Anchors and Anchoring
The Gallery below shows the anchors, click manual to stop the slideshow and view the anchors individually
Normally used in MFVs, boats and small craft.
It is the most cumbersome to stow.
This is now the standard anchor in most yachts and small craft.
This is the type used on Royalist and is particularly effective for its size and weight.
A ship's largest anchor used for anchoring the ship, and is stowed in a hawse pipe.
A ship cannot anchor where the water is too deep.
It is not only a question of whether the cable is long enough to reach the
bottom.
It is important to remember that the anchor is designed to hook firmly into the sea-bed when the cable is pulling straight along
the ground from the anchor; and to break out of the ground easily when the cable is pulling from above.
Therefore the anchor will hold only so long as part of the cable nearest to it is lying along the bottom, exerting a horizontal pull.
ANCHORING / SECURING TO A BUOY
Anchoring and mooring are related techniques in that they both involve securing the boat to a fixed point surrounded by water. In both cases the way you approach and leave the site will be the same but when mooring the means of securing the boat is provided by the buoy and when anchoring you have to provide it yourself. This involves additional equipment and preparation and more complicated crew routines.
Anchoring is a skill, which is becoming less used as harbours are filled up with moorings, piles and of course, marinas. Nevertheless, there are many times when the ability to anchor correctly can be a great asset, whether for a lunch stop or to ride out a gale.
It is in the latter case that you need to have complete trust in your equipment.
The size of the anchor is critical. A small anchor may well hold in a good holding ground and light winds, but will drag or break loose if the wind increases.
CHOOSING AN ANCHOR AND CABLE
There are several different types of anchor on the market. The type you choose will depend on the seabed in the area that you will be sailing in most often. Recent developments in anchor design include the CQR, Danforth and Bruce anchors. All of these are designed to bury themselves in the seabed and can hold up to 30 times their own weight.
The traditional Fisherman's or Admiralty Pattern anchor will hold up to 10 times it's own weight in a sandy bottom. It will also hold on rocky or weedy ground on which other anchors may not hold. Whichever type you choose, it must be heavy enough to hold your boat in all conditions.
Most boats are supplied with anchors which are the minimum weight needed and, since you should always carry at least two anchors, it is often best to keep the one supplied as the second, or kedge anchor, and invest in a heavier one for the main, or bower anchor.
If you need an anchor that is too heavy for your crew to handle, it may be necessary to fit an anchor winch on the foredeck. You will also need a sturdy bow fitting to take the anchor cable.
The type of cable and its length will greatly affect the holding power of your anchor. Chain is usually recommended because it is resistant to chafe and because it's own weight creates a curve between the anchor and the boat. This helps absorb the shock of the boat jerking (snubbing) on the anchor. It also helps keep the pull on the anchor near horizontal, which provides the best hold. However, the weight of a chain cable can be a disadvantage.
Nylon rope used for the anchor cable solves the problem of weight, but it is subject to chafe and does not assume a natural curve between the boat and the anchor. It's stretch properties do, however, help prevent the anchor from being pulled free.
A compromise is to use chain for the first 4.5m (15ft) from the anchor and nylon rope for the remainder. It helps to reduce snubbing if you lower a weight about half way down the cable. The overall length of the cable is important. You will need to let out, or veer, a minimum of three times the water depth if you are using chain alone, or five times the depth if you are using rope and chain. In rough conditions you may need to veer up to ten times the depth. It is helpful to mark off the length on your anchor cable so that you can see how much has been let out.
The more cable a ship has out the less likely she is to drag. Accordingly the amount of cable used by a ship when anchoring is normally at least four times the depth of water.
Cables vary from chain in the case of ships down to cordage in the case of small boats. Chain cable is normally made of forged steel or wrought iron. In all chain cable except the smallest, the links are studded to prevent kinking.
The size of cable is measured by the diameter of the metal forming a link.
Cable is supplied in lengths of a shackle, which is 27.5 metres long.
In HM Ships, shackles of cable are joined by means of joining shackles.
The anchor is secured to the outboard end of the cable by means of an anchor
shackle.
CHOOSING AN ANCHORAGE
When planning on lying to an anchor, it is important to choose the site with care if you are to have a trouble free stay. There are several considerations to take into account before the anchor can be dropped.
It is important to know what the holding ground is like. Information on the type of seabed can be found from a chart, or once in-situ, by the use of a lead line. If the ground is not suitable for your anchor, you should look for another spot.
The water must be shallow enough for you to be able to lay the correct amount of cable, but you must make sure that it will be deep enough at low tide to keep you afloat. If you anchor at any time other than high tide, you must calculate what the depth will be at high water and allow sufficient cable for that depth.
To ensure that the boat lays as still as possible, try to choose an anchorage sheltered from the wind and out of a strong tidal stream. A spot away from busy traffic will give a more comfortable stay, as the boat will not be rolling around in the wash of passing boats.
If the anchorage is a crowded one, you must ensure that the boat has room to swing a full circle without colliding with other boats or obstructions (see diagram).
Different types of boat react in different ways to the effects of wind and tide. Boats with a lot of wind age and little underwater area will be affected more by wind than current, but deep keel boats with less wind age are likely to swing to the tide.
If the boats are all of similar type, their swinging circles may intersect slightly without danger of collision, so always try to lie near boats similar to your own. Where this is not possible, you must calculate the swinging circles of nearby boats to make sure that yours will not intersect. To do this you will need to find out where their anchors are laid. If there is no one on the boats to ask, you must estimate by looking at the direction and angle to the surface of their anchor cables.
Should you find that you are in danger of fouling another boat, then it is up to you to move.
DROPPING ANCHOR
All the preparations for dropping anchor must be completed before you approach the anchoring spot, so the coxswain must brief the crew well in advance.
You must remove the anchor from its stowage and hang it over the bow fitting with the cable made fast on a cleat or bollard. Pull the amount of cable that is likely to be used from its locker and flake it down carefully on the deck. This ensures that the cable will run out without snagging when you let go. Once you have pulled the right amount out, make the cable fast at this point.
When approaching the anchoring spot, you should do so head into wind or tide whichever is the strongest. The boat should be allowed to come to rest and then the coxswain will give the order to drop anchor. Because it is quite difficult to hear spoken orders along the length of the boat, it is best if a pre-arranged signal is used.
When signaled, uncleat the part of the cable, which is holding the anchor on the bow, and lower the anchor into the water. Allow the cable to run out under control until you feel the anchor hit the seabed. Then veer the remainder of the cable previously flaked out and when it is used up, you will feel the strain on the anchor as it bites into the seabed.
The coxswain must then decide if he wants to let out more cable. Once the correct amount has been veered, make fast the on board end. If for any reason, the anchor does not bite straight away, try letting out more cable. If this doesn't work, you may need to pull it up and move to another spot.
WEIGHING ANCHOR
The ease with which the anchor can be retrieved will depend upon the conditions, the weight of the anchor & cable and the strength of the crew.
The first stage of retrieval is to bring the boat over the anchor. In light winds or in a weak tide this can be done by hauling on the anchor cable, but it is usually best to sail or motor to the right position, as the crew takes in the cable.
As soon as the angle of the cable from the boat to the anchor is vertical, the crew must signal to the coxswain so that he knows that the anchor will soon break out. The crew continues hauling on the cable until they feel the anchor break out of the seabed and they signal to the coxswain. The anchor is then hauled to the surface but care must be taken to prevent it swinging against the hull.
If there is time, the anchor should be cleaned off before bringing it on deck.
Once on board, the anchor and cable should be stowed as soon as possible.
There is always the danger that the anchor may become fouled in the seabed and it may be impossible to free it in the normal way. Motoring around the anchor and pulling from several different directions sometimes helps but it is best to avoid the problem by securing a tripping line to the anchor. The anchor can be released by pulling on the line.
SECURING ALONGSIDE
When berthing alongside a pontoon or quay, or rafting up alongside another boat, you must carefully consider how to attach the warps to keep the boat from moving around and possibly damaging itself and other craft.
Each line to the shore affects the boat in a particular way, so in order to moor alongside safely, you must understand the function of each line.
As most cruising boats spend a good deal of time berthed alongside, it is also important to pay special attention to the equipment used for tying up. While you will always try to avoid stopping in a berth exposed to the full forces of the wind and waves, sometimes you have no choice, and your gear must be reliable under such conditions.
All cleats and fairleads must be securely bolted into the deck and designed to keep wear on warps to a minimum.
The warps themselves must be of good quality rope and you must check them regularly for signs of wear - it is too late to discover that a warp is worn when it gives way in a gale in the middle of the night.
Fenders must be of suitable size and shape for your boat and must be strong enough to withstand chafing against rough walls, sometimes under considerable pressure.
WARPS / HAWSERS
Each warp used for berthing a boat has a different function.
The bow and stern lines position the boat and can be used by he crew when coming alongside, to check the boats speed. They must be strong enough to carry the main load of the boat and long enough to allow for the rise and fall of the tide (unless you are berthed at a floating pontoon). As a general rule, their length should be three times the tidal range. If your bow and stern lines are long enough and are adjusted at half tide, they may not need to be adjusted at high and low water.
Springs prevent the boat from moving backwards and forwards. These need not be as long as your bow and stern lines, one and a half times the tidal range should be sufficient. However, you will need to adjust your springs periodically with the rise and the fall of the tide. If you are going to leave the boat for some time, you must allow sufficient length for the full tidal range. When lying alongside a wall or quay, do not lead springs through or under the rails, but take then through the fairleads and then outside of all rigging.
Fore and aft breast ropes keep the bow and stern close alongside, particularly when loading. They are not essential when bow & stern lines and springs are fitted, but when lying alongside a floating pontoon, they can be used to replace the bow and stern lines.
Slip lines, which are sometimes rigged when leaving an alongside berth, should never be used instead of permanent lines. This can result in your warps becoming worn in the middle rather than at the ends and may waste a whole warp instead of only a short length at the end.
