Vermeer engineered two unique variations on its D36x50 Series II Navigator horizontal directional drill as its entry into the rock drilling.
The D36x50R Series II is equipped with the rock-focused MAGnum drilling system. Spinning magnets of alternating polarity create a variable-frequency percussive action to fracture and effectively bore through tough formations, including solid rock. Operators can tune blow frequency to most effectively cut rock. The magnetic hammer technology was developed in collaboration with FlexiDRILL, a New Zealand-based engineering company, and is licensed for exclusive distribution by Vermeer.
Not a dedicated rock drill, the MAGnum hammer can be disengaged with the flip of the switch, and the D36x50R Series II will perform as a conventional HDD drill. The MAGnum drilling system does not require special drill rod — utilizing standard Firestick — or any auxiliary support equipment such as an air compressor. This versatility qualifies the drill for a range of ground conditions to help boost the machine's overall utilization.
The D36x50DR Series II features a dual-rod (rod-inside-rod) drill stem with dual threaded makeup. With a rated rotational torque of 1,500 ft.-lbs., the inner rod powers the downhole tri-cone as the outer rod provides steering and backreaming rotation. The dual threaded rod , with fluid flowing between the rods and through the innner rod, is designed to move plenty of bore flluid down the hole for effective flushing.
Automated rod makeup and breakout can be engaged to reduce manual operator interface, or it can be overridden and operated manually. The D36x50DR Series II can carry up to 500 ft. of drill rod.
For downhole performance throughout the entire bore, the 140-hp D36x50R Series II and D36x50DR Series II Navigator HDDs feature the same rated 38,000 lbs. of thrust/pullback and 5,000 ft.-lbs. of rotational torque as the conventional drill. All configurations are available with a 70-gpm drilling fluid pump.