Millimetres Decide in New Swedbank Arena

Football or soccer is one of the most popular sports around. It’s a game for every place, a beach in Rio, a grass field in a tiny Swedish town or a world class entertainment at Old Trafford in Manchester or at Nou Camp in Barcelona. Now Stockholm will get a new national arena for football, Swedbank Arena in Solna, just a few kilometres north of the city centre. The roof is movable to shelter the players and the audience for heavy rain or snow. In order to secure the function of the roof millimetre accuracy is required – a demanding task for Inspecta.

The measurement specialists of Inspecta in action

On the top you must be prepared to strong winds. At the roof of Swedbank Arena, 55 metres above the new grass lawn, Inspecta’s Finnish specialists Tuomas Hietanen and Marko Tommila have been working with advanced 3D measurement of the beams and rails, which carry and guide the movable roof covering the new super arena.

”The influence of winds is no actual problem for our laser measurement device, but the precision of the results is sensitive to temperature changes, since we are working with steel. The set point is the guide rail – the 272 measurement point network is orientated according to the coordinates of the rail. The steering rails are fixed to eight beams, each of them around 140 metres long”, Tuomas and Marko explain.

The duo forms exactly half of Inspecta’s specialized measurement team, which has solid international experience from 3D measurement by laser tachymetry.

”We have been working in Finland, Sweden, Russia, China, the US, Slovakia and several other countries. This technology is applied mainly for installation of machines, tanks and other production equipment in the process industry, but it can also be used for measurement in three dimensions of ship hull sections or oil drilling rigs. The customers may be small engineering companies or large nuclear power plants.” 


Toumas Hietanen, Inspecta

In Sweden the 3 D experts of Inspecta have been measuring a mulish kiln and a running paper mill. The way to the roof of Swedbank Arena went via contacts to Finnish steel producer Ruukki, which delivered the steel frame, exactly as they made to the famous Globe of Stockholm in 1989.

Specialist skills wanted

”No Swedish companies were able or wanted to perform the task, to measure the arches. I visited the site in May 2011 for an analysis and I made the assumption that the measurement was possible”, Tuomas tells.

The mission contains alignment of the position of the rails in relation to the guide rail, in respect of both horizontal and vertical coordinates, judgement of the profile of the arch and measurement of the straightness of the rail.   

”The postulated tolerance is +- 5 mm in the horizontal plane and +- 10 mm in the vertical position. The arch is not allowed to vary strongly from a positive to a negative deviation within short distances to prevent deforming forces”.

Each measurement takes half a day to perform, while calculation and graphic presentation needs another half day – i e temperature variations have to be compensated. The results are handed over to the team of Ruukki, which continuously adjusts the beams by using shim elements.

”We manufactured special tools by ourselves – quite successfully; we did not have to modify them afterwards. The sixteen measurement positions for each alignment process are marked by aluminium poles, which are exactly defined in a prismatic net.”   

Tuomas and Marko agree that the method of Inspecta is both fast and reliable.

”Since the measured area is large and the geometry is demanding 3D laser tachymetry is a good solution. In Finland Inspecta has received a utility model certification for the method including 3D measurement and CAD-based calculation. The level of technology allows millimetre precision also for large objects, but so far it is still the eye of the football player that decides whether the free kick will pass into the goal or not when football teams meet at Swedbank Arena! “

Facts about Swedbank Arena:

Owner: The Swedis Football Association (Svenska Fotbollsförbundet), City of Solna, Fabege, Jernhusen, Peab
Architect: Krook & Tjäder in cooperation with Berg Arkitektkontor and HOK Sports
Project owner: Arenabolaget i Solna KB
Main contractor: Peab AB
Measurement of the playground:

68 x 105 m

Foundation: Grass on a concrete floor, also ice, snow, parquet floor and gravel
Height to ceiling:  55 metres
Completion:  August 2012
Capacity:  30 000 seats (football), 50 000 (concerts, public events), 65 000 incl  standing spectators

 

By: Tage Ericsson

 

Page created: 19 Oct 2011