Abstract: A support tower for heavy loads or large structures such as a wind turbine generators, constructed of a plurality of telescopic tower sections with the outer lower tower section having a lower end supported from a foundation and at least one or more inner upper tower sections telescoped in an initial vertical nested relation within the outer lower tower section. The heavy load is mounted on an upper end of the inner upper tower section while in the initial vertical nested relation. The inner upper tower section or sections are then lifted upwardly to an extended tower height by lift mechanisms and the tower sections are secured in vertically extended position by inter-engaging wedge joint structure with bolt fasteners extending through mating wedge surfaces to retain the telescopic tower sections vertically extended and position the heavy load in a vertically elevated position.