Static and mobile Tower Crane are available in a wide variety of types and configurations according to the particular combination of tower, jib and type of base which they employ.
Tower cranes are available with either fixed or slewing towers. On the fixed tower type the slewing ring is situated at or near the top of the tower and the jib slews about the vertical axle of the stationary tower. The slewing ring on the slewing tower type is situated at the bottom of the tower and the whole of the tower and jib assembly slew relative to the base of the crane. The towers can be further classified as being mono towers, inner and outer towers and telescopic towers.
Mono Towers – The jib is carried by a single tower structure which may be either fixed or slewing. Provision may be made in the design to permit the tower to be extended
Inner and Outer Towers – They are characterised by the jib being carried by a fixed or slewing inner tower which is supported at the top of the fixed outer tower. Provision may be made in the design to permit the outer tower to be extended
Telescopic Towers – The tower structure consists of two or more main sections which nest into each other to enable the height of the crane to be altered without the need for partial dismantling and re-erection. Telescopic towers are usually of slewing type and more common on rail-mounted and mobile tower cranes