A crane equipped with a vertical mast that supports a superstructure (rotating section)--typically with a jib, counter jib and operator's station mounted to it--powered by an electric or internal combustion engine that can vary operating radii by means of a traversing trolley, luffing boom, or a combination of the two. The crane may be mounted on a fixed base as freestanding, guy supported, braced or assembled inside a structure. The crane may also be mounted on a traveling base by means of bogies and tracks to allow travel within a jobsite.
Tower Crane Website