Sky Tower (Auckland)

The tower was constructed as a part of the Skycity casino precinct. The Skycity Entertainment Group's initial brief for the project were that they required a tower that was both a high-quality tourist attraction, and a marketable telecommunications facility.[14] 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. Harrison Grierson provided surveying services.[15] It was designed by Gordon Moller of Craig Craig Moller Architects[2] and has received a New Zealand Institute of Architects National Award as well as regional awards.[16][17][18] The project architect was Les Dykstra.[19] Taking two years and nine months to construct,[20] the tower was opened on 3 August 1997.[21]

The tower is constructed of high-performance reinforced concrete.[14] Its 12-metre (39 ft) diameter shaft (containing four lifts and an emergency stairwell) is supported on eight "legs" based on 16 foundation piles drilled over 15 m (49 ft) deep into the local sandstone.[17][18] The main shaft was built using climbing formwork.[18]

The upper levels were constructed from composite materials, structural steel, precast concrete and reinforced concrete,[18] 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 (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).[18][22] 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.[18]

The tower is designed to withstand wind in excess of 200 km/h (120 mph) and designed to sway up to 1 metre (39 in) in excessively high winds. As a safety precaution the Sky Tower's lifts have special technology installed to detect movement (such as swaying due to high wind) and will automatically slow down. If the building sway exceeds predetermined safety levels the lifts will return to the ground floor and remain there until the high winds and building sway have abated.[23]

The Sky Tower is built to withstand an 8.0 magnitude earthquake located within a 20-kilometre (12 mi) radius.[24] There are three fireproof rooms on levels 44, 45, and 46 to provide refuge in the event of an emergency, while the central service lift shaft and stairwells are also fire-safety rated.

H = Horizontal V = Vertical

The following table contains television and radio frequencies currently operating from the Sky Tower:

The top half of the Sky Tower is lit by energy efficient LED lighting which replaced the original metal halide floodlights in May 2009. The LEDs can produce millions of different colour combinations controlled by a DMX lighting controller. The original lights used 66 per cent more energy than the current LED system. The bottom half remained lit by metal halide lamps, until they too were upgraded to LED lighting in 2019.[37]

In an effort to promote power saving, SkyCity turned off the tower lighting in Winter 2008, retaining only the flashing red aviation lights. SkyCity is also minimising façade flood lighting across its complex. Simon Jamieson, general manager SkyCity Auckland Hotels Group, said: "Like every New Zealander, we are concerned about the country's electricity supply, and we believe it is our responsibility to make this move to assist with the power saving request."[38] The tower was reilluminated on 4 August in support of New Zealand athletes competing at the Beijing Olympics.[39]

Panorama as seen from Sky Deck, Sky Tower, Auckland

The Sky Tower is used in support of special charity events. The Leukemia and Blood Foundation of New Zealand organises annual fundraising stair climb challenges, notably the "Firefighters Sky Tower Stair Challenge" which sees firefighters from around New Zealand race up 1,108 steps (out of 1,267 total steps).[40] Climbing the Sky Tower stairs has been described as a "vertical marathon".[41]

The Sky Tower is also the venue of the annual "Tower de Force" competition. It includes a climb up 1,226 steps (out of 1,267 total steps), and various other military skills tests that change yearly.[42] Participants include the RNZAF, RNZN, New Zealand Army, New Zealand Defence Force veterans, New Zealand Police and, more recently, units from the New Zealand Cadet Forces. The competition is used to raise funds for numerous charities, including in 2019 Mike King's The Key to Life Charitable Trust.[43]