Anchor chain supplier introduces the types and functions of anchor chains

Anchor chain consists of a number of chain links, the size of which is expressed by the diameter of the chain in millimeters. According to the chain ring in the middle of the gear or not, divided into Stud auchor chain and Studless Link Chain. anchor chain can be forged, casting and welding and other legal system into a marine anchor chain by a number of “sections”, each section is 25 ~ 27 meters long, section to section with a chain ring or unloading buckle connected. After winching the anchor, the anchor chain is stored in the anchor chain compartment in the bow of the ship. The specification of the anchor chain is calculated according to the ship construction standard.

Types of Anchor Chain

Anchor chain is a chain that connects the anchor to the hull of the ship, and is used to transmit and cushion the external forces on the ship. It can also generate part of the friction force.

1. According to chain ring structure: anchor chain with gear and anchor chain without gear.

2. According to the manufacturing method: cast steel anchor chain, flash welded anchor chain, forged anchor chain. 

3. According to the use: marine anchor chain and marine mooring chain. 

4. According to steel grade: marine chain is divided into AM1, AM2, AM3, and mooring chain is divided into R3, R3S, R4, R4S, R5.

Description of Grade Types

1. Classification according to material and strength grade

AM2 grade: Yield strength 400 MPa, breaking strength 600 MPa, suitable for medium-sized merchant ships and coastal operations.

AM3 grade: Yield strength 490 MPa, breaking strength 710 MPa, designed for large container ships, tankers and severe sea conditions.

Special grade (e.g. R4/R5): breaking strength of 800 MPa or more, used for deep-sea oil platforms and single-point mooring systems.

2. Classification according to chain diameter specifications

Standard mooring chain: chain diameter ranges from 12.5-81 mm, covering the needs of small yachts to super-large cargo ships.

Heavy duty offshore chain: chain diameter up to 162 mm, breaking load over 5,000 kN, suitable for offshore wind power installation vessels and other special operations.

Role of Anchor 

For an anchor chain to work, the most basic condition is to hook something on the seabed and so on. If the anchor chain is not long enough, the anchor will not work. If the bottom of the sea is flat, or the anchor hooked things are not fixed, or hooked not too firmly, if the wind and waves are calm can be, but the waves are too big, resulting in the anchor can not hook things, will make the anchor lose its role, which is called “go anchor”, the ship is at anchor during the time of anchor, appear to go anchor, it is very dangerous, because the ship is at anchor when the general The main engine is stopped when the ship is anchored, if the ship is started immediately, it takes time, and it is very dangerous for the ship to drift around without power. That's why the concept of anchorage came about. Anchorage, by implication, is rougher under the sea, and in addition, it should be sheltered from the wind.

The weight of the anchor chain is negligible for the boat, and that little bit of friction, won't play much of a role. Generally, when anchoring a boat, the anchor chain is straight, which is basically negligible friction. If you're on the beach, you'll find a lot of small fishing boats that have thick rope anchor chains. 

When viewed from above the boat, the anchor chain is straight, but underwater there is a section that is close to parallel to the seabed (actually, it's against the bottom). For example, the Spek anchor provides the gripping force that is transmitted to the ship through the anchor chain to resist the effects of external loads from currents, wind and waves on positioning, and the reason for the section against the seabed is to take into account the effects of forces. Think about it, an anchor, the anchor chain is easy to go out of the anchor when pulling straight. And there is a section against the seabed, can provide a margin within a certain range is possible.