MEDATech has launched what it considers to be the world's first precision-controlled pumping units for down-the-hole water hammer drilling (also known as Wassara drilling).
The MEDATech Borterra WaterBox is a self-contained diesel- or electric-powered unit that pumps water at the exact flow rates that DTH drills require. A digital control system manages pump speed and engine throttle to maximize efficiency and fuel economy. Precise pressure, flow and other key data (up to 20,700 kPa at 7.5 L/sec) are displayed on the colour screen of the radio remote control.
MEDATech’s Borterra drilling division designed WaterBox to solve a specific problem. The company had built a drill with two drilling technologies, the WS6000, for Alabama Power’s Southern Company in 2020. The hybrid water hammer and sonic drill was built to drill through embankment dam overburden and karst without destabilizing the surrounding ground, for grouting. But it required a more precise flow rate and pressure control than any pump could deliver at the time in order to keep holes straight, true and uniform. So it built its own.
“Water hammer can be a very precise drilling technology,” says MEDATech Borterra product manager Scott Dalrymple. “Creating effective grout curtains in embankment-dam drilling requires hundreds of straight holes. One thing that will throw a hole off is inconsistent water pressure and flow rate. We had to solve that for the WS6000.”
The issue with traditional pumps for water hammer drilling has always been that flow rate and pressure are hard to control. This causes drilling irregularities and can result in a slower drill time and/or a less accurate hole. With WaterBox, the operator sets the precise desired flow rate and/or pressure. Both values are displayed in real-time on the remote control and the operator can fine tune as needed, as drilling gets deeper or ground conditions change. Fine-tuning is necessary to maintain maximum penetration rates while ensuring precision and repeatability for each hole drilled.
Part of the WaterBox's attraction is its lower noise profile: a recent Princeton University study has found that WaterBox produces less pump noise, which can be important in certain situations, such as proximity to residential areas and unground drilling. The pump can come powered either by an EPA Tier 4 diesel engine or an electric motor.
The self-contained, self-sufficient pumping unit is built into a modified 3 by 2.5 by 2.5 metre shipping container complete with forklift pockets, crane lifting points and an automatic ANSUL fire suppression system.
Click here to learn more about the MEDATech Borterra WaterBox.