Ijin Marine Limited

Ijin Marine Limited

Professional Supplier of Machinery & Hardware

A Boat Owners Guide to Choosing an Anchor

With such a vast array of anchor types now available for the leisure and commercial marine sectors, choosing the right model for your vessel can be difficult. 

In this article, Karl Pentin, Director of Safety Marine, looks at the differences between anchor types, their relative advantages, where they can be used, and what you should be aware of.
 
Use Local Knowledge
 
There are many types of anchor available and each model will have its own features and benefits. Each manufacturer will understandably reinforce the particular advantages and characteristics of its own particular product, so it is probably a good idea to have a look at what other boats are using in your area, and use this as a basis for your own anchor inventory. Ask around!  Most boats owners usually love chatting about what they find works best for them.
 
As every boat should really have a main anchor and a secondary or kedge anchor on board, it may be a useful to have two different types. Then if one does is not holding well in one particular cruising area, the other one might!
 
Fishermans Anchor
 
This design is a non-burying type, with one arm penetrating the seabed and the other standing ‘proud’. The anchor is ancient in its design and has not changed substantially over time.
 
• It has a good reputation for use in rock, kelp and grass as it can dig through weed and hook into cracks in the rock.
• On soft ground it is important that the anchor has large flukes. Even with large flukes, it has less holding power to weight ratio than more modern anchors.
• This is a good all around anchor when you need to anchor on all types of seabed.
What to be aware of:
• If anchored under conditions where the boat can drift over and around the anchor (such as with changing wind and tides), the anchor can easily be fouled by the chain and lose its holding power.
• This type of anchor is more difficult to stow than more modern designs, as it does not stow in a hawse pipe or over an anchor roller. The foredeck and rail must therefore be designed specifically to hold it.
• Most models include a folding stock so the anchor can be stowed flat on deck.
Unfortunately this then requires the anchor to be assembled for use and connected to an appropriate anchor rope, making fast deployment difficult.
 
CQR and Plough Anchors
 
CQR and plough-type anchors are some of the most popular designs.  The original CQR (secure) design was developed in 1933 by mathematician Geoffrey Taylor for use on flying boats.  This design is particularly popular with experienced cruising sailors.
 
• These anchors have good holding power and can stow easily over a bow roller.
• They are generally good in ‘all bottom’ types, but they are not exceptional in any one particular type.
• The CQR and plough anchors have a hinged shank, allowing the anchor to turn with directional changes in the tide rather than breaking out of the bottom. This also helps force the point of the plough into the bottom if the anchor lands on its side.
• The CQR and plough anchors can easily be stored on most regular bow rollers.
 
The Genuine CQR Anchor which is now manufactured by Lewmar, has Lloyds Register Type
Approval as a High Holding Power Anchor.
Delta Anchor
 
The Delta anchor is designed to self launch off a bow roller.  It features a fixed fabricated shank welded to a fabricated geometrically designed plough with a ballasted tip.
 
• A Delta anchor will slide off the front of the roller as soon as the chain is eased but it will require a suitable bow roller fitting to do this.
• It has a unique shank profile and ballasted tip to make it self-launching and the low centre of gravity and clever geometry give this anchor a self-righting ability which helps it set in most bottom types with good consistency.
 
The Delta anchor also has Lloyds Register Type Approval as a High Holding Power Anchor.
 
Danforth and Fluke Anchors
 
The Fluke-type anchors consist of a stock at the crown, with a cross bar and two large flat pointed flukes attached. The stock is hinged so the flukes can orient downwards towards the bottom.
 
The most recognised brand is the Danforth, which is sometimes used as a generic name for this type of anchor.
 
• The design is a burying type, and once set properly can develop an amazing amount of resistance.
• Danforth and fluke-type anchors have very good holding power in soft mud and sandy conditions where many other anchors may not hold as well.
• They can be relatively lightweight and their flat design makes stowage in a locker easier than Plough or Claw type anchors.
What to be aware of:
• These anchors do not hold as well in firm or rocky bottoms. The Fluke-type anchor can also have difficulty penetrating kelp and weed-covered bottoms.
• If there is much current or the vessel is moving whilst dropping the anchor, it may skate over the bottom with the large fluke area acting as a wing.
• The best method is best to remain stationary, dropping the anchor vertically to the sea bed and then drifting backwards to allow it to set.
• Once set, the anchor only tends to break out when the direction of force changes dramatically, such as with the tide changing.  However in suitable bottom types, they will often reset quite easily.
 
Fortress and Guardian Alloy Anchors
 
The Fortress and Guardian range of alloy folding anchors have a reputation for offering good performance in most bottom types.  Ultra lightweight, these anchors are designed to replace primary steel anchors on many smaller vessels without a powered anchor windlass, or alternatively as a secondary kedge anchor. 
 
All Fortress and Guardian anchors are made from hardened aluminium-magnesium alloy in a tough anodised finish.
 
• These anchors will provide many times their weight in holding power.
• They are supplied disassembled in a box, which is great for stowage if you are using it as an occasional secondary or kedge anchor.
• Once assembled the Fortress and Guardian anchors are noticeably larger than the equivalent steel anchors of the other types.
• Completely rust proof and non-magnetic, these anchors are similar in design to the Danforth and other Fluke type anchors.  However, the Fortress anchor is unique in that it has flukes that can be adjusted from the normal 32° to a 45° angle to increase holding power in softer muddy bottoms.
 
What to be aware of:
 
• As the anchor is stored disassembled, this could make it difficult if you need it in a hurry as correct assembly takes about 10 minutes with the right-sized tools to hand.
• In stronger wind or sea conditions, the manufacturer recommends choosing the next size up for security, making things bigger once again.
• Due to their lightweight nature, it is always advisable to use at least 10m of chain with any Fortress or Guardian alloy anchor to add additional weight and to ensure that the pull of the anchor rope is horizontal along the bottom first before leading up to the boat. This should prevent them breaking out too easily.
 
Bruce and Claw Anchors
 
The original Bruce shaped anchor was designed by Peter Bruce from the Isle of Man in the 1970s.  Bruce Anchors gained its early reputation from the production of large scale commercial anchors for ships and fixed installations such as oil rigs. Bruce Anchors has now stopped manufacturing the original Bruce pattern small boat anchor, however its copies, known generically as ‘claws’ have become a popular option for smaller vessels.
Its design was intended to address some of the problems of the Plough anchor:
 
• Claw-type anchors set quickly in most sea beds
• Although this is not a hinged design, claw anchors have the reputation of not breaking out with wind or tidal changes, instead slowly turning in the bottom to align with the force.
 
What to be aware of:
 
• Bruce and Claw anchors are a type of plough anchor which hold well in most conditions. However, because they do not swivel they can be bulky to stow.
• Claw-type anchors can have difficulty penetrating weedy bottoms and harder mud.
• They offer a fairly low holding power-to-weight ratio and generally have to be over-sized to compete with other anchor types. They do perform relatively well though with shorter anchor ropes and set fairly reliably.
 
Spade Anchors
 
Frenchman Alain Poiraud developed the Spade anchor in the 1990s – a huge leap in performance over existing types. Originally designed to penetrate Mediterranean sea-grass, the Spade anchor has now been proven in tests around the world.
The Spade was the first anchor to successfully make use of a concave fluke, which provides the greatest efficiency – as opposed to the convex shape of Plough or flat Fluke types.
 
• The Spade anchor’s unique triangular ballast chamber is designed to ensure that the anchor lands at the optimum angle for penetration every time.
• As well as tipping the anchor to the optimum angle, the ballast chamber is designed to position 50% of the anchor’s weight directly over the penetrating tip, maximising its ability to dig in. 
• The Spade anchor actually begins to dig in as soon as it lands on the seabed, in exactly the same way as your foot starts to bury if you stand in a sand pool for a few minutes.
• Having the right angle and weight distribution allows the Spade to penetrate thick weed and kelp, where other anchors would simply slide over the top and gather the weed.
• Once it has dug in, the Spade presents its full surface area towards the direction of load – the larger the surface area, the greater the holding power.
• Any load sufficient enough to move the anchor will cause it to bury further.
• Whereas a traditional convex anchor blade can pull out with any sudden wind or tidal shifts, the Spade anchor’s concave blade will remain buried. 
• A concave blade acts almost like a parachute under the seabed and continues to remain buried and offer maximum resistance even when the load is so great that it begins to move.
• If you choose the aluminium Spade anchor, it will be lighter than its steel equivalents but have the same holding power. However, aluminium models are more expensive.
Spade Anchor models range from the smaller model 40 then 60, 80, 100, 140 and 200. The models are available in galvanized steel, aluminium and stainless versions. The model numbers are based on the surface area of the anchor.
 
Grapnel Anchors
 
A traditional design, the Grapnel has the advantage that no matter how it reaches the bottom, one or more of its flukes will be aimed at the sea bed ready to set.
 
• The design is a non-burying type, with one or more flukes digging in with the remainder above the seabed.
• A grapnel is often quite light, and may have additional uses as a tool to recover gear lost overboard
• Its weight also makes it relatively easy to bring aboard.
• The folded shape is generally compact, and is easy to stow under a seat or in a locker.
What to be aware of:
• In rock it is often possible to set the grapnel quickly by hooking into the structure, but may be more difficult to retrieve without a tripping line.
• Grapnels rarely have enough fluke area to develop a really strong hold in sand, clay, or mud and as such are usually only used for short-term anchoring of vessels such as small sports boats, RIBs, day sailing and angling boats.
• These anchors should always be used with a length of chain to add additional weight and to ensure that the pull of the anchor rope is horizontal along the bottom first before leading up to the boat. This should prevent them breaking out too easily as the boat moves around on the waves
 
BEWARE OF CHEAP ANCHORS!
 
There are numerous anchors imported from India and China that are now being sold in the UK. These ‘budget anchors’ often have very low quality castings and suspect hinge designs.
Unfortunately many are usually nothing more than sub-standard copies of genuine products. With no attention made to the mechanics of how they are supposed to work, they are usually made from extremely weak and low quality materials.
And inferior casting processes used during production often exacerbate the weakness of the materials.
 
If its cheap… it probably means that QUALITY WAS LEFT OUT to make it cheap!
As a anchor chain supplier and trader, Ijin Marine Limited supply Grade 2(U2),Grade 3(U3) anchor chain in China.We have directly delivered stud anchor chain and studless anchor chain in Dalian COSCO Shipyard,Jiangyin Chengxi Shipyard,etc.They are certified by ABS,LR,NK,DNV,CCS,and so on.Besides anchor chain, Ijin is also able to trade chafe chain, buoy chain,offshore chain used for oil rigging,etc.Ijin can supply and trade accessories such as kenter shackle,joining shackle,anchor swivel shackle,end shackle,swivel,triangle plate,etc.In China, Ijin help supply directly anchor chain on board in anchorage,shipyard,dockyard,port.In other more than 80 countries,Ijin trades anchor chain and accessories made of steel or stainless steel.So never mind where you will need the chain,Ijin can deliver them as you request.Pls send e-mail to sales@ijinmarine.com for more information.
 

Blog Stats

  • Total posts(135)
  • Total comments(15)

Forgot your password?