Rosslyn-based mechanical engineering company Impco Engineering has completed the development and construction of its first automated and energy-efficient Jumbo shaft sinking drill rig, which has been ordered by an overseas client and was shipped at the beginning of February.

Impco, which has been making previous generation Jumbo drill rigs since 2015, started the 
design of the automated Jumbo at the start of 2022 and six months later started construction, which took about another six months.

Impco, with its drill rig expertise, has supported drill projects in Mongolia, Germany and Russia, as well as domestically with Ivanhoe Mines’ Platreef project and De Beers’ Venetia mine.

The Jumbo drill rig employs five powerful S140 hydraulically-powered drills that enable it to drill 3.5 m deep in a typical 2.5- to 3-hour drill cycle, following which blasting teams will conduct blasting and another team will case the shaft in concrete throughout a typical 36-hour cycle.

Impco MD Kobus Duvenage says the S140 drifter is manufactured by Impco and is the most powerful in the market, capable of drilling a 2-inch hole to a depth of a metre in about 45 seconds. This offers between a “25% to 30% improvement in cycle times”, he says.

Capable of folding to 1.9 m in diameter, the Jumbo can be assembled to drill a 9-m-wide pattern to sink shafts of the same size.

In an effort to commission the Jumbo quickly and easily, Impco has developed it to use only an incoming pneumatic line with a recommended pressure of 6 bar at 3 500 cubic feet per minute. The pneumatics are used to power the hydraulics of the drills, as well as to power a pneumatically-driven alternator that powers the rig’s electronics and charges a 24 V battery pack as a redundancy backup.

However, Kobus says the S140 drifters can operate at pressures as low as 3 bar, should the need arise.

To reduce noise levels of the pneumatic systems, Impco has also incorporated powerful mufflers, which reduce noise pressure by about a factor of four, compared with older generation systems. This results in a reduction in noise levels of about 12 dB.

“It is still pneumatically-driven, but has modern features such as hydraulics that can sense different loads and adjust drilling advance rates 
accordingly,” says Impco technical director Dylan Duvenage.

Despite being autonomous, the rig can also be operated manually, should a system fail or should the operator prefer manual mode. Having a manual mode also enables drillers to finish the job without having to remove the rig and remedy the issue.

“Our design philosophy is that we integrate redundancy features that can be used if the primary system fails to ensure work can continue in a manual mode. Shaft sinking is time-sensitive work, requiring the rig and its operates to do the job within specified time frames,” says Dylan.

In addition, the manual override provides benefits to veteran rig operators who are more familiar and prefer older, manual systems. “This enables us to bridge the gap between new and proven technology,” he says.

Kobus adds that within the automated and modern technology are rig management reporting systems that enable both the operator and Impco to monitor the equipment and be alerted to any 
issues that can be remedied through preventative or general maintenance.

Dylan also says the rig has been incorporated with an electronic stop feature which immediately stops all operations on the rig, once activated. This, he says, is an essential safety feature on such a complex piece of machinery with so many powerful moving parts.

Load sensing technology is able to determine the hardness of the ground and rock through which the rig is drilling and adjust the progression rate accordingly, as well as to account for wear on drill bits.

He adds that the stage that accompanies the rig during shaft sinking will be equipped with WiFi, enabling wireless connectivity to the rig and allowing the operator or Impco to do software updates while the rig is on site and monitor its performance.

Further, Impco is currently in the process of finalising tenders for various sinking projects across the globe.

 Tel: 012 541 0932 

Email: kobus@Impco.co.za 

Email: dylan@impco.co.za