Drilling: Bit by Bit

Remote control is often mentioned in connection with drilling, but there are many other innovative solutions in the lockers of the drill manufacturers as they look to improve their offering.

For example, the new Commando DC130Ri – a rubber tired compact size top hammer drill rig – is the latest addition to Sandvik Construction’s surface drilling product offering, and the company said the new machine included a large number of upgraded features developed through consultations with customers.

The foundation of the unit is based on the series of drill rigs launched in 1988, and Sandvik said that it was the years of experience that guaranteed a “versatile, highly productive drill rig combined with intelligence and top-rated mobility”.

The core features of the machine are said to be a modular design and practical layout of components, new efficient rock drill and a new intelligent control system with large on-board touch screen.

The fully remote-controlled, hydraulic and self-propelled compact size drilling unit, with four-wheel carrier, is designed for drilling 22 to 45mm holes. Sandvik said the new Commando DC130Ri had been built on the feedback received from customers that had resulted in nearly 100 practical changes and upgrades that made this unit a user-friendly drill rig.

A new RD106 rock drill providing a high 5.5kW output power, and a new intelligent drilling control system, form the basis for Commando DC130Ri’s high penetration rates, it said. The company said that performance was further enhanced by the machine’s large drilling coverage area, and a new forward pointing feed that allows it to drill closer to structures than before.

The machine is also said to possess the functionality to have roll-over for the feed, change drill steels on the rock drill, and to adjust the drill rig to challenging environmental conditions with additional appliances such as the fuel powered engine heater.

Sandvik said the new intelligent control system of the Commando DC130Ri provided modern machine control features that until now have been found only on larger drill rigs.

Remote control

In 2014, Sandvik introduced a radio remote controlled drill rig to its surface top hammer drill rig offering with the Dino DC400Ri.

Ilkka Lahdelma, product line manager for surface drilling at Sandvik Construction, said, “Customer co-operation is essential in product development and especially in testing the new ideas in practice.

“We want to involve our customers to provide us with valuable feedback for product improvements already in product development phase, not only after the product is released to the market.”

One of the latest such products developed by Sandvik is the remote screen, which is a wireless screen solution for radio remote controlled drill rigs.

Traditionally drill rig operator screens have been attached to the drill rig itself, but this new solution enables the attachment of the screen to the radio remote controller instead.

The remote screen is based on a common mobile device hardware platform with an Android operating system.

The remote screen will be available as an optional extra for the Dino DC400Ri this year. The system is currently being field tested by selected customers that applied for the remote screen beta-test programme earlier this year.

Andreas Gundersen from Vestfold Fjellboring in Norway was the one of the first to try out latest drill rig technology when his employer bought its first compact Dino DC400Ri rig.

This was used for site clearance work among the rocky outcrops of a building project beside a fjord in southern Norway.

Within hours of starting to work with the combination of the Dino and the remote screen, Gundersen, an experienced rig operator, was finding new ways to perform many of the tasks needing to be done on the busy site better. He realised that many tasks could be done in parallel, including such activities as marking-up the next drill holes, planning and grinding bits, all while the Dino was drilling.

These were accomplished as Gundersen was using the remote small screen to monitor the rigs performance safely as he moved around.

To provide new and enhanced remote control capability to help drilling rig operators, Sandvik has created an app that is installed on an ordinary Android phone. The rig operator can click the phone into place on a mobile grip, itself locked to the operation console hanging from the shoulder, and then tap the app and the remote screen is ready to go.

Sandvik said that as the operator moved around, choosing to be either close to or far from the Dino DC400Ri, the operator received the same key drilling data to read on the phone screen as standing by the rig.

High torque

New drilling products from Wimmer feature high torque, large bore diameter and the use of in-hole hammer drills.

Among the drilling units launched recently by the Austrian-based manufacturer are the patented AB2300 Drill & Split rig. It is described as a tailormade high-performance drilling unit with automatic split mechanism.

It is equipped with a Darda splitter, and is described as a perfect interaction of drilling and splitting, specially developed for quarries. It features 360° endless rotation, as well as a 90° tilt function.

The AB2300 also has a no load stroke system, hollow protection and an anti-jamming system. With a smooth drill start, it is fully radio remote controlled, with drilling functions proportionally controlled.

Rockmore International has introduced a new vector rod system which is said to be a major breakthrough in improving performance and service life of extension drill tools in surface and underground percussive drilling applications.

After several years of research and development followed up by monitored field tests in various ground conditions, Rockmore engineers have developed a new thread design, XT, for the vector rod system. The new XT design incorporates new guided cylindrical contact zones between the male and female thread joints. These guided surface features are located in the nose and rear of the thread connections and claim various benefits and improvements over traditional threads.

The XT thread profile is based on the traditional trapezoidal T thread design and is, therefore, compatible with industry standard thread types such as T38, T45 and T51. Rockmore said that while they could be interchanged and connected using standard T-style threaded components with the new XT thread, the new advantages would be neglected. For example, it said, a T45 threaded bit or shank adapter could be connected to a XT45 threaded rod with full compatibility.

The company said that in order to achieve the full engineered benefits of the XT thread, however, the drill string should be considered as a system of connections between the shank adapter, rods and the bit in extension drilling applications. The XT thread design used in the vector rod system is said to enable many performance and reliability benefits leading to major overall cost savings in the drilling cycle.

Pejman Eghdami, executive vice president of Rockmore International, said, “We specifically targeted to increase thread service life while enhancing drilling performance in extension drilling applications.”

The dual cylindrical contact zones in the nose and rear of the XT threads are said to increase significantly the lateral support between thread joints, and stabilise the connections with more rigidity to provide better energy transfer.

Eghdami said that the enhanced thread support and geometry extended thread life and increased the overall component service life of the shank adapters, rods, and bits with XT threads that comprise the vector rod system.

Because the XT thread guide feature improves thread alignment, the impact duration when rattling rods, as required in uncoupling connections, is minimised, said Rockmore. This leads to lower wasted energy transmission, cooler couplings on rods, and ultimately to longer rod life, it said. Thread grease is also better retained on the thread pitches resulting from the new XT geometry, further increasing thread life in all XT components, it added.

Another key advantage of this rod system over traditional threaded components, according to Rockmore, is providing straighter holes and minimising its deviation, and it added that this was inherently critical in modern drill and blast techniques.

The guided XT thread feature increases the rigidity and stability of the connections between the shank adapters, rods, and bits so significantly that overall rod bending is minimised and hole straightness improved, it said. This improvement allows for larger and deeper blast holes to be achieved using existing rod diameters, but only by converting to XT threaded components, said Rockmore.

Eghdami said, “As a major breakthrough for extension drilling systems, we have significantly improved drilling productivity and increased drill string lifetime by introducing new design features in the XT thread configuration.

“And just as important, the new XT design is fully reverse compatible with industry standard T-style threads, enabling the vector rod system to be truly remarkable, yet a practical choice for premium drilling tools.”

Dry drilling

Last year, Austrian-based Tyrolit introduced what it claimed was the world’s first solution for easy, cost-effective dry drilling of reinforced concrete.

The dry drilling system consists of the DME19DP*** drill motor with soft impact function and TGD dry drill bits that have been specially developed for dry drilling.

Tyrolit said the new dry drill bits featuring TGD technology were vital to the success of the drilling process for reinforced concrete, setting new standards with their intelligent distribution of the diamonds.

Product manager Sergiy Avramenko said, “Our TGD dry drill bits have proved their worth in a variety of situations, including decommissioning nuclear power plants. We’re not at all surprised that our customers on smaller construction sites also achieved excellent results.”

The company claimed that unlike other methods on the market, the new system did not need accessories such as air compressors. In addition, any conventional dry vacuum cleaner can be attached to the integrated vacuum cleaner connection.

The drilling system can be operated as a handheld tool or mounted on the DRU160*** drill rig.

General Equipment Company has launched a new M235 two-man hole digger, saying the new model was well suited for a range of hole digging applications in various soil types.

The M235 features new polymeric Gen 2 Comfort-Flex operator handle technology with integrated flex-type handle grips, which the company said took the next step in absorbing torque-related kickback forces and damping machine vibrations.

It said operators would benefit from the reduced physical stress, strain and fatigue normally experienced when digging holes. It is also a lighter weight, more compact unit – 30% lighter than other General two-man hole digger models.

The newly-designed, heavy-duty, oil-cooled transmission includes a centrifugal all-metal clutch and machine-cut spur gears with a 25.4mm diameter output shaft. The new transmission lock feature is said to allow for easy removal of a stuck auger from the ground without disconnecting the power unit from the auger and helping prevent damage to both.

Improved performance

Numa, designer and manufacturer of down hole hammers and bits, has released a Vortex Backhead design that is said to improves drilling performance and hammer/bit life.

It is available for Numa’s 12” (305mm) hammer line when drilling conditions require a significant amount of water injection.

It said that typically when water was injected into the air supply of a conventional backhead, the water would travel through all hammer components and exhaust out the bottom of the bit to improve hole cleaning.

Water is not a concern when small volumes are used but a drop-off of drilling performance can occur when significant amounts of water are required, it said, adding that drawbacks could include slower drilling due to wet bottom conditions and a reduction in hammer/bit life as a result of cavitation from water.

The Numa Vortex Backhead avoids a drop-off of drilling performance by ejecting water out the top of the backhead before it can go through internal hammer components, said the company.

Numa said its engineers had accomplished this by creating a spinning process (vortex) in the backhead that leveraged the density difference between water and air.

Fluids at the top end of the hammer are spun, pushing heavy material (water) to the outside to be ejected out the top of the backhead. Lighter material (air) stays to the inside and travels down the feed tube to power the hammer and clean the bottom of the hole.

The amount of water ejected by the Vortex Backhead can be controlled by the two jets, or chokes, found at the top of the backhead.

Pile Dynamics is claiming to have revolutionised shaft inspection with its
new SQUID (Shaft Quantitative Inspection Device).

It said that an important part of bored pile or drilled shaft construction was the cleaning and inspection of the bottom of the hole for cleanliness ahead of the placement of reinforcement and concrete.

Once drilling is complete, any material unsuitable for end bearing support is removed. Bottom inspection is then performed, often by lowering a camera down the bore hole, a procedure that gives a rough idea of the thickness of any debris left at the bottom.

Pile Dynamics said the SQUID was an alternative to the camera-based visual inspection of the excavated shaft base. SQUID assesses cleanliness by measuring the thickness of the debris or non-competent material remaining at the shaft base, and can also provide a quantitative evaluation of the strength of the bearing layer.

The company explained that the drill stub column adaptor allowed for a quick pinned connection to the Kelly bar of any drill rig. The rig itself lowers the SQUID body to the base of the shaft.

The SQUID body includes three retractable contact plates attached to displacement transducers, and one instrumented cone penetrometer for each contact plate.

The penetrometer cones move through the debris layer and into the bearing material under the weight of the Kelly bar and measures pressure, while the transducers measure displacement.

The SQUID body connects by cable to a wireless transmitter at the edge of the borehole, and the transmitter sends pressure and displacement data to the SQUID tablet.

Minnich Manufacturing has introduced a concrete barrier wall drill – a powerful new drill which is said to help contractors maximise the efficiency and safety of drilling vertical holes for the pins used to secure temporary concrete traffic barriers.

Air-driven and self-propelled, the Minnich concrete barrier wall drill straddles and rides along the top of the temporary wall. The company said that the tethered controller enabled the operator to drill three accurate, consistent pin holes simultaneously – through pre-moulded holes in the wall, through the road, into the sub-base – while positioned on the non-traffic side of the barrier.

Todd Jurjevic, Minnich Manufacturing sales director, said, “The new drill saves contractors significant time and cost, and promotes safety by eliminating the need to hand-drill pin holes on the traffic side of the barrier.”