In 2004, Chris started as a driller’s assistant with Drillcorp at Sunrise Dam, drilling initial diamond coring holes at Tropicana mine when it was still an exploration site, before moving onto deep directional drilling programs at Leonora and Forrestania. In 2006, Chris joined Boart Longyear (BLY) initially as a driller, before moving into a supervisory role at BHP Billiton’s Leinster and Mt Keith operations. This was when Chris developed a thorough appreciation of industry safety, and he’s grateful for the front row seat during a notable period of change in safety systems and workplace cultural maturity. In 2014, the Great Financial Crisis adversely impacted Australia’s mining and exploration with widespread reduction across all surface drilling. Chris was redirected to BLY’s Waterwell division across multiple Pilbara sites. Chris eventually returned to the Goldfields to assume a regional supervisor role before being rewarded with his current role as operations manager for BLY’s underground division, APAC.

Chris Hopkins: My father worked within Chevron’s lubrications business, collecting many small-scale models of heavy mining equipment. As a kid, I was fascinated by his ‘toys’ – sparking my interest and a subsequent stream of questions to my patient, receptive Dad who has since retired. I greatly admire my Dad for his genuine want to be of value to his community and local church. At age 24, I became a father for the first time while working in the liquor industry and wanted to veer to an industry where hard work, commitment and dedication were appreciated. I was also itching for adventure and a change in scenery, having been inside a lively wine store for too long. The prospect of working in the great outdoors at remote locations, being physical, and solving mechanical issues really appealed, so I made the switch.

CH: My professional role models and mentors include the esteemed and respected likes of Dale Barron, Des Forde, Gregor Stephenson, the late John Emerson, and Murray Hillier. Their collective drilling knowledge, willingness to engage and educate, while offering support has had the most profound effect on my career.

CH: I can’t recall a specific moment or project, as I’ve enjoyed many adventures during my career. Drilling challenges me on so many levels – from working and living away in remote locations and interesting environments, to geological undertakings through difficult formations, and the eventual satisfaction of completing a deep directional drilling program. In true A-type style, I beam with unwavering pride when my rig, fleet and team present well and drill effectively.

CH: 1. Good work habits and a positive mental attitude: the underground space is a very physical and challenging workplace, but it’s also a great place to work – I love it! Every task has an exacting set of measures which must be followed, as short cuts are not tolerated. Determination and attention to detail is necessary given the restricted work areas, equipment limitations and specific underground drilling requirements that can vary from +90 to -90 degrees. Excellent communication is paramount as daily interaction with mining teams is necessary to deliver quality samples within specific time frames. It is quite common for a mining team to immediately assume an area once drilling is complete.

2. Safety culture maturity: we must respect and understand our working environment, and maturity toward safety is a prerequisite to the underground mining sphere, given the inherent risk in what we do. I cannot and will not tolerate immaturity or lack of focus as either will result in someone being hurt and equipment being damaged.

3. People: are the most important and defining facet to success – in any industry. People who genuinely care and take pride in their work and accomplishments are who you want on your team. I’ve been fortunate to have worked with talented and capable people, and I’m most proud of my current team – they are enthusiastic, professional, highly motivated and experienced. We’ve developed an amazing and supportive working culture as a result.

CH: My somewhat cheeky response is whatever drilling type I’m currently focused on and involved in. Seriously, every discipline – underground or surface drilling has its own challenges including ground conditions, technical drilling requirements to achieve targets, underground grade control programs requiring multiple rig locations and set-ups per shift, to large diameter holes requiring large tooling to complete. The challenge of individual hole completion is what deems the drilling industry such an exciting business to work in. Up-hole drilling is a constant challenge, as underground geology departments strive to keep costs down. Sometimes the only way or location to achieve target is to drill ‘up’. Boart Longyear’s Roller Latch system allows crews to successfully and safely do so while following best drilling practices.

CH: Underground mining and drilling teams work closely, attending the same pre-start meetings and engaging more frequently than would occur at surface. When underground, everyone is under the supervision of the shift boss and underground mine manager, with increased engagement with the mining safety team. My drilling team has forged greater cohesion between the two groups, implementing exemplary practice and innovation that has been adopted by all, and I couldn’t be prouder.

CH: There are two reasons – risk and cost. Drilling is dangerous especially when poorly managed, so it makes sense to hire a professional contractor to complete the work. Contractors must be accountable and continually improve to secure future work. A lot of effort goes into delivering safe, seemingly hassle-free (for the client) drilling. Then there is cost. Most mining companies are incapable of cost-effective and productive in-house drilling. Contractors remain focused on achieving safe and productive outcomes for their ongoing financial survival and reputation.

CH: Delays associated with mine blasting and other mining activities significantly reduce the amount of time drilling crews must complete work, while eliciting an added expense to the client. BLY’s Drill Control Interface (DCi) system enables continuous drilling, even while the rig is unattended. Semi-autonomous capability within the underground drilling space is subject to an anticipated transformation, and it’s an exciting time. Many mines have, and continue to install underground Wi-Fi communication systems for enhanced communication between the drill crew and surface-based support crew.

CH: The underground space is in need of innovation, and Boart Longyear’s dynamic approach has meant that I’ve been involved in the development and release of some of the industry’s leading improvements including Roller Latch, diamond coring bits – designed and tested in the field by our drillers, and safety improvements to both drilling equipment and in the field training systems. Our fleet features machines that enhance the driller interface with improved safety and increased performance thanks to BLY’s ability to design and manufacture reliable rigs and drilling equipment, backed by adept and supportive maintenance teams, and an extensive global supply chain. I’m particularly excited about current innovations and advancements we expect to release within the next year. I can’t elaborate just yet, so watch this space.

CH: Most Australian underground drilling is N-size as it yields clients respectable sized core samples for the cost. For drilling contractors, N-size improves productivity with wireline systems, reduces manual handling when compared to conventional systems, and improves hole completion in poor formations. Boart Longyear’s Roller Latch system also provides much safer operations when drilling up holes, veering away from conventional processes.

CH: The potential to intercept an underground water source when drilling underground is both great, and undesirable. Thorough planning, detailed risk assessment and experience round out the high-pressure prevention trifecta, coupled with having the necessary tooling at the ready – should it be required.

CH: Drilling fluids are critical to hole completion in broken, unstable or pressurized formations – supporting all aspects of hole conditioning from reducing torque, assisting in the removal of cuttings, increasing hydrostatic pressure, stopping hydro sensitive formations from reacting, and some products hold together loose formations. Cost is critical and all staff – not just drilling crews must be educated as to correct usage to ensure zero to minimal wastage as this can greatly affect cost per meter. Reliable terminal equipment is key to ensure the most time down the hole. I’ve encountered many holes where formation stability is greatly reduced due to tripping of rods or introducing unnecessary pressures onto the formation, leading to extensive hole cleaning which then increases the likelihood of an unsuccessful hole completion.

CH: Boart Longyear makes use of wedging in both surface and underground operations. Wedging needn’t be a safety concern if effective planning and good communication are upheld. Importantly, we work closely with our clients to ensure this is the best option for them, as the cost to drill a new hole within the underground space can be cheaper than attempting directional drilling.

CH: Cementing works best when it is kept simple, checking everything twice. Like the carpentry adage, ‘measure twice; cut once.’ Training is key – as it is with all aspects of drilling. Be mindful of setting and correctly calculating grout volume. Other points to note: is the cement type correct or best suited to the formation? Is the product within its best before date, and has it been stored correctly? Are the slurry volume calculations correct? Is the potential for contamination being limited while mixing and displacing slurry? Be sure to extract a slurry sample to reference. Importantly, if you’re using an additive, be sure to follow the manufacturer guidelines as more is not always better. Lastly, don’t feel pressured when attempting as this is when most mistakes do occur. In Australia, we use VAN RUTH® cementing plugs as they’re a proven product that work well.

CH: Lack of preparation. A driller’s day starts with the all-important pre-start meeting, where supervisors outline and ensure that their teams understand what is expected to occur during that shift. Appropriate and reliable equipment is made available for the crew to safely complete every task and activity. Rushing to complete a job, particularly due to failure to plan, or lack of preparation is a recipe for disaster – namely injury.

CH: I’ve been fortunate to have been involved in many deep directional drilling programs throughout Western Australia, however, it’s important to note that this drilling method varies from production-based drilling within the underground space. The focus is on hole completion and hitting the desired target. It’s complex, extremely technical, and requires intensive supervision, as every decision affects how the hole is drilled from start to finish. I enjoy drilling at depth – the planning, preparation, and necessary attention to detail (correct choice and use of equipment, barrel configurations and monitoring the hole’s deviation) to achieve target. It’s a proud moment to be part of a team that successfully reaches end of hole, delivering a sample of an ore body to a client from over 2000-meters depth.

CH: Directional drilling using down hole motors is an effective method to hit multiple targets from a ‘parent’ hole. The method is best applied to deeper targets and areas where the cost to drill through waste rock exceeds the cost to complete the directional requirements to reach the targeted zone.

CH: The survey industry and its products are rapidly advancing in capability and reliability, with fantastic products available. Most importantly, the system must meet client requirements and be easy to operate, with flexibility for drilling teams to utilize tools to maintain effectiveness. I’m a firm advocate of the Azimuth Aligner® as it reduces rig set up time and relieves pressure on mine survey teams.

CH: Mining is critical to Australia’s economy, and every operation has been closely monitored to eliminate or minimize risk. Australia truly is the ‘lucky country’ for a few reasons – our geographic isolation and relatively small population combined with our swift acting government’s measures (international and state border lockdowns and mandatory 14-day self-isolation), has so far protected us as a nation. Over 25 million people live in Australia, yet our death rate from the pandemic is deemed low – just over 100 people. We must never be complacent and we’re mindful of the much talked about second and third phases, hence Australia’s strict border controls.

CH: Exciting technologies are being harnessed and adapted within diamond drilling. Many contractors are relentless in their pursuit to remove manual handling for a twofold result – eliminate and minimize injuries, while encouraging the broader community to consider the profession. Drilling cannot occur without people and the industry benefits when dedicated, focused and diligent people continually strive to improve perception and conditions. People are the future of drilling, so we must ensure that our industry evolves with safety, education, innovative systems and solutions at its forefront, as evidenced by key groups such as Australian Drilling Industry Association (ADIA) – endeavoring to improve standards and protocol for collective success – now and in the future. I’m currently involved at a research and development level, applying expert advice and feedback to hone various soon-to-be-released Boart Longyear equipment and tools that will greatly improve safety and productivity, while questioning how we approach drilling. It’s an incredibly exciting time to be in the industry and I personally cannot wait to see it come to fruition. Watch this space!

What many people may not know is that the drillers and engineers of Boart Longyear have been involved in some exciting historical drilling projects in a variety of other applications, too. Drilling equipment for moon exploration is one such example (read Drilling Beyond Earth); but closer to home, the company has assisted with projects to explore and define foundation and structural integrity below the earth or even under bodies of water.

In the late 1920s, members of the Longyear team were contracted to test drill the route of a proposed vehicular tunnel under the East River to connect Manhattan to Brooklyn in New York, USA. The tunnel was intended to reduce transportation congestion due to the slow and unreliable ferry service that existed at the time. The Longyear company provided preliminary boring samples used to determine what was beneath the surface of the river. Characterizing the samples’ type of rock and its hardness allowed geologists and engineers to determine what equipment should be used for tunneling, how long it should take, and at what cost. Although the initial tunnel project didn’t receive support and funding, it laid the groundwork for a later project—the Brooklyn-Battery Tunnel—which was started in 1940 and opened in May of 1950.

A similar challenge of traversing a wide body of water required assistance from the Longyear team in 1929. Joseph B. Strauss, a visionary engineer, was tasked with his team to design the proposed Golden Gate Bridge in San Francisco, California, USA. As chief engineer, Strauss requested the services of Longyear to investigate the rock formations beneath the San Francisco Bay where the bridge would be constructed. Longyear started boring in the Bay in November 1929 along the sites of the proposed piers and anchorages. [i]

Due to the turbulent waters of the channel, the drillers had to be creative as to how they would retrieve the core samples beneath the tumultuous surface. Strauss was big on safety, requiring bridge workers use safety lines, work over safety nets, and even wear some of the first hard hats. The Longyear crew constructed a platform over the water supported by a boom—an A-frame—and guy-wires anchored to the shore. The platform allowed the team to suspend their drilling equipment securely on top and safely above the bay. Despite the problems of deep water, ocean traffic, storms, and tidal movement, the team was able to finish the work on schedule with complete core sample recovery.

The geological samples and subsequent data supplied to Strauss proved that the rock formations could bear the weight of the foundations and enable the huge bridge structure to be built. The information was provided in a full report to the board of engineers in February 1930 and the bridge was determined to be “feasible economically and structurally.”

This great news meant Strauss and his design team could move on to the next phases of engineering and constructing the Golden Gate Bridge. In gratitude for Longyear’s contribution, Strauss wrote, “The work done by your company, having been entirely satisfactory, and the relations between us and your drillers having been cordial and pleasant, I am glad to make immediate payment of the balance due.” [ii]  

Payments received by the company totaled close to $15,000 for the boring contract. It wasn’t for another three years (January 1933) that construction began and a groundbreaking ceremony for the bridge was held. The Golden Gate Bridge was completed in May 1937 at a total cost of $35,500,000.

Click below images to view larger.

From left to right

Images 1 and 2: “Engineers Speed Plans for Golden Gate Bridge” - A Pacific Street and Road Builder article from March 1930 stating “test borings reveal solid rock foundations and showing a photo of boring operations at the Lime Point side of the bridge in Marin County, California.

Image 3: “Borings Started for Gate Span” – Photos shows in the Vallejo California Chronicle, Sebastopol California Times, and Cresent City Triplicate newspapers on November 29, 1930. The article shows a photo of Longyear’s diamond-tipped drills used for bore sampling the rock at the San Francisco end of the bridge, next to Fort Point.

Image 4: “Getting Down to Bedrock” – A San Francisco Examiner article, dated February 14, 1930, picturing engineers, including Strauss, inspecting boring samples from the Golden Gate Bridge project.

A truck-mounted LS600 sonic rig taking core samples near a dam site.

Shortly after the Golden Gate boring project, the Longyear company became involved with drilling projects for the construction of hydro dams around the country. In the 1930s, Longyear drillers did test borings for several of the twenty planned dams under the jurisdiction of the Tennessee Valley Authority. These dams were part of a comprehensive plan for the reclamation and development of the Tennessee River—covering an area of more than forty thousand square miles and over seven states.[iii]

Later twentieth-century construction-type projects for Longyear drillers included boring for core samples for the Missouri River Project, and the first foundation test borings for the Fort Peck Dam in Montana—the project’s first major hydro dam.

Today, Boart Longyear continues to assist with construction and rehabilitation projects around the world using even more advanced technologies and equipment. The company regularly uses sonic drilling technologies which are ideal for avoiding many of the challenges experienced with conventional drilling methods.

Sonic drilling offers quality control in conjunction with the production and installation of geotechnical construction elements. The sonic method can actually eliminate the need for circulation-type drilling allowing the driller to work safely in situations that involve sensitive structures, vulnerable site conditions, difficult geology, or have restrictive conditions. Sonic drilling also provides measurements and samples to evaluate actual conditions across a given site during the progress of exploration and construction.

A few examples of Boart Longyear’s sonic drilling assistance with tunnel, bridge, and hydro dam projects in the twenty-first century include: [iv]

• Casing installation for the Boston Central Artery / Tunnel Project CO9A4, Massachusetts, USA. As part of the process of installing three jacked tunnels under the 13 railroad tracks at South Station in Boston, specialized sonic drilling was used to install casing through some of the most difficult combinations of historical fill materials—steel rails, brick tanks, woodpiles, granite seawalls, reinforced concrete slabs, track ballast rock, clay, stratified sands, till and weathered bedrock.

• Installation of a grout curtain at Clearwater Dam in Missouri, USA. The project required a drilling method with the ability to penetrate and sample both the body of the dam and its foundation without the use of air or water circulation. Sonic drilling was used to investigate a deep sinkhole and affected a remedial plan involving drilling 15-degree battered grout holes through embankment fill to construct a grout curtain.

• Sonic drilling comparison for a tunnel design pilot study on the Combined Sewer Overflow Control program, Anacostia River Project in Washington DC. Sonic drilling was used to perform continuous soil coring with approximately 100% core recovery and careful installation of multiple piezometers.

• Micro-pile installation testing near the Holland Tunnel in New Jersey, USA. Sonic drilling was compared with conventional drilling to advance micro-piles through silty sand overburden, overlying till, and schist. Not only was the sonic drilling 33% quicker for installation of the micro-piles, waste was also eliminated to nearly the volume of the sonic core, which minimized disposal costs. 

Bridges, tunnels, dams, and even buildings are all safer because of the work done to investigate, test, and secure the foundations. Although considered a small contribution to these engineering marvels, Boart Longyear employees are proud of the heritage the company has earned and its involvement in each part of history.

For more information on Boart Longyear’s construction drilling capabilities, including sampling core, anchoring, micro-piling, jet grouting, and ground freezing, visit the overburden and construction tooling section.

[i] https://www.goldengate.org/bridge/history-research/bridge-construction/joseph-strauss/

[ii] Edmund J Longyear, and Walter R Eastman. 1984. “The Mesabi and Beyond”; Pg 181

[iii] Edmund J Longyear, and Walter R Eastman. 1984. “The Mesabi and Beyond”; Pg 192

[iv] George R Burnhart, Boart Longyear Technical paper. 2006. “Sonic Drilling Offers Quality Control and Non-Destructive Advantage to Geotechnical and Construction Drilling on Sensitive Infrastructure Sites.”

Golden Gate Bridge Photos from historical records, the Golden Gate Bridge, Highway and Transportation District and found here https://www.goldengate.org/exhibits/engineering-the-design/

Golden Gate Bridge Photo courtesy of Umer Sayyam

The drill string’s resistance to deviation—otherwise known as ‘stiffness’—can be determined by its material and mechanical properties. Since all wireline tubular components are made from cold-drawn steel tubing, they all have the same fundamental properties. Specifically, regardless of chemistry, heat treatment, or hardness, all steel grades respond with the same amount of bend to a given load (the ratio of stress (load) to strain (bend) is known as the “modulus of elasticity”). Furthermore, any two steel tubular components with equal dimensions will have equal stiffness, even if produced by different suppliers, regardless of the steel grade, heat treatment, or hardness.

The directional response or sensitivity of the drill string to changes in drilling loads or speeds, or in formation changes, depends heavily on the drill string stiffness. The stiffness of wireline drill rods more than doubles in moving to the next larger system (e.g. BQ to NQ, NQ to HQ, etc.). As a result, larger systems drill straighter but have much more resistance and greater lateral loading when drilling through borehole deviations. Given a typical impregnated coring bit, and constant drilling parameters (assuming no formation changes), the borehole will tend to form a slow helix that is determined primarily by the stiffness of the drill string. With borehole friction, the drill string itself can become unstable, buckling into a helical shape which tightens or loosens with changes in drilling loads and speeds, but then elastically returns straight when unloaded.

The Q wireline core barrel was originally designed to utilize an outer tube with a substantially larger diameter and wall thickness than the unstable string of drill rods behind it. Standard outer tubes provide approximately 40% greater stiffness, and full-hole style outer tubes provide approximately 70% greater stiffness! The outer tube can then act as a stabilizing bearing or collar. The greater the increase in stiffness, the more effective a directional control to resist changes in the formation, drilling parameters, or drill string stability. This control can be enhanced with stabilized reaming shells, stabilized adapter couplings, and stabilized locking couplings.

Consider the directional impact if the outer tube is replaced with another drill rod, completely removing any difference in drill string stiffness, and the related directional control. Originally developed in the 1980’s in an attempt to direct borehole deviations, core barrel configurations, known as “flexi-barrels,” replace the outer tube with an equivalent length assembly of a drill rod and adapters. However, the lack of directional control combined with the lack of directional predictability, typically results in erratic deviations requiring either corrective deviation attempts or reaming to reduce excessive deviations. Therefore, the use of flexi-barrels is not recommended.

When planning holes, consider the potential impact of rod deviation. The stiffness of steel tubes is relatively high, and as mentioned before, increases with system size and section thickness. As a result, the drill string will respond with high side loads against the borehole wall, especially just before and after a deviation. For example, an NQ size drill rod deflected to the recommended maximum deviation of 1.0 degrees over its length produces approximately 9kN (2,000lb) of side load, and an HQ produces 18kN (4,000lb) at only 0.8deg per rod length. Depending on the formation, these high side loads can produce high torque, heavy rod wear or even ‘heat check cracking.’ Additionally, these contact points generate drag and ‘stick-slip’ conditions, which can produce a dynamic response sufficient to permanently deform the drill string into a helical shape. In extreme cases, where the drill string completes enough rotations approaching or exceeding maximum deviation, fatigue failures will occur. Using the minimum deviation possible to hit target and sticking to NQ size rod will reduce the side loads, torque and chances of twisting or cracking rod.

Originally published in Australasian Drilling Magazine, February/March 2020

The COVID-19 outbreak and how it affects everyone’s health and safety is of huge concern for Boart Longyear. Being in an industry that already has many risks due the nature of drilling and manufacturing, employees have learned that fostering a safety culture means that no matter what they do, they always need to take time to make safety part of their daily activities*.

As everyone grapples with the changes and the unfortunate consequences we are seeing and are personally affected by, it is good to take a deep breathe and re-evaluate what you are doing to keep yourself and your loved ones safe and healthy.

The web is full of helpful information on what to look for, how to act, how to respond, and how to give assistance. In regard to the drilling industry, we recently came across this well written article published online by National Driller magazine.

In the article, author Brock Yordy asks, “How do we prepare for abnormal operating conditions?” and responds with, “We start by creating a procedure that minimizes the hazard and prepares our crews to be safe. Next, we implement that procedure by training our people. Finally, we review our procedures and continue to improve as new information arises.” 

Mr. Yordy goes on to compliment the drilling community as we all pull together to provide each other information and figure out the best ways to tackle this crisis. With his research, he interviewed Jeff Williams, former National Ground Water Association (NGWA) president. Mr. Williams and other industry experts have created a guideline for operating procedures during the COVID-19 pandemic. We highly recommend you read this interview and review the findings and procedures set forth.

Read the full National Driller article and excerpts from Mr. Yordy’s interview with Mr. Williams here: What are Best Practices for Drillers During the Coronavirus Pandemic?

Stay safe everyone!

*The employees of Boart Longyear have long prided themselves on a robust safety culture. Embodying a core value of “Safety First” is evident in the company’s recent 2019 safety achievement with the company hitting an incredible milestone of 14.5 million consecutive man-hours worked with no Lost Time Injuries (LTI), and 18 months completely LTI-free. 

Boart Longyear’s Response to COVID-19

On one particular project, Boart Longyear mobilized underground coring rigs to a client’s mine in the US where the mine was faced with a big water problem that was making the underground exploration coring impossible to complete. The mine had two shafts located at different levels, one above the other. The deeper shaft had pumps installed and was ready to pump water to the surface. However, the upper shaft had flooded with water – where there were no pumps.

Typical underground coring setup.

Rather than attempt to install additional pumps in the flooded upper shaft to remove the water, Boart Longyear moved their underground coring rigs down to the lower shaft and drilled a fan-shaped series of up-holes to the flooded shaft above. The idea worked, effectively using gravity to drain the water from the upper shaft to the lower shaft where the pumps were then able to move the excess water to the surface. The mine was able to continue operations in the upper shaft and Boart Longyear was able to start the diamond coring exploration drilling.

On another project, the mine was thought to be dry. After the underground coring began, the Boart Longyear crew ended up finding water – a lot of it, quite unexpectedly. The crew was able to come up with a plan to manage the water so the exploration drilling could be completed. After pressure grouting in a cement collar casing, a blow-out- preventer (BOP – used to seal, control, and monitor water to prevent blow outs and the uncontrolled release of high-pressure water) and rock pack were installed successfully, shutting the water in. Most instances where that amount of water is encountered play out quite differently. Everyone has experienced, or knows someone who has, a situation where a high volume of water blows all your tooling out of the hole, resulting in a complicated mess.

Other examples of unexpected challenges include creative solutions using Boart Longyear’s own engineered underground rigs on the surface. The Drilling Services Underground Coring division mobilized rigs to a mine site where a delay in underground diamond coring exploration had the underground rigs idle on the surface. Someone saw the rigs waiting and asked if the idle underground rigs could drill flat-angled holes on the surface. Accepting the challenge, the underground coring rigs have been drilling these low, flat-angled boreholes ever since.

The mine site has a limited surface disturbance permit – which means that to reach the geological formations outside the area of their disturbance permit, Boart Longyear’s Underground Coring division is operating underground rigs on the surface to drill low-angled and flat holes that surface rigs often can’t reach because of their truck-mounted tall masts.

The underground rigs can drill at low angles from -40 degrees down to flat. They drill underneath the area where the mining client isn’t allowed to disturb the surface. This means exploration coring can follow ore veins without disturbing the surface and drill beneath the area outside of the issued disturbance permit.

The boreholes are 2600 ft to 2700 ft (792.48 m to 822.96 m) at a -40 to -12 degree angle. Boart Longyear has the tooling and the expertise for that type of drilling but was unable to accomplish the job with surface rigs because when set up flat, you’re going to be 12 ft (3.66 m) off the ground because the mast is way up on a truck carrier. With the underground rigs, a work platform or deck was constructed, which enabled the team to work right up close to them.

The Boart Longyear Drilling Services Underground Coring division in the US runs all Boart Longyear-engineered and manufactured LM and MDR rigs. The LM series of rigs feature easily interchangeable components, allowing for space constraints without sacrificing depth requirements. These modular coring rigs offer easier access in tight underground spaces and mobility for easier moves from hole to hole or shaft to shaft. Boart Longyear’s patented tooling offers safer and more efficient up-holes at any angle.

The underground coring rigs in the Drilling Services’ fleet are modified and customized, as compared to the commercially available Boart Longyear underground coring rigs. For example, the LM90 is souped up with a 150-horsepower engine instead of the typical 90-horsepower engine and includes additional modifications for increased depth capacity and core size.

The Drilling Services Underground Coring division has the experience and technical expertise to drill dewatering galleries, geotechnical borings, tunnel investigations, grouting services, and utility borings. The division also has experience with overcore drilling to measure in-situ stress. Overcore drilling involves drilling a hole to depth with a small diameter EX- or AX-sized bit, placing a probe to measure strain response data, and then using a special resin to glue the probe in place. After drilling out a larger diameter core to retrieve the probe, the overcore sample and probe are used for stress testing the rock formation to plan for ground support. This method is often used in both horizontal tunnels and vertical shafts to measure the amount of stress the rock can take.

Another unique application for underground rigs and crews is drilling on the surface into high walls for dewatering purposes. Flat to close-to-horizontal boreholes – from 10 degrees up to 10 degrees down – can be used to create self-draining dewatering boreholes in high walls. Pressure grouting in a cement collar casing keeps the hole from collapsing and can be used with a BOP valve in case the mining client wants to shut the water in the rock formation.

To maintain the integrity of the hole, installing slotted polyvinyl chloride (PVC) keeps the hole from collapsing. If you go through a broken zone, when water starts flowing, the hole can bridge off after a couple of months. The PVC keeps the hole open and the water running.

The benefit of using underground rigs for this type of drilling is the difference between large rotary rigs that produce chip samples and use lower rotation per minute (rpm) and higher torque whereas a coring rig operates at higher rpms and less torque. Chuck-drive underground coring rigs drill slower, straighter, and deeper and collect core for further analysis.

Geologists can use core samples from horizontal drilling into a high wall to look for fractures, faults, and oxidation (to identify water-bearing zones). They can also be identified in chip samples using rotary drilling rigs, but it’s more difficult to see them that way. A core sample provides a better physical view of the rock formation. Drilling high walls with underground coring rigs accomplishes two goals with one borehole – dewatering and obtaining core samples for assaying for fractures, faults, and oxidation.

LM90 with customized feed frame. Expert drillers from left to right: John Sanchez, Jimmie Maggard, Marcus Woody, and Sal Renteria.

Whether it’s an underground coring project or a surface application for underground coring rigs, the drilling crews are the real heroes at Boart Longyear. They have wide-reaching (global) resources to find unique and inventive solutions for complex, technical, and sometimes immense drilling challenges and they’re not afraid to ask questions.

More than just a can-do attitude, great work ethic, diverse skills, vast experience, technical knowledge, and a commitment to safety and each customer’s success, they get the job done. Drillers, driller assistants, welders, mechanics, supervisors, and other support personnel travel to work in remote locations, in all kinds of challenging weather, climates, and altitudes, all while spending extended time away from their families. The work is strenuous, involves extensive training, and requires their full attention for safety’s sake.

These real heroes all contributed to Boart Longyear’s latest safety achievement of 10 million man-hours and one year of being lost-time injury-free. A big congratulations to all the drilling crews and support personnel on this company-wide accomplishment! Denis Despres, Chief Operating Officer stated, "On a site level, we value the everyday procedures from standardized pre-start information meetings that focus on daily job tasks and associated hazards and risks, our online data management system, including the system’s mobile app, and the daily team and individual-based field level risk assessments. At Boart Longyear, it is everyone’s responsibility to work safely."

Originally published in Issue 11 of Coring Magazine, November 2019

Martin Rivet is the Director of Engineering for Drilling Services at Boart Longyear. Growing up in Haileybury, Ontario, he took an early interest in the mining industry, joining the company at age 16 as a mechanic’s assistant. He continued his education earning a degree in mechanical engineering and with his gained experience took on new positions as an engineer, an EHS professional, a product manager, and most recently, the director of the Drilling Services engineering team. Martin now lives in Salt Lake City, Utah working on global engineering projects, including the development and implementation of TruProductivity.

Our host, Jon Peterson (Geo Jon for fun), works for the Products division as a Customer Service Representative. Jon graduated from the University of Utah in 2015 with his Bachelors of Science in Geology. He’s worked for Boart Longyear for the last two and a half years and interned as a geologist with an exploration company for about six months prior to coming to work for Boart Longyear. Jon has been married for a year and a half and in his free time enjoys trail running, hiking, working on his yard, spending time with family, and playing with his black lab Dexter. 

We would love to hear your questions and comments below. Thanks for listening and if you liked this episode, share it on LinkedIn, Facebook, or Twitter. 

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with Boart Longyear Drilling Services

Born and raised in Colac, Victoria, Australia, Lyn had an older brother and a younger sister, and always wanted to be different thanks to growing up with “middle child syndrome”. What once started as a desire to be a graphic designer and work in fashion design gradually changed to drilling. We sat down with Lyn Ferrari to find out more about her path to becoming a driller, her current experiences, and what it’s like to be the only driller in Australia working for Boart Longyear.

Boart Longyear: “When did you first decide you wanted to become a driller?”

Lyn Ferrari: “My Pop had a cattle farm in Beeac (just outside Colac) where he ran Murray Grey Cattle. When I was 14, my Pop taught me how to break the cattle in and I started showing them at local cattle shows where I won a few ‘Best in Show’. This led me to work for TeMania Angus, which led me up to Gyranda Station near Cracow in Queensland.

Gyranda specialized in Santa Gertrudis and just by chance, some Boart Longyear employees were drilling out on the station. The station employed a number of Jillaroo’s (female stockmen) and the Boart Longyear guys jokingly referred to the station as McLeod’s Daughters (which is a reference to a 90’s Australian TV drama about a farmer and his three daughters located on an outback property). The Boart Longyear guys challenged me to come out and give drilling a go – so I did! Eleven years later, I am still with Boart Longyear and still drilling!”

Boart Longyear: “What’s your most interesting experience drilling?”

Lyn Ferrari: “It’s amazing to me to think that you are drilling down sometimes hundreds of meters into the earth and pulling out core samples with fossils embedded in the core samples that are millions of years old. One of my most interesting experiences was as an offsider where I was sure we had struck gold, to the point where I noted down on the geo’s sheet ‘We found gold!’ only to find out later from my Driller that it was actually ‘fool’s gold’ otherwise known as Pyrite. I was very disappointed that day.”

Boart Longyear: “What’s the worst thing that has happened to you drilling?”

Lyn Ferrari: “One extremely cold (below zero) morning at Cracow, we were standing around the diesel salamander heaters trying to keep warm. I had bangs hanging down from under my hat when one of the Drillers said he noticed a burning smell. All of the sudden, we realized it was my hair smouldering. It took me a while to live that one down!”

Boart Longyear: “Where have you travelled to in your drilling career?”

Lyn Ferrari: “I have worked on Diamond Rigs – Underground and Surface Rigs, RC Rigs, and ‘super’ Sonic Rigs. Some of the places I have worked are Cracow – Newcrest, Lake Cowal – Barrick, Coolgardie in WA – Focus, Creswick and Horsham – CRC, Prominent Hill Surface – Oz Minerals, Olympic Dam – Underground and Surface – BHP and Whyalla – Arrium.”

Boart Longyear: “Who have you enjoyed working with at Boart Longyear? Who do you consider to be influential leaders in the workplace?”

Lyn Ferrari: “Neville ‘Hurricane’ Hodgetts and Jacko ‘Daddy’ Turnbull have been wonderful mentors and awesome bosses. In and out of work they are the ‘calm in the storm’.”

Boart Longyear: “Why do you enjoy working for Boart Longyear?”

Lyn Ferrari: “I really like the job, but I would have to say it’s the people I work with that keep me here. It doesn’t necessarily feel like work when you get to work with your mates every day. Being the only female driller working in Australia at present is also a motivation for me; it’s a privilege and I am glad I have been able to stick it out and prove I can stand the heat as much as the next fella.”

Boart Longyear: “Do you think drilling presents any unique challenges for women?”

Lyn Ferrari: “I’ve had amazing adventures working with the ‘BLY Boys’. I enjoy learning with the guys and due to the technology we employ to drill nowadays, it is more about using your brains than your brawn. There is nothing that a female should not be able to do. I go to the gym every day alongside the guys and look after my physical fitness. I feel this gives me the edge and keeps me fit and healthy to do my job. At my current job, the crew has all purchased Fit Bits and we track our steps each day on the rigs and compare our steps. It’s not unusual to come in with 20,000+ steps per day!”

Spell out key aspects of the project timing and any key milestones. Do federal (national) or state (provincial) permits only allow the drilling contractor on site at certain times or durations? Are there exceptions in the permit due to habitat/breeding concerns with local wildlife? Will site access become problematic during a change in weather, ie. rain, snow, heat? If site access is only helicopter accessible, are there firm start and end dates? Are the dates pertaining to any site visits, question periods, tender submission, and project award clearly spelled out? 

There are many variables that contribute to the overall success of a drilling program. Setting clear expectations around anticipated penetration rates (if applicable, historic rates are best), acceptable core recovery percentage, drilling accuracy/hole deviation, survey intervals, core orientation, consumable supplies, sample storage / core boxes, water sourcing and transport, automated rod handling, accommodations for geotech support, etc. provides those bidding the work with consistent information, allowing a better value comparison in the end. Failing to define expectations often leads to operational confusion, delays, cost overruns, change orders, and future discussion around cost containment. No one wants their program shortened because time and money were wasted resolving issues that could have been clarified up front.

Unique site conditions can make or break a project. Understanding your permit and the applications to your drilling program are paramount. Requirements for water usage and drilling fluid disposal are vitally important. A drilling contractor can incur significant additional costs to complete a drilling project if drilling fluid management is not clear in the RFQ. Many drilling projects are now moving to drilling fluid management systems that produce a semi-dry solid and do not put any drilling fluid on the ground or in an onsite pit. What about noise? Are there requirements regarding wildlife disturbance, breeding periods, migration areas, nearby housing, or other potential issues where noise from the drilling activities on the site would impact a drilling contractor’s ability to operate?

Site disturbance has also become an increasingly important issue as it is typical for permits to only allow so many acres of active disturbance prior to reclamation activities. Given your site locations, how many active sites can you have with proper regard to safe operations?

Clearly defined travel routes to the drilling locations and laydown areas as well as expectations about off-road travel and potential one-off events are important and best sorted prior to bid submission so that all the potential service providers know what is required. Many contractors have seen instances where the drilling crews identify alternate travel routes, for various reasons, that do not meet project or permit expectations.

During the bidding process it is inevitable that questions will arise no matter how well the RFQ has been prepared. Having a clearly identified team and communication process speeds up resolution and keeps all the bidders on the same page. Identifying representatives from Geology, Hydrology, Health and Safety, Engineering, and Supply Chain/Procurement and having them in the loop on the project specifications assists potential bidders in getting questions answered and any necessary clarifications made easily and quickly.

Be clear about non-conforming bids. Will they be accepted and considered?  Accepting a non-conforming bid that may seem to provide a better value often ends up adding confusion to the decision-making process by straining accurate comparisons between contractors and lengthening the tender process through additional questions and needed clarifications. Take the time to be thorough up front and the outcome will be better served without wasting time trying to sort out how to compare a non-conforming tender.

At the end of the day, a strong contract is the best way to guarantee project success and if things get off track, it provides a clear backstop to discussions and issue resolution. Thinking through the key aspects of the program and vetting ideas and mitigation plans prior to issuing the RFQ results in bid submissions aligned to your expectations, allows for easier comparison among contractors, and keeps your project timing and costs on track from day one. Happy Drilling!

Nelson Mandela, a South African anti-apartheid revolutionary, inspirational leader, public servant, and philanthropist, served as President of South Africa from 1994 to 1999 and gained international acclaim for his activism including winning the Nobel Peace Prize in 1993.

The idea of Mandela Day was inspired by Nelson Mandela at his 90th birthday celebration in London’s Hyde Park in 2008 when he said: "It is time for new hands to lift the burdens. It is in your hands now." The United Nations officially declared July 18th as Nelson Mandela International Day in November 2009, recognizing Mandela’s "values and his dedication to the service of humanity" and acknowledging his contribution "to the struggle for democracy internationally and the promotion of a culture of peace throughout the world."

Boart Longyear offices around the world were invited  to organize a service project on July 18th to celebrate the humanitarian in all of us, fight poverty, and give back to our communities. Here are some of Boart Longyear’s results from this worldwide initiative:

The Salt Lake City Operations Center (Boart Longyear’s global headquarters) organized a fundraiser, donation, and volunteer opportunity to celebrate Mandela Day. They partnered with the United Way of Salt Lake to complete a snack kit packing project.

In surrounding community schools, a large percentage of the students come from low income families. Kit packing projects benefited these students and provided them with basic items that allowed them to enter the classroom ready to learn.

In order to contribute, employees:

1. Purchased individually wrapped snacks for the snack kits.

2. Donated funds to purchase additional snacks.

3. Volunteered on July 18th to assemble snack kits and prepared them for local delivery.

The goal was to donate enough items to pack 300 snack kits – roughly the number of employees in the Salt Lake Operations Center. However, employees were able to pack over 1,400 snack kits for a local elementary school so that students could enter the classroom ready to learn. As an added touch, employees wrote notes of love and encouragement and included a note in each snack kit.

The Johannesburg, South Africa office partnered with Bethany House Trust, a child protection agency, and provided over 90 children with food on July 18th.

The Bethany House Trust provides several specialized programs for orphaned children and children at risk. The center is located across several residential properties and has been in operation since October 1999. It currently accommodates 90 children, with ages ranging from infant to 18 years old. The aim of Bethany House is to break the cycle of abuse in the child’s life and facilitate healing and re-integration into the community as a productive member of society. Following a holistic approach, the physical, educational, emotional, and spiritual needs of the child victims are met. Teenagers also participate in an independent living program to prepare them for life outside the children’s home.

The Boart Longyear team prepared and served lunch for the children at Bethany House Trust. The day was a huge success, and over 90 children were fed by employees on July 18th. The Boart Longyear team is committed to continuing their relationship with Bethany House and the children. The team considered the experience to be eye-opening and view this act of kindness as a great starting point to continually turn outward and support the local community.

There’s a special connection with Nelson Mandela and Indonesia… and it happens to be his signature printed shirts. Known as the "Madiba Shirt," the informal garment was a way for Mandela to identify with most of his people who never wore suits, according to Yusuf Surtee, Mandela’s longtime tailor.

While the history of the shirt dates as far back to Egypt’s first dynasty, Mandela first became fond of the item when he was given batik print shirts by Indonesia’s President Suharto in 1990. The pattern is a traditional Indonesian one that’s still worn by world leaders today.

To honor Mandela’s legacy, the Boart Longyear Jakarta office dressed in traditional batik print shirts and collected clothes and donations to give to a local foundation that manages child education and aids with poverty.

The Boart Longyear Vientiane office organized a luncheon for Nelson Mandela Day to celebrate the idea that each individual has the power to transform the world and the ability to make an impact to fight poverty, promote peace, reconciliate the diversity of culture, and make the world a better place for people.

During this special occasion, the Boart Longyear Laos team donated personal funds to support the local community. The collected funds will buy educational materials for neighboring rural school communities.

In honor of Nelson Mandela Day, the Boart Longyear team at the Mississauga office sponsored a food donation to support the local Mississauga Food Bank. The Mississauga Food Bank is the central food bank in Mississauga, providing food for over 217,000 meals each month through a network of 50 agencies. Their objective is to provide adequate food from the four categories of Canada’s Food Guide – fruit and vegetables, protein, grains, and dairy products – to provide a balanced diet to food bank users for 7+ days each month. Thousands of individuals and families across Mississauga rely on the Mississauga Food Bank every day.

In order to contribute, employees:

1. Collected non-perishable food items to donate.

2. Delivered food donations to the Mississauga Food Bank

The food collection initiative was a success, and all employees enjoyed participating and contributing to local individuals in need.

With one in seven people hungry across the world, it was a humbling experience to join forces and contribute in a small way.

Boart Longyear historically named their overburden and construction drilling products line for this type of drilling “Delta” tools. In addition to being the fourth letter of the Greek alphabet, and a code word representing the letter D, (used in radio communication), delta is also defined as the difference between two things or values, or the average change of any changeable quantity. In short, the overburden construction drilling product line was designed for drilling through changing ground conditions typically encountered above bedrock.

With more and more challenging and larger specialty geotechnical construction projects in difficult, complex, and varying ground conditions, rotary and percussive drill rigs in the construction industry were getting stronger and more powerful. Bigger, stronger, and more powerful rigs subsequently required larger, stronger, longer-lasting construction drilling tools – including better designed and manufactured casing bits.

Casing bits are used in deep, difficult overburden when a casing shoe is not sufficient to drill to depth. There have not been any significant advancements made in casing bit designs since the 1990’s. The so called “proven, bullet-proof” bits were made day after day without questioning the physical mechanics or what might be possible with a new or improved design.

In light of this, Boart Longyear decided to partner with its customers to look at redesigning casing bits in the geotechnical construction drilling field.

The first discovery in this initiative was that drilling site feedback often compared apples to oranges about bit designs and there was no real definition of drilling bit designs or any so-called standard. The sum of differing opinions needed more segmentation and analysis. After interviewing customers, experienced drillers, and engaging our internal engineers, all of the feedback was segmented and combined with proven manufacturing information and our new Z Design casing bits were created, tested, and are now available to the industry.

Combining the three main aspects in faster and longer lasting casing bits: cutting, flushing, and gauge protection, Z Design casing bits provide improved flushing, faster ROP (rate of penetration), and longer lasting bits. The difference is in the design and materials. Using premium tungsten carbides, high quality steel, improved gauge protection, and induction brazing to reduce blistering, Z Design casing bits are manufactured in our ISO-Certified, Eiterfeld, Germany manufacturing plant.

CONSTRUCTION

Casing bit bodies are constructed of high strength quenched and tempered steel. The high-quality tungsten carbide inserts are induction brazed into the steel bodies ensuring a secure fit without overheating issues associated with flame brazing. Strict machining control of the carbide seats prevents premature loss of carbide inserts.

GAUGE PROTECTION

Tungsten carbide gauge protection on casing bits prevents excessive wear on the outer diameter of the bit in abrasive ground conditions. Additionally, in unconsolidated conditions where the ground is caving in on the drill string, gauge protection assists in freeing the bit and casing by providing another cutting surface.

SHRINK FIT CARBIDES

When required, Boart Longyear offers shrink fit installation of all hemispherical, ballistic, and two-step tungsten carbide inserts instead of the standard induction brazing. This very precise construction method is often utilized when drilling in extremely hard ground conditions and provides both increased button retention and longer overall life.

ADVANTAGES

• Computer controlled induction brazing of tungsten carbide inserts for superior process control and overheating prevention, common with flame brazing
• High-grade body construction with quenched and tempered steels
• Optional tungsten carbide gauge protection available for unconsolidated grounds and increased bit life in abrasive conditions
• Specialized designs for unique drilling situations such as drilling through reinforced concrete and drilling without inner bits.

Better casing bits means better drilling outcomes and ultimately results in better ROI (return on investment). Casing bits are designed for rotary percussive or rotation only drilling based on the tungsten carbide inserts utilized as well as the geometry of the bit. Customized tools for unique drilling applications are also available upon request.

Contact your local Boart Longyear representative or distributor to order the best casing bits in the overburden drilling market. Still not convinced? Contact us for help designing and implementing a testing drilling program to prove using Boart Longyear casing bits have a higher ROI.

For part numbers, download the Boart Longyear Overburden and Construction Tooling catalog here.