Work to build the 60-metre tall shaft for the new £16m air traffic control tower at Manchester Airport has been completed by main contractor Morgan Sindall.
Morgan Sindall poured concrete continuously for 222 hours from the morning of Tuesday 13 March to the evening of Thursday 22 March building the tower at an average rate of 27cm an hour. This method of pouring concrete into a continuously moving form is known as 'slipform' and is the same construction technique that was used to construct the famous CN Tower in Toronto, officially recognised as the tallest free-standing structure in the world from 1976 to 2007.
Teams of 20 construction operatives worked 24-hours-a-day on an elevated hydraulic platform surrounding shaft, inserting steel reinforcing rods into the concrete and 'polishing' the shaft as it grew, to ensure a smooth finish to the structure.
Around 600 cubic metres of concrete and 65 tonness of steel reinforcement form the nine-metre wide shaft of the new ATC tower in the centre of the airfield.
Andrew Harrison, chief operating officer of Manchester Airport, said: "The completion of the slipform process is a key milestone for the project. After three years of planning, it is fantastic to see the tower take shape and rise out of the ground to become an iconic landmark of local skyline. The amazing speed at which the tower has risen is testament to the outstanding work of the project team and we look forward to the completion early next year."
The tower is pre-let to NATS, the UK's leading air traffic control company, which will relocate its existing Manchester air traffic control centre from its current location on top of the Tower Block building in between Terminals One and Three at the airport.
Paul Jones, general manager for NATS at Manchester, said: "From our vantage point in the current air traffic control tower it has been astonishing to see how quickly the new tower has risen over the past nine days – it seems to have appeared almost out of nowhere."
The next stage of the project is to build a 'sub-cap' unit, which will house the new visual control room providing 360-degree panoramic views of the airfield. The sub-cap will be the equivalent size of a four-storey detached house and once it has been built on the ground, it will be hoisted up by crane and permanently placed on top of the newly built tower shaft.
Jim Morgan, area director for Morgan Sindall's Manchester office, said: "We are delighted to have reached such a significant stage in the development at Manchester Airport. The slip form process has allowed us to create a robust and resilient tower in a relatively short period of time.
"This is an exciting project to be a part of and we are enjoying working closely with Manchester Airports Group's in house team as well as architects, CPMG, and engineers, URS Scott Wilson."
The tower is due to be operational in spring 2013.