In September of 2012, wooden cable frames at a potash mine in Rocanville, Saskatchewan, caught fire, trapping 20 workers underground. From inside the mine, the workers were able to communicate with the outside world and stay safe, despite being...
In September of 2012, wooden cable frames at a potash mine in Rocanville, Saskatchewan, caught fire, trapping 20 workers underground. From inside the mine, the workers were able to communicate with the outside world and stay safe, despite being trapped in smoky conditions for a day. No one was injured.
Six years earlier at a Mosaic Company potash mine in Esterhazy, Saskatchewan, 72 workers were trapped underground for 32 hours. A fire had burnt the communication lines, so this time the workers could not be reached. “We anticipated it would go bad,” recalls Neil Crocker, Saskatchewan’s chief inspector of mines with the Ministry of Labour Relations and Workplace Safety in Saskatoon. Remarkably, after the fire was put out, the workers resurfaced safely without injury.
How did so many workers, trapped underground in such dangerous conditions, manage to evacuate and stay safe? The answer lies in the sophisticated — if not delicate — system of mine rescue and mine emergency response.
In Canada, ground collapses may be the most dangerous of all. “You’re working under rock,” Crocker says. “It’s not a homogeneous, consistent medium like concrete. You can’t predict rock all the time.”
Providing access to clean air can also be a challenge, as underground air supplies can be easily contaminated. James Baumgartner, who works in mine safety with The Mosaic Company, says ensuring effective ventilation can be especially complicated in potash mines, which tend to be much bigger than other types. “You’re in a really large confined space,” he says, likening the area to “a paper bag with two straws.” Fresh air is circulated in one mine shaft, while exhaust comes out the other.
Underground mines also contain large, mobile equipment, some of which can pose electrical hazards. “Last year, we had some equipment fires underground,” Gryska recalls. The fires were caused by massive rubber tires or by diesel fuel, and could have threatened the safety of every worker, he says.
Coal mines in particular pose additional risks, since they feature what Crocker calls “an explosive, burnable” atmosphere. Michael Nelson, chair of the Department of Mining Engineering at the University of Utah in Salt Lake City, explains that if minerals are exposed to air, coal can release methane or hydrogen sulphide. This can be toxic to workers and even lead to explosions. At uranium mines, Nelson adds, miners can be exposed to radioactive particles in the air.
Despite all these risks, Nelson says mine safety is better managed compared to many other industries. The rate of serious injuries and fatalities in mining accidents has declined in many provinces. According to the Ontario Mining Association, the mining sector in the province has improved its lost-time injury rate by 91 per cent over the last 20 years.
Some of these risks have been mitigated by relatively new technologies that can help prevent disasters. Consider that carbon dioxide, carbon monoxide and nitrogen in the air quickly trigger alarms. Today, nearly all mines are equipped with sophisticated phone and radio systems to keep workers — both inside and outside the mine — in contact with one another.
Employees going into dangerous areas might also wear tracking devices, which can facilitate a quick rescue effort in the event of a rock fall. Other mines, including the Mosaic potash mine in Esterhazy, now include a card-tracking system which requires workers to swipe in every time they go underground, documenting their name on a computer for dispatchers off site.
In other cases, mining equipment has been automated or remote-controlled to reduce the number of workers entering perilous areas.
In some mines, a new device has been employed which can even determine whether or not an equipment operator is falling asleep by measuring their eye direction and blinking rates, reports Al Hoffman, chief inspector of mines for British Columbia. If an operator is deemed to be sufficiently tired, an alarm may sound to alert the worker and the pit control operator of his or her condition.
Despite these advancements, mining disasters can and do continue to happen across the country, and when they do, every site has a plan. Mine safety regulations vary slightly from province to province, but their procedures are fairly consistent.
When employees spot problems, they are instructed to first protect themselves. If the issue is minor, they might fix it themselves, whether that means putting out a small rag fire or turning off a vehicle with an electrical problem. But if the issue cannot be addressed or contained by workers in the immediate area, Crocker says “their job is to retreat to a place of safety” and start the emergency warning system.
To alert workers to emergencies, these systems take several forms, including flashing lights, phones, horns and sirens. Sometimes, workers are informed of emergencies by ethyl mercaptan injected into a mine, giving off a rotten egg smell. “It is distinctive, you can’t miss it,” Crocker says with a laugh. The goal is to ensure that all workers, regardless of whether or not they are using loud equipment or working in low-light, get the message.
Once workers are alerted to an emergency — be that a fire, ground collapse or a gas leak — their responses will vary depending on the type of emergency and the type of mine. In coal mines, Crocker says workers are evacuated immediately since there is a risk of explosion. If they must stay in a safe area within the mine, it must be one without electricity.
In most other underground mines, employees are typically directed to their nearest refuge stations — self-contained units where they can go to stay safe until they can be retrieved by a mine rescue team. These units usually contain air masks, breathable air, first aid equipment, potable water and any other equipment workers may need to survive for days. Some even contain toilets, food and entertainment, such as playing cards or board games.
Refuge stations vary in form depending on the size of the mine and the risks it poses. Some are permanent structures, a number are excavated out of rock while others are fully mobile — “like a big CN box[car] on skids,” says Jay Dooley, mine rescue co-ordinator at Grande Cache Coal in the Alberta town of the same name.
While they cannot be entirely explosion-proof, the majority are fire-resistant and located far from combustible materials. According to Randy Waylett, Winnipeg-based manager of sales for RANA Mine Refuge Systems, most stations feature a double-entry door system so that dangerous gases cannot enter the area. Some also have air conditioning, since body heat alone can bring the temperature in a station up to 38 degrees Celsius.
The number and location of refuge stations varies from province to province. Saskatchewan, for one, requires refuge stations to be present in all active areas of a mine. This requirement can be particularly challenging for potash mines, where work areas can be separated by thousands of feet vertically or miles underground, necessitating 10 or 15 refuge stations, Crocker says.
The Esterhazy site, for instance, is the largest potash site in the world, and covers as much area as Winnipeg. At any given time, there might be 200 to 300 workers underground. Workers must be within 10 minutes of a station by vehicle or 15-20 minutes on foot, Baumgartner says.
Although refuge stations are used infrequently, mine personnel inspect them regularly to make sure that supplies are in good condition, the air system is adequate and the fire extinguishers and other devices are functioning and up-to-date, he adds.
OUTSIDE THE BOX
Baumgartner says workers are also trained in constructing their own makeshift refuge stations in the event that they cannot get to an established one safely. For instance, if a worker’s vehicle has broken down or if they are facing smoke, they can use equipment in a nearby lunchroom or vehicle to construct their own safe, smoke-free place and wait for assistance.
In an even less likely scenario, workers can take cover in dead-end areas using plastic and respirators to protect themselves from smoke. Once they reach a refuge station safely, workers can usually communicate with above-ground operators who can direct them on what to do next. The next step, which is often at the same time that workers report to refuge stations, involves highly specialized rescue teams.
When disaster strikes, a mine rescue team — rather than local emergency personnel such as police and firefighters — will handle the crisis. “A lot of people just assume that if you call 911, they can do anything for you,” Gryska says. “What we tell people is if you’re relying on 911, you better call them and find out what they can and can’t do.”
Generally, he says fire services will not go underground as they lack training and equipment for the unique hazards associated with underground mines.
Instead, emergencies are handled by specialized mine rescue teams composed of on-site mine workers who voluntarily undergo additional training. “There isn’t a higher risk job,” Gryska argues. In some cases, such as underground fires, “the situations you’re confronted with are extraordinarily unforgiving.”
Mine rescue teams typically consist of five or six miners, including a supervisor or captain and vice-captain. Before the first team on active duty can begin to assess the situation, a back-up team must be ready to go at the surface of the mine with a third team en route. “I cannot send anybody underground in a mine unless I have a minimum of 15 mine rescue personnel,” Dooley says.
The teams are often composed of active mine workers with wide-ranging skills such as mechanics, electricians, miner operators, and engineers. The goal is to have a team that can handle any emergency. “It’s handy to have an electrician,” Crocker says. “They can do things others shouldn’t.”
“Personally, I like to be involved and always thought I could help in a way,” says Rick Kretzschmar, safety co-ordinator at Nyrstar Myra Falls on Vancouver Island. “Instead of being on the outside looking in, I’d rather be inside looking out.” Kretzschmar, his safety manager and fellow mine rescue worker Rory McFadden both come from families with a long tradition in mine rescue.
When selecting new mine rescue volunteers, the Nyrstar team looks for people who are medically cleared, fit, competent, level-headed and have a history of being good employees. “If you have a perforated ear drum, you can’t join mine rescue,” says Dooley, adding that rescue workers also need to be able to handle stress well and think on their feet.
In an emergency situation, “you need the total commitment of the gentleman beside you,” he says. “If one of those individuals is taken over by fear… the whole mission is scrapped and we all must return to surface together.” In view of the high-risk nature of the task, joining a mine rescue team is voluntary.
The number of mine rescue personnel required at a given site is often dictated by the number of workers in the mine. For example, Hoffman says British Columbia requires three people to be trained in mine rescue if there are less than 20 people in the mine.
Once rescue personnel are selected, all team members undergo a standardized training course, where they learn basic first-aid and mine rescue standards. In the initial training program, which can take up to 80 hours, Crocker says the volunteers learn about safety procedures, fires, mine gases and other dangers.
Over two weeks, they learn basic mine rescue and how to use a four-hour self-contained breathing apparatus. Otherwise, in some scenarios involving smoke or toxic gases, the “outside air would kill you within a minute,” Dooley cautions.
Once they have learned to use the equipment, workers get a chance to use it underground. In that training, they work as a team on the surface and undergo a simulation such as an underground fire. Following that, teams will receive refresher training. Using sophisticated simulations, the team runs through specific operations designed to make sure that they know how to use their equipment in the face of different disasters. To stay qualified, the rescue teams then practice and continue training anywhere from 40-80 hours a year, depending on the province.
“I’ve been in mine rescue 31 years and called to active duty three times,” Dooley states. “One guy did 43 years and was never called to active duty. But we train once a month. It’s law, in case of such an emergency.”
PRACTICE MAKES PERFECT
In Dooley’s view, camaraderie and trust in the safety devices they are equipped with are very important to rescue teams. The other mantra, he says, is “practice, practice, practice.” A more experienced rescue worker may eventually become the rescue team captain, who supervises the other workers.
As a final precautionary measure, rescue teams and workers alike are subjected to regular emergency drills, where the entire rescue team is put to the test. If there is any problem or a worker cannot be accounted for within about half an hour, the emergency procedures at a mine are revised, Crocker says.
During an emergency, the rescue team’s task can vary greatly. A surface mine team might work and train with fire trucks and emergency vehicles, and may need to extricate people from their trucks. Other situations might call for high-angle rescue where ropes, baskets and other tools are lowered down the walls of a pit, cliff or waste dump to pull out trapped employees. “Often, you can’t just use a ladder, because the distances are too great,” Hoffman notes.
In smoke-filled areas in underground mines, rescues can be particularly challenging. “There was a fire at Smoky River Coal [near Grande Cache] in 1991, going on for five days,” McFadden recalls. “You couldn’t see anything. You could see your finger if you touched your mouth,” he says, noting that he and Kretzschmar, the safety co-ordinator at Nyrstar Myra Falls on Vancouver Island, took six trips each underground.
Though no one was injured, the teams faced hazards from built-up methane, smoke and fire in a coal mine. Today, some teams may use infrared cameras to locate workers in such conditions.
Specific tasks aside, the fundamental principles remain the same. The team’s first mandate is to protect
itself and do everything in its power to ensure its own safety as it navigates potentially dangerous situations. Then, rescue workers do whatever they can to ensure the safety of all workers.
“If you know someone is in trouble, that’s the first point you go to,” Crocker says. After they have been rescued and their safety is assured, the team can address the disaster directly and protect the mine from further damage.
“If everyone is accounted for, the team goes and looks for the problem. If not everyone is accounted for, they look for that person or crew at last site known,” Baumgartner explains. As a final step, the team helps return the mine to safe conditions so that operations can resume.
LENDING A HAND
In more protracted operations, multiple rescue teams may need to be called to the site, with mines often pairing up with neighbouring mines to assist each other in the event of an emergency. These mutual aid agreements are typically written documents, identifying who would do what and how, Gryska notes. In these cases, rescue personnel could come from local communities, neighbouring mines or even be flown in from other sites.
Smaller mines in particular do not require full mine rescue teams on site and may be dependent on these partnerships with larger sites. In 2007, there was an incident where a mine rescue team from Highland Valley Copper, southwest of Kamloops, British Columbia, provided assistance at Graymont Pavilion Plant near Cache Creek, British Columbia. An excavator operator was buried by a rock fall, Hoffman recalls. The team travelled to Graymont, took over the situation and dug the worker out 12 hours later. “He walked away with virtually no injuries. It saved his life.”
Hoffman says the incident command system, which outlines roles and responsibilities for responders, has been a helpful catalyst for these kinds of partnerships. “We all train to the same standards now, so larger mines can help smaller mines,” he says, adding that despite facing several emergencies, the pair has never had a rescue team member injured.
“It’s a brotherhood,” says Kretzschmar, noting that he and McFadden partner with a nearby coal mine and even practice mine rescue together at times. “In the past we saw each other as competition,” he says. “Now, we practice, and know we’ve got each other’s back.” Even without agreements, when someone calls for help, McFadden says they never refuse a call for assistance. “If there are people at risk and we can help them, it’s hard to say no.”
Of course, a little inter-mine competition never hurt anyone. To keep mine rescue teams in top shape, teams from across the country participate in regional, provincial and national mine rescue competitions.
“You can’t get into a more realistic environment,” Gryska says. In competitions, rescue teams fight live fires, perform high-angle rescue on “injured” workers, and often work in makeshift tunnels filled with smoke and fire obstacles.
The competitions — held across the country and open to the public — also often include a written exam and a machine check test where competitors have 15 minutes to check machines from top to bottom, while judges evaluate the 100 or so checks on the machine.
“They encourage people to train harder, study harder,” McFadden says, stressing that the competitions play an important role in sharing expertise across mines. “It keeps every company fresh and up-to-date with technology.”
At the end of the day, “there are a lot of hazards in underground mines,” Nelson concludes. “They’re only dangerous if not properly managed.”
Follow us on Twitter @OHSCanada
Riva Gold is a writer from Toronto.
Thinking Inside the Box
Randy Waylett, Winnipeg-based manager of sales for RANA Mine Refuge Systems, says that virtually every underground mine in Canada provides refuge stations to protect workers during emergencies, whether it is a fire or explosion underground, a partial ground collapse, contaminated gas in the air or another hazard.
His company’s Refuge One Air Centre, for example, purges carbon dioxide by passing the chamber’s air through carbon dioxide scrubbers and replenishes oxygen from a high-pressure cylinder at a metered rate, based on the number of occupants, a product information sheet notes.
“It is compact, sturdy, easy to operate and can work independently despite the loss of the mine’s electrical power or compressed air supply,” the information says.
It adds that the units offer a ten-year underground expectancy; a heavy-duty steel base to accommodate forklift use; skid mounting for portability between or within refuge chambers; a battery indicator light and alarm; and easy-to-use controls, making them simple to operate under stressful emergency conditions.
The single bed unit (for 15 people) and the double bed unit (for 30 people) provides oxygen for a minimum of 30 hours and battery capacity for 36 hours, with longer duration options available.