Anchor chain
An anchor chain is part of a ship's equipment and is used to deploy and retrieve the anchor . Due to its weight, it ensures that the pull on the anchor is as parallel to the ground as possible, thus increasing the anchor's holding force.
A jewelry chain is also known as an anchor chain if its links are made in the shape of a "real" anchor chain.
history
The region of origin of the anchor chain is the Mediterranean . The first chains are documented from the Bronze Age . The first iron chains can be identified from iron finds from Khorsabad (1400 to 800 BC). Historical research has shown that these are ship chains and that the Assyrians were familiar with fire welding iron. Also Caesar (De Montebello gallico, III, 13) and Strabo (Geographica, IV, 4) report anchor chains.
One of the first anchor chains in Northern Europe was found on the Ladby ship unearthed in Denmark . It was attached to an iron anchor and shows that the Vikings knew and used iron anchors and chains.
Anchor chain and anchor rope
Anchor chains and anchor ropes were used in parallel for a long time. It is believed that the anchor chain has since been forgotten and only caught on again in the first third of the 19th century. One reason for using hemp ropes could be that the chain required a payload, which was preferred for transport goods. In addition, the link structure of the chain made it difficult to hoist the anchor and required a special anchor winch .
For large ships, the anchor chain has an important advantage over a rope because its weight increases the effectiveness of an anchor. With today's ship sizes, an anchor without the weight of the chain could only hold a ship in one position in calm seas and moderate winds and would not be able to do so in heavy seas.
Dimensioning
In shipping today, anchor chains are designed according to the regulations of classification societies, such as Germanischer Lloyd . The type (normal chain or bridge chain), strength, length, etc. are specified here using tables. The size, weight and number of anchors can also be found in these tables. The equipment code is decisive for the design of the chain and anchor. In anchor chains for larger ships, each chain link (shake) is usually reinforced by a web (cross support).
In inland shipping , the anchor chains and anchor are designed so that they can hold the ship against the current when anchoring.
Anchoring in the stream
When anchoring in the stream, two anchors are deployed in a V shape. After the first anchor has been set, a lot of chain is left out so that the ship can "sag", then the machine moves to the same position laterally offset by about 30 meters and the second anchor is set. Then you let the ship sink again and run 60 to 70 meters of chain. Then the ship is slowly "braked" with the help of the machine.
literature
- Carl Meyer: Anchor Chains - Since When? In: Schiff und Zeit 3. Koehlers Verlagsgesellschaft, Herford, 1976, p. 48.
Web links
- More about the equipment code (here: seagoing ships) at Germanischer Lloyd ( Memento from September 28, 2007 in the Internet Archive ) (PDF; 148 kB)