Australia, C&L, Cranes & Lifting, Features, Products

Andromeda’s rubber blast mats perform on Coffs Harbour Bypass

Tunnelling Solutions uses rubber blast mats to act as attenuation when blasting for the Coffs Harbour Bypass.

Senior Project Engineer on the Coffs Harbour Bypass, Jean-Luc Lejeune, discusses the efficacy of Andromeda Industries’ rubber blast mats when it comes to tunnelling in hard-rock areas in urban environments.

  • Subscribe to our free weekly newsletter to receive the latest news from Australasia’s lifting industry.
  • Don’t miss a lift and subscribe to our monthly magazine.
  • Download our latest digital magazine to catch up on the biggest news and developments in the crane industry.

Located six hours from Sydney on the North Coast of New South Wales, Coffs Harbour possesses an abundance of beautiful sights to go and see. Ranging from its beautiful beaches to the Big Banana, from the fantastic Forest Sky Pier to the magnificent Muttonbird Island Nature Reserve, the residents have plentiful wildlife, coral reefs and seasonal animals coming virtually to their doorstep, to enjoy in tandem with scenic sunrises on Australia’s East Coast. And, better yet, the town is set to be enhanced by a new 14km long bypass that will improve road safety and road freight efficiency for heavy vehicles, and ease congestion within the Coffs Harbour CBD. The Coffs Harbour Bypass is set to make life easier for the residents of the town and anyone who has the fortune of venturing through the area; in short, it seems as though the residents have it all. What they don’t have, however, is repetitive blasting noises caused by tunnelling on the new Coffs Harbour Bypass – and it’s down to Andromeda Industries’ unique rubber blast mats. 

“Andromeda’s blast mats have been extremely helpful for us,” says Senior Project Engineer, Jean-Luc Lejeune. “We can’t erect our permanent attenuation structures straight away which are to keep the noise down for the residents because they would be blown up – Andromeda’s rubber blast mats have been a perfect temporary fill in for us to manage flyrock and air overpressure.”

Working for Tunnelling Solutions, Jean-Luc’s six-year-career in civil construction and, more specifically, providing tunnelling solutions to infrastructure problems, has seen him work on Brisbane’s Cross River Rail using tunnel boring machines and the Kidston Pumped Storage Hydro Project in Kidston, FNQ – just to name a few. Across these projects, he’s used an array of different tunnelling techniques to get the job done. The Coffs Harbour Bypass being delivered  by the Ferrovial Gamuda JV, however, presented a unique challenge; hard rock drill and blast tunnelling in an urban environment. 

“What’s unique about this road tunnel is that we need to drill and blast as the ground is exceedingly hard” he says. “Tunnels in Brisbane, Sydney or in Melbourne typically use roadheaders for tunnels of this diameter, or even a TBM (tunnel boring machine) – which is a massive logistical operation and difficult to justify for our shorter tunnels.”

“Drill and blast is the more suitable excavation method for shorter tunnels with very hard rock,” he continues. “What we’ve got here is really, really hard rock that you can’t just dig with an excavator or roadheader: you’ve got to blow it up.”

And, as Jean-Luc says, that’s where Andromeda enters the picture. Australian standards are very stringent with air overblast requirements. Further complicating matters is the presence of residents just 200m away from the job.

Tunnelling Solutions uses rubber blast mats to act as attenuation when blasting for the Coffs Harbour Bypass.
The mats are acting as a temporary structure until Jean-Luc and the team can build a permanent structure. Image: Tunnelling Solutions.

“Andromeda’s mats assist in suppressing fly-rock from our blasts, and then we’ve also got the air overpressure or sound,” he says. “What we’re doing is using the blast mats as attenuation; as that force wave of sound pressure comes from the blast, it hits the mats and dissipates.” 

Andromeda’s rubber blast mats are designed to specifically counter these forces. Labelled as a “niche” product by Jean-Luc, the mats come in three different sizes: 6000mm x 3000mm, 3000mm x 3000mm, and 2000mm x 1500mm. Also factored in is the respective weight of the products: 630kg, 300kg, and 90kg. According to the manufacturer, the high density and weight of the rubber provides mass to absorb the energy of flying rocks while slowly releasing the gas pressure that comes from the blasting. 


The blast mats are used in a variety of industries and applications such as ground blast mats, suspended blast curtains in mining and construction, or as protection curtains in civil and demolition. The blast mats can be lifted and hung from their load rated plaited wire rope cable handles or bolted together using their unique eyelet design. The products lend themselves well to sustainability and the concept of reusing. The mats recycle conveyor belts that have becoming obsolete, using a special technique to fix the weft and warps together. As they are made from recycled materials with minimum embodied energy, they provide a high level of durability under “normal conditions”, according to the manufacturer, with the mats allowing for multiple control blasts creating a greater ROI. 

What’s more, on top of providing a niche solution, the service that ensued was also of a high level, with Jean-Luc praising the availability of the Moonbi-based company when it came to providing  solutions. 

“Andromeda were super responsive and quick to help out with anything,” he says. “Whatever they couldn’t get us, they came up with an alternative, and that really helped us a lot.”

Because, despite the plethora of delights the residents of Coffs Harbour possess at their doorstep, it’s a “very quiet place”, as Jean-Luc says.

“Nobody wants to disturb the peace here,” he says. “And, with Andromeda’s rubber blast mats, we certainly won’t be either.”

Send this to a friend