An elevator drive cassette configured for use in driving the movement of an elevator car along a rail or rack, the elevator drive cassette including: a driven pinion and drive shaft configured to be driven by a drive motor associated with the elevator car; a mechanical coupling; at least one further pinion configured to be driven by the driven pinion or drive shaft via the mechanical coupling, wherein both the driven pinion and at least one further pinion are configured to engage the same rail or rack.

A kit provides an elevator system defining an elevator transport axis with respect to an exposed vertical face of a vertical structure. The kit includes an elevator platform, rail segment modules having elevator rail element(s), a base structure and a rail segment stacking system. The rail segment modules can be serially stacked contiguously via the rail segment stacking system to provide a mast stack, forming contiguous vertical elevator rail(s) parallel to the elevator transport axis. The elevator platform can be transported along the mast stack via the vertical elevator rail. The base structure has a module receiving station which receives from a rail segment module source each rail segment module in turn, and feeds each one to the rail segment stacking system, allowing on-site coupling and bottom-to-top stacking of the fed rail segment modules, providing a progressively elongating mast stack, and transporting the progressively elongating mast stack vertically and progressively further away from the ground after each rail segment module is stacked thereto.

A wind turbine assembly includes a falling weight system to store potential energy within the wind turbine assembly. The falling weight system utilizes a pair of gears that can rotate to raise and lower weights within a cavity of the tower section. In addition, an assembly ring that is configured to climb a tower section of a wind turbine assembly may be used to assemble a wind turbine assembly or to perform maintenance on wind turbine assemblies. In some examples, a ballast weight system utilizing a ballast weight tank that lowers by being filled with water may be used to input rotational energy into a generator to create electricity.