Sky Tower

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Looking up at the Sky Tower / Sky Tower lit up at night.

The Sky Tower is an observation and radio tower located on the corner of Victoria and Federal Streets in the central business district of Auckland, New Zealand. It is 328 metres tall, as measured from ground level to the top of the mast, making it the tallest free-standing structure in the Southern Hemisphere, and the 13th tallest member of the World Federation of Great Towers.^[1]

The landmark is part of the SKYCITY Auckland casino complex, owned and operated by SKYCITY Entertainment Group.

1 Uses
2 Construction
3 References
4 See also
5 External links

[edit] Uses

Sky Tower in the Auckland skyline.

The upper portion of the tower contains two restaurant levels (one with revolving seating) and one cafe level, as well as two observation decks (including some with sections of glass floor). The tower attracts over 600,000 visitors a year.^{[citation needed]}

The tower also features the SkyJump, a 192-metre 'fan descender' jump (an experience between a bungy jump and a base jump) from the observation deck, during which a jumper can reach up to 85 km/h. The jump is guide-cable-controlled to prevent jumpers from colliding with the tower in case of gusts.^[2] Climbs into the antennae portion are also possible for tour groups.

As well as entertainment, the tower is used for telecommunications and broadcasting with the Auckland Peering Exchange (APE) being located on Level 48. A group of radio broadcasting companies share a transmitter, while television company Canwest (who runs the TV3 and C4 channels) has a secondary transmitter, their primary one being at Waiatarua.

[edit] Construction

Sky Tower illuminated in Christmas colours. Various other lighting schemes and colours are also often used.

[edit] Project history

Taking two and a half years of construction time, the tower was opened on March 3, 1997, six months ahead of schedule.^[3]

Fletcher Construction was the contracted builder for the project, while engineering firm Beca Group provided the design management and coordination, structural, geotechnical, civil, mechanical, electrical, plumbing, lighting and fire engineering services. It was designed by Gordon Moller of Craig Craig Moller, and has received a New Zealand Institute of Architects National Award as well as regional awards.^[4]

[edit] Facts & Figures

The tower is constructed of reinforced, high-performance concrete. Its 12 metre diameter shaft (containing three lifts and an emergency stairwell) is supported on eight 'legs' based on 16 foundation piles drilled over 12 m deep into the local sandstone.^[5]

The upper levels were constructed from composite materials, structural steel, precast concrete and reinforced concrete, and the observation decks clad in aluminium with blue/green reflective glass. A structural steel framework supports the upper mast structure. During construction 15,000 cubic metres of concrete, 2,000 tonnes of reinforcing steel and 660 tonnes of structural steel were used. The mast alone weighs over 170 tonnes.^[6]

[edit] Emergencies

The tower is designed to withstand wind in excess of 200 km/h and resist earthquakes with a 1000 year return period. Analysis shows that an earthquake centered 40 kilometers away and reaching 7.0 on the Richter magnitude scale is expected to leave the tower practically undamaged. Even an earthquake measured at a magnitude of 8.0 (10 times stronger than a 7.0 quake), and located only 20 km away, is not expected to collapse the tower. As an additional safeguard against emergencies, fireproof rooms on the lower levels of the observation deck would provide refuge in the unlikely event of a conflagration, while the stairwell itself is also fire-safety rated.^[6]