Fighting fire with training
An accidental fire that started just after midnight on Sunday, Jan. 29, 2006, in the world’s largest potash mine trapped 72 people underground in a potentially dangerous situation. Within a day and a half, the fire was put out and the miners were rescued, without injury. The rescue went remarkably well. There were no heroics; it was just a matter of everyone doing what they were trained to do.
The Esterhazy potash mine in southeast Saskatchewan is owned by The Mosaic Co. of Plymouth, Minn., a company formed through the 2004 combination of IMC Global Inc. and the fertilizer businesses of Cargill Inc.
To its credit, both during the event and following, the mine’s management has been open with the public about how the fire started and the actions of its employees. The manager of human resources Marshall Hamilton and the mining manager Gary Phillips both spoke to CMJ in late February about the ordeal and what has been learned.
The Esterhazy potash mine is spread over an area the size of the city of Regina — 20 km by 30 km. It is served by two shafts, about 10 km apart, both of which are used for hoisting ore. K1 vents exhaust air, while K2 is the fresh air intake.
The mine has just one level, excavating a horizontal 2.4-m-thick seam of potash ore that lies about 945 m below surface. It has 21 permanent or temporary refuge stations, which can be sealed off in the case of a fire. They are equipped with a telephone, water and some emergency food rations. The permanent refuge stations double as lunchrooms.
The underground communications system is a hardlined telephone, with no radio backup. Says Phillips, “With our testing over the years, we have not found a radio system that works. It seems like the signal’s attenuated in the potash. Maybe it’s just the low height [of the back], but we’ve never found a system that works, so we stay with the telephones.”
The fire
An investigation by the fire inspector has confirmed what management suspected early on. Between 1 and 2 am on Jan. 29, employees were cutting bolts off a flange on a 41-cm-diameter Sclair (polyethylene) pipe using an oxy-acetylene cutting torch, about 1.6 km south of the K2 shaft. This was a discharge pipe to control water inflow on the south side of the mine, where there is no longer any mining. The pipe was suspended from the back by chains at eye-level, with pipe sections joined by the metal flanges.
The flame from the torch must have ignited the pipe. When the bolts were cut, the two sides of the pipe were flopped down to the floor, and they landed fairly close to each other. The employees could not see the fire that must have been burning inside. They checked everything, and then went back to the shaft, took the cage to surface and went home.
Testing by Mosaic employees before and since the fire has shown that it is virtually impossible for polyethylene pipe to catch on fire. Unfortunately, once it ignites it gives off a thick, black smoke like burning rubber tires and is very difficult to extinguish. According to Phillips, the pipe must have been in contact with the flame for some time, perhaps hidden from view, before it started burning.
Reaction of miners
The burning pipe was discovered 60 to 90 minutes later by a crew of contractors as they rounded a corner on their way back to the K2 shaft at the end of their shift. Likely within minutes of starting, the fire had burned through the power cable and telephone lines that were suspended directly above the pipe. This put out the lights and ventilation fans as well as communications in this area.
The crew had only headlamps for light, and were unable to contact dispatch to signal a fire alarm. They tried but failed to put the fire out with the small extinguishers that they had, so they put up some brattice, went back to the nearest refuge station (500 m away), sealed themselves in and waited. The group comprised 31 Dynatec employees and one Mosaic worker.
Three miners were very near the K2 (fresh air) shaft when the fire was detected. They proceeded to the shaft, reported the fire to dispatch and then took the cage to surface.
North and east of K2 shaft were another 40 Mosaic employees, some as far as 16 km from the fire. The telephone and power worked in their parts of the mine. When they were notified of the fire, they headed to seven refuge stations that housed 15, 8, 7, 5, 2, 2 and 1 workers, respectively (see the sketch map). The groups each sealed off their stations and waited. These 40 workers had regular telephone contact with the command centre, and later on could phone their spouses directly.
Command Centre
A command centre was set up on surface comprising mine management, safety and rescue professionals from Mosaic. They quickly developed a strategy and alerted mine rescue teams to prepare to go underground. There had to be at least two teams ready at surface before one could go underground, in case the first experienced difficulties. When a team returned from underground, its captain would be debriefed and the captain of the next team would be briefed. That team would pick up where the last one had left off.
The command centre kept in regular contact with the employees in the refuge stations with working phones, which was all of them except the one housing the 32 nearest the fire. The centre also gave regular updates to Dynatec and Mosaic supervisors, so they could keep the miners’ families informed. “Some of the spouses chose to come to the mine,” says Hamilton, “but that was a really small percentage. Most of them just stayed home. Some gathered together for emotional support.” Dynatec supervisors phoned the spouses of its 31 employees every couple of hours, and Mosaic supervisors received calls from family.
During the rescue operation, the mine management was joined by company executives, including CEO Fritz Corrigan, VP public affairs Linda Thrasher and chief legal counsel Rich Mack from the Minneapolis head office. From other parts of Saskatchewan came Norm Beug (VP of potash operations), Brian Warren (VP of human resources) and Lorne Cooper (director of health and safety).
Says Hamilton, “We clearly had the support of all of our most senior Mosaic people, but they left it to the people from Esterhazy to manage. We knew the terrain, and could therefore mobilize the rescue teams very quickly.”
The Rescue
In all, 54 people participated in the rescue teams: 33 from the Esterhazy mine as well as 13 from Potash Corp. of Saskatchewan’s Rocanville mine about 30 minutes drive away, and eight from Mosaic’s Colonsay mine a 3.5-hour drive away. Their job was to find the fire and put it out, account for the miners trapped underground, and then rescue them. Before they could be rescued, the smoke had to be dissipated and the tunnels reventilated.
The first team was ready to go underground within an hour of being called out, but the rescue was slowed down significantly by the thick smoke and the fact that the communications lines were down in the area.
The five-person rescue teams went underground, one team at a time, with members tied to each other (when required) so no one would be lost. They traveled underground in vehicles (with headlights) and occasionally on foot (with only the headlamps for light). They would do part of the mission, then come back to report by telephone what they’d seen, the gas readings, which fans were on or off and which rooms had smoke. Then they would come to surface. The self-contained breathing apparatus they were wearing had four hours of oxygen, but the rescuers returned in 2 to 2.5 hours, following company procedures.
The fire was extinguished about 6 pm on Jan. 29, 17 hours after it had started, but the first trapped employees did not reach surface until 3 am Jan. 30, with the last ones out by 9 am. The 72 had been underground for 25 to 31 hours following their work shift.
Handling the media
Hamilton became a central figure
in a media frenzy that lasted throughout the ordeal, a situation for which he had no previous experience. The public were riveted to the situation, probably because of the tragic result of an underground explosion at the Sago coal mine in West Virginia, just four weeks earlier, in which 12 miners died before they could be rescued.
After nine hours of trying to respond to an impossible number of requests for information, Hamilton set up a media centre in the truckers’ shack, from which he conducted a media scrum about 15 minutes after every hour. At 15 minutes before every hour he held a conference call. In the call he provided updates and answered questions. This worked remarkably well. It gave him time to get updates from the command centre, and do radio and television interviews. It also kept the media away from the rescue work.
The media centre operated for 14 hours until the press conference at 7 am on Jan. 30. “If I could do that all over again,” says Hamilton, “I probably wouldn’t have done it any differently; I just would have started the conference calls sooner, because it made so much sense.”
Lessons learned
“I can’t speak highly enough about refuge stations,” says Hamilton. “Make sure you have them and that your people understand why they’re there, and what they need to do in the event of a fire underground.”
The biggest lesson that Mosaic Potash Esterhazy learned from the mine fire was to relocate the power and communication cables away from anything that could burn. That includes polyethylene pipe, which had not previously been considered a fire hazard. Much of the relocation had already been done by the end of February.
The mine is looking into other ways to safeguard its telephone system, such as doubling up the line in places, and to restore communications quickly.
“We’re doing things to make sure that our refuge stations are more comfortable,” says Hamilton. “They’re not bad for an hour, but for 30 hours… We’re thinking of having some cots or softer benches. We’ve had people complain about the food, but we’re not about to stock them with pizzas.”
From a communications standpoint, he advises, “Be prepared for this to get bigger than you ever thought. Co-operate with the media, tell the truth and be factual.” He adds: “Don’t forget about the spouses; it’s really important that they get regular updates as to your progress.”
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