Silencing the boom

In the midst of Australia’s rapid construction growth, Hushpak has created new panels designed to help reduce transmission of noise.

To ensure that noise limits are not exceeded adjacent to industrial sites and busy roads, Hushpak, an acoustics and engineering specialist, has developed a new innovation called HushPanel. It provides high-quality, light-weight, easy-to-install, transferable and customisable panelling that aids in noise reduction.

The idea for the creation of the HushPanels came from Managing Director of Hushpak Engineering, Michael Neville, when driving home in the evenings. “I noticed a timber acoustic fence that had deteriorated, split and rotted over time. Further along, I saw another barrier that was essentially an old fence with horizontally installed corrugated steel cladding running along a rail line and I thought, ‘we could do that using our HushClad product’,” he says.

HushClad is sound attenuation cladding for traditional steel framed buildings and is one of the company’s original products. It is manufactured with a patented polymer layer and genuine Colorbond steel sheeting. HushClad is used for cladding buildings containing noisy equipment such as wood chip mills or coal preparation plants.

Hushpak supplies a range of other products designed to enable clients to comply with noise limits. As well as HushClad for building construction, Hushpak supplies custom-designed mufflers, low noise fans, acoustic panels and acoustic louvres for mobile mining equipment and track noise attenuation kits for earthmoving dozers.

“We wanted to develop our HushClad product to be readily used in noise barrier applications,” says Mr. Neville.

Subsequently, Hushpak was asked to supply a number of roadside noise barriers for an overpass on the New England Highway near Maitland, NSW.

“Then, when Hushpak was asked to provide a noise barrier for a conveyor system on a mine site, we knew we had to make these noise barriers modular so they could be quickly and easily installed anywhere” says Mr. Neville. “Taking the HushClad product and transforming it into modular HushPanels was the logical next step,” he says.

The development of HushPanels is so recent that they have only been supplied to one roadside project to date. However, Hushpak has received an enquiry to supply them for another noise barrier in a mining application.

“We are now looking at supplying a mining customer with a large noise barrier. The client has equipment that is disturbing their neighbours and they require a barrier about 5 metres high by over 60 metres in length to combat this issue,” Mr. Neville says.

The panels are pre-engineered up to 5.4 metres in height but could go higher, with a post spacing of 3 metres for the panels.

HushPanels have been tested in an independent National Association of Testing Authorities (NATA) accredited Acoustic Testing Laboratory. When using the standard corrugate in the Custom Orb profile, the HushPanel Premium has a sound transmission class of 25. The sound transmission class gives a rating of how well a barrier attenuates airborne noise passing through.

Clients also have the option to go with the HushPanel Ultimate, using a Trimdek profile it has a sound transmission class of 28. This gives a sound reduction equivalent to a 45mm thick sheet of plywood.

The Environment Protection agency sets limits on sites to ensure those living in close proximity to the road or construction project are not disrupted by noise. Each project will conduct a noise modelling study that will determine what needs to be done to reduce noise.

“There are a number of things that can be done to meet noise compliance requirements on road construction projects. This includes going to owners of properties to treat their residence, possibly installing solid core doors, sound insulation, laminated windows or air conditioning so windows can be kept closed,” Mr Neville says.

However, in areas of higher population density, roadside noise barriers are more cost effective than treating individual houses.

In recent years, VicRoads have looked at the effects of roadside barriers in keeping tired drivers more alert. The VicRoads Supplement to Austroads Guide to Road Design found that drivers are stimulated by variation but dulled by monotony.

One advantage of making the panels from standard Colorbond steel sheets is that the colours of each side of the panels can be easily customised. Similar to the colourful horizontal panels used on the Autobahn in Germany, HushPanels can be designed to fit in with surroundings or to meet any other client needs.

Made with galvanised steel posts and Colourbond steel panels, HushPanels have a long service life making them sustainable over a period of time. Improved colour durability with advanced paint technology resists peeling, chipping and cracking HushPanel is also quickly and easily installed.

“Companies want to minimise the amount of time on site. HushPanel installation involves bringing a post hole digger to site, boring the post holes, standing the posts and concreting them in, dropping the panels into place, then screwing them on and you’re done,” Mr. Neville says. “It’s a rapid installation.”