A mast (10) which includes an elongate post (12) with a first end (14) and a second end (16), the first end (14) being pivotally secured to a ground-engaging support base, at least a first mechanism (22) to restrict pivotal movement of the post (12), a winch (26) which is attached to the post (12), and a cable (28) which is engaged with the winch (26) and which is secured at one end to an anchor (30), wherein the winch (26) is actuable to allow the post (12) to pivot, from an elevated position, in a first direction (54) which lowers the post (12) against the action of the movement restricting first mechanism (22), and which is actuable to pivot the post (12) in a second direction (56) which opposes the first direction (54) to elevate the post (12).

Hoists, platforms and davits are described as well as methods of securing same to telecommunication and other towers. The hoists, platforms and davits may be secured to the towers on a temporary basis using clamps. The clamps may include brackets and cables. The cables may be attached to the brackets, may wrap around the outer surface/perimeter of the tower pole/leg and may use tension to keep the bracket in place.

A side saddle slingshot drilling rig includes a left and right substructure including a left and right lower box. The side saddle slingshot drilling rig includes a drill rig floor mechanically and pivotably coupled to the left and right lower boxes such that it is pivotably movable from a lowered position to a raised position. The drill rig floor includes a V-door. The V-door is positioned on the V-door side of the drill rig floor. The V-door side of the drill rig floor is oriented to face the right substructure. A mast coupled to the drill rig floor may include an open side, defining a mast V-door side. The mast V-door side may be oriented to face the right substructure. The mast may pivot into its raised position or may be a bootstrap mast.

A method of building and operating a land-based drilling rig with a high-capacity mast include providing a platform collapsed on a substructure over a proposed well drilling location and building the high-capacity mast in a horizontal condition by attaching a lower portion of the high-capacity mast to the platform. The high-capacity mast having an opening formed therein sized to accommodate four Range 2 pipes or three Range 3 pipes. The high-capacity mast may be raised from the horizontal condition to a vertical condition by pushing the side of the high-capacity mast to pivot the high-capacity mast about a pivot point on the platform. The platform may be raised from a collapsed condition to a raised condition over the substructure. Some implementations include dual racking boards on the high-capacity mast.

Hoists, platforms and davits are described as well as methods of securing same to telecommunication and other towers. The hoists, platforms and davits may be secured to the towers on a temporary basis using clamps. The clamps may include brackets and cables. The cables may be attached to the brackets, may wrap around the outer surface/perimeter of the tower pole/leg and may use tension to keep the bracket in place.

A method of assembling a drilling rig may include aligning a trailer with a drilling rig support structure, the trailer carrying a mast and the drilling rig support structure including a step-down substructure. A first end of the mast may be positioned over the drilling rig support structure and arms may be extended from the mast to the drilling rig support structure so that the drilling rig support structure supports the first end of the mast. The mast may translate along a length of the drilling rig support structure. The mast may be coupled to the drilling rig support structure.

This application relates to hinged tower segments and transport methods, and particularly to methods and apparatus for transporting and storing hinged segments of steel wind turbine towers. The wind turbine tower comprises a plurality of cylindrical vertical tower sections, which in the finished tower are mounted on top of one another. The vertical section of the tower has a longitudinal axis and comprises a plurality of wind turbine tower segments, the tower segments have vertical and horizontal edges and combine to form a complete vertical tower section by joining along their edges. Adjacent vertical tower sections are joined to each other along the horizontal edges of the wind turbine tower segments. Hinges are secured between tower segments and the tower segments rotated about the hinged axis to make them suitable for transport or storage. A method of assembling a tower section is discussed.

A land-based drilling rig includes a first substructure and a second substructure, the second substructure being positioned generally parallel to the first substructure. The land-based drilling rig also includes a drill rig floor coupled to the first and second substructures, the drill rig floor including a V-door. The side of the drill rig floor has the V-door defining a V-door side of the drill rig floor, where the V-door side of the drill rig floor is parallel to the first substructure. The first and second substructures pivotably support the drill rig floor. The land-based drilling rig also includes a mast, the mast mechanically coupled to one or more of the first substructure, the second substructure, and the drill rig floor. The mast is pivotably coupled to one or more of the first substructure, the second substructure, and the drill rig floor by a mast pivot point. The mast includes a V-door side, the V-door side of the mast parallel to the first or second substructure. In addition, the land-based drilling rig includes a mast hydraulic lift cylinder coupled to the mast at a mast lift point and a choke manifold, the choke manifold positioned on the drill rig floor.

A pole erection apparatus comprising a guide portion for receiving a pole longitudinally; a support portion that is pivotable with respect to the guide portion and which receives the pole and supports it pole longitudinally; and actuator for pivoting the support portion with respect to the guide portion between a relatively reclined state and a relatively upright state. In the relatively upright state, the respective bodies of the guide portion and the support portion are aligned with one another to allow the pole to slide longitudinally from the support portion into the guide portion.

A portable lightning protection system including a multi-section conductive mast assembly including at least a base mast section and a top mast section; an air terminal attachable to the top mast section; and a base assembly attachable to the base mast section via a hinge assembly, wherein the hinge assembly may be configured to allow the base mast section to hinge relative to the base assembly. A catenary lightning protection system including at least two lightning protection systems, each lightning protection system may include a multi-section conductive mast assembly including at least a base mast section and a top mast section; an air terminal attachable to the top mast section; a base assembly attachable to the base mast section; and may further include a catenary wire connected between the at least two lightning protection systems.