Definition of Anchor
An anchor is a heavy
object, often made out of metal, that is used to attach ships to the bottom
at a specific point. There are two primary classes of anchors—temporary and permanent. A
permanent anchor is often called a mooring,
and is rarely moved; it is quite possible the vessel cannot hoist it aboard
but must hire a service to move or maintain it. An alternative to using an
anchor under these circumstances may be to use a pile driven into the
seabed. A temporary anchor is usually carried by the vessel, and hoisted
aboard whenever the vessel is under way.
Mooring System
The
most common mooring line configuration in water depths of up to 1000 m is
the catenary mooring line
consisting of chain and wire rope.
For exploration and production in water depths beyond 1000m, the
weight of the mooring line starts to become a limiting factor in the design
of the floater,then the use of synthetic ropes in the mooring line
(lessweight) and/or a taut leg
mooring system.