Skip to main content

Ship Anchor

An anchor is used by a ship to make itself fast to the sea-bed so that it will stay in one place and will not drift due to wind and current. A shop normally carries three anchors, two working anchors, one on each bow, attached to cables and stowed up the hawse pipes. These are called Bower Anchors. One Spare Bower anchor lashed and well secured in the vicinity of the forecastle deck. If one of the working bower anchors is lost, this spare anchor is shackled on to the anchor cable and used.
A fourth anchor may also be carried on small vessels known as Stream anchor, lashed and secured at or near the stern of the vessel. It is meant to be used in narrow channels for preventing the stern of the vessel from swinging. But these days it is hardly ever used for this purpose.

Earlier all anchors had a stock, which was just before anchoring, fixed in position at right angles to the arms. The stock helped the anchors to turn itself so that the arms became vertical and one of the flukes dug itself into the seabed. But this type of anchor was difficult to stow, as it could not heave up the hawse pipe, unlike the stockless anchors.

Nowadays a stock anchor is used on ships only for a stream anchor. Small boat anchors are also stock anchors. Both the Bower and the Spare Bower are stockless anchors. A stock anchor holds better but a stockless anchor is easier to stow as it can be hove up the hawse pipe.

Anchor Parts:


Ring (Shackle): The device used to shackle the anchor chain to the shank of the anchor. The ring is secured to the top of the shank with a riveted pin.

Shank: The long center part of the anchor running between the ring and the crown.

Crown: The rounded lower section of the anchor to which the shank is secured. The shank is fitted to the crown with a pivot or ball-and-socket joint that allows a movement from 30 to 45 degrees either way.

Arms: The parts that extend from each side of the crown.

Throat: The inner curved part of an arm where it joins the shank.

Fluke or palm: The broad shield part of the anchor that extends upward from the arms.

Blade: That part of the arm extending outward below the fluke.

Bill or pea: Tip of the palm or fluke.


Labels:

Comments

Post a Comment

Popular posts from this blog

Difference Between A, B & C-Class Divisions?

IMO Symbol A Class Division  IMO Symbol B Class Division  SOLAS has tables for structural fire protection requirement of bulkheads and decks. The requirements depend on the spaces in question and are different for passenger ships and cargo ships. The Administration has required a test of a prototype bulkhead or deck in accordance with the Fire Test Procedures Code to ensure that it meets the above requirements for integrity and temperature rise. Types of Divisions: "A" Class "B" Class "C" Class "A" Class: "A" class divisions are those divisions formed by bulkheads and decks which comply with the following criteria: They are constructed of steel or equivalent material They are suitably stiffened They are constructed as to be capable of preventing the passage of smoke and flame to the end of the one-hour standard fire test. they are insulated with approved non-combustible materials such that the average tempera
14 comments
Read more

Load Line & Why it is Important

Merchant ships have a marking on their hull know as the Plimsoll line or the Plimsoll mark, which indicates the limit until which ships can be loaded with enough cargo, internationally, the Plimsoll line on a ship is officially referred to as the international load line. Every type of ship has a different level of floating and the Plimsoll line on a ship generally varies from one vessel to another.  All vessels of 24 meters and more are required to have this Load line marking at the centre position of the length of summer load water line. There are two types of Load line markings:- Standard Load Line marking – This is applicable to all types of vessels. Timber Load Line Markings – This is applicable to vessels carrying timber cargo. These marks shall be punched on the surface of the hull making it visible even if the ship side paint fades out. The marks shall again be painted with white or yellow colour on a dark background/black on a light background.  The comp
9 comments
Read more

Pump Shaft Alignment Procedure

Types of shaft alignment methods: Visual Line-Up Straightedge/Feeler Gauge Rim and Face Cross Dial Reverse Dial Laser Visual Line-Up The visual line-up method is the most common method of alignment. Used in initial installations, visual line-up allows technicians to analyze the working conditions and feasibility of installation. Straightedge/Feeler Gauge Straightedges are used to determine the offset between coupling halves. Corrections are made under all four of the machines feet. Feeler gauges or taper gauges measure the gap between coupling halves at the bottom and top of the coupling. Rim and Face This method is similar in principle to using a straightedge and feeler gauge, but more accurate since dial indicators are used. The rim reading measures the offset between the coupling halves. The face reading measures the angular difference between the faces of the coupling. Changes are calculated with the same formula as the straightedge/feeler gauge met
2 comments
Read more