Dando Drilling International has launched a new drilling rig designed for ground investigation and remediation work on steep slopes.
The new Ibex Slope Drilling rig is track mounted and is capable of undertaking of dynamic sampling, SPT and rotary drilling on inclines of up to 55°.
“Last year the launch of our Dual Mast Terrier broke new ground by offering rotary and percussive drilling methods from two masts mounted side by side on the same small rig,” explains Dando rig designer Rupert Coler.“We quickly realised that there was a market requirement for a rig like this but with the additional capability of drilling safely on steep slopes.”
Award of rail embankment drilling work to Bridgeway Consulting led to the rig being taken from concept to reality after the contractor approached Dando for assistance following previous collaboration on innovative equipment.
“The finished rig has exceeded expectations,” said Bridgeway sales engineer Jon Boltwood. “We’ve recently completed thorough testing and training at two locations in which the rig safely took samples and ran SPT on slopes over 55°.”
The Ibex rig uses the Sauer Danfoss Plus+1 automated levelling system to provide a perfectly vertical mast and horizontal deck and walkway on very steep terrain. A longitudinal slewing mechanism allows for uneven ground between the tracks, compensating for roll up to 15°.
According to Coler, deployment of the rig also focuses on safety. “First you anchor cables from the onboard winch to a point high up the slope using so called ‘duck bill’ ground anchors,” he said. “These provide stability when ascending and tether the rig safely while drilling.
“The operator then tracks the rig forward while simultaneously pulling in the cable on the winch using a specially designed radio remote control unit. When you reach the desired location, the deck can be progressed toward the embankment on a scissor mechanism so that there is effectively no gap between the deck and the bank.”
Once the rig is in position, a walkway is hydraulically deployed to provide a safe, level work area for the drill team, and easy access to the workbench, sample storage boxes and drill mast.
Boltwood added that one of Bridgeway’s key design criteria was that the rig should be as compact as possible for easy transportation and to facilitate access to limited space environments. To accomplish this, Dando designed the track unit to expand on hydraulic rams from 1.5m wide to 2.1m providing a stable base when climbing slopes and drilling, but a much smaller footprint when needed. The walkways also fold up to form a very compact unit.
A variable height mast extension allows 4m sections of rod to be tripped out on the winch.
Powered by a 27Kw Hatz silent pack diesel engine, the two speeds hydraulic top-drive rotary head can produce 362rpm for open hole drilling or coring, or alternatively be switched to 50rpm at 4189Nm of torque should the job require larger diameter drilling, with hollow stem augers for example.
Switching between the rotary mast and percussive mast takes only a pull on a lever; a hydraulic ram slides the mast unit across on a carriage and into perfect alignment over the borehole. Using Dando’s Duplex Drive system which advances the casing at the same time as taking a sample, high quality undisturbed samples in a clear teflon liner can be retrieved, capped, and sent directly for analysis.