Digging deep into trench rescue training
There’s a term for operations like trench rescues that fire and rescue workers know well: low frequency, high hazard events.
Basically, a firefighter may go through his or her entire career and never be confronted with a person trapped in a ditch. But when and if they do get that call, there's something — well, a few things — it'd be good to know.
Just ask Ashland Fire & Rescue Chief John Karns. About 15 years ago he was a firefighter for the Beverly Hills Fire Department when he was sent out to a construction site to help free a man from a trench that had collapsed in on him.
“All of our folks had the training,” Karns said. “We did have one guy who jumped into the trench to help and we're like, ‘OK, let’s just step back,’ and got him out. It wasn’t a body recovery, which a lot of these are. It was a rescue. The patient was viable and we knew that, so to protect him we did a lot of exactly what you’re seeing here.”
“Here” was a flat, yellow, barren turnout above the Ashland Municipal Airport off Dead Indian Memorial Road, where fire and rescue workers from throughout the Rogue Valley, along with a handful of Ashland public works employees and two firefighters from Ashland’s sister city of Guanajuato, assembled Wednesday to practice the trench rescue techniques they had spent the morning learning about in a classroom. Waiting for them on the site was an L-shaped trench about three feet wide and 10 feet deep at the short side, 8 feet deep on the long side, and all of the equipment they would need to complete the task — sheets of plywood, other lumber, ropes, ladders, a circular saw, hammers and nails.
The training was handled by California Health & Rescue Training, whose owner and head instructor, Kent Freeman, was on hand for the three-day course.
Fire and rescue crews define a trench as any excavation at least 5 feet deep and deeper than it is wide. They are common on construction sites, which is part of the reason Karns decided to call on CHRT.
“There are a lot of trenches dug in the area, lots of construction, and a lot of them are done without permits,” he said. “Those are the ones we worry about.”
For good reason.
According to the National Institute for Occupational Safety and Health, 271 workers died in trenching or excavation collapses between 2000 and 2008, and more than half of those victims were would-be rescuers. It’s a rare emergency, said Karns, but often tragic. On May 3 in Boise, Idaho, three men were buried alive in a collapsed trench while digging a path for a sewer line. Two died of asphyxia, crushed under a mound of dirt few would consider a serious threat.
That’s where the danger lies, explains Freeman. Construction workers may not realize the dangers associated with a trench, and that’s especially true for homeowners attempting a do-it-yourself project.
“Most of these people, when there’s been a collapse, it’s the sheer weight of the soil (that prevents escape), Freeman said. “We know that the weight of the soil runs between 100 and 200 pounds per cubic foot. Good dry soil will be about 114 to 115 pounds per cubic foot. That means if we were to drop a cubic yard of soil on this person, it’d be somewhere between 2,700 and 3,000 pounds, so the effects of that make it impossible for them to breathe and even if they do survive in the trench this crush syndrome occurs and there are huge repercussions following that event, so it’s imperative that we’re able to get them out as quickly as possible.”
The 22 students on hand Wednesday — 11 Ashland Fire & Rescue, six Ashland Public Works, one Medford Fire & Rescue, one Jackson County Fire and the two Guanajuato firefighters — learned how to do just that during the morning classroom session, and were hard at work that afternoon under the blazing sun putting what they learned into practice. After a brief review by Freeman, the crew got to work, nailing 2x6’s to sheets of plywood which were then lowered into the trench.
Plenty of steps must be taken before rescuers even get to that point, however, and there are protocols for everything, from how to approach the trench to how to “shore” the trench.
A failure to adhere to those guidelines can endanger the rescue workers as well as the initial victims. For instance, if rescuers fail to find out what kind of soil they’ll be working with, or don’t take into account variables such as rain, another unexpected collapse, which is common, could be deadly.
Was it more complicated that they expected?
“In ways,” Ashland Fire & Rescue captain Marshall Rasor said, “because it’s kind of like, you’ve got a hole, you gotta get somebody out of that hole. I think what surprised me is just how labor intensive it is. This isn’t something you’re going to do with four or five guys. You’re going to need a lot of people and there are a lot of roles to fill, and a lot of resources that are needed and can be used.”
Freeman quizzed the class as he went over the safety procedures, covering everything from eye protection at the saw station to trench basics.
“You can then take that line off,” he told the crew, which formed a semicircle around him, “once we’ve got the system in fully pressurized with positive connections. A positive connection would be what, gentlemen?”
Four hundred pounds of holding force.
“Which I can get with what?”
"Two face nails."
This review went on for about 20 minutes, after which the would-be rescuers got busy hammering nails, measuring and methodically planning the mock rescue.
At one point, a firefighter stood a few rungs down from the top of a ladder dropped into the ditch on the 10-foot side and measured the width of the hole, which was by then lined with a sheet of plywood on either side.
“Here’s the deal guys, let’s go over the shoring,” said CHRT trainer Stan Klopfenstein, a 30-year fire service veteran kneeling down beside the hole. “What was your measurement? Thirty-five and a half. So what are we subtracting for wedges?”
Adjacent to that simulation, against the top of the “L,” another crew goes through its own calculations as it drops in the recently built plywood structures.
Freeman said the rescuers will leave his class well-equipped to deal with a trench rescue.
“We would expect at the end of the class that they will have a really good idea how they’re going to deal with a trench rescue operation, if it was to occur,” he said. “Which it will. It’s just a matter of time.”
Joe Zavala is a reporter for the Ashland Daily Tidings. Reach him at 541-821-0829 or email@example.com. Follow him on Twitter at @Joe_Zavala99.