Excavators Australia has been operating for five years and runs a large fleet of excavators, with hammers, ranging in size from mini to large . The contractor mainly carries out rock work on major projects such as freeways, tunnels, optical fibre lines and pipelines. Its recent projects include the M5 freeway extension in Sydney, Geelong freeway to Melbourne, Carlsruhe Bypass, Nextgen Networks and the Docklands development in Victoria.

On one of its current projects, the construction of the Craigieburn Bypass in Victoria, Excavators Australia needed a heavy hammer to break through the basalt on the site. Due to the proximity of a busy freeway, railway and power lines in selected areas the hard rock could not be blasted.

According to Laurence Eales, Director of Excavators Australia, the client, Abigroup Contractors wanted a 45 tonne excavator and hammer to speed up production in the basalt.

“I suggested using a hammer range for a 45 tonne excavator with more power on a smaller 35 tonne excavator,” said Mr Eales.

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“We chose to trial the Krupp HM2300 based on the past performance of our fleet of smaller Atlas Copco hammers,” he said.

After the trial Abigroup agreed to allow the use of the smaller 35 tonne carrier, and Excavators Australia bought two HM2300 hammers for the project.

“We’ve had a really good run with the Atlas Copco hammers. They come with a two year warranty and are headache free. They’re very good, very productive and very reliable,” said Mr Eales.

“The things that sold me on the HM2300 were its quietness, lack of vibration, hitting power and the back up service from Rock Tools & Equipment. We were only going to buy one, but I was so impressed, I bought two.”

Rock Tools & Equipment is the distributor of Atlas Copco hammers in New South Wales. “We’ve had really good service from RTE. They have parts in stock; they arrive overnight if we’re working interstate. If a hammer needs major repairs, it’s in and out of their workshop the next morning,” said Mr Eales.

All Atlas Copco Krupp hammers are equipped with a Vibrosilenced, noise and vibration dampening, system. The Vibrosilenced system reduces noise levels by around 8 dBA.

“With the HM2300 there’s no vibration to the excavator’s cylinder rods. Other hammers shake the machine’s rods, cause seals to leak, and can snap the rods. Vibrations from the hammer knock the machine around,” said Mr Eales.

The hammer has a variable impact energy of between 320-600 blows per minute, making it the highest in its class, delivering maximum power to the job.

“We wanted a large productive hammer. We’re also doing a lot of crushing to reduce oversize boulders which are a couple of metres in diameter. The HM2300 only takes two big blows to split a boulder in half that would take any other hammer 8-12 blows or even more,” said Mr Eales.

The HM2300 hammer is equipped with StartSelect which allows the operator to set the hammer’s start-up and shut-off functions according to conditions. In Autostart mode, the hammer starts working as soon as the tool comes into contact with the material and if idle blows happen, the hammer continues at reduced energy and starts up again when in contact with the material.

“We use the StartSelect on Autostop when breaking oversize. The hammer stops when the rock breaks and starts again when it touches the next boulder,” said Mr Eales. Although the HM2300 has only been a recent addition to Excavators Australia’s fleet, Mr Eales wishes it had been around for earlier jobs such as the laying of the optical fibre network from Sydney, Melbourne, Adelaide and Perth.

“If I’d had a hammer like the Krupp on that job, it would have been a lot easier. You can’t compare the Krupp to any other hammer I’ve used on the market.”