Helical anchors have been used in construction in such applications as transmission tower foundations, pipeline anchors, excavation bracing, and tunnel support systems.
It’s the application as a boat mooring that is new. This may be the boat mooring system that saves the harbors in the next hurricane.
The benefits are many, says David Kaiser, spokesman for the yard which installed the first one in Mattapoisett in late September.
Helical pier moorings are “virtually hurricane proof”; have a measureable and predictable holding power; bury the shaft so there is nothing to tangle the chain; have a life expectancy of a minimum of 25 years; costs the same or less then a conventional mooring system; and, most important for our crowded harbors, requires less scope, providing as good or better holding power than a conventional system.
If the anchors function as advertised, they would forestall the kind of devastation we saw in Marion and Padanaram during hurricane Bob. Boats with properly quipped deck and rode gear could not drag their moorings and ideally would not break free, as some 3000 boats did between Narragansett Bay and Hyannis during Bob.
Helical earth anchors have been used in land and construction since early history. For 80 years the company manufacturing the Mattapoisett example, A.R. Chance of Centralia, MO, has been building them for land applications.
But not until July, when David Merrill 43, of Jager Corp. of Amherst, NH headed out to the Cape and islands to sell the A.B. Chance product for light commercial and residential applications, did anyone consider using the anchors to moor boats.
“I was made aware of the fact that in Barnstable they were looking for a solution to their mooring problems,” said Merrill, describing how the idea occurred to him.
“I contacted them and learned that FEMA (the federal Emergency Management Agency) was doing a study workshop on the mooring issue. I also contacted a number of harbormasters, (described the helical pier anchor), and found they believed that this could possibly be a good solution to the mooring problem.”
Since then, Merrill has installed four of the anchors; two in Mattapoisett, through the Mattapoisett Boatyard, one in Hyannis, at the Hyannis Marina, installed by Bradbury Mooring Service, and one in Hull, at the Waveland Marina, installed by Kehoe’s Ships Chandlery of Hingham.
He has also presented the product to Massachusetts and Rhode Island harbormasters.
“Everyone I talk to says, `Yes, of course. It’s so simple. I thought of doing something like that but never got around to it,’” said Merrill.
The helical pier mooring or anchor has been used in virtually every type of soil, he said. The only type of bottom where it could not be installed is solid ledge.
“But we’re working on that,” he said.
Cost of the hardware and installation is similar to that of conventional mooring devices – unless you’re using the bathtub your mother-in-law threw out last year, filled with cement. The basic helical hardware – shaft with helical and mooring adapter retails for about $530 [1992 prices].
As with other mooring gear, the helical anchor can be re-turned out of the harbor soil for inspection at whatever interval that harbor regulations require, said Merrill.
The biggest problem he anticipates is converting the older mooring service companies. Perception among harbormasters so far has been universally favorable he said.