A method of transporting a first vessel having wind turbine components to an offshore installation vessel. The method includes (i) securing the first vessel to a second vessel using a first tow line attached to a front end (or bow) of the first vessel, and (ii) securing the first vessel to a third vessel using a second tow line attached to a back end (or stern) of the first vessel. The method further includes transporting the first vessel to the offshore installation vessel using the second vessel and the third vessel secured to the first vessel via the first and second tow lines, respectively. The method also includes securing the first vessel to the offshore installation vessel. The first vessel can include one or more fender walls. The first vessel can be secured to the offshore installation vessel using one or more mooring lines.

A catamaran lifting apparatus is disclosed for lifting objects in a marine environment. The apparatus includes first and second vessels that are spaced apart during use. A first frame spans between the vessels. A second frame spans between the vessels. The frames arc spaced apart and connected to the vessels in a configuration that spaces the vessels apart. The first frame connects to the first vessel with a universal joint and to the second vessel with a hinged connection. The second frame connects to the second vessel with a universal joint and to the first vessel with a hinged or pinned connection. Each of the frames provides a space under the frame and in between the barges that enables a package to be lifted and/or a marine vessel to be positioned in between the barges and under the frames. In this fashion, an object that has been salvaged from the seabed can be placed upon the marine vessel that is positioned in between the barges and under the frames.

A method of ballasting a vessel comprises positioning a vessel having a first draft adjacent to or underneath an offshore installation. The vessel has at least one ballasting tank and at least one port in fluid communication with the at least one ballasting tank. The at least one ballasting tank is arranged to selectively adjust the flow of ballast water in and out of the at least one ballasting tank. The method comprises pushing down from the offshore installation on the vessel to increase the draft of the vessel from the first draft to a second draft. The method further comprises opening the at least one port when the vessel is at the second draft and the at least one port is below a waterline. The method also comprises filling at least part of the at least one ballasting tank.

To upend and lift an object, e.g. a foundation member of an offshore wind turbine, e.g. a monopole, use is made of an upending and lifting tool, wherein, with the tool suspended from one or more hoisting cables, e.g. from a crane hook of a crane, and with the frame of the tool initially in vertical orientation, a routine is performed which includes operating one or more shifting actuators, thereby moving a cable shifting member and engaging a cable engagement surface with the one or more hoisting cables at a height above a pivot axis. Further continuing this motion of the cable shifting member and thereby applying a cable shifting force on the one or more hoisting cables results, in reaction, in a pivoting of the frame into the horizontal orientation thereof.

A method is provided for handling wind turbine blades aboard a vessel, the method including providing on the vessel a blade rack assembly configured to accommodate more than one blade, the rack assembly having at least a root rack and a tip rack, and the root rack and tip rack defining between them a blade support plane. The method also includes providing a jack acting between the vessel and one of the root or tip rack; and raising or lowering one of the root or tip rack aboard the vessel by the jack to thereby move the blade support plane through an elevation angle θ. A jack assembly on a wind turbine installation vessel and an offshore wind turbine installation vessel are also provided, each capable of raising or lowering a rack of wind turbine blade root or tip support frame elements.

An assembly includes an object with a vertical height of at least 30 metres placed on a bearing frame and a motion compensation platform including a base attached to a vessel. The platform includes an x-y actuator system for rotating the bearing frame with respect to the base about an x-axis and a y-axis, a sensor system configured to detect an x-axis rotating movement, and a y-axis rotating movement, and to generate a corresponding sensor signal, as well as an x-y control system configured to adjust the position of the bearing frame with respect to the base, depending on the sensor signal. The bearing frame is supported at a vertical distance above the base by means of a three-point support having a hinged, fixed first support and hinged second and third supports which are telescopic in the longitudinal direction of the z-axis.

A support device configured to be positioned on a lifting vessel in order to support a topside of an offshore platform, the support device comprising: a main cylindrical casing having an upper opening, the main casing defining a main vertical axis, the main casing further defining an upper support rim, a reservoir located inside the main casing for holding a granular material or a fluid, the reservoir having a discharge opening for emptying the reservoir, a spring support slideably arranged within the main casing, the spring support resting on the granular material or the fluid and being movable from an upper position to a lower position in dependence on a filing degree of the reservoir, a spring device positioned on the spring support, a receptor support positioned on the spring device, the receptor support defining an upper surface, and a receptor device.

The present invention relates to a monopile fastening system for retaining one or more elongated monopile during sea transport and/or quay transport, which can be used to accommodate monopiles with section having different diameters by the combination of complementary supporting elements that can be singularly activated.

The present invention also relates to a monopile fastening structure comprising a plurality of monopile fastening systems, and to a vessel, a barge or a sea transport unit comprising a monopile fastening structure or a monopile fastening system and to a method for fastening a monopile using a monopile fastening system.

The present application provides a semi-submersible immersed tube transportation and installation integrated ship and a construction process; the integrated ship includes: a deck structure; two floating structures, ballast water being able to be injected therein; and upper portions or top surfaces of the two floating structures are connected by the deck structure; and two support mechanisms, disposed on opposite sides of the two floating structures respectively; and each support mechanism is disposed at a lower portion or a bottom of the floating structure. The integrated ship can reduce the draught of the integrated ship carrying an immersed tube and realize the transportation requirements of shallow waterway.

System for transporting and installing wind turbines on the seafloor, made up of a structure that has adjustable flotation capacity and is made up of two floating hulls and a series of columns onto which they are mounted with the capacity to move over the same, an upper peripheral frame and a lower peripheral frame, on which means are mounted for fastening and manipulating the wind turbines and piles and ferrules for anchoring said wind turbines to the seafloor.