Bad foils so not good to steer upwind, beautiful directional stability downwind. About 2,000 miles on these. I'm biased, I own one.

Narrow-ish (other Spencers like the famous sled Ragtime were very narrow) and light but the 73 has done several circumnavigations and raced aroujnd Cape Horn with no worries. V safe in my opinion.

Multis - 3+ weeks coastal cruising - great in some conditions, crap in others (ie cat in beam swell or short chop).

 

thank you ag, for the benefit of your considerable experience. i notice the consideration of pitch is mentioned often. it seems to be a very important characteristic in terms of comfort. is this a product, primarily, of bouyant ends?

conversely, the boat we're discussing is a 12-meter design. the bow is long and streamlined but not very bouyant. you described the cole 43 as similar in shape and prone to take green water over the bow. i expect this boat will do the same [the pic will show an apparently bouyant stern but fine bow] and i'm debating eliminating a fwd hatch because of it; i may just stuff styrofoam fwd and glass it in, keeping the bow light.

also, you mentioned the 12-meter "Wouldn't be so nice offshore in a swell, tho'." what would be the characteristics?

 

I think pitch is a combination of buoyancy in the ends, and weight in the corners; ie keel, bow, stern rig. The higher the inertia (more weight) in the ends, the greater the motion but the slower it is (I think). Boats with a very high concentration of weight ijn internal ballast and effective wave-piercing bows (like some IOR boats) had very nice motion, but it was a bit quicker than a heavy boat and they had other problems.

The 12s tend to bury their bows deeply; there's a huge amount of weight, very little bouyancy in the bow, and when that heavy keel pitches the boat forward it's dive, dive time. I think old 12s (like American Eagle) just sealed the forward hatch when racing long races. In big swells they had a rather ponderous but graceful motion but I've never really watched an alloy 12 in big swells, they may be better.

The few modern maxis I;ve sailed also get wet onthe bow, but not as badly.

See if you can rent the movie "Wind". it's about 12 metres. Bad movie (the best acting is Kim Sheridan and Walshie, both sailors who got speaking roles 'coz the rest were so crap) but good sailing shots showing the 12s bouncing off Fremantle.

 

Did you see this thread, T?
http://boatdesign.net/forums/showthread.php?threadid=1992

 

now i have to figure out how to make the inboard rudder work. the one on the boat is aluminum on an aluminum post. no tiller, no bearings, no way to keep the rudder in the boat except by locking down the post. any ideas, references?

 

Are there pintles and goudgeons attaching the rudder to a skeg?

 

no, just a post. the keel isn't that large. it has a wing on the aft part. you can see it at: http://www.acmuseum.com/portfolio/starsstrips87.htm

 

You'll need a bushing at each end of the rudder post tube. A shoulder on the shaft at the bottom end will keep the rudder from lifting. On the top a collar with set screws will keep the rudder from dropping.

 

well, the whole thing is aluminum so i don't know how it would lift. the top [inside the hull] already has a collar. so maybe a nylon bushing between the collar and the hull fitting?

 

That would work. To keep the rudder from moving up and down, you can install a bushing on each side of the collar. The bottom bushing is necessary for wear.