Principles, functions, types and daily inspection of boat anchors

Principle of Anchor

From top to bottom the structure is the anchor release buckle, bolt, anchor rod, anchor shank, anchor wrist, and the symmetrical part on both sides is called the anchor claw. The claw is the most important part of the anchor that grips into the mud. When the ship anchors, the anchor sinks to the bottom of the water under the pull of the anchor chain. At the bottom of the water, due to the action of the anchor rods, the plane of the anchor wrist will be perpendicular to the bottom of the water, and then the anchor claw will be in contact with the bottom of the water.

 

Ship's anchor chain length is often greater than the depth of water, so the anchor chain in the underwater part of the anchor chain is in a flat state, when the ship receives disturbances, such as the top of the wave, the anchor chain will be pulled, the anchor in the water at the anchor chain connection will be subjected to a horizontal force, and at the same time the anchor of the ship's own gravity on the claw and the bottom of the anchor contact, the synthesis of the two forces make the anchor to the diagonal downward movement, which is the process of the anchor in the ground. After the anchor is pulled into the water, it can provide the ship with the ability to moor. It should be noted that this ability is not only accomplished by an anchor, but also by a long anchor chain that also plays an important role.

 

Role of Anchors

The role of the anchor is mainly to fix and stabilise the ship, which can be said from the following aspects:

1, the most basic condition for an anchor to work is to hook something at the bottom of the sea and so on.

If the anchor chain is not long enough, the anchor will not work. If the seabed is flat, or the anchor hooked things are not fixed, or hooked not too firmly, if the wind and waves are calm, but the waves are too large, resulting in the anchor can not hook things, will make the anchor lose its role, which is called "go anchor", the ship at anchor during the anchor, appear to go anchor, is very dangerous.

2、The weight of the anchor chain is negligible for the boat, it will not play a big role.

Generally speaking, when the boat at anchor, the anchor chain is straight, do you think there will be any friction on the anchor chain at this time? If you are on the beach, you will find a lot of small fishing boats with anchor chains that are thick ropes.

3, in the boat above, the anchor chain is straight, but underwater there is a section of the seabed and the seabed is close to parallel, in fact, the anchor is attached to the seabed to provide grip, and then through the anchor chain to the ship, thereby resisting the currents, wind and waves of the external load on the positioning of the impact. The reason why there is a section against the seabed is to take into account the effect of forces, and having a section against the seabed can provide a margin, within a certain range is possible.

The weight of the anchor is not great, but there are rules about how big an anchor should be for how big a boat, and this is due to the fact that the anchor can generate a grip as well as its own inertia, and the anchor chain friction also plays a role.

 

Types of Anchors

There are many kinds of anchors, according to the structure and use of different, can be divided into rod anchor, rodless anchor, big grip anchor and special anchor; commercial ships mainly use the first anchor rodless anchor, the tail anchor sometimes use rod anchor and dovetail anchor.

1、Rod Anchor

Also known as naval anchor, this kind of anchor is the early anchor, also known as naval anchor, this kind of anchor structure is simple, the grip weight ratio is big, the stability of the grip bottom is better, but the anchor operation and collection is not very convenient, the upturned anchor grip is easy to entangle the anchor chain as well as scrape the bottom of the ship, this kind of anchor is not easy to be used as the first anchor of the merchant ship, generally used for small boats or sailing ships.

2、No Pole Anchor

Also known as mountain anchor, common for Hall anchor and Speck anchor, belong to the activities of the anchor claw (along the anchor stem before and after about 45 °) of the rodless anchor, rodless anchor anchor rods and anchor arms are cast separately. The anchor claw, anchor crown and anchor arm are cast as one piece. The anchor stem is inserted into the rectangular hole of the anchor crown, and fixed in the two semi-circular grooves in the lower part of the anchor crown with a pin and a cross pin to achieve the purpose that the anchor stem can be rotated.

3、Large Grip Anchor

Large grip anchor combines the advantages of rod anchor and rodless anchor, generally are rod turn claw anchor. Commonly used anchor, Danfusi, which is characterised by the wrong claw wide and long, engaging the soil depth, good stability, so as to obtain a larger grip, the grip ratio of up to 11 ~ 17 times. But the anchor claw strength is weak, easy to deform. And because of the greater resistance to the earth, generally only applicable to engineering vessels, but also some do spare anchor or tail anchor.

4、Special Anchor

Special purpose anchor, commonly used in floats, buoys, lightships, floating docks and floating docks and other permanent mooring. There are single claw anchor, screw anchor and fungus-shaped anchor.

Daily inspection of anchor

1、Anchor inspection

1）Check the wear and deformation of anchor unloading buckle, and pay attention to whether the cross pin is loose for inspection and maintenance.

(2) Pay attention to whether the anchor claw is bent, whether the rotation is flexible and whether the angle is normal, carry out inspection and maintenance.

2、Anchor chain inspection

(1) Usually use the left and right anchors in turn.

(2) Pay attention to whether the anchor chain mark is clear, if it falls off, it should be made up in time.

3）Check whether the rotating ring is flexible and add oil for lubrication at the right time.

3、Anchor inspection

1）Check whether the brake is good frequently.

2) Refuel and test drive before each use. Steam anchor should be discharged from the cylinder before use, until the water discharge hole spews out steam and then test drive.

(3) Often refuelling the clutch to ensure that the operation is light and flexible.

(4) Pay attention to the wear and tear of the sprocket teeth and worm threads.

4、Chain maker

The friction surface of the chain maker should be oiled frequently, and the rest of the parts should be painted with antirust paint. Frequently check the tightness of the base and deck connection. Abandon the chain maker to check the intactness of the handwheel protection cover, and the rotating parts are often refuelled.

 

The above content is the principle, role, types and daily inspection of boat anchor popularised by xianjie net editor for everyone. Anchor is more than essential equipment in ship operation, ordinary ship is generally port and starboard each with an anchor, plus a spare anchor to prevent the loss of port or starboard anchor after an emergency backup. Special purpose ships may be equipped with more than 5 anchors, e.g., engineering ships, salvage ships, etc.