The Sky Tower in Auckland: the second tallest building in the southern hemisphere

Since its completion in 1997, the Sky Tower in Auckland has become the symbol of the city, as well as the main attraction of this great New Zealand city. We should point out that at its inauguration this building was greeted as the tallest building in the southern hemisphere: the tower is 328 metres tall, in fact. The record has now been surpassed, however, so that the Sky Tower in Auckland has become the second tallest building in the southern hemisphere. It is the Autograph Tower in Jakarta, Indonesia, completed in 2022, that has captured the title of the tallest freestanding structure in the southern hemisphere, at 382 metres tall. But the fascination of the Sky Tower definitely remains unchanged and it continues to attract the interest and curiosity of over 1,000 visitors a day. Let’s take a look at the features of this famous New Zealand tower.

 The height of the Sky Tower in Auckland

What is the function of the Sky Tower in Auckland, with its height of 328 metres? The tower has 2 main roles: it is a telecommunications tower, having an antenna located on the top, and it is an observation tower. It was erected in the Auckland Central Business District, so it is in the nerve centre of the city, and dominates the Auckland skyline unchallenged. Considering that the tallest skyscraper in the city, Commercial Bay, is just 180 metres tall, the Sky Tower outstrips it by a full  148 metres. To give you an idea of the height of this observation tower, the Eiffel Tower is 300 metres tall, while to compare it with another European tower, the famous television tower in Alexanderplatz, Berlin is 368 metres tall. Since the Sky Tower is neither a residential building nor an office building, we cannot really talk about the number of “floors” in the building: however, the equivalent corresponds to 71 floors.

The design and construction of the Sky Tower in New Zealand

The tower is part of the SkyCity Auckland Casino complex, which was built between1994 and 1997. The Skycity Entertainment Group had two main requirements: they wanted a building that could be used for telecommunications while at the same time it would be an important tourist attraction. The design was created by Gordon Moller, from the Craig Craig Moller Architects studio, which won several awards for the Sky Tower design, including the New Zealand Institute of Architects National Award. The construction of the tower was entrusted to the Fletcher Construction company. Work started in 1994 and was completed 2 years and 9 months later, with the inauguration taking place on 3 August 1997. The total cost of the building was 85 million New Zealand dollars.

The features of the Auckland tower

The Sky Tower in Auckland was built using high-performance reinforced concrete, with an internal 12-metre diameter shaft housing 3 lifts; next to the lifts is an emergency staircase. The highest levels were constructed using precast concrete, structural steel and reinforced concrete; the observation platforms are clad in aluminium panels and reflective glass, which can also be seen from below. The upper mast structure is supported by a structural steel framework.

According to the figures that have been made public, the construction of the tower required 15,000 cubic metres of concrete, 2,000 tons of steel and 660 tons of structural steel. The tower rests on 16 foundation piles which were drilled 12 metres down into the rock below.

It is calculated that the mast of the Sky Tower in Auckland weighs a total of 170 tons. Since it was too heavy to be raised by helicopter, it was hoisted by means of a crane attached to the structure; to remove this crane afterwards, it was necessary to put a second crane in place, which was eventually dismantled into pieces small enough to be transported in the lifts to the ground floor.

Floors accessible to the public

The floors that are accessible to the public are at the top and can be reached by means of the lifts inside the shaft. The 50th floor houses the Sky Cafe, while on the floor above that is the Main Observation Deck, where visitors can enjoy a first view of Auckland and the surrounding area from above. The 52nd floor is devoted to the Orbit 360° dining, while The Sugar Club restaurant, the Sky Walk and the Sky Jump are all located on the 53rd floor. The highest floor that is accessible to the public is the 60th floor with the Sky Deck: from here visitors can enjoy a superlative view from 186 metres above ground, with a panorama extending 80 kilometres in all directions, so you can see the many volcanos located in the surrounding area, for example.

The resistance of the Sky Tower in Auckland

The Sky Tower structure has been built to withstand hazards of various kinds. For example, as regards wind resistance, it has been calculated that the tower can withstand gusts of wind of up to 200 kilometres an hour, and can sway up to 1 metre in the event of extremely strong gusts. To ensure the safe use of the lifts, a system of sensors can detect the presence of excessively strong wind, and thus regulate the speed at which the lifts move up and down. In the event of particularly intense gusts of wind, the lifts return immediately to the ground floor until the situation returns to normal. It has also been calculated that the tower can resist earthquakes of magnitude 8 with an epicentre within a 20-kilometre radius. In the event of an emergency, there are fireproof rooms on floors 44, 45 and 46.