A noise barrier constructed without posts—could that even be done?

Hammerglass leads the way with a post-free barrier!

A noise barrier constructed without posts – is that even possible? HMG iNFRA and Hammerglass have just proven it is, and the installation is now underway in the bypass Stockholm area, fully in line with the Swedish Transport Administration’s innovative thinking.

Many raised their eyebrows in 2018 when the Swedish Transport Administration issued a request for a post-free, overlapping noise barrier in three different shades of green for the major infrastructure project "Bypass Stockholm", section Hjulsta South and North. The screen was also to feature screen printing to act as bird strike protection.

– It’s a very unusual type of screen, and we had never bent polycarbonate in this way before, but innovation is exciting and we enjoy challenges – the more advanced, the better. This is a sleek design that aligns perfectly with future demands for infrastructure and societal benefit, says Ulf Bergström, HMG iNFRA / Hammerglass.

What challenges did you face?
– The bending process is complex and took time to perfect. The mounting also differs significantly from that of a traditional noise barrier. In a post-free construction, you need to have a perfect understanding of how temperature changes and other movements affect the kinetic energy in the material and ensure the barrier remains sealed. There were many factors to consider.

"Pleased to make the architect happy"

Bends at 90-degree angles in three different directions are the “secret” behind the post-free noise barrier’s stability. Designer and bending specialist Kenneth Sonnäng had his work cut out before he cracked the code for the 90-degree bending.

 

– We’re proud that I managed to pull it off. Everything shifts with heat and cold, and we use expansion joints everywhere, but it was really the bending that challenged us in the beginning—making sure the polycarbonate sheet wouldn’t crack.

 

How many tries did it take before you got it right?
– I’d rather not say! But now everything’s running smoothly. We do the bending here on-site in Förslöv, and we’re talking about over a thousand bent Hammerglass panels going up in Hjulsta.

 

What do you think of the design?
– This is really an architect’s dream, so it feels great to have fulfilled that for Mats Broman, architect at the Swedish Transport Administration.

"Lightness, transparency and elegance"

The architect behind the post-free noise barrier is Mats Broman, who, in close collaboration with colleague Richard Rotstein, has created something that no one had seen before.

 

There were several requirements on paper during the development of the barriers:

 

  • Self-supporting and identical (mounted orthogonally on the edge beam)

  • Aesthetic and give a "light" impression

  • Easy to handle and install

  • Contain a minimum of components

  • Easy to mass-produce

The complete noise barrier was not allowed to contain any bulky or unsightly steel structures.

 

See project specifications here

Learn more about our noise barrier systems

Mats Broman, Swedish Transport Administration:
– We chose to give the barriers a green tint because the viaduct they are mounted on runs through a green area. It feels like a natural fit, with three different shades of green creating a vibrant variation in the barrier. An added bonus is that it will be easier to replace damaged panels in the future, since small variations in shade won’t be as noticeable.

 

How do you feel about the result?
– I'm very pleased. The long bridge has received an architectural refinement with screens that express lightness, transparency, and elegance – while also being smart and cost-effective from a production, installation, and maintenance perspective.

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