The new rig also needed to be below the weight class of the proven KR 807-7 series. KLEMM Bohrtechnik's new KR 806-4GM with attached MAG 6.1 drum magazine and manipulator (patented) meets the goals the company set itself.

With a newly developed kinematics system and a net weight of approximately 21.9t (without pipes), the new KR 806-4GM rig allows for a maximum magazine load of 1,100kg. The maximum diameter for the casings is 178mm and the usable length of the pipe pairs is 3,000mm. Both plain drill rods and drilling augers can be used as internal rods.

The MAG 6.1 is an upgrade of the tried-and-tested MAG 7.0 magazine. These types of magazines feature a rotatable drum, which ensures that the equipment operator always has a good view of the drill rod to be positioned.

For the drive system, KLEMM copied the proven design of the KR 806-3G. The Volvo-Penta diesel engine with an output of 160kW complies with the latest emissions regulations.

The KR 806-4GM allows the installation of heavy double heads for drilling in rotary/rotary-percussion mode (KD 25/KD 1215R) and in rotary/rotary mode (KH 25/KH 21). It also allows for the use of powerful hydraulic hammers (KD 2524).

The hydraulic system uses two load-sensing primary pumps, each with a flow rate of 240L/min and operates at pressures of up to 350 bar. The optimal power distribution is automatically adjusted by the patented power-sharing feature, which is part of the EEP (Energy Efficient Power) system. The EEP also features an adaptive speed control feature, which adjusts the speed of the diesel engine to the current drilling situation. In addition to lower noise emissions, this results in fuel savings of up to approximately 25 per cent.

Numerous equipment parameters can be adjusted via the standard touchscreen, without the need for additional tools or removal of hoods. In the event of an error, a detailed diagnosis can be performed via the display (or via the optional DTR module for remote transfer of equipment and process data).

The control system uses mobile hydraulic control blocks with integrated CAN bus technology and high-precision position control for the valve pistons. The direct communication between the control panel significantly improves the response times of the valves and allows the operator to run the equipment with extreme sensitivity and precision.

The KR 806-4GM comes with a portable radio control with a built-in display for monitoring operating pressures. This is a big advantage because it allows the rig operator to position him- or herself outside the hazard area and with the best possible view of the working environment. Alternatively, the operator can use a height-adjustable, swivelling control platform mounted to the base machine, which is available as an option.

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