Anchor Gaming Business Information, Profile, and History

Related information about Anchor

A device which prevents a vessel from drifting. The flukes or arms of an anchor dig into the seabed, thus resisting a horizontal pull; it is made fast to the ship by a heavy cable, usually of studded chain. There are two basic types: the old-fashioned anchor with a stock, usually depicted on badges and flags; and the modern, more common, stockless anchor. The stockless anchor consists of a shank and a crown, which are free to move in relation to each other, so that when in use the flukes will adopt an angle of about 45属 to the shank. When stowed, the flukes are parallel to the shank.

otheruses

An anchor is a heavy object, often made out of metal, that is used to attach a ship to the bottom of a body of water at a specific point. A temporary anchor is usually carried by the vessel, and hoisted aboard whenever the vessel is under way; A sea anchor(q.v.) is a related device used when the water depth makes using a mooring or temporary anchor impractical.

An anchor works by resisting the movement force of the vessel which is attached to it. It may seem logical to think wind and currents are the largest forces an anchor must overcome, but actually the vertical movement of waves develop the largest loads, and modern anchors are designed to use a combination of technique and shape to resist all these forces.

An interesting element of anchor jargon is the term aweigh, which describes the anchor when it is hanging on the rope, not on the bottom; An anchor is described as aweigh when it has been broken out of the bottom and is being hauled up to be stowed.

Development

The earliest anchors were probably rocks and many rock anchors have been found dating from at least the Bronze Age. trying to move a large enough rock to another bay is nearly impossible.

A simple anchor using a pair of wood arms under a rock mass is a primitive anchor which is still in use today. Almost all future anchor developments combine these two elements?a penetrating point and a reasonable mass.

In the western world the vast majority of anchors worked on the concept of the grappling hook?multiple points on arms such that at least one will be aimed toward the bottom. Suddenly the concept of the stock, a bar placed perpendicular to the hooking arm at the other end of the shank which would roll the anchor over so the point would penetrate the bottom, was developed and within a single century became the standard anchor type.

In the East, however, another model of anchor had been known for some time which also used a stock, but with the stock located at the crown along with the arm.

Designs of temporary anchors

A modern temporary anchor usually consists of a central bar called the shank, and an armature with some form of flat surface (fluke or palm) to grip the bottom and a point to assist penetration of the bottom; There are many variations and additions to these basic elements?for example, the whole class of anchors which include a stock such as the fisherman and fluke anchors.

The range of designs is wide, but there are actually trends in designs for modern anchors which allow them to be classed as hook, plow, and fluke types, depending on the method by which they set.

• Hook designs use a relatively small fluke surface on a heavy, narrow arm to penetrate deeply into problematic bottoms such as rocky, heavy kelp or eel grass, coral, or hard sand. Two of the more common versions of this design are the fisherman and the grapnel.
  

• Plow designs are reminiscent of the antique farm plow, and are designed to bury themselves in the bottom as force is applied to them, and are considered good in most bottom conditions from soft mud to rock. Although they have less ability to penetrate and are designed to reset rather than turn, their light weight makes them very popular.
  

In the past 20 years or so, many new anchor designs have appeared. Driven by the popularity of private pleasure boats, these anchors are usually designed for small to medium sized vessels, and are usually not appropriate for large ships. The anchor is popular as the ultimate storm anchor, and has a good reputation for use in rock, hard bottoms, and kelp or eel grass covered bottoms. The three piece versions can be stowed quite compactly, and most versions include a folding stock so the anchor may be stowed flat on deck.
The primary weakness of the design is its ability to foul the cable over changing tides. In comparison tests the fisherman design developed much less resistance than other anchors of similar weight. It is difficult to bring aboard without scarring the topsides, and does not stow in a hawse pipe or over an anchor roller.
A fouled kedge or killick features on the badges of RN non-commissioned officers.

Fluke

The most common commercial brand is the Danforth, which is sometimes used as a generic name for the class. some anchor rollers and hawse pipes can accommodate a fluke-style anchor. A few high-performance designs are available, such as the Fortress, which are lighter in weight for a given area and in tests have shown better than average results.

The fluke anchor has difficulty penetrating kelp and weed-covered bottoms, as well as rocky and particularly hard sand or clay bottoms. If there is much current or the vessel is moving while dropping the anchor it may "kite" or "skate" over the bottom due to the large fluke area acting as a sail or wing. Once set, the anchor tends to break out and reset when the direction of force changes dramatically, such as with the changing tide, and on some occasions it might not reset but instead drag. It is not unknown for the anchor to foul on its own rode, or to foul the tines with refuse from the bottom, preventing it from digging in. The CQR design has a hinged shank, allowing the anchor to turn with direction changes rather than breaking out, and also arranged to force the point of the plow into the bottom if the anchor lands on its side. Both can be stored in most regular anchor roller systems.

Owing to the use of lead or other dedicated tip-weight, the plow is heavier than average for the amount of resistance developed, and may take a slightly longer pull to set thoroughly. It cannot be stored in a hawse pipe.

The genuine CQR and Delta brands are now owned by Lewmar, although they have both been on-sold several times during their lifetimes.

Bruce / Claw

Claimed by the inventor to be based on a design used for anchoring floating oil derricks in the North Sea, the Bruce and its copies, known generically as "claws", have become a popular option for smaller boaters. They cannot be used with hawse pipes.

Bruce Anchor Group no longer produce the genuine anchor and the only options are knock-offs, mostly inferior in build quality.

Modern designs

In recent years there has been something of a spurt in anchor design. Primarily designed to set very quickly, then generate superior holding power, these anchors (mostly proprietary inventions still under patent) are finding homes with users of small to medium sized vessels.

• The German designed B端gel, first built by steel producer WASI, has a sharp tip for penetrating weed, and features a roll-bar which orients the anchor to the correct attitude on the seabed
  
• The Bulwagga is a unique design featuring three flukes instead of the regular two. Manufacturer's website
  
• The New Zealand designed Rocna is a new anchor gaining popularity amongst cruisers. Its roll-bar is similar to that of the B端gel, and means the correct setting attitude is achieved without the need for extra weight to be inserted into the tip (an inefficiency common in other anchor types). The anchor needs to hold the vessel in all weathers, including the most severe storm, but only occasionally, or never, needs to be lifted, only for example if the vessel is to be towed into port for maintenance. An alternative to using an anchor under these circumstances may be to use a pile driven into the seabed.
  
  Permanent anchors come in a wide range of types and have no standard form. Modern moorings may be anchored by sand screws which look and act very much like over-sized screws drilled into the seabed, or by barbed metal beams pounded in (or even driven in with explosives) like pilings, or a variety of other non-mass means of getting a grip on the bottom. One method of building a mooring is to use three or more temporary anchors laid out with short lengths of chain attached to a swivel, so no matter which direction the vessel moves one or more anchors will be aligned to resist the force.
  
  A mushroom anchor will normally sink in the silt to the point where it has displaced its own weight in bottom material. These anchors are only suitable for a silt or mud bottom, since they rely upon suction and cohesion of the bottom material, which rocky or coarse sand bottoms lack. The holding power of this anchor is at best about twice its weight unless it becomes buried, when it can be as much as ten times its weightwww.inamarmarine.com/pdf/Moorings.pdf. Consequently deadweight anchors are used where mushroom anchors are unsuitable, for example in rock, gravel or coarse sand. An advantage of a deadweight anchor over a mushroom is that if it does become dragged, then it continues to provide its original holding force. The disadvantage of using deadweight anchors in conditions where a mushroom anchor could be used is that it needs to be around ten times the weight of the equivalent mushroom anchor..

  Screw

  Screw anchors can be used to anchor permanent moorings, floating docks, fish farms, etc.
  
  These anchors must be screwed into the seabed with the use of a tool, so require access to the bottom, either at low tide or by use of a diver.
  
  Weight for weight, screw anchors have a higher holding than other permanent designs, and so can be cheap and relatively easily installed, although may not be ideal in extremely soft mud.

  Anchoring gear

  The elements of anchoring gear include the anchor, the cable (also called a rode), the method of attaching the two together, the method of attaching the cable to the ship, charts, and a method of learning the depth of the water.
  
  Charts are vital to good anchoring. One can get by without referring to charts, but they are an important tool and a part of good anchoring gear, and a skilled mariner would not choose to anchor without them.
  
  The depth of water is necessary for determining scope, which is the ratio of length of cable to the depth measured from the highest point (usually the anchor roller or bow chock) to the seabed. For example, if the water is 25ft (8m) deep, and the anchor roller is 3ft (1m) above the water, the scope is the ratio between the amount of cable let out and 28ft (9m).
  
  A cable or rode is the rope, chain, or combination thereof used to connect the anchor to the vessel. Generally speaking, most anchors will hold well in sandy mud, mud and clay, or firm sand. Rock, coral, and shale prevent anchors from digging in, although some anchors are designed to hook into such a bottom. Grassy bottoms may be good holding, but only if the anchor can penetrate the bottom. You need enough depth for your vessel throughout the range it might swing, at low tide, not just where you drop the anchor. However, no matter where you anchor you need to consider what the largest possible swing range will be, and what obstacles and hazards might be within that range. Boats on permanent moorings, or shorter scope, may not swing as far as you expect them to, or may swing either more rapidly or more slowly than your vessel (all-chain cables tend to swing more slowly than all-rope or chain-and-rope cables.)
  
  There are techniques of anchoring to limit the swing of a vessel if the anchorage has limited room.

  Methods

  The basic anchoring consists of determining the location, dropping the anchor, laying out the scope, setting the hook, and assessing where the vessel ends up. there may be other boats whose crew thought that would be a good spot, or weather conditions may be different from those expected, or even additional hazards not noted on the chart may make a planned location undesirable.
  
  If the location is good, the location to drop the anchor should be approached from down wind or down current, whichever is stronger. The anchor should be lowered quickly but under control until it is on the bottom. The vessel should continue to drift back, and the cable should be veered out under control so it will be relatively straight.
  
  Once the desired scope is laid out (a minimum of 8:1 for setting the anchor, and 5:1 for holding, though the preferred ratio is 10:1 for both setting, and holding power), the vessel should be gently forced astern, usually using the auxiliary motor but possibly by backing a sail. A hand on the anchor line may telegraph a series of jerks and jolts, indicating the anchor is dragging, or a smooth tension indicative of digging in. If the anchor continues to drag, or sets after having dragged to far, it should be retrieved and moved back to the desired position (or another location chosen.)
  
  With the anchor set in the correct location, everything should be reconsidered. Is the bottom a suitable holding ground, and is the anchor the right one for this type of bottom? Will another vessel swing into us, or will we swing into another vessel, when the tide or wind changes?
  
  Some other techniques have been developed to reduce swing, or to deal with heavy weather.
  

  • Forked moor
    
  • Bow and Stern
    
  • Bahamian moor
    
  • Backing an anchor
    

  Forked moor

  Using two anchors set approximately 45属 apart, or wider angles up to 90属, from the bow is a strong mooring for facing into strong winds. To set anchors in this way, first one anchor is set in the normal fashion. Then, taking in on the first cable as the boat is motored into the wind and letting slack while drifting back, a second anchor is set approximately a half-scope away from the first on a line perpendicular to the wind. After this second anchor is set, the scope on the first is taken up until the vessel is lying between the two anchors and the load is taken equally on each cable.
  
  This moor also to some degree limits the range of a vessel's swing to a narrower oval.

  Bow and stern

  Not to be mistaken with the Bahamian moor, below.
  
  In the Bow and Stern technique, an anchor is set off each the bow and the stern, which can severely limit a vessel's swing range and also align it to steady wind, current or wave conditions. One method of accomplishing this moor is to set a bow anchor normally, then drop back to the limit of the bow cable (or to double the desired scope, e.g. By taking up on the bow cable the stern anchor can be set. After both anchors are set, tension is taken up on both cables to limit the swing or to align the vessel. One of the primary characteristics of this technique is the use of a swivel as follows: the first anchor is set normally, and the vessel drops back to the limit of anchor cable. A second anchor is attached to the end of the anchor cable, and is dropped and set. A swivel is attached to the middle of the anchor cable, and the vessel connected to that.
  
  The vessel will now swing in the middle of two anchors, which is acceptable in strong reversing currents but a wind perpendicular to the current may break out the anchors as they are not aligned for this load. With the leading anchor holding the cable down and the tension between the anchors taking load off, this technique can develop great holding power and has been used in "ultimate storm" circumstances.

  Kedging

  Kedging is a technique for moving or turning a ship by using a relatively light anchor known as a kedge.
  
  In yachts, a kedge anchor is one or more anchors carried in addition to the main, or bower anchors, and usually stowed aft. Every yacht should carry at least two anchors - the main or bower anchor and a second lighter kedge anchor. It is used occasionally when it is necessary to limit the turning circle as the yacht swings when it is anchored, such as in a very narrow river or a deep pool in an otherwise shallow area.
  
  For ships, a kedge may be dropped while a ship is underway, or carried out in a suitable direction by a tender or ship's boat to enable the ship to be winched off if aground or swung into a particular heading, or even to be held steady against a tidal or other stream.