|Late afternoon in Isla Testigo Pequeño
(Los Testigos, Venezuela)
As most pieces of gear on a boat, each anchoring element has one or more function(s),
and must meet several requirements. Let's list them as references for the following
- Function: The anchoring tackle is intended to temporarily "tie"
the boat to the seabed.
- Req. 1: A perfect anchoring tackle should hold the
boat whatever the predictable local wind and sea state. It should withstand
the corresponding efforts without damage (working load limit).
- Req. 2: Setting as well as weighing the anchor should
As far as anchoring safety is concerned, the anchor and
rode are the weakest elements. Moreover, they
are difficult to select and size according to the surrounding conditions;
the rode length that needs to be adjusted "in the field" and "in
Other components, either essential (anchor rollers, shackles,
bollards, etc.) or optional (windlass, swivels, etc.) can be chosen once for
all (see the Accessories chapter).
- Function: The anchor is the "fixed point" of the anchoring.
- Req. 3: An ideal anchor should "hold" (=
remain in the same place) whatever the direction and magnitude of the forces
that act on the boat.
A real anchor will hold under 2 external necessary conditions:
- The anchor has been correctly set.
- The rode pulls the anchor in an appropriate direction (see
Req. 4 below).
More on that in the Anchor chapter.
- Function: The rode acts as a link between the anchor and the boat.
- Req. 4: The rode should
pull the anchor in a direction that allows it to offer the required holding
- Req. 5: The rode should be easy to stow, wind and
- Req. 6: The rode should reduce the tensile stresses
caused by gusts/waves on the anchor and boat accessories.
Req. 4 and 5 are dealt with in the static
Req. 6 is studied in the dynamic behavior chapter.
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