Buy Boats, Sell Boats, Review Boats

Posted by on Aug 7, 2014 in Safety and Seamanship, US |

Fortress Anchor Testing: When It’s Good To Be a Stick in the Mud

Wonder which anchor works best? Fortress Anchors is hoping science can answer that question.

If I had to pick one boating-related activity that usually raises my blood pressure, it’s anchoring. There’s something about trusting your pride and joy to a piece of metal stuck in the bottom that’s inherently anxiety-inducing.

A variety of new-fangled anchors sit lined up on the aft deck of the research vessel Rachel Carson during Fortress Anchors' 2014 anchor testing in Solomons, MD, on Chesapeake Bay.

A variety of newfangled anchors lined up on the aft deck of the research vessel Rachel Carson, ready for Fortress Anchors’ testing session in Solomons, MD.

So wouldn’t it be better if our anchor choices were based on science, rather than on what’s most visible at our local marine store? Turns out Fortress Anchors had the same idea, and they even invited me along to watch their testing. With the promise of another work-supported day on the water, I headed down to Solomons, MD, to try and answer an age-old question: “Which anchor holds the best?”

Fortress, which manufacturers lightweight Danforth-type anchors made of high-tensile aluminum alloy, undertook its first anchor tests in early 1990. It dragged and pulled all sorts of Fortress and competing anchors through both sand and mud bottoms with big, powerful tugs in Miami, FL, and San Francisco, CA, measuring the amount of force in pounds it took to break each anchor out.

Fortress Anchor representatives get ready to put a 44-pound Delta anchor through its paces. Note the blue tension meter on deck to the right.

Fortress Anchor representatives get ready to put a 44-pound Delta anchor through its paces. Note the blue tension meter on deck to the right.

Fast forward 24 years and there are all sorts of new anchor styles on the market, with names such as Mantus, Rocna, Spade, Manson, and Ultra. These anchors are what sparked Fortress Anchors to conduct a whole new series of tests. It chose the Chesapeake Bay because its bottom is primarily comprised of oozy, slick mud—perhaps the most difficult type of bottom for secure anchoring.

Our test platform for the day was the research vessel Rachel Carson, an aluminum 81-footer with twin 1,205-horsepower MTU diesels and a pair of Hamilton jet drives that can push the boat to 23-plus knots. She’s equipped with all the right gear for scientific testing, but it’s her ability to “hover” in one place on the water, as well as her powerful electric winches, that make her the perfect anchor-yanking vessel. Heck, she’s even air-conditioned, which was a nice bonus.

Monitors aboard displayed live results as the pull tests were being conducted. The top number in the upper-right corner of this image shows 370 pounds of wire tension being exerted on a Manson "Boss" anchor.

Monitors aboard displayed live results of the pull tests. The top number in the upper-right corner of this image shows 370 pounds of wire tension being exerted on a Manson “Boss” anchor.

We headed out into the Patuxent River off Solomons for the tests. I’ll save a detailed explanation of the test procedures for a full-length article, but this is essentially how it worked: An anchor would go over, we’d move forward and pay out about 230 feet of rode, and as the Rachel Carson hovered perfectly in place, a big winch would place an ever-increasing load on the anchor. Meanwhile, instruments measured and displayed what was happening.

So, which anchors did best? Fortress and Danforth performed exceptionally well during the day I was present, with both exceeding 1000 pounds of tension. But Fortress anchor testing continued for two additional days, which means the full results aren’t in yet. Stay tuned for a full breakdown of those results, once they become available.