A-REX M9300 DEMOLITION WITH A BITE
“If it doesn’t exist, it can be built to meet our needs” – words to live by for Aregger AG in Buttisholz in the Canton of Lucerne. The innovative family business specializes in civil engineering and construction with a focus on complex demolition projects where timing is crucial. When it couldn’t find the ideal demolition excavator on the market, it designed its own.
What comes to mind when you think of demolition? The good old wrecking ball, perhaps an excavator and a dump truck or two? That’s how it was many years ago … Today, not only the methods used to demolish complex structures have changed, but also the legal requirements, and especially the expectations of developers. By the time a major building is demolished, the start of a new construction project is already in view.
A CHALLENGING SPECIALTY
Complex demolition demands high performance under difficult conditions. The work has to be done in a restricted space with a minimum of dust, noise, vibration and disruption of traﬃc, in accordance with the highest safety standards and in compliance with environmental regulations. Aregger AG specializes in rapid demolition of large, sprawling structures (skyscrapers, viaducts, smokestacks, industrial buildings, etc.). At the start of a project, specialists draw up a detailed demolition plan, taking every factor and all parties involved into account. Heavy-duty, perfectly dimensioned machinery, often with custom-designed tools, bites into concrete slabs up to 2.3 meters thick and steel beams up to HEB 100. Work at up to 65 meters above ground or 20 meters below is nothing unusual. With the right coordination, large volumes of concrete can be removed per hour. A survey of potential contaminants (asbestos, PCB, PAH, etc.) is required before every demolition. These materials must be removed, separated and properly disposed of under strict precautionary measures. Meanwhile the start date for the new construction project draws ever closer …
MORE PERFORMANCE = LESS TIME
It’s no surprise that high-performance equipment is a big advantage on large-scale projects. When the unexpected occurs – contamination, bad subsoil, ﬂooding – high-performance machines can help keep the work on-schedule. That’s when the A-Rex comes into its own. After much thought and investigation, the A-Rex was designed in-house by Aregger AG engineers and built to order. “Now we can reach buildings up to 65 meters tall with the excavator arm and work twice as fast,” explains Franz Muri, head of demolition for Aregger AG and father of the A-Rex.“That massively reduces the time pressure.” It took three years before the enormous machine stood ready on the company’s grounds.
A NEW BREED CHALLENGES OLD RECORDS
Unlike the precisely calculable loads on cranes, for example, those on demolition excavators can hardly be predicted, much less calculated. To stay on the safe side, everything on the A-Rex is oversized. The machine is based on a Liebherr excavator designed for 24-hour operation in mines. But that’s the only thing standard about the A-Rex, which was re-engineered from the ground up, massively reinforced and rebuilt for its intended performance class.
NO ROOM FOR SLIP-UPS
Big is cool, but operating a machine of these dimensions takes plenty of experience and a steady focus. When the operator uses Aregger’s custom-designed Magnum pincers (net weight: 14 t) to take a bite out of a multi-tonne concrete slab 40 meters off the ground, he has to be able to gauge the risks. Like smaller demolition excavators, the A-Rex is controlled by just two levers. That’s why only experienced machine operators with extensive training are allowed to operate the A-Rex, or for that matter any of the other large equipment. Whether demolishing a highway viaduct, a skyscraper, a 50-meter tall steel tank at a reﬁnery or a portion of a still-functioning chemical plant, the operator’s experience and ability to estimate the static forces in a structure are constantly tested.
UNTIRING HYDRAULIC MUSCLES
A full 2000 liters of hydraulic ﬂuid ﬂows from the tank through numerous pumps, valves, and hydraulic motors via several hundred meters of hoses and tubes to the cylinders. Pump pressures can reach 350 bar. Workplace safety is a top priority at Aregger. That’s why besides scrupulous maintenance, the company depends on MOTOREX quality operating ﬂuids and lubricants. Excavators play the main role in major demolition projects. Only when the material is on the ground can it be triaged for crushing, separating concrete from steel and other materials before hauling it oﬀ. At the demolition of Messe Basel, for example, 47 dump trucks were kept in circulation to carry oﬀ the materials, making some 180 trips per day. Having an excavator fail on a project of that scale would be about as much fun as a nighttime encounter in the woods with a T-Rex.
Watch the demolition of the Baloise Park: