June 4, 2013

You need to know about toggles

I HOPE YOU KNOW about toggles. It’s quite important that you should. And no, they’re not the things that keep Boy Scouts’ scarves neatly wrapped around their necks. Those are woggles, not toggles. Big difference.

The reason you should know about toggles is that the wires holding up your mast are subject to metal fatigue where they join the mast and the hull. The problem is vibration, or repeated cycling and flexing. Most metal, if you repeatedly work it back and forth, will crack and break.

Only a year after the world’s first commercial jetliner, the De Havilland Comet, was put into service, Comets started to fall out of the sky. Extensive investigation revealed a devastating design flaw — metal fatigue. The constant stress of repressurization would weaken an area of the fuselage near the Comet's square-shaped windows and the wings broke off. In those early days, the effect of metal fatigue through flexing was not sufficiently understood.

A similar thing can happen to your stays and shrouds if they’re not properly attached. While the result may not be as catastrophic, it’s inconvenient, to say the least, to have your mast fall down.

Even though your rigging appears to be firmly attached at either end, it’s actually able to flex slightly under certain circumstances. Even when your boat is at the dock, or at anchor, the wires will jiggle back and forth when the wind is right. You might also have noticed the jingling noise the rigging makes sometimes when the engine is running. That means it’s flexing, and the effect of all this jiggling back and forth is cumulative.

The answer is to use small universal joints at the mast tang and the hull chainplates. These are known as toggles, and they allow the wire to jiggle to its heart’s content in all directions without getting bent. And if it doesn’t get bent, it won’t get fatigued.

Some turnbuckles have toggles built in, but many do not. If you desire your fair share of peace of mind, and if you want to sleep at night, especially at sea, be sure to check yours.

Today’s Thought

Coffee stains on the flip-down trays mean (to the passengers) that we do our engine maintenance wrong.

— Donald C. Burr, former chairman, People Express Airlines


An Irish priest offered  $5 to the boy in his divinity class who could name the greatest man in history.

“George Washington,” said one.

“Julius Caesar,” said another.

“St. Patrick!” shouted a little Jewish boy.

The priest awarded him the $5 and said:  “What made you say St. Patrick?”

“Well, sir,” said the boy, “I know the real answer is Moses — but business is business.”

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

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