A joint for a modular pole comprises a lower flange, an upper flange, and a transition section. The lower flange may have a lower flange external dimension which is greater than an upper flange external dimension. A fastener which may be useful in connecting the joint to a pipe or a stud comprises a through hole having an inner thread which does not span the entire distance of the through hole, and an outer thread on an exterior surface of the fastener with the inner thread and the outer thread having opposing thread directions. A modular pole comprises P.sub.n+1 pipes, T.sub.n joints, and a plurality of fasteners where n is an integer greater than or equal to 1.

This invention uses a hybrid of latticed steel and tapered tubular steel technologies. Namely, latticed steel and tapered tubular steel pole technology, to provide a more economical structural support with the advantages of each. It utilizes latticed steel hot-rolled angles for bracing elements and cold formed steel plate for main leg elements. The tapered geometry of the leg elements provides a more optimum utilization of material by the use of a non-prismatic (tapered) element profile. This element consists of a bent plate shape profile that varies in structural section modulus vertically along the height of the structure which optimizes the use of steel material to resist the applied structural loads. The arms include an invention that allows for post-tensioning and thereby provides deflection control and/or the ability to modify the natural frequencies of vibration to mitigate vortex induced vibrations caused by wind. The main support elements in the arms are developed using plates formed into angle shapes that provide inherent gusset plate material to accommodate the bracing bolted connections without the need for separate gusset plates. The direct embedded portion of the structural design allows for transverse passive soil pressures to be collected by trapezoidal plates and resisted by the grillage superstructure. A transition section is subpart of the embedded structure portion and accommodates multiple structure heights as a standard foundation system.

A retrofitted wind turbine installation for replacing a prior wind turbine installation includes the foundation of the prior wind turbine installation and a replacement wind turbine supported by the foundation, wherein the tower of the retrofitted wind turbine installation is a cable-stayed tower to reduce the bending loads imposed on the foundation. A method of retrofitting an existing wind turbine installation with a replacement wind turbine includes disassembling at least a portion of the existing wind turbine, assembling a replacement tower to a remaining portion of the existing wind turbine installation, attaching a plurality of stay cables between the tower of the retrofitted wind turbine installation and stay cable foundations, and attaching the replacement energy generating unit to the replacement tower.

A method of forming a wind turbine foundation includes providing an anchor cage in an excavation pit, the anchor cage including an upper flange, a lower flange, and a plurality of anchor bolts extending therebetween. A first cementitious material is directed into the excavation pit so that the anchor cage becomes at least partially embedded in the material, which is allowed to cure to form a rigid body. A connecting element is selectively engaged with the upper flange and an actuating element is positioned in operative relation with the connecting element, the connecting and actuating elements positioned in non-contact relation with the anchor bolts. The actuating element is actuated relative to the connecting element to raise the upper flange from the rigid body into a leveled position. A second cementitious material is directed into a space beneath the raised upper flange and is allowed to cure to form a support layer.

A method of forming a wind turbine foundation includes providing an anchor cage in an excavation pit, the anchor cage including an upper flange, a lower flange, and a plurality of anchor bolts extending therebetween. A first cementitious material is directed into the excavation pit so that the anchor cage becomes at least partially embedded in the material, which is allowed to cure to form a rigid body. A connecting element is selectively engaged with the upper flange and an actuating element is positioned in operative relation with the connecting element, the connecting and actuating elements positioned in non-contact relation with the anchor bolts. The actuating element is actuated relative to the connecting element to raise the upper flange from the rigid body into a leveled position. A second cementitious material is directed into a space beneath the raised upper flange and is allowed to cure to form a support layer.

The invention relates to a method for forming a connection between two pipe segments of different widths, preferably of a tower-like structure, in particular of a wind turbine. In order to be able to connect pipe segments of different widths more easily, reliably and cost-effectively to one another, it is provided that the wider pipe segment is pushed with one end partially over an end of the narrower pipe segment , that the pipe segments are positioned apart from one another by forming an annular gap between the pipe segments, that in the annular gap between the two pipe segments a separating layer extending in the longitudinal direction of the pipe segments and/or in the radial direction is provided, that the annular gap adjacent to the separating layer and at least one side of the separating layer is at least partially cast with a casting compound, that during the hardening of the casting compound the casting compound forms a firm connection on one side of the separating layer with only one of the pipe segments and/or the casting compound forms a firm connection on the other side of the casting compound , only with the other pipe segment and that the pipe segments after the hardening of the casting compound are separated again along the separating layer with the assigned separate connecting elements in particular formed by the hardened casting compound.

Provided is a cross arm with one end connected to a tower body and a free end for connecting a conducting wire. Free end comprises an end connecting piece and an extension piece. Extension piece is fixed with end connecting piece. Extension piece protrudes horizontally from end connecting piece. Conducting wire is connected to extension piece. An angle between extension piece and a cross arm center line is greater than that between conducting wire and cross arm center line. Cross arm free end includes a jumper wire device horizontally arranged on end connecting piece for hitching jumper wire. Extension piece use increases distance between conducting wire and tower body when turning angle condition is met. Gap requirement between conducting wire and tower body is met, and cross arm length increase is eliminated. Horizontally arranging jumper wire device on end connecting piece reduces distance between wire layers and tower body size.

A transition piece for a wind turbine tower including a hollow frustoconical piece that is connected to an upper ring and a lower ring. The upper ring is connected to crossbars and the lower ring to radial columns. The transition piece also includes three connectors, each of them being connected to a crossbar, two radial columns and two connection profiles that keep the three connectors joined together, so that a pair of radial columns is arranged between a connector and the lower ring and the crossbars are arranged between the upper ring and a respective connector. The radial columns form an angle of between 65° and 75°, measured between the longitudinal axis of the corresponding radial column with the normal axis of the frustoconical piece.

A mobile well servicing system and method are provided for performing well services. The mobile well servicing system can include a work surface on a platform supporting an equipment such a jack, a blowout preventer (BOP), a coiled tubing (CT) injector and a mast. The mast is pivotable between a first position, with a lifting point positioned over the work surface, and a second position, with the lifting point positioned behind the platform. A hoist winch assembly mounted at the platform raises the equipment from the platform when the mast is at the first position. The equipment then pass through a space between two parallel legs of the mast, and lowered to a wellhead when the mast is at the second position. Multiple tasks such as well completion, change of dynamic temperature sensor (DTS) and electric submersible pump (ESP) can be achieved using this system.

Disclosed are tower erection systems and tower climbing systems and associated methods of operation. A tower erection system, in accordance with various embodiments, includes a ground-installed lifting structure, and a lifting frame configured to latch onto individual tower sections and traveling vertically inside the ground-installed lifting structure, lifted by a winch-and-cable or other lifting mechanism. Using this system, a tower may be assembled from multiple sections from the top down. A tower climbing system, in accordance with various embodiments, includes upper and lower climbers that can latch onto the lateral surface of a tower and a lifting mechanism that can move the climbers vertically relative to each other. The system can be used to carry a crane or other heavy equipment up and down along the tower. A climbing crane may be used, for example, during tower construction, or to reach the top of the tower for maintenance or repair.