Ontario-based MEDATech has completed what it says is a world first with the development of a self-contained diesel- or electric-powered unit that pumps water at the exact flow rates that down-the-hole (DTH) water-hammer drills require.
The MEDATech Borterra WaterBox™ water hammer drill pump digital controls deliver precise pressure and flow rate, according to the company, allowing such drilling (also known as ‘Wassara drilling’) to be carried out precisely in sensitive applications.
A digital-control system manages pump speed and engine throttle to maximise efficiency and fuel economy, while precise pressure, flow and other key data (up to 3,000 psi at 120 gallons per minute (207 bar at 454 litres per minute) are displayed on the colour screen of the radio remote control.
MEDATech’s Borterra drilling division designed the WaterBox to solve a specific problem, it said.
“The company had built a drill with two drilling technologies, the WS6000, for Alabama Power’s Southern Company in 2020,” it explained. “The hybrid water-hammer/sonic drill was built to drill through embankment dam overburden and karst without destabilising 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 we built our own.”
MEDATech Borterra Product Manager, Scott Dalrymple, says water hammer drilling is a very precise science.
“Creating effective grout curtains in embankment-dam drilling requires hundreds of straight holes,” he explained. “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, MEDATech says. 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 goes deeper or ground conditions change. Fine-tuning is necessary to maintain maximum penetration rates while ensuring precision and repeatability for each hole drilled, it said.
The self-contained, self-sufficient pumping unit is built into a modified 10 ft x 8 ft x 8 ft shipping container complete with forklift pockets, crane lifting points and an automatic ANSUL Fire Suppression system. Compact, rugged and highly portable, it is proving popular within the Wassara-drilling community, MEDATech says.