An Overview of the Manson Supreme Anchor
History, design, and construction
History
Manson is a company located near Rocna, in Auckland. The designer of the Rocna, Peter Smith, was originally involved in talks with them concerning licensing production of the Rocna (at the start of the Rocna’s commercialization). Smith rejected Manson’s proposals to sell out, and about six months later the Supreme appeared.
Manson produce five different anchors, none of which is an original design:
- CQR (“Plough”)
- Bruce (“Ray” – claw style)
- Pool (“Kedge” – stockless type)
- Danforth
- Rocna (“Supreme”)
“At first glance the genuine Bruce anchor and the look-alikes that have flooded the market appear to be the same anchor. Close inspection will reveal that the look-alike is different in a number of disturbing ways. If you line up a row of the look-alikes you will find further disturbing features: whereas the genuine Bruce anchor has the same geometry throughout the anchor range, the look-alikes have shank angles that vary widely throughout the anchor range and even between same-size look-alikes…”
– Bruce Anchor Group, representing an unfortunate example of a copied type, as the multitude of copies have resulted in the genuine anchor no longer being produced. The knock-offs now available are all of inferior quality. Bruce have one parting shot: “Would you leap from a plane with a haversack on your back because it looks like the real thing and comes at a rock bottom price? Remember an anchor is a safety device upon which the survival of you and your boat may ultimately depend.”
Originals vs. Copies
Copying is recognized as ethically wrong. Patents, utility and design, exist to protect inventions such as new anchor types. Sometimes the copies are technically legal, such as if the patent has expired (e.g. the CQR and Bruce), or if patents were never filed in specific countries. Even if illegal, an expensive fight in court to prove infringement is not usually a practical option to a small company producing anchors.
These issues notwithstanding, a range of nothing but copies in a company’s product line surely indicates a distinct lack of imagination and creativity. If the manufacturer can only copy the developments of others, what else are they incapable of? There are subtle but very important aspects to the original anchor which are critical but may be ignored by the copier.
In general, original anchors are superior to the copies, since the copies have limited ways in which to differentiate themselves in the market. The usual manner is to sell at a lower price, which means lowering costs. That would be fine, except that there is usually a good reason for the cost of the original. The copies generally take obvious construction short-cuts, such as cheaper methods of fabrication or lower quality castings, or use lower priced steel, which the original manufacturer clearly elected not to. These compromises taken by the copier result in an attractive retail price, but the axiom “you get what you pay for” has never been truer.
Although principally these issues are about build quality, which has consequences to strength and durability, sometimes the differences are evident in performance. The Manson “Plough” is a CQR knock-off. Manson started off with this copy decades ago, reported by the NZ Herald as looking at the CQR and deciding they could build “the same thing” more cheaply. However, decide for yourself whether their copy really is the same – consider this series of photos comparing the Manson plough to a genuine CQR during independent testing.
Below it is argued that in the process of their “research and development”, Manson haven’t completely understood the principles of the Rocna, and have made several mistakes that affect both quality and performance.
Manson’s Rocna Look-Alike
“Manson’s Supreme anchor, launched last year, is similar to the Rocna design. It also copies Sarca’s shank slot…”
– Yachting Monthly in their December 2006 write-up of the West Marine anchor comparison testing. The testers commented that while the Supreme performed well at first, “at other locations it wasn’t quite as steadfast”. The article and full results are available below.
“[The Manson Supreme is] very similar to the Rocna but with the superficial inclusion of a slot for tripping the anchor in rock. The advantages of this are questionable as it could be argued that it weakens the shank. This is virtually a copy of the Rocna although some tests have shown it not to perform as well.”
– Blue Water Supplies discussing the merits of new generation anchors.
“I tried to get out on the cheap by buying a Manson Supreme anchor, as opposed to a Rocna, for my main anchor. Both anchors have very good ratings. Over the last few months I have not been able to get the Manson to really set well once. Not once! So after using only the Rocna during my month in the Bahamas on Vick’s 55' cat, I decided to sell my Manson and get the Rocna. I can’t believe it! The anchors look the same. The Rocna has set first time every time so far and I’ve even anchored in the same places that the Manson dragged. The Rocna bites instantly. There’s no discernable boat movement as you pull the anchor into the bottom. Diving on the anchor has shown that it’s completely buried with only the chain leading back to the boat. Who would have thought that two so very similar anchors would perform so very differently.”
– www.klutch-kargo.com (SV Felix, USA) on experience with both anchors in identical conditions
There are several fundamental aspects of the Rocna, which are the defining characteristics of the anchor. In the form of the Rocna, they are refined and have been in testing since 2000. The Manson Supreme of course also has these characteristics, but, as outlined below, not in the correct form and of lower build quality.
Below: Note the ground-down edge weld, and the obvious problems with the lamination
The skids are the plates attached to the back of the fluke. They are intended to help the anchor set. On the Manson Supreme, they are not done properly; in the opinion of the Rocna inventor the angles are wrong, and this creates setting issues in very soft mud, where the heel of the anchor may not be held up by the skids.
The shank design is another major issue, a consequence mostly of the full length slot it features. This is discussed in more detail below.
When compared to the Rocna, Manson appear to have taken several shortcuts during construction. The blade is a 1-dimensional roll, rather than a 2-dimensional fold. This means the front of the fluke (the tip) is relatively flat, and doesn’t have the reinforcement of the crease that the Rocna features from brake-pressing. Stamping or rolling is a cheaper process than brake-pressing, as the latter requires more expensive machinery and also necessitates several other processes.
Furthermore, the toe of the Supreme is laminated. Steel laminate does not benefit from the strength of other laminate materials. Manson just edge-weld the metal plate together, leaving a hollow space between the faces, so the strength is greatly reduced when compared to solid metal. The tip, hung on rock or some obstacle, may bend easily. The weld is also ground off to be flush (there is no recess), and galvanizing seems to create issues. The tip of the Rocna is solid metal.
The shank is also welded only to the top layer of the laminate, reducing the strength of this essential attachment. The shank, through which the entire force of the boat’s pull is transferred, is joined only to the upper face of the comparatively thin plate, with no other reinforcement.
Tip-weight is an important characteristic of any anchor. Many anchor designs resort to dedicated tip-weight in the form of lead inserts. The Rocna’s weight-on-tip is 33% of the total mass of the anchor. The Supreme should be similar; however, it is much lower, varying inconsistently between 17% and 23% depending on the size. This is mostly on account of the shank design.
Possibly in an attempt to compensate for this flaw, which adversely affects setting, Manson have made the fluke edge of the Supreme very sharp. While this does help setting performance, it is not a practical solution, as the galvanizing will not last on such sharp edges. Once worn off, the edges themselves will quickly rust away, and the benefit is lost.
Relative Performance of the Manson Supreme
While most of the issues concerning the Supreme relate to design and construction, and compromised build quality, there are also tangible consequences to pure performance.
The most recent comprehensive independent anchor test happens to include the Manson Supreme. The testing was written up by SAIL magazine in the USA, and Yachting Monthly in the UK. Results are graphed here.
The below chart shows averaged results as ratios of holding power to relative anchor weights. “Max Before Releasing” is the force the anchor withstood before moving (i.e. the effective holding power). “Max Pull” is the peak force measured after the anchor started moving.
Commensurate with the failure of the Manson plough when compared to the genuine CQR, is the performance of the Supreme. Combined with the cheap construction as discussed above, it should be clear why it is recommended that, as always, copies should be avoided.
The Supreme "in six pulls never held less than 2,300 lb, and held over 5,000 lb three times. Seemed to engage the bottom immediately.” – West Marine commenting on the Supreme’s lower holding limits in their testing. They do not appear sure about the anchor’s setting ability. On the other hand, their comments on the Rocna are more succint: "Superb, consistent performance. Held a minimum of 4,500 lb and engaged immediately.” The nature of these comments are all the more compelling when it is considered that at the time of their publication, West Marine was a reseller of the Supreme.
