New Generation Anchors Explained

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.

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A new generation anchor is one that meets the following criteria:

• It is of the new generation, i.e. not the old generation of traditional types. Obvious? Maybe not. We consider the Delta (1980s) to be the last of the old generation – although a modern anchor, it is still a plow and therefore effectively just a moderately improved CQR – and the Bügel (1986) to be the first of the new generation.

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:

• The anchor always positions itself correctly – if it falls upside down, it automatically turns over under natural conditions
• It turns (veers) with the wind and tide without pulling free
• It offers high relative holding power and will not roll out even if dragged
• It will hold on rock or coral as well as possible

Examples of new generation anchors are the Bügel, Spade, SARCA, Sword, Bulwagga, and Rocna.

Bügel features:

• A straight bar shank
• Roll-bar to turn anchor (patented 1986 together with the shank configuration)
• Flat fluke with sharp tip to gain rapid penetration
• Original design featured skids to assist with setting (patented 1986 with above)

Spade features:

• Angled ballast chamber with lead insert to generate tip-weight
• Hollow triangular/trapezoidal shank profile as an attempt to retain strength as weight is removed from the shank in order to achieve the desired weight distribution (except smallest two models)
• Ears, similar to the Bügel's skids, to prevent blade edge penetration
• Concave fluke for optimum holding power (patented 1999: specific angles of fluke faces combined with above)

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 isn't any good if the anchor can't penetrate

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.

Rocna features:

• A concave fluke similar in form to that of the Spade but with more surface area
• Tip-weight in the form of a thicker tip section, which keeps the tip profile slim while adding strength to the tip
• Skids to assist with setting
• Sensible shank designed with a practical fit on most bow rollers in mind

Rating: «««	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: Simple design – cheap and easy to manufacture Good performance in a wide range of bottoms Against: Flat blade does not offer maximum holding power Most Bügels are built as shown in the picture to the left, not according to the original patent, and so lack skids and a reinforcing edge on the underside of the fluke Little tip weight with no ballast and fluke is one-piece plate Simple design – lacks the sophistication of others
Rating: ««««	Spade This 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: Concave fluke Demountable shank for easy stowage Ears to prevent edge penetration Good holding power Against: Expensive to manufacture & high retail price Smaller fluke surface area for a given weight than some other new generation anchors due to ballast chamber Strength issues with the hollow shank, particularly with aluminium versions Shank design does not lock home properly on some rollers
Rating: ««	SARCA The 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: No tip ballast, and a full length slotted shank which could be useful for small boats and short term anchoring Against: Just a modified plow with a convex blade Slot creates huge problems and doesn't work well Often requires a modified bow roller
Rating: «««	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: Concave shaped blade very similar to that of the Spade Good surface area to weight ratio Cheap Ears to prevent edge penetration Against: Limited tip-weight The complete lack of reinforcement in the rear section of the anchor makes it flimsy and vunerable; as such Spade do not make a version larger than 20Kg (44lbs) The presence of the shank at the tip can be an obstacle to good penetration of the tip A compromised version of the Spade
Rating: ««««	Bulwagga The 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: Excellent setting ability including grass and weed Good holding power, has out-performed Spade in magazine testing Against: Its design only utilizes two thirds of the available fluke area, since one fluke is always unused Flat flukes have no reinforcement and are easily damaged Difficult to stow either on bow rollers or elsewhere Top-most fluke may foul rode
Rating: ««««« PREMIUM PRODUCT BEST BUY	Rocna The 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: Concave fluke No tip ballast and sharp tip profile Good surface area to weight ratio Shank locks home securely and does not allow vertical movement while at sea Skids to prevent edge penetration Well made with high tensile steel shank Against: The roll-bar can be a problem on some boats as it may clash with bow platforms or bowsprits

Anchor Classification

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:

1. A ballasted tip, in the form of either a lead insert or a solid steel tip, will ensure this by way of balance. Examples are plows (CQR) and Spade, which feature a lead insert, and the Delta (solid cast steel). Provides good amounts of tip-weight but takes up volume, restricting setting ability, and requires an allotment of weight, which is inefficient.
2. A roll-bar. Examples are the Bügel, SARCA, and Rocna. A roll-bar should be thick enough that it can't just sink in soft mud. It should weigh very little although they do not affect the tip-weight of the anchor if it is well designed. In the history of anchors to date, this seems to offer the best solution.
3. Other anchors simply do not bother about a correct orientation, such as a Danforth, which can work whichever way it falls, or a Bulwagga, which has three identical working positions.

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.

How anchors perform (period)

(figures are not theoretical and are based on scientific testing)

More (slightly more serious) reading of interest:

• A Process of Evolution: The Failings of the Old Generation, and the Introduction of the New (an essay on boat anchors by New Zealand boatbuilder, offshore cruiser, & consultant Peter Smith)
• The Bottom Line: Anchoring In 2007 (Coastguard Member's Handbook)
• Chain, Rope, and Catenary – Anchor systems for small boats
• Kellets or Anchor Angels/Sentinels – Uses and Applications
• Two to Tandem: Maximizing Holding Power With Tandem Anchoring / Dual Anchors – An outline of the theoretical & practical aspects of tandem anchoring
• Tuning an Anchor Rode – understanding and optimizing your anchor rode (external link)
• Rocna Anchors website, with exciting things like video