The main tasks of the transportation systems in a maintenance
operation are to provide accommodation for crew and technical
personnel, loading, transporting and assembling failed turbine
components in the offshore environment. During the operational
span of an offshore wind farm, a number of scheduled and
unscheduled maintenance tasks have to be performed in order
to keep the turbines operational and to sustain power generation.
In this respect, there are two main categories of O&M vessels in
the offshore wind energy market: vessels for minor maintenance
and vessels for major maintenance.