A Busted Mast Step and a Popped Shackle
Shortly after we published the July 1, 1998 article on mast steps, reader Jim Lyons mailed off a little box. He lives in Tampa, Florida, and is, as he said, “Eight years into our 10-year plan to retire and go cruising,” aboard a Cabo Rico 38.
In the box was a folding aluminum step. “It failed me, all 170 pounds,” Lyons said. “Fortunately, it was the bottom step, not the top.”
An examination of the fractures in the two lobes of the cast aluminum step reveals, by the collection of white powder, that one arm apparently suffered either crevice corrosion or a structural crack. We tasted the whitish powder; it’s salty. The crack permitted the infusion of water, which encouraged further corrosion over 75% of the cross section of the lobe.
When that weakened lobe failed, the other, stressed unevenly, immediately snapped off cleanly, exposing the uniformly gray, typically granular surfaces of cast aluminum. The step still bears on its backside a clear plastic label on which is printed “ABI MADE IN TAIWAN.”
If you recall, there were in our report on mast steps two nearly identical aluminum folding steps. One was made by ABI; it’s offered in the West Marine catalog for $15.99. The other is a Mast Walker, made and sold for $14.50 by a company called Damage Control, in Pasadena, Maryland.
Damage Control’s Mast Walker, made of Almag 35, just went a leg up on the more expensive ABI.
It’s a reminder that great care should be exercised when climbing a mast. As we concluded in our two-part report on mast steps and ladders, the use of a device such as a SafBrak is wise. The SafBrak (see the July 1, 1998 issue) has a cam cleat on a strap that connects the user’s safety harness to an unused, snugged-down halyard.
Now It’s a Paperweight
Sailboats necessarily are very efficient arrangements of form and function. Slipping through very heavy water with nothing but whimsical air as the impetus makes almost everything critical. So it’s not good when something lets go. Like a snap shackle. Ingenious little things.
But they fail fairly often, especially if they rest in a position that encourages water to run down into, rather than out of, threads and other cavities. Moisture in small places = corrosion.
A professional rigger told us that, generally, it’s the pins that disappear when inexplicably freed by the split rings that hold them in place.
“Check the split ring and give each moving part and joint an annual phsssssssst with WD-40 and the breakage nears zero,” he said.
Most shackles, proof-tested by hard usage, are strong. In fact, the West Marine catalog says that Ronstan’s Nicro Marine snap shackles come with an unlimited lifetime warranty. More about this in a moment.
It was a Nicro Marine shackle from Ronstan that a reader, David Hay sent to us. It’s an RF 6351 trunnion toggle swiveling model made of investment cast 15-5 PH stainless. It weighs 9 oz. and will take a 3-1/2-ton load before it deforms. It lists for about $100. David Hay’s snap shackle went utterly useless because the locking pin and spring dropped out and vanished.
When we checked the catalogs, we noted that, despite the “unlimited lifetime warranty,” Nicro Marine snap shackle repair kits are offered. A kit includes a plunger pin, spring and split ring. There are seven sizes, ranging in price from about $12 to $25.
We called Nicro Marine and were told that “nothing lasts forever.”
When we asked about the “unlimited lifetime warranty,” we were told, “Covers everything but the plunger pin, spring and split ring.”
Why was that no surprise?
Our local chandler had but two sizes, neither of them the one we needed. Neither could we find the proper repair kit in any discount catalog.