A View from Here

Bill's Sisson's weekly Trade Only blog

Simple technology in a high-tech world

There is nothing fragile or complex about the small gray mooring barge, its hydraulic torque motor hanging from a 15-foot steel mast. It works day after day, year after year, screwing what are typically 10- to 15-foot steel shafts with two or three helixes at the base into mud, sand, clay and gravel bottoms. Think of them as big mooring screws, which essentially is what they are.

Dave Merrill’s 24-foot barge is anything but high-tech. It’s all about utility and practicality, about getting a job done with just the right amount of efficiency, economy and reliability, which is how you stay in business these days.

Pushed by a fairly new-looking Yamaha 60-hp 4-stroke, the barge and the helix anchors it installs are a far cry from the complicated and costly hybrid technology I discussed in last week’s blog. The contrast between those two worlds is part of what made Merrill’s story interesting to me.

Merrill is one of scores of independent small-business operators who collectively are so important to our industry, providing the expertise and know-how to build and reshape our marinas and waterfronts.

His platform is a “good working barge,” says Merrill, 62, whose business — BoatMoorings.com — is based in Milford, N.H. And the helix anchor he installs, Merrill notes, “is basically a screw.” Simple, proven, reliable — and invented in the 1830s by Irish civil engineer Alexander Mitchell (who later patented it) to anchor lighthouses, ships and buoys in place.

Technology that keeps your boat safe is technology I can get my head around. Helix anchors have been in wide use for years in the utility industry, securing telephone poles, guy wires and the like.

For the past 20 years Merrill has been installing helix screw-type anchors in mooring fields from Fiji to the Seychelles, from the Caribbean to Florida to Maine. He estimates that he’s put in “thousands” of anchors and trained maybe five dozen or more installers and companies around the world, many of them in marine parks with coral reefs, where the helix is the environmental standard.

Helix anchors provide much better holding power than traditional mushroom anchors, and because only about 8 inches of the shaft pokes up above the seabed once they’re screwed into place, their impact on the ecosystem is much reduced, compared with other moorings or boat anchors.

“Low-tech but eco-friendly,” Merrill says.

That’s a good formula.

Merrill developed a floating elastic rode — the Eco-mooring rode — two years ago that makes his system even more environmentally compatible. Suspended off the bottom, the Eco-mooring rode can’t scour the sea floor when the boat swings, like a traditional mooring chain does, the installer says. That has enabled his system to replace traditional moorings in eelgrass beds on Nantucket, Mass., for example, where chain scouring was killing the submerged grasses, which provide important habitat for juvenile finfish and shellfish.

The elastic rodes (which he also sells as storm pennants) also allow Merrill to use less scope, which means more moorings can be installed in a given area — another benefit. And they aren’t subject to electrolysis, as chains are.

I caught up with Merrill several days ago in New London, Conn., where he was installing 41 helix moorings and elastic rodes in a town mooring field for Crocker’s Boatyard.

He demonstrated a bit of the stretch of the rope-sheathed rode by looping one eye over a cleat and really leaning into it. The line has a breaking strength of more than 33,000 pounds and will stretch when fully loaded from 12 to 19 feet.

Merrill got into the business after Hurricane Bob struck New England in 1991, dragging hundreds of boats ashore attached to everything from mushroom anchors to engine blocks, train wheels, even an old bathtub. Out of the wreckage of that storm came a revived interested in helix anchors for the marine industry.

When Merrill started, he faced non-believers in one harbor after another. “Show something new to a New Englander and say, ‘This is better than that,’ ” Merrill recalls, shaking his head. “A lot of skepticism. It just took time to prove it.” Merrill works with one diver and one other worker who helps make up the anchor rodes.

A warm wind is blowing on the Thames River, and Merrill has more work to do. “I love being out on this thing,” he says, standing on his barge. “It’s been a great gig.”

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