A wind turbine installation vessel (WTIV) is a vessel specifically designed for the installation of
offshore wind turbine
Offshore may refer to:
Science and technology
* Offshore (hydrocarbons)
* Offshore construction, construction out at sea
* Offshore drilling, discovery and development of oil and gas resources which lie underwater through drilling a well
* Of ...
s. There were 16 such vessels in 2020.
[
Most are self-elevating ]jackup rig
A jackup rig or a self-elevating unit is a type of mobile platform that consists of a buoyant hull fitted with a number of movable legs, capable of raising its hull over the surface of the sea. The buoyant hull enables transportation of the unit ...
s. To enable quick relocation in the wind farm it is self-propelled. It also has a slender ship shaped hull to achieve a quick turnaround time
Turnaround time (TAT) is the amount of time taken to complete a process or fulfill a request. The concept thus overlaps with lead time and can be contrasted with cycle time.
Meaning in computing
In computing, turnaround time is the total time ...
with the vessel carrying several foundations or wind turbines each time.[ ]Azimuth thruster
An azimuth thruster is a configuration of marine propellers placed in pods that can be rotated to any horizontal angle (azimuth), making a rudder redundant. These give ships better maneuverability than a fixed propeller and rudder system.
Type ...
s are used to position the vessel during jack-up operations.[Pacific Orca Wind Farm Installation Vessel]
/ref> Some vessels use the thrusters in dynamic positioning
Dynamic positioning (DP) is a computer-controlled system to automatically maintain a vessel's position and heading by using its own propellers and thrusters. Position reference sensors, combined with wind sensors, motion sensors and gyrocompas ...
(without jacking up) to keep the vibrating pile driver
A pile driver is a heavy-duty tool used to drive piles into soil to build piers, bridges, cofferdams, and other "pole" supported structures, and patterns of pilings as part of permanent deep foundations for buildings or other structures. Pili ...
steady when installing foundations. Some may carry five modern wind turbines and lift 700 tonnes above deck.
A vessel can cost $335 million, or $220,000 per day.[ A 3-year leasing may cost €90 million.
The fleet of 16 vessels are scheduled to expand to 23 vessels by 2023, of which seven can handle the largest turbines.]motion compensation
Motion compensation in computing is an algorithmic technique used to predict a frame in a video given the previous and/or future frames by accounting for motion of the camera and/or objects in the video. It is employed in the encoding of video ...
. Some WTIVs have a crane but no legs.
Projects include a crane height, and lift capacity of 1,600–3,000 tonnes.
Some WTIV use biodegradable
Biodegradation is the breakdown of organic matter by microorganisms, such as bacteria and fungi. It is generally assumed to be a natural process, which differentiates it from composting. Composting is a human-driven process in which biodegrada ...
hydraulic fluids
A hydraulic fluid or hydraulic liquid is the medium by which power is transferred in hydraulic machinery. Common hydraulic fluids are based on mineral oil or water. Examples of equipment that might use hydraulic fluids are excavators and backhoes ...
to minimize ecosystem impact during leaks. In Korea, some vessels are approved for liquefied natural gas
Liquefied natural gas (LNG) is natural gas (predominantly methane, CH4, with some mixture of ethane, C2H6) that has been cooled to liquid form for ease and safety of non-pressurized storage or transport. It takes up about 1/600th the volume o ...
.
Construction of the four-legged US Jones Act-compliant ''Charybdis'' started at Keppel in Texas in late 2020, at a cost of 715 million dollars, scheduled for the 700 MW Revolution Wind in 2023 and the 924 MW Sunrise Wind in 2024. Such vessels require 500–800 MW of installation per year for five years to be economical. The Jones Act makes it much more difficult to install offshore wind, introducing complications of transferring parts between ships and raising costs.
See also
* Ring crane
References
{{reflist
Wind turbine installation vessels