July 31, 2015

Finding the right balance


A READER in Anchorage, Alaska, who calls himself or herself “Iceberg” asks if I could repeat a column I recently wrote about balance in sailboats. Well, I don’t remember writing about that subject recently, but I did write about it many years ago. So here’s hoping that this is what you’re after, Iceberg:

 

THERE ARE MANY DESIGN FAULTS that sailboat owners will admit to, but unseaworthiness is not one of them. A skipper might well shrug off a lack of accommodation. He or she might well agree the boat is slow, or hard on the helm. But nobody wants to own an unseaworthy boat.

Seaworthiness is the happy result of a lot of factors but there is one that is often overlooked. It’s called balance.

According to Tony Marchaj, a sailor, pilot, naval architect, and research scientist, “Almost by definition, seaworthiness cannot be achieved if the boat is badly balanced.”

So what do we mean by balance? That question was answered by a famous British designer, J. Laurent Giles. He said good balance is “freedom from objectionable tendencies to gripe or fall off the wind, regardless of angle of heel, speed or direction of wind.”

He added that a well balanced boat had an easy motion in a seaway, that is, she passed easily over the waves, neither tending to plunge the bow deeply into the next wave ahead, nor throwing her nose high in the air as a wave passed the fore body. She would also unfailingly lift her stern to a following sea.

“One requires of the balanced yacht that she should retain the utmost docility and sureness of movement in manoeuvering at sea, in good or bad weather,” he added. “She must maintain a steady course when left to herself, but must be instantly responsive to her helm so that the heavier seas may be dodged if circumstances permit. She must be capable of being left to her own devices, sailing, hove-to, or under bare poles.”

That sounds like a very tall order to me. What sort of hull has this wondrous quality of balance? Here’s Marchaj again:

“In a narrower sense, this means that the inherently balanced hull does not substantially alter its longitudinal trim, and does not alter its course during the process of heeling and rolling.” In other words, to be well balanced, a hull, when heeled, should immerse about the same volume of topsides forward and aft.

Marchaj points out that many of the good old boats still sailing now were either designed for, or affected by, the old International Offshore Rule, which produced shallow, beamy hulls with pinched bows. “Usually, when they heel, the stern is lifted and the bow falls. Consequently, these boats are difficult to control by rudder and are unseaworthy.”

If the bow digs in as the boat heels, a boat will try to round up into the wind, of course, not only because of the wedge effect of the forward sections but also because the center of lateral resistance has moved forward while, at the same time, the center of effort of the sails has moved outward and gains more leverage. This is when the person at the helm suddenly finds the tiller up under his chin. Not that it does much good if the boat heels too far and the rudder comes out of the water.

Luckily, most of us don’t often sail in sea conditions that challenge the full seaworthiness of our boats. But if you should be of a mind to cross an ocean or sail around Cape Horn, balance might be a good thing to keep in mind as you search for the right boat.

Today’s Thought

Everything splendid is rare, and nothing is harder to find than perfection.

— Cicero

Tailpiece

“Are you allowed to smoke at school?”

“No.”

“Are you allowed to drink at school?”

“Of course not.”

“How about dates?”

“Oh, dates are fine, as long as you don’t eat too many.”

5 comments:

Allan S said...

I think a boat with a motor well for an outboard should never leave sight of land. Speaking from experience.

biglilwave said...

I had a S&S Yankee Dolphin 24 with a motor well and sailed her 50 plus miles offshore many times. These boats crossed oceans...so I fail to understand how your experience applies to all boats with motor wells.

John Vigor said...

I have to agree with biglilwave. Cal 20s have outboard wells in the cockpit, and several have crossed the Pacific from San Francisco to Hawaii.

What was your experience, Allan S?

John V.

Allan S said...

My experience, and remember it's my experience. We were in our Coronado 25 on the Western edge of Lake Ontario sailing between Hamilton and St. Catharines Ontario when "it" happened. We got pooped. As pooped goes, I thought it was pretty bad but then again, I had never experienced a poop before (we are talking the wave breaking on the stern of the boat and not the biological function just for clarification).

The force of the wave blew the engine hatch cover open, leaving it dangling by one broken hinge. The worst was the mighty 9.9 Evinrude, it was also forced off its mount, held in place by it being diagonal to its original and natural position.

I get the wife to take the tiller, neglecting to change course, (that is an important misstep on my part), rip what remains of the engine cover off and begin a rescue operation of the outboard.

No soon as I have braced myself, clasped the outboard in my hands and begin twisting it to free it, than we get pooped again.

Remember those movie scenes of a rocky shore where the waves break and shoot up like a geyser through a hole in the rock formation? Well, the engine well was that rock formation! I pert near drowned, the geyser shot up like three feet. That may not seem like much to you, but when the next poop happened I just finished draining my lungs and averted my head and politely asked my wife to alter course a touch, (and yes, we are still married).

Managed to get the engine back in place. So there. There were some modification to a few things after that.

BTW, that Coronado 25 was a wonderful boat, but we sold that and bought a 38 footer with a full keel which comes with its own stories...lol

John Vigor said...

A frightening and chastening experience, Allan. I hadn't thought of that happening. The Cal 20's motor well just goes straight down through the cockpit floor well forward of the transom, so your kind of "blow-out" isn't so likely to happen. Glad to see you're still married, though. You obviously kept your cool.

Cheers,

John V.