Robots built for demo
Demolition robots add a new dimension to interior demolition. West Bend, WI-based Interstate Sawing used its Brokk demolition robots to transform its business. “Our specialty is confined space demolition,” says Duke Long. “We are not just concrete cutters.”
The machines allow the company to complete projects that most concrete cutters could not accept. “I bought my first Brokk four years ago. Now I have four of them,” says Long. “They really give us a very competitive edge. We have grown our customer base tremendously.”
The demolition robots allow Interstate Sawing to handle difficult jobs, such as removal of 30-in.-deep concrete before digging 1,000 ft. of trench in a weekend. They also allow the contractor to re-think conventional demolition methods.
For example, floors in buildings and stairways can be removed without shoring and with less saw cutting required. Plus, the robots can be sent into trenches without shoring, since there is no need for a person in the trench. The ability to mount a camera on the unit opens up even more possibilities. “When you do a walk through, you have all of these different options in your arsenal and you become more competitive,” says Long.
Demolition robots have a more narrow application focus and can cost significantly more than a mini-excavator, but there are advantages that make them the most effective choice in certain applications. “Unlike mini-excavators, demolition robots are unmanned and allow the operator freedom to move around the jobsite,” says Ekstrm. “Husqvarna’s demolition robots are operated by a remote control feature with Bluetooth technology.”
The company’s models include the DXR 310, DXR 250 and DXR 140. “From the smallest model to the largest, our machines can lift 700 to 2,000 lbs.,” says Ekstrm. “This number varies depending on how the machine is positioned and how far out the lifting point is from the machine. The robots are able to climb stairs, and the outriggers, on various models, allow the robots to fit in tight spaces while still ensuring stability.”
Brokk currently offers six models from 900 up to 12,000 lbs. “We look at it from a 100-ft.-lb. breaker up to a 1,500-ft.-lb. breaker,” says Martin. The three smallest models, the Brokk 50, 90 and 160, are best suited for interior demolition where you need to drive through a 30-in.-wide door and down a hallway. “The benefits of the machine are you can drive it up a flight of stairs. You can put it in a standard freight elevator and take it up to the third floor.”
Because you don’t need to have an operator in the cab, you can potentially run the machine suspended from a crane on the outside of a building, while the operator is in an aerial lift operating the robot via remote controls. “Just being away from the body of the machine sometimes gets you out of harm’s way,” says Martin.
Interstate Sawing just completed a job at the Kohl Center in Madison, WI, where maneuverability was critical. A 170-ft. section at the top of the stadium stairway needed to be removed for installation of luxury boxes. Using the robots to climb up a stairway, the contractor was able to reduce sawing by two-thirds.
The contract originally called for cutting the stairway into 1’ x 1’ cubes, with each cube weighing about 150 lbs. “We cut them into 1,200-lb. pieces,” recalls Long. The Brokk was able to handle these larger sections. “That concrete was 6,000 psi, loaded with steel. To cut that into 1’ x 1’ cubes would have been insanely expensive. I came in with a lower price, yet my margins were better because I used less labor and fewer consumables — fewer diamonds and less diesel in the generator.”
But the biggest productivity enhancement is allowing the operator to position the machine where he or she can best see the work. The operator is not sitting in a cab where the view can be blocked by the cab body or boom.