Introduction To The Anchor Chain

The anchor chain is a chain connected between the anchor and the hull, which is used to transfer and cushion the external forces on the ship.

A complete anchor chain consists of several sections of anchor chain connected by joint links or shackles, and each section of anchor chain is composed of many chain links.

According to the chain structure, the anchor chain is divided into two types: studless chain and stud chain. At the same time of size and material, the strength of the stud chain is larger than that of the studless chain, the deformation is small, and it is not easy to twist when stacked, so it is widely used on the ocean ship. Studless chains are generally only used for small boats. According to the manufacturing method, the anchor chain is divided into cast steel anchor chain, electric welded anchor chain and forged anchor chain. The carbon steel grades used for the production of stud chains are divided into AM1, AM2 and AM3. AM1 steel is sedated steel, AM2, AM3 grade steel is sedated fine crystal treated steel. For the same ship, if the steel with high strength is selected, the size of the chain link can be appropriately reduced.

Anchor chain link according to its function is divided into common chain link, enlarged chain link, swivel, end shackle, end link, and joint link.

The length of the anchor chain is "shot" as the unit, China stipulates that the standard length of each anchor chain is 27.5m, and the number of links of each anchor chain should be odd.

Chain links are connected by connecting chain links or joint shackles. If a connecting chain link is used to connect each anchor chain, the two ends of the connecting chain link are common chain links. If the connecting shackle is used to connect each section of the anchor chain, both ends of the connecting shackle are connected to the end chain ring (also known as the studless chain ring), increase the chain ring and then connect the ordinary chain ring to ensure the smooth transition of strength.

The stud chain is mainly composed of the stud chain link, and each anchor chain is composed of the anchor end chain shot, the middle chain shot and the end chain shot. A complete anchor chain consists of an ordinary chain link, an enlarged chain link, an end chain link, a connecting chain link or a connecting shackle, a swivel and an end shackle.

The anchor end link is the first link of the anchor chain, which is connected to the anchor. The cross pin of the end shackle and anchor shackle in this chain link shall face towards the anchor, that is, the circular part faces towards the middle chain link. The collar of the swivel should face towards the middle link to reduce friction and sticking. The purpose of the swivel is to prevent excessive twisting of the anchor chain.

The end link is the last link of the anchor chain and is connected to the chain dropper. The ring pin of the swivel shall also face towards the middle chain link. If the middle link is connected with a connecting shackle, the circular part of the connecting shackle should face towards the anchor to avoid jumping, impact and blocking when the anchor is thrown through the sprocket.