HANSA 06-2019

Offshore
nance, with construction jack-ups typically
of four-leg design rather than the
familiar three in the oil and gas sector.
Specialised tonnage
In comparison to traditional offshore
wind service operations using crew transfer
vessels or helicopters, an SOV promises
a range of operational benefits for
both windfarm operators and service
teams, including enhanced safety and
comfort for technicians; accelerated onsite
service; increased weather availability
and improved productivity.
The biggest safety challenges in offshore
turbine service work arise from
the use of CTVs, which are the traditional
means of transferring technicians to
and from the wind turbines. The gangway
system (which employs motion compensation
system to keep it in a fixed position
relative to the turbine) reduces the
risk in crew transfers, can operate in almost
any weather conditions, and can
cope with high wave heights. However,
the main advantage that an SOV offers
is the ability to concentrate skills and
resources; because the service team and
technicians can be based offshore, no additional
travel time to or from the wind
farm is necessary.
With warehouse space immediately below
the main cargo deck, SOV carries almost
every spare part the project requires
in order to respond quickly to component
failures and minimize turbine downtime.
In addition to the hydraulic gangway arrangement,
an SOV provides further flexibility
by acting as the Mothership for an
additional Safe Transfer Boat which can
also be used to move technicians to and
from the wind turbines in a range of different
weather conditions.
Battery system
Seacor Marine requested the ABS BAT-
TERY-Li notation for »Seacor Maya«.
Modifications to the OSV were completed
in May 2018, upgrading »Seacor Maya«
to use lithium battery power. The lithium-ion
battery energy storage system is
designed to keep the generators running
at between 75% and 80% of the maximum
continuous rating. At higher power
demands, the batteries supply power
and, at lower power demands, the generators
recharge the battery. The Corvus batteries
are enclosed in a 20’ container with
a weight of approximately 28 t.
Assessing the energy storage system of
a precedent-setting hybrid-electric power
system such as on SEACOR Maya is a
complex process. The systems allow for
use of alternative energy sources, which
can store energy as a backup for the main
power source. Part of their attractiveness
is that they can enhance safety by allowing
a response to emergency scenarios
where all main power is lost.
Author: Wei Huang
Director, Offshore Support vessels, ABS
Cranes & life-saving packages
To reach a safe place you need more than just a boat.
Hall C, Stand C02-16d
Made in Germany.
Davits Cranes
Aftersales Industry
www.di-hische.de
HANSA International Maritime Journal 06 | 2019
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