Over 400 Tension Bars from Ancon Building Products have been installed on the Forsyth Barr stadium in Dunedin, New Zealand, where England will play their first three matches in the 2011 Rugby World Cup.
The steel tension bars are installed in the roof and in the South and West stands of this brand new stadium, to brace the impressive overhead structural steelwork.
It is the first sports stadium, anywhere in the world, to feature a permanent roof over a natural turf playing surface.
The Ancon system includes bars with a special, high strength, rolled thread which was designed and tested to meet the specific dynamic conditions in the stadium roof, caused by wind loads.
The dimensions of the project are immense. The stadium is almost 50 metres high, equivalent to the height of a 12 storey building. The iconic roof is formed from five arched steel trusses, each with a span of 105 metres, and the main steel truss in the South Stand is 130 metres long. The largest Ancon bars were 42mm in diameter and 15 metres in length.
Ancon Tension Systems comprise a range of components that can be used to create a variety of assemblies, from simple tie bars to complex bracing systems involving several bars joined at one point. Unlike standard tie bars that require turnbuckles, adjustment to the system length is accommodated within the fork connector at each of the bar. Locking nuts firmly lock the bars to the forks and ensure the connection is secure.
The project, known as Otago Stadium during the construction phase, was started in June 2009 and completed in August 2011. The roof canopy is transparent and is angled towards the north to optimise light in the winter months. The venue will host four matches in the 2011 Rugby World Cup.
Ancon designs and manufactures a wide range of construction products and has supplied numerous international sporting venues including the City of Manchester Stadium, Benfica’s Estadio da Luz and the Melbourne Cricket Ground.