
Nb.: This is a slight parody of a similar article published by SPADE (makers of the Spade anchor). That is not to say the following is incorrect or untrue, but it is limited to dealing with the inaccuracies and bias in the Spade publication. If you have seen the latter, you will “get it” – if not, just consider it slightly tongue-in-cheek.
There are many modern designs which could be considered “new generation”, but in addition to the above certain performance criteria should be considered minimum requirements:
Examples of new generation anchors are the Bügel, Spade, SARCA, Sword, Bulwagga, and Rocna.
The key difference between these two concepts is that the Bügel relies on force from the anchor rode to set the anchor (assisted penetration) whilst the Spade is supposed to use weight distribution and an angled ballast chamber to ensure the optimum angle for penetration (passive penetration) even before any force is applied. In fact the specially weighted tip makes little difference to its setting performance, and is present for the same reason the CQR featured a lead insert way back in 1933: to make sure it rolled over and couldn’t stay upside-down, hence the term “ballast”. The Bügel avoids this requirement by using its roll-bar, and so greater blade area or structural strength can be attained by allocating the weight of the lead to other things. The Spade will normally penetrate within its own length, but so will the Bügel, and the latter enjoys an additional advantage: a slimmer fluke profile, which presents less resistance to penetration than the bulky lead-filled tip of the Spade, helping setting in hard sand or weed.
Holding power is a result of anchor form, pulling angle and surface area. It therefore follows that an anchor with more of its weight in surface area can offer greater holding power once penetrated than one which has weight in lead ballast. In addition to this, such lesser holding power is of little use if the anchor has not penetrated properly. So one should choose an anchor with the greatest surface area, all else equal, but also avoid anchors with bulky tips which might impede setting on seabeds where a sharp tip will be advantageous. Testing and feedback demonstrate that a well-designed roll-bar anchor such as a Rocna offers both greater holding power and setting ability than a ballasted-tip anchor such as a Spade.
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Bügel (AKA “WASI”)Bügelanker is German for “handle” or “roll-bar” anchor. It is simple design now very popular, particularly in the Mediterranean. A flat blade is shaped to form a sharp point, while a roll-bar ensures that the anchor always lands the right way up. Once a load is applied to the rode, the anchor adopts the optimum angle for penetration and its sharp point will penetrate most bottoms with ease. For:
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SpadeThis anchor was designed to be the ultimate performance anchor, but is expensive and unnecessarily complex. A spoon-shaped blade, gives good resistance but features a lead-filled ballast chamber which not only ensures that the anchor adopts the right angle for penetration, but positions a massive 50% of the anchor’s total weight over the tip. To attain this percentage, weight is removed from the shank, which is fabricated and hollow. The Spade is available in aluminium, galvanised or stainless steel. For:
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SARCAThe Sand And Rock Combination Anchor is an Australian design which features a thin roll-bar. Its classification as a new generation anchor is questionable due to its shallow convex blade (it is really just a plow). Its shackle attachment slot runs the full length of its shank to allow the anchor to be pulled out backward if it is fouled. This is only really useful for picnic anchoring as there is always a risk that the anchor may trip itself when you don’t want it to, and it also severely weakens the shank. For:
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Sword (AKA “Océane”)The latest offering from Spade, this anchor used to be called the Océane but was slightly redesigned and re-branded following poor reviews and market acceptance. Like a Spade without a ballasted tip, the Sword seems to contradict the fundamental values of the Spade itself. Its shank is mounted at the tip in an attempt to give it some tip-weight, and it is much more cheaply built than the Spade. For:
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BulwaggaThe Bulwagga is an American design originally intended to work well in weed and grass. It also happens to work quite well in sand and mud. It features three flukes, two of which penetrate, and a pivoting shank which adjusts itself to the correct angle of pull. In some senses it is like a new generation Danforth, in that it has multiple flat flukes, a straight shank, and no ballast – however it performs much better and more reliably than a Danforth. For:
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RocnaThe Rocna is a New Zealand design, at first glance a combination of a Spade’s fluke and a Bügel’s roll-bar. This is a clever mating, solving the Spade’s problems whilst remaining far more sophisticated than the Bügel. The fluke is hard-chined and is built from two-piece plate, with the tip being much thicker than the rear. These two factors give the tip enormous strength and resistance to bending. The skids are attached to the fluke in such a way that they, in addition with the roll-bar, reinforce the rear of the fluke, again providing excellent strength. The shank is designed to lock home securely on all bow-rollers. For:
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Although there are many different types of anchor, most can be classified on how well they meet the seven factors that make a good anchor.
1 - The anchor must set quickly and reliably in any seabed
In order to bury fast an anchor needs to have the right angle for penetration every time, this can be achieved by several methods:
2 - The anchor must bury deeply
The deeper an anchor buries, the greater the mass of seabed above the anchor and therefore the less likely it is to pull out. Furthermore, seabeds are usually layered, and the substrate gets denser with increased penetration, providing better holding power. Concave flukes can be made to bury further than convex flukes, which tend to plow just below the surface.
3 - The anchor must give high holding power without dragging
This is a bit of a compromise, since the largest fluke area for the amount of weight will do well in this category, but it will be at the expense of strength and durability. For example, Danforths can offer excellent holding power, but their shape offers no reinforcement and they are easily damaged. Similarly aluminium anchors are light and give good holding for their weight, but are weak.
4 - The anchor must offer a constant resistance to movement, even if it moves under extreme load
Any anchor will drag if the force is high enough. When it does move, however, it should remain roll stable, which means it shouldn’t pop out as it drags, and the resistance force should increase as its speed increases. Anchors with more than one fluke are particularly unstable when dragged, such as the Danforth and Bruce (claw). However the CQR is also quite notorious. Once these anchors let go, they are very unlikely to reset and their holding ability drops severely, meaning a dragging boat is likely to continue dragging.
5 - The anchor must hold despite wind or current shifts of direction
This is partly a product of roll-stability. Most anchors that are roll stable will remain properly set as the direction of pull alters. Some anchors will roll out if a 90 degree veer is applied to them and these should be avoided.
6 - The anchor rode must not be able to foul the anchor
This is not a problem usually a problem associated with new generation anchors, as they will turn with the rode pull. Some anchors such as Danforths and Fishermans are renowned for getting caught up on their own rodes.
7 - The anchor must be strong enough to endure foreseeable usage
Anchors do not live an easy life. Most are built strong enough to withstand the normal forces applied to them even during strong wind conditions, but once must consider the scenario of jamming the anchor in rock or otherwise fouling it – it should not fail once in such a condition. As such, a strong shank is desirable, one resistant to sideways bending forces. The fluke should be reinforced and strong, not just flat plate which will bend easily. Laminated steels should be avoided, as it does not acquire strength in the same way that other laminates do.
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How anchors perform against the seven key factors that make a good anchor(figures are theoretical and not based on scientific testing) |
#1 - The anchor must set quickly and reliably in any seabed | #2 - The anchor must bury deeply | #3 - The anchor must give high holding power without dragging | #4 - The anchor must offer a constant resistance to movement, even if it moves under extreme load | #5 - The anchor must hold despite wind or current shifts of direction | #6 - The anchor rode must not be able to foul the anchor | #7 - The anchor must be strong enough to endure foreseeable usage | Score /70 |
Bügel |
8 |
6 |
7 |
10 |
8 |
10 |
8 |
57 |
Spade |
6 |
8 |
6 |
10 |
10 |
10 |
6 |
56 |
SARCA |
8 |
2 |
5 |
8 |
8 |
8 |
3 |
42 |
Sword |
7 |
7 |
8 |
8 |
8 |
8 |
3 |
49 |
Bulwagga |
10 |
6 |
9 |
8 |
8 |
4 |
5 |
50 |
Rocna |
10 |
10 |
10 |
10 |
10 |
10 |
10 |
70 |
Bruce (claw) |
6 |
5 |
2 |
3 |
2 |
10 |
10 |
38 |
CQR (articulating plow) |
2 |
5 |
4 |
2 |
2 |
8 |
9 |
32 |
Delta (fixed-shank plow) |
6 |
6 |
6 |
6 |
4 |
10 |
9 |
47 |
Danforth |
5 |
5 |
8 |
0 |
0 |
5 |
5 |
28 |
Fisherman |
8 |
0 |
1 |
3 |
5 |
2 |
8 |
27 |
(figures are not theoretical and are based on scientific testing)