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The right tools for the job

Jul 09, 2023Jul 09, 2023

For interior and top-down demolition, many contractors have come to rely on remote-controlled demolition robots. Their popularity among demolition crews mostly is because of the equipment’s small size and power-to-weight ratios, which enable the machines to be used in multiple applications. Despite their compact footprint, these robots can provide hitting power on par with excavators three times their size when paired with a breaker.

This power comes from a perfect pairing between carrier and breaker—standard equipment for these machines. However, a variety of attachments are available for remote-controlled demolition robots to help contractors complete different tasks, such as material handling, excavation and surface preparation. Selecting the right attachments is important to unlocking the full potential of remote-controlled demolition robots.

Next to hydraulic breakers, crushers are probably the most common attachment used by demolition contractors. Crushers reduce noise and vibrations, so they can be used in environments where noise should be minimized and vibrations can cause damage.

Where breakers use force to knock down a wall, crushers chew the concrete, leaving rebar exposed. Crushers require access to an exposed edge of the structure being demolished to break it down.

For top-down applications where noise and vibration are primary concerns, crushers allow contractors to work during the day, sometimes without neighbors noticing.

Recently, a Canadian contractor removed 38 stories during a demolition project using remote-controlled demolition robots outfitted with crusher attachments.

The Canadian company’s primary focus was mitigating disruptions, such as dust and noise, in the immediate area. After erecting a hoarding system around the top of the building, the demolition area essentially was hidden from the ground and neighboring buildings.

The contractor worked down through the building’s floors, systematically crushing concrete and cutting reinforcement steel. Working with two demolition robots, crews were able to complete one floor every three to four days, taking down the 38-story structure in nine months.

In addition to enabling “silent demolition,” crushers make material handling easier. The resulting debris is a uniform size, and steel is separated for recycling during the initial stage of demolition rather than later.

For maximum efficiency, contractors should pay attention to the jaw opening and crushing force.

To easily take on concrete slabs 17 to 22 inches thick, a crushing force of 44 to 54 tons is best. Wear-resistant, replaceable steel alloy crusher tips and cutter blades, as well as 360-degree rotation, also are recommended.

Shears are another attachment that, when paired with demolition robots, can increase safety and productivity on a demolition job site. As with breakers, crushers and grapples, manufacturers have taken advantage of the maneuverability and precision available from demolition robots to optimize shear attachments, further reducing the need for larger crews and hand-held torches in certain applications and scenarios.

Because of floor load limits and other access restrictions for larger equipment, contractors traditionally have relied on hand-held torches to cut metal on interior demolition projects. The use of hand tools for cutting concrete reinforcement, sprinklers, conduit, wire and cable comes with potentially life-threatening risks for workers. In addition to hazards such as electrical shocks, falling debris, burns, fumes and fire hazards, falls are possible because these tasks often require scaffolding. These potential hazards can lead to increased health and safety concerns for workers, which are reflected in workers’ compensation claims and higher insurance premiums for employers.

Using a remote-controlled robot with a shear attachment for these tasks eliminates many of the associated risks. Shears pierce or cut through material rather than burn through it as a torch does. By removing heat from the equation, operators also eliminate the likelihood of sparks, flying embers and fumes. Additionally, compact demolition robots can access confined spaces and areas with low floor loads.

Using shears in these situations offers a mechanical solution that keeps operators safely on the ground while providing a good view of the work at hand. While contractors still should ensure electricity is shut off before cutting wires or other conduits, it is better for a robot to receive an electrical shock than an employee.

Look for shears with high power-to-weight ratios to allow for optimal cutting power in a smaller package, and a hydraulic 360-degree rotary drive for accuracy.

Perhaps the most underused demolition attachment is the grapple. This versatile tool is ideal for soft demolition, separation and sorting applications. It also can be used for support tasks before, during and after primary demolition activities.

Grapples function as a rudimentary hand with two fingers and a thumb for pinching, pulling and sorting. When paired with a flexible, remote-controlled machine, the grapple can save significant time and money compared with manual demolition methods in confined spaces. In many cases, grapples can eliminate the need for harnessed workers on ladders or scaffolding.

For example, the attachment can be used to grasp structural elements, including drywall, ceiling sections, piping, steel drums and HVAC ducts, which the remote-controlled tool carrier easily can pull down. Remote operation also means workers can position themselves away from any falling debris while maintaining a good view of the work.

Another example would be elements that require support, such as a 4-inch-diameter overhead pipe that needs to be cut with a torch. The grapple clamps onto the pipe and holds it, while a worker torches through it on either end. Once it is free, the grapple safely lowers the pipe to the ground.

Grapple attachments also can lift, move and support material during construction. Depending on the jaw opening and carrier size, these tools can lift materials up to 30 inches in diameter. When paired with a demolition robot with exceptional reach, this means operators can remain safely on the ground and out of the drop zone during various overhead tasks.

Once materials have been pulled down, the precision and flexibility of the remote-controlled demolition machine with the grapple attachment make it easy to pick up and sort small debris. For picking, sorting and material handling, boltable grip plates allow operators to complete those tasks without switching attachments.

Finally, no suite of robotic demolition attachments would be complete without a bucket. These multi-purpose tools increase efficiency during confined work, such as excavating, digging trenches, handling material, sorting, separating and loading debris.

Since they are primarily designed to optimize breakout forces while hammering above and in front of the machine, the demolition robots’ boom design provides ample power for digging in rocky soil or heavy clay. It also provides increased reach and maneuverability compared with most similar-sized mini excavators.

A three-part arm allows demolition robots to work close to the carrier body, minimizing the need to reposition. Compared with the two-part excavator boom, the demolition robot’s flexible three-part arm also requires less height to extend, making it ideal for confined spaces.

Most models only require 72 to 84 inches of height for excavation, allowing operators to work in various situations with low overhead clearance, such as tunnels and utility applications. Smooth, precise movements and a wide range of motion mean operators can dig both toward and away from the machine by changing the bucket’s orientation, and a strong boom means the demolition robot can handle larger buckets and heavier loads than similar-sized excavators.

Using remote control machines also eliminates the need to climb into or out of a cab, a leading cause of job site injuries such as sprains, strains and other minor ailments.

Manufacturers often offer customized buckets to fit an operation’s specific needs for maximum efficiency.

These tools are a small sample of what some manufacturers offer. More than 80 attachments are available to choose from, including planers, descalers, rock drills, saws and shotcrete guns. A demolition robot can become a true multipurpose machine, creating new revenue opportunities and speeding up return on investment.

Forward-thinking contractors can capitalize on the versatility provided by the right suite of attachments, turning a demolition robot into a remote-controlled tool carrier. The right combinations can streamline work and enable firms to take on new applications to grow their businesses.

Jeff Keeling is vice president of sales and marketing for Brokk Inc., a Monroe, Washington-based manufacturer of remote-controlled demolition robots and attachments. He can be contacted by emailing [email protected].

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