Sydney Tower
Construction of Sydney Tower Centrepoint began in late 1970 with the first 52 shops opening in 1972. The office component was completed in 1974 and the final stage of the complex, the Sydney Tower, was opened to the public in August 1981.
Ranked as one of the safest buildings in the world the design has made the tower capable of withstanding earthquakes and extreme wind conditions. 56 cables stabilise the tower, and if the strands of these cables were laid end to end, they would reach from Sydney to Alice Springs, or from Sydney to New Zealand.The turret has a capacity of 960 persons, and contains two levels of restaurants, a coffee lounge, an Observation Deck, two telecommunication transmission levels and three plant levels. Three high speed double deck lifts take approximately 40 seconds to travel from top to bottom.
The 1504 stairs, constantly monitored by security, provide emergency exit from the tower. Divided into two fire-isolated sets of pressurised stairs, they allow patrons direct access to street level.
The 420 windows of the tower are cleaned by a semi-automatic window-cleaning machine, which recycles and filters 50 litres of water. This machine takes two days to clean all 420 windows.
A 162,000 litre water tank, the tower's primary damping system, one million dollars worth of fire protection equipment and countless sprinklers add to the safety standards which far exceed normal building requirements.
Sydney Tower construction
The construction of Sydney Tower is an interesting tale of engineering and quality construction. Individual barrel units, arriving on-site virtually pre-made, formed the shaft of the tower. The turret structure, making up the four levels of viewing areas at the top of the tower, was in fact constructed at the base of the shaft. As work on the shaft progressed, the actual turret was raised up the shaft.
The shaft supporting the turret is made up of 46 barrel units, each weighing 27 tonnes. These were brought on to the site in seven pieces and welded together. Once the first three sections were in place, a gantry crane was erected to hoist the remaining 43 barrel units.
Each barrel unit was completed with lifts rails, stairwells and hydrolic risers before hoisting. The shaft contains two sets of fire stairs, fire, electrical and plumbing ducts in one half and the lift shafts in the remainder.
Once the tower structure was complete, the spire was erected. This was done in two parts, by placing one half and then lifting the top section onto the bottom section. The crane did not have the reach to lift the spire from the top, so it was lifted from the side. This was achieved despite the difficulties of maintaining adequate balance.
Find out more about the construction of the tower
when you next visit Sydney Tower.
