A tower crane for performing a lifting a load includes an extendable tower assembly having a central axis and including a plurality of separate tower sections, a climbing assembly including a climbing frame positioned on the tower assembly and a latching assembly to transport the climbing assembly vertically along the tower assembly, and a boom assembly atop the tower assembly and including a crane floor, a boom supported on the crane floor, a lifting member coupled to the boom, and a slew bearing coupled to the crane floor and configured to permit the crane floor to rotate about a rotational axis, wherein the slew bearing includes a first bearing position and a second bearing position spaced from the first bearing position relative to the central axis of the tower assembly.