As the American Club warns, the unpredictable force of the wind, often underestimated, significantly impacts large sail area (profile) vessels, especially when moored.
Their large sail areas expose them to potential beam wind hazards, leading to risks like a vessel breakaway that can result in a grounding, allision, collision, or damage to third party property.
Factors affecting mooring
If the vessel captain decides to stay moored after considering
the expected wind speed, estimated wind load, and other general considerations,
the vessel should deploy extra mooring lines taking into account the following
factors:
§
Conditions and age of the mooring ropes;
§
Brake render settings of the mooring winches;
§
Availability and safe working load of shore/terminal mooring
points;
§
Conditions of shore/terminal mooring points;
§
Maximum number of moorings allowed to each mooring point;
§
Mooring pattern/arrangement and lead of the mooring lines;
§
Terminal recommendations for mooring arrangements;
§
Availability of tug assistance and linesmen that may be required
to assist on short notice;
§
Potential wake effects of passing vessels on moored vessels;
§
Any forthcoming high tides or currents at the location that can
put additional strain on the mooring lines;
§
Availability of clear and constant communication between the
ship’s crew, the terminal staff, and tug operators; and
§
Familiarity with port and terminal procedures, rules and
guidelines that are relevant to mooring in high wind conditions, as may be
applicable.
Complications
There are several mooring operations related complications that
may arise during periods of high winds that should be considered:
§ overloading bollards due to the
load from one or multiple mooring lines
§ using older and weaker mooring
lines
§ incorrect settings on constant
tension winches or winch render settings
§ lack of situational awareness and
monitoring of weather conditions
§ inability to deploy additional
mooring lines due to unavailability of line handlers
Lessons
learned
§ Plan for the expected weather, especially if
wind gust velocities are anticipated to be high.
§ Plan the mooring arrangement in advance of
arrival as ashore mooring points can vary
§ Know the capacities of the available mooring
points ashore.
§ Increasing the number of mooring lines before
the weather deteriorates is much easier.
§ Anticipate that thunderstorms can often include
high winds.
§ Training and drilling for high wind events can
include line handling drills, emergency departure and engine start drills, and
ensuring crew readiness in an actual situation.
§ Establish and prepare an emergency action plan
to mitigate the consequences of a mooring failure or vessel breakaway. For
large sail (profile) vessels, such considerations should be part of the safety
management system’s emergency preparedness procedures.
§ Perform a risk assessment before the vessel is
berthed to help identify any possible issues and to enable planning for
mitigation actions.
§ Identify and liaise with local port authorities
and meteorological departments.
§ Cooperation with these authorities can be
beneficial for gaining an understanding of local weather patterns and berth
characteristics.
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