When working with reinforced concrete, there will always be the “rodbusters”, a highly skilled, yet underappreciated group of men and women who perform the tedious and backbreaking task of tying the rebar together every time they cross, either with wire or plastic. For a large project, like a bridge, this can mean many thousands of ties—all done manually. It is difficult, repetitive work that must be done, but often leads to injuries, particularly repetitive-motion injuries or back problems.
While there is an automated system to aid in this, the TyBot, a rail-mounted gantry the rolls above the rebar, it can only be used in certain applications (in a road, yes, but on top of a skyscraper, no). A new startup, SkyMul, aims to solve the problem with technology. They’ve developed a rebar-tying drone which flies to the necessary spot and can tie two crosses at a time.
The CEO, Eohan George, said that they evaluated many methods but only drones were workable. Legged robots had trouble walking through the rebar, and tracked and wheeled vehicles couldn’t travel over the unsecured bars.
A mapper drone flies over the section of rebar and creates a digital map of the area, and the tying drones go to work. Each drone has a 25 minute battery charge and can tie one cross every twenty second, which is about on par with humans.
The cost savings has the potential to be high, once the fleet is fully developed, because in some places rodbusters can make as much as $80 per hour. That said, on other places, the price is much lower, so it’s hard to know how much money will actually be saved. Still the market spends $40 million on rebar tying nationally every year, so there’s definitely an opportunity for technological disruption.