Finding the right fit

The Geita Gold Mine, located in the Lake Victoria gold fields of northwestern Tanzania, has a tough combination of hard, often broken, rock and large amounts of water which puts pressure on the drilling equipment. For the team on site, the goal is clear: drill efficiently, minimize downtime, and keep production moving. To add value for shareholders, customers and itself, Capital Limited, the mine’s drilling services partner, continually explores new technologies on the market.

The search for ideal down-the-hole (DTH) drilling tools sparked a long-term collaboration between Epiroc and Capital Limited. Through iterative trials at the Geita Mine, this partnership contributed to the development of the COP M-series – the fastest DTH hammers to date. Capital Limited was using a 6" hammer to drill 203-millimeter holes, but when Epiroc introduced a unique 7" hammer, everything suddenly fell into place. 

Woolfe explains that the difference was obvious from the very first hole. “When we looked at real-time penetration rates, it knocked the previous hammer out of the park,” he says.

With its patented air cycle, the COP M-series allows for a shorter, lighter and faster hammer than ever before. Tests show that the COP M7 drills 27 percent faster than the M6 using 203-millimeter bits. The M-series fits various drill rigs and is easy to adjust to different air pressures and volumes. It also weighs about 30 percent less than other hammers in its class, making it easier and safer for handling by operators.

Reilly elaborates: “You can build the best hammer in the world, but if it’s not made for the guys on the ground, they will not use it. The COP M7 is built for real conditions – resistant to water and easy to maneuver and assemble. Even less experienced operators can use it with confidence. That’s why the operators keep asking for it – it just works,” he says.

However, the success of the COP M7 is not solely due to the hammer itself, but also the entire Epiroc drill string – from the rig downwards. It has been developed to be a perfect marriage, ensuring that the rig’s settings are precisely aligned with the hammer for maximum performance. The unique piston design of the M-series hammers allows them to strike at a much higher frequency than other hammers. This means less fuel consumption, which means lower running costs for Capital Limited. 

More meters in the ground in less time also means lower CO2 emissions. That’s a massive win for us as we begin reporting on our greenhouse gas emissions,” Woolfe says.

Today, capital limited runs about 75 percent of Geita’s fleet with the COP M7 and is steadily moving toward full adoption. The joint mission to optimize equipment continues. Due to the abrasive ground at Geita, a slightly thicker barrel was needed. And now, an even more refined M7 hammer is on its way.

“Our collaboration with Epiroc is strong. We provide feedback, they listen, we discuss and move forward together. It’s actually a really good partnership,” Woolfe concludes.