Measurements to prevent noise from aluminium factory 

The first time Rasmus Stilling Krogh, Project Manager in COWI’s Environment, Noise & Acoustics Department, was asked to measure the noise levels at the aluminium smelter, construction hadn’t even begun. In fact, the only thing being measured was very low local traffic and Mother Nature herself.

“This was the first time we’d been asked to measure a plant that hadn’t yet been constructed, and it was quite challenging because the sound levels were very low,” recalls Rasmus Stilling Krogh.

Birdsong and babbling brooks

The only sounds picked up by the sound level meter were produced by some rather disgruntled birds and babbling brooks. “It was almost as if the only real noise was the noise we were making ourselves,” says Rasmus Stilling Krogh.

Fjardaál is the first aluminium smelter to be built by Alcoa in 20 years and Iceland was chosen as the location because energy costs were low. Bechtel, the American contractor developing the smelter, has subcontracted COWI to perform the noise measurements.

Continous computerised calculations

Concurrently to the measurements in Iceland, COWI has built a computer model of the smelter. Each time a new machine has been added to the construction, COWI has incorporated the noise data in the computer model in order to calculate the noise impact.

”We continuously receive more and more details about the plant, which we then take into account in our model. This makes it easier for us to identify exactly where we can reduce the noise levels and assists Bechtel in optimizing the plant design”, explains Rasmus Stilling Krogh.

Noise from cars and ventilation

The next trip to Iceland is scheduled for the autumn and will involve new measurements of the plant currently under construction. More data will be gathered at the end of 2007, when the factory is due to be completed,.

”We have to measure the building and construction activities plus the vehicles that drive back and forth during construction in order to determine how much noise they actually generate. When the factory is completed the primary noise sources will be the ventilation, handling of materials and internal transport,” concludes Rasmus Stilling Krogh.

By Gitte Roe Eriksen
Published: 01.06.2005