A method for assembling a wind turbine blade is disclosed. The method includes providing a root end element 70 of the wind turbine blade 10, providing a tip end element 72 of the wind turbine blade 10, and inserting one or more alignment members 82 at pre-defined positions in at least one of the root end elements 70 and the tip end element 72. The one or more alignment members 82 is of a pre-defined shape. The method further includes aligning the one or more members 82 with a receiver portion of at least one of the root end elements 70 and the tip end element 72 in which the one or more alignment members 82 is not inserted, along a joining portion. Then, joining the root end element 70 and the tip end element 72 wherein, during joining, the one or more alignment members 82 align along a longitudinal axis of at least one of the root end elements 70 and the tip end element 72.

Indicator device (90), for indicating proper alignment of bolt-and-nut holes of two abutting flanges (72,72′) of two tower sections (2,5) of a wind turbine tower structure (1), the indicator device (90) comprising a connector (122) for connecting the indicator device (90) to an inner face (71) of one of the flanges, and a body (100) having a first body end (101) and an opposite second body end (112) closer to the connector (122), the indicator device (90) including a resiliently deformable part (150), a pneumatic system or a hydraulic system allowing for the indicator device (90) to assume a normal configuration wherein the first body end (101) is distant from the connector (122), and a second configuration wherein the first body end (101) is located closer to the connector (122), the resiliently deformable part or pneumatic system or hydraulic system urging the first body end (101) from the second configuration towards the first configuration.

A wind turbine blade vortex generator unit and a method for installing it, where a wind turbine blade has at least one series of vortex generator units formed of fins extending substantially perpendicular to the surface of the airfoil and substantially in a direction from the leading edge towards the trailing edge of the wind turbine blade. The vortex generator units each comprises a fin connected to an outer side of the fin base, and where the fin is delta shaped tapering from a trailing edge towards a leading edge and where each of the vortex generator units has a layer of adhesive on an inner side of the base that extends to an outermost periphery of the base. The vortex generator unit has exactly one fin, and the base has an airfoil shaped periphery with a rounded leading edge and a trailing edge.

A crane (2) comprising a base portion (4), two arms (6, 8) displaceably connected to the base portion and a lifting boom (22) displaceably connected to the base portion, said lifting boom being provided with a lifting wire (32) and a lifting member (30), for example a lifting hook, for lifting a load, wherein the two arms and the base portion in combination comprise at least three tower flange connection element (10) is arranged to be detachably connectable to cooperating crane connection elements on a flange of a wind turbine tower section, wherein each arm comprises one of the tower flange connection elements, and wherein the vertical distance between any two tower flange connection elements in the normal operating position of the crane is less than 1 m, less than 50 cm or less than 25 cm. In this way a crane is provided which can be attached to a flange located at the upper portion of a tower section.

A self-aligning interface for assembling a powertrain housing 210 of a wind turbine onto a support base 220 is provided. The support base 220 comprises a support surface 230 and the powertrain housing 210 comprises a housing surface 240. The support hsurface 230 and the housing surface 240 are configured to be in contact after assembly. The self-aligning interface comprises: one or more protrusions 250 on the support surface 230, wherein the one or more protrusions 250 comprises one or more walls 260 which are inclined with respect to the support surface 230; and one or more recesses 270 on the housing surface 240. In addition or alternatively, the self-aligning interface comprises one or more protrusions on the housing surface, wherein the one or more protrusions comprises one or more walls which are inclined with respect to the housing surface, and one or more recesses on the support surface. The one or more protrusions 250 are complementary in size and shape to respective ones of the one or more recesses 270, such that, during assembly of the powertrain housing 210 onto the support base 220, the one or more protrusions 250 act as a guide for the one or more recesses 270, and the one or more protrusions 250 fit directly into the respective one or more recesses 270, to enable direct contact between the support surface 230 and the housing surface 240.

A method for erecting a wind turbine tower is disclosed. A tower section (8) comprising a lower flange (9) and an upper flange (10), and a plurality of stud bolts (6) and nuts (7) are provided. The tower section (8) is oriented in an upright position with the lower flange (9) below the upper flange (10), and stud bolts (6) are positioned in bolt holes (12) in the lower flange (9) with nuts (7) arranged on an upper side of the lower flange (9). The tower section (8) is lifted to a mounting position on top of another tower section (13), and a flange combination is formed by aligning the bolt holes (12) formed in the lower flange (9) of the tower section (8) with bolt holes (15) formed in an upper flange (14) of the other tower section (13), while advancing the stud bolts (6) through the bolt holes (12, 15). The invention further provides a socket tool (16) for screwing nuts (7) onto stud bolts (6) in a manner which positions the stud bolts (6) correctly with respect to a flange (9).

Provided is a method for moving an object between a platform of a wind turbine and a deck of a vessel, wherein the platform is located at a tower the wind turbine, wherein the object is moved vertically by a hoist coupled between the object and at least one fixation site the wind turbine located above the platform and the deck, wherein the object is deflected radially from the tower by a puller coupled between the object and the vessel.

A jointed rotor blade includes a first blade segment and a second blade segment extending in opposite directions from a chord-wise joint. Each of blade segments has at least one shell member defining an airfoil surface and an internal support structure. The internal support structure of the first blade segment includes a beam structure extending lengthwise that structurally connects with the internal support structure of the second blade segment via a receiving section. The rotor blade further includes one or more pin joints positioned on at least one of internal support structures of the first blade segment or the second blade segment. Thus, at least one of internal support structures of the first blade segment or the second blade segment includes varying material combinations along a span of the rotor blade at locations of the one or more pin joints so as to reinforce the one or more pin joints.

Provided is a coupling assembly for connecting a tower or a transition piece of a wind turbine to a monopile including a first coupling part configured to be connected to the monopile and a second coupling part configured to be connected to the first coupling part. Further provided is a tower end of a tower of a wind turbine connected to a second coupling part of the coupling assembly. Finally, a method of driving a monopile of a wind turbine into the ground, a top end of the monopile being connected to a first coupling part of the coupling assembly is also provided.

A method (100) of mounting a blade (22) to or unmounting a blade (22) from a rotor hub (20) of a wind turbine (10), the wind turbine (10) comprising a tower (12) and a nacelle (16) mounted on the tower (12), the rotor hub (20) being coupled to the nacelle (16), the method (100) comprising gripping the blade (22) using a gripper (50), the gripper (50) comprising gripping members (58) configured for gripping the blade (22) and teeth (60) protruding from the gripping members (58), wherein gripping comprises inserting the teeth (60) of the gripper (50) into receptacles (78) of the blade (22); and rotating the blade (22) about a rotation axis (54) perpendicular to a longitudinal blade axis (53) using a blade rotation device (52) of the gripper (50), wherein the teeth (60) are configured for transmitting an axial load (57) of the blade (22) between the blade (22) and the gripping members (58).