The Sky Tower in Auckland is 328m (1,076 ft) tall and is the largest free standing structure in the Southern Hemisphere. The building is used as an observation and telecommunications tower and is located in Auckland's CBD. It was completed in 1997 and designed by Craig Craig Moller Architects.
The tower forms part of the Skycity Auckland casino complex, attracting approximately 1,450 visitors per day. Situated up in the tower in an observation deck, two restaurants and a cafe, including New Zealand's only revolving restaurant.
Additionally the tower is used for telecommunications across Auckland city. The aerial at the top of the tower hosts the largest FM combiner in the world.
The tower is constructed of reinforced, high-performance concrete with a 12m (39ft) diameter shaft which houses three lifts and an emergency stairway. This is supported on eight 'leg' piles.
The upper levels were constructed from composite materials, structural steel, precast concrete and reinforced concrete, and the observation decks are clad in aluminium with blue/green reflective glass. A structural steel framework supports the upper mast structure. During construction 15,000 cubic metres (20,000 cu yd) of concrete, 2,000 tonnes (2,200 short tons) of reinforcing steel and 660 tonnes (730 short tons) of structural steel were used.
The mast weighs over 170 tonnes (190 short tons). It had to be lifted into place using a crane attached to the structure, as it would have been too heavy for a helicopter to lift. To then remove the crane, another crane had to be constructed attached to the upper part of the Sky Tower structure, which dismantled the big crane, and was in turn dismantled into pieces small enough to fit into the elevator.