Christchurch gets a big tower ... only smaller

The airport control tower was designed to complement the Chalice sculpture in Cathedral Square. Photo / Simon Baker

It may not have the Sky Tower, but Christchurch can at least boast the country's highest airport control tower.

At 45m - against the Sky Tower's 328m - the new tower opened yesterday by Prime Minister John Key is the tallest of 19 at New Zealand airports.

Construction took just over a year and cost $6 million.

Designed to complement the Chalice sculpture in Christchurch's Cathedral Square, the structure will watch over all air traffic at the city's international airport. The old 20m tower will be demolished.

"When we began the design of the tower, we had a genuine desire to create an iconic structure that would ensure people arriving into Christchurch Airport would have an unforgettable experience," said Airways New Zealand project manager John Pringle.

"Now that it's completed, I think most people would agree we have achieved that."

Construction was a complicated process.

"There were a number of geometrical and logistical challenges to overcome, not least of which was producing the chalice shape, starting at around 64 square metres at the base and spiralling 45 metres up to the control cab with a 12-metre diameter at the top," Mr Pringle said.

The control room needed 12 tinted glass panels, each 30mm thick and weighing about half a tonne, and the foundations contain took 38 truckloads of concrete.

Among events to mark the opening yesterday were races to the top of the tower.