Demolition

Washington state issues hazard warning over demolition robots

Demolition robots are quickly gaining popularity among contractors as a way to work in tight spaces, get tough jobs done quickly and protect workers in the process. Although the technology can be safer for laborers in some respects, the robots don’t come without their risks.

The state of Washington State Department of Labor & Industries’ Fatality Assessment and Control Evaluation (WA FACE) program recently released a construction hazard alert to warn contractors of the risks associated with demolition robots after two construction workers were severely injured in separate incidents involving the remote-controlled machines.

WA FACE says the workers operated similar machines with three-part articulating arms powered by electric-controlled hydraulics. Both used remote controllers intended to keep them outside the machine’s risk zone, which varies by specific machine, attachment and task.

In the first incident, an operator working for a specialty trade contractor bumped his remote control against the machine. He had not put the machine into emergency stop mode, so it moved and pinned him between the outrigger and the wall.

His chest was severely crushed, causing him to be out of work for several months. He had been with his employer six months and was reported to be an experienced operator of these machines. He usually worked with a partner but was alone at the time of the incident.

The second incident occurred when an operator was using a machine with a breaker attachment to chip concrete as part of a generator installation project on the road.

He was standing in a tight spot between the excavation wall and the machine. As he tried to apply more pressure on the tip of the breaker, the front outrigger raised off the ground. The machine suddenly shifted forward, and the outrigger came down, crushing his foot.

He was able to use the remote control to raise the outrigger but suffered broken bones and nerve damage, WA FACE says.

He had worked in construction for 23 years but had only operated the machine for five days. His training consisted of a hands-on demonstration and a brief review of the operator’s manual.

The employer conducted a job hazard analysis that identified the swing radius of the arm as a hazard but did not recognize the potential of being crushed under an outrigger.

Following the incidents, WA FACE put together a list of safety recommendations when using demolition robots:

• Prepare a job hazard analysis with operators for each new job to identify and control hazards. Use the manufacturer’s safety instructions to establish the risk zone for the specific machine, attachment and task.
• Always stay outside the risk zone when the machine is in operation, and do not enter until the demolition robot is put into emergency stop mode or deenergized.
• Consider using a proximity warning system, such as those based on radio frequency identification (RFID), to maintain a safe worker-to-machine distance.
• Train operators to manage power cables and to continually monitor the process for hazards and redefine the risk zone.
• Ensure operators always read and follow manufacturer’s provided safety instructions.