ANCHORS, CHAIN CABLE AND ASSOCIATED EQUIPMENTS • INTRODUCTION : An Anchor is a hook, attached to a length of chain called a cable by which a ship can be held temporarily to seabed . In olden days the Anchor was a rock attached to a rope. Then when iron and steel replaced wood in ship construction and sail gave way to steam engines steel Anchors of various designed were made, from which the modern Anchor is derived, and iron and steel cable gradually developed in to 1
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ANCHORS, CHAIN CABLE AND ASSOCIATED EQUIPMENTS
• INTRODUCTION : An Anchor is a hook, attached to a length of chain called a cable by which a ship can be held temporarily to seabed . In olden days the Anchor was a rock attached to a rope. Then when iron and steel replaced wood in ship construction and sail gave way to steam engines steel Anchors of various designed were made, from which the modern Anchor is derived, and iron and steel cable gradually developed in to the very strong modern studded cable used today.
• ANCHORING : A ship can be secured to the seabed by means of her Anchors and cables, either with a single anchor or with two Anchors. The method evolved in doing so is called anchoring and lifting the anchor from seabed is called weighing Anchor. A dragging Anchor can be checked by veering some more cable . If this does not work engine should be started to take the strain off anchor and cable. As a final resort the ship must proceed to sea.
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Anchor Ring
Shank
Fluke
Pea or Bill
Tripping Palm
Crown
Fluke can move 35 degree
PARTS OF AN STOCKLESS ANCHOR
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TYPES OF ANCHORSThe bigger the vessel , the heavier must be her anchor. Anchor also vary in
design and performance as well as in size.. The most common types in use are as follows:-
• ADMIRALTY PATTERN ANCHOR : Sometimes referred to as a ‘fisherman’s’ anchor. It has been in use for many years and have good holding pull 3 to 3 1/2 times its own weight depending upon the nature of sea bottom, but it can not be stowed in house pipe due to its long stock. It is hardly seen on board merchant vessel
• ADMIRLTY STANDARD STOCKLESS ANCHOR : This is by far the most popular anchor in general use today. The stockless anchor great advantage is its close stowing properties and easily housed in to house pipe when not in use. Holding pull varies depending on the nature of the bottom but as a rule of thumb it is considered to be three times of its own weight.
• ADMIRALTY CLASS 14 ANCHOR : It looks same as stockless Anchor and used as bower anchor. This anchor due to its good holding properties has become very popular in the shipping industry. The AC type 14 Anchors developed by UK has more than twice the holding power of a stockless anchor of the same weight.
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• CQR ANCHOR : CQR Anchor is referred as Plough anchor. It is generally used only for small craft because it is difficult to stow in the Hawsepipe. The holding power depend upon the nature of the bottom but still have good holding power to its weight ratio. The ratio between holding pull and anchor weight increases as the size decreases
• DANFORTH ANCHOR : Generally called as stocked close stowing anchor , accepted as small boat anchor . It has a stock passed through the crown of the anchor to prevent the anchor from rolling when its flukes digs into the ground. It can be stowed in to the house pipe same as stockless anchor. The ratio between holding power and anchor weight increases as the size decreases. It fits neatly into the hawsepipe and can be secured as efficiently as stockless anchor.
• Note : The bigger the vessel, the heavier must be her anchor. Anchor weight to its holding power ratio also differ depend upon the design of the anchor.
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TYPES OF ANCHORS
Admiralty Pattern Standard
Stockless
Admiralty Class( AC 14, 17 and 16A)
CQR Danforth
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TYPES OF SHIPS ANCHORS
• BOWER ANCHOR : The ships main anchors are called her bower anchors. They are used for anchoring the ship and are stowed one on each bow.
• SHEET ANCHOR : It is an extra anchor carried for safety sake to back up main anchors in case one is lost.
• STREAM ANCHOR : A anchor Lashed and secured at or near the stern of the vessel . It is mean to be used in narrow channels for preventing the stern of the vessel from swinging. But these days it is hardly carried and used.
CHAIN CABLE
• The long shank of the stockless bower anchor fits inside the house pipe, whereas its arms rest snugly against the ship side. The Anchor shackle on top of the anchor is connected to a long studded chain cable . The chain is made up of lengths of 27.5 meters each, joined together by lugless joining shackle. Each length is called one shackle of chain. A length of chain cable will always contain an odd numbers of links to ensure that the joining shackle will pass around the cable holder in correct plane . Joining shackle being slightly larger than common links should lie vertically round a cable holder and horizontally over the gypsy of windlass. This will ensure they do not jam. There may be 8 or 9 shackles of chain in each bower anchor. The studs make the chain stronger and prevent the chain from kinking.
TYPES OF JOINING SHACKLESThe shackles which join length of cable together may be either
lugless or lugged is called joining shackle. Joining shackles are also used during towing and securing to Buoy evolutions.
LUGLESS JOINING SHACKLE : It is a three part shackle joined together with a pin and pallet ,used to join two shackles of anchor cable.
LUGGED JOINING SHACKLE :It is a straight shackle
made of two parts and joined together with a pin and pallet.
SECURING TO BUOY SHACKLE : It is used to secure a ship to a buoy.
LUGGED ANCHOR SHACKLE : It is used to join outboard end of cable to anchor ring.
JOGGLE SHACKLE : It is long and slightly curved shackle .Used for connecting a wire rope to the cable.
PARTS OF A LUGLESS JOINING SHACKLE AND ITS TOOLS
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WHY AND HOW A CABLE IS MARKED • When anchoring , it is important to know how much cable has run out . The cable is
therefore marked at each joining shackle to assist in its identification.• The shackles and joining shackles of a cable are numbered from its outer to inner
end. The first joining shackle being that which joins first and second shackle together. Every joining shackle is painted white . One link on each side of joining shackle is also painted white and marked with turns of seizing wire around the STUD . These marked links are separated from the joining shackles by a number of unmarked links which serves to indicate the join between two particular shackles; for example ;-
• To indicate 1st joining shackle the first link on both sides of joining shackle is marked with wire turns and painted white.
• To indicate 2nd joining shackle the second link on both sides of joining shackle is marked with wire turns and painted white.
• To indicate 3rd joining shackle the third link on both side of joining shackle is marked with wire turns and painted white. And so on till end.
• Cable marking should be remarked as necessary whenever weighing Anchor.
HOW CABLE IS MARKED
PARTS OF A LUGLESS JOINING SHACKLE AND ITS TOOLS
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ASSOCIATED ANCHOR AND CABLE GEARS
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TERMINOLOGY USED IN ANCHOR WORK
DROPPING ANCHOR OR LETTING GO ANCHOR
WEIGHING ANCHOR ( HEAVING OR PICKING UP ANCHOR)
Method of communication when working cables
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SECURING ANCHOR FOR SEA
As soon as ship leaves port and is clear of narrow waters the anchors are secured for sea, so that with rolling and pitching it may not run out on its own. The following need to be done.1.Heave anchor close in to the house pipe.2. Put on Bow stoppers3. Put on Devil’s Claw4. Hard brake on windlass.5. Seal spurling pipe.