Which Type of Anchor Has Little Holding Power?
An anchor in the shape of a mushroom gains stability by settling into the sediment of the ocean floor. Due to its poor holding power, it shouldn’t be used to anchor vessels bigger than a small canoe, rowboat, tiny sailboat, or inflatable boat.
Although recreational sailors most frequently use anchors to “park” their boats while going swimming or fishing, anchors are also essential tools in an emergency. If your boat breaks down, anchoring could be a safety precaution.
You are probably wondering which type of anchor has little holding power. There are many kinds of anchors, and choosing the right one will depend on the type of bottom that you’ll be drilling. This article will discuss the Bruce, Grapnel, Mushroom, and CQR/Plow anchors. They all have strengths and weaknesses, but which one should you use?
The Danforth anchor is a twin-fluke symmetrical anchor. Its twin flukes are molded from steel, and each flops to either side of the shank. This design is superior in that it is solid but lacks the flexibility of the CQR. American Richard Danforth developed the Danforth after he first developed the CQR. It was patented in 1948.
The Delta-style boat anchor is made of corrosion-resistant 316 stainless steel. The Delta anchor is deployed from 28 feet to 42 feet. The Delta and CQR anchors are similar but have different holding power. The difference between the two types is the design of the anchors. The Delta anchor is hinged, while the CQR anchor is one-piece. As a result, it struggles to anchor on rock and soft bottoms.
The Delta anchor was developed by Simpson-Lawrence and had a fixed-shank design. It prevents articulation and guides the anchor through its setting process. Its Fluke retains the basic shape of a plowshare. It has a brake-pressed plate heel and solid steel cast tip. The Delta is the most popular type. However, this design is more expensive than the Delta and is only used on narrow bottoms.
The two anchors were tested for the same amount of time. During the test, they were compared for holding power and setting. The former won by a wide margin, while the latter was a close second. The new Spade and Bulwagga anchors are the winners in the second round of testing. The CQR/Plow anchors had the least holding power.
While the Delta and Bugel have the best holding power of all three, they have limited flexibility. They do not fit the Delta or Rocna roll bars. But they are compatible with both. However, Danforth and Delta are not compatible with both. Although the Delta is the best-fitting anchor for both CQR/Plow and Rocna, they still lack the holding power of the latter.
The Bruce anchor is a tried-and-true anchor design. It has no moving parts and is made of a single piece. It is not very storable, but it is an effective secondary anchor. It attaches to a roller on the bow of the boat. While it lacks elegance, its holding power makes it an excellent secondary anchor. It also has little weight. So, if you want to use one anchor for several different vessels, the Fluke is a good choice.
Peter Bruce designed the Bruce anchor in the 1970s, drawing inspiration from oil rigs and drilling platforms. This anchor has gained a solid reputation as an effective recreational anchor thanks to its claw-shaped design and ability to set and right itself when it hits bottom. It is reliable and works well on rocky or semi-hard bottoms. It also works well in muddy conditions. While its holding power is limited, its ease of use makes it a popular choice for charter fleets.
A vital advantage of the Bruce anchor is that it is lightweight and has good burying and holding power for its size. The point and wingtips of the anchor are curved so that they automatically roll to a straight position, reducing dragging when the wind changes direction. This enables the anchor to remain embedded even when the boat is veering, despite changes in tide or wind direction. Moreover, the Bruce anchor’s high holding power is maintained through 360 degrees, despite its compact size and lack of moving parts. It can be easily broken out and stowed in a bow roller system.
The Bruce anchor has little holding power compared to other types of anchors. It has to be heavy to achieve the desired holding power. Its claw design can become foul at times. Moreover, it does not perform well on sandy or clay bottoms. It is still one of the most affordable anchors and can be a good fit in certain conditions. However, the Bruce anchor has few pros. So, the final decision lies with you.
The grapnel anchor is a common choice for small boats. Its compact size makes it ideal for smaller craft, and its open flukes make retrieval difficult. Despite its small holding power, the mushroom-shaped cap allows it to offer adequate holding power even on muddy bottoms. A mushroom anchor’s base features drainage holes for easy retrieval and displacement of water. It is not recommended for heavy-duty marine use.
The plow anchor is another type of single-point anchor. Its shank is either hinged or solid. Grapnels are marginal when anchoring in rocky bottoms. In addition, claw anchors and Bruce anchors have scoop-like designs, while Lewmar and Bruce have four large arms. The grapnel anchor typically has four large flukes, five fixed spikes, and a centrally-weighed shaft.
Although the mushroom anchor is small and does not have much-holding power, it is a valuable option when cruising on a light-air day. In light-air conditions, it can be helpful to make a quick swim stop or for a “picnic.” But, if dragging is an issue, a giant mushroom anchor might be a better option. Moreover, when anchored by the stern, the mushroom anchor rarely yaws.
The holding power of an anchor is measured in pounds and is based on several environmental factors. Generally, 90 pounds of holding power is sufficient to hold a twenty-foot boat in 20-mph winds. For larger boats, they are getting an anchor with a holding power twice the boat’s weight is recommended. Mushroom anchors are not recommended for smaller or lighter boats because they have limited holding power.
In grassy bottoms, this anchor is not very good. Its wide-angle and larger fluke areas make it less suitable for use in grassy bottoms. However, the mushroom anchor has adequate holding power in silty sand and may even work as a temporary anchor. This anchor is not recommended for very soft or loose mud. However, it is suitable for most other bottom types, including rocky ones.