February 9, 2016

Sailing science advances slowly

IT TOOK MANKIND a long time to figure out how to represent the shape of a boat on paper. Indeed it is quite an achievement to be able to “see” the three-dimensional shape of a hull in the mind’s eye just by looking at a set of lines drawn on a flat surface. It took centuries before waterlines, buttock lines, and stations became the everyday tools of naval architects.

In fact, before the sixteenth century little was known of the science of ship design, according to Steve Killing, author of Yacht Design Explained: “It was experience rather than theory that taught the shipbuilder (who was often the designer) what was fast and what was seaworthy.”

In those days, experimentation was the only way to make a new ship better than the last, and sometimes progress wasn’t progress at all, Killing says. “In 1697 Paul Hoste, a French Jesuit priest and professor mathematics, was beginning to explore the new science that Newton’s example had inspired.”

Hoste wrote: “It cannot be denied that the art of constructing ships . . . is the least perfect of all the arts . . . . The best constructors build the two principal parts of the ship, viz. the bow and the stern, almost entirely by eye, whence it happens that the same constructor, building at the same time two ships after the same model, most frequently makes them so unequal that they have quite opposite qualities.”

Progress in the early days was very slow, and we might be forgiven for presuming that science is making much greater strides in this modern age. But we are forced to think again when accidents happen such as the sinking of OneAustralia during the 1995 America’s Cup Challengers’ Series. That catastrophe came about because of simple structural failure.

So much for computer-aided design. “Even with the latest scientific know-how on hand, we’re still learning things the hard way,” notes Killing.

Today’s Thought
There is a period of life when we go back as we advance.
— Rousseau, Émile

“How much is a bottle of brandy? It’s my nephew’s birthday and he likes brandy.”
“Well, madam, it depends on the age. Seven-year-old is quite reasonably priced. Ten-year-old costs a bit more. Twelve-year-old can be quite expensive.”
“Gee, that’s terrible. My nephew is 25.”

(Drop by every Monday, Wednesday, Friday for a new Mainly about Boats column.)


Alden Smith said...

We Kiwis wept when One Australia sank. Being deprived of soundly trashing them on the water was very traumatic for us; although every cloud has a silver lining as we were able to view Australians jumping into the water in the various videos of this event.

Mike K said...

I seem to recall we (NZ) were losing the race - the only one we were behind in - until the Aussie's sank. They had a sense of humour though - next race they fronted up in their back up boat, all wearing life jackets.

Mark The Skint Sailor said...

Fairly recently there have been a number of keel failures on cruising/racing yachts. The response from builders seems to be that there must have been prior damage from groundings, without any deep scrutiny of the engineering around the failure. The highest profile loss in the UK was Cheeky Rafiki, sadly with the loss of lives.

I get the impression that builders are sailing a bit close to the wind with their models of stress tolerance when it comes to modern composites. Especially foam cored ones.

Last Autumn's Transat Jaques Vabres with it's long list of heavy weather retirements shows how designers are pushing the envelope regarding boat design. Okay, those were highly stressed, on the limit racers with cutting edge designs, but they were still built for a trans-Atlantic race, so they should have been able to withstand a lot of punishment. Luckily most failures happened before they got too far out, but if they had failed mid-Atlantic, things could have been worse, lives could have been lost.

It's possible that present-day boat builders are making similar errors to their forebears.

It's why I like GRP yachts from the early days of composite use. They are over-engineered and able to take punishment over several years without failure.