Damping

Zone of shelter for a ship

a damping is a sheltered place of the wind and waves along the coast in which a boat can stop in safety while mooring on its anchors . Ideal damping can be characterized in the following way:

Estuary, bay, handle or roads closed on more than 180 degrees, cutting the swell and the sea and located under the wind prevailing (of western sector in Handle and the Atlantic, therefore an open bay towards the east),
Height of sufficiently important water with low tide taking into account the Draft of the boat,
Presence heights over the coast allowing to reduce the force of the wind (a few meters are enough),
general Profil of the coast deadening the swell (low coast in seaside rather than cliff),
Dimension allowing a sufficiently important swing taking into account characteristics of the boat (size…),
Nature of the funds facilitating the fixing and the behavior of the anchors (muddy or sandy bottom rather than rock),
Of the remarkable land-marks, even an alignment of presentation, allowing an easy approach, avoiding the possible dangers and facilitating a precise localization of the place of damping,
Côte not very far away from the place of damping providing an easy access inside the grounds if the crew wishes to unload.

The sea charts and them guides of navigation indicate best dampings. However, the quality of a damping also depends on the direction of the wind and the swell. A damping which constitutes a good shelter under weather conditions given can be transformed into trap in the event of rotation of the winds or the swell. On the other hand, by very good weather and in the absence of swell, the possible places of damping multiply. The examination of a Sea chart detailed makes it possible to identify favourable dampings under conditions of sea and wind given. However certain characteristics of a damping can be known only by the use: existence of corridors of wind, forces thermal breezes and undertow, swells " contournant" the sheltered zone, etc

Material

Damping or line of damping is also the together material making it possible to wet : anchors S, chain, bump S and possibly textile cablet prolonging the chain. The chain of the lines of damping of large ships consists of elements called meshs , the reference length used is the Maillon . Contrary to its definition with ground, the link is not an element of chain but a length which is worth 15 brews S, the pitch-stirrer being worth 6 feet is 1,80 m roughly. The chain link thus measures about 27,50 Mr. a large ship is generally gréé of two lines of damping including/understanding each of 8 to 14 links, the links are connected between them by dismountable meshs, the lines of damping being stored on board in a compartment called Puits with the chains.

Operate

damping is also the operation consisting in wetting i.e. to pose the anchors in a damping. One can wet with wanders ahead or behind.

One of the possible operations:

to come to the place chosen according to the swing awaited and of the place available,
to release the anchor with a length of chain in connection with the depth,
to spread out the chain by making Culer (to go behind, to move back) the ship to make crocher the anchor (one says “to make head”, because as soon as the anchor has eighth note, the ship which had started to derive will be recalled by the tension of the chain),
to spin an additional length of chain (or possibly of cablet), sufficient to avoid the foreseeable weather conditions.

There exist particular techniques of damping to answer conditions of time or provisions of specific places:

the empennelage : damping is lengthened with the second line of damping allowing best held by strong winds.
the affourchage which consists in wetting two anchors in “V” on before with an angle ranging between 60 and 120 degrees. This technique guarantees the best held of damping and makes it possible to decrease the sector of swing of the ship

damping head and bottom requires the installation two lines of damping: one in front of the ship and the other with the back. This technique is used in dampings encumbered to remove the swing

Mediterranean damping

It is a question of putting the ship the bottom at quay, and of maintaining it in balance with the two anchors and the Aussière S backs. Advantages: the risks of the weather do not affect the position.

If it is not necessary to have very precise angles, nor a perfect symmetry, this operation is nevertheless not very easy to carry out.

Damping on buoy or trunk

One calls also damping, point of anchoring permanent constituted of Dead-man (concrete block posed on the bottom) connected by chain to buoy (called trunk when damping is intended for ships), in a sheltered place. Damping can be held with the ships visitors (in the ports) or be the property of a private individual, or a company of navigation. The operation of damping is called then a catch of trunk and consists in mooring the chain of the line of damping (after having désaisiné the anchor) on the trunk. The operation requires the setting with the water of a boat.

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