Technical rescuers are trained to use their knowledge, skills, abilities and specialized equipment to solve problems in a safe and efficient manner.
We convince ourselves that we can solve the rescue equation every time. When we don’t, we should be highly motivated to evaluate, educate and train to make sure we don’t duplicate our shortcomings.
Every once in a while, though, we come across a scenario or environment that is untested, unproved and outside of our scope. These events can be a recipe for disaster and the best way to confront them is to be proactive.
In the next few articles, we will address some current topics in the fire and rescue world that meet the “unprepared for” criteria. For this installment, we will dive into deep holes.
Across the United States, cranes outfitted with giant augers drill large holes into the earth. By giant, we are talking about diameters ranging from 6 to 20 feet and depths down to 75 feet.
The holes can be deeper and larger or smaller and shallower, but one thing remains the same — they carry all of the same hazards as any excavation or trench. In addition to these hazards, the holes are often created to support energy production, particularly electrical.
Risks to workers
So, we have just added the hazard of high voltage power lines in close proximity to the holes and the drill rigs creating them. Tack on arcing hazards and electrocution. The rigs themselves and other heavy equipment on the scene also bring the “caught and struck by objects” hazards.
Holes like these are also used for deep wells and access for oil and gas production and other natural resource access. And these are often being drilled on mountains or other remote locations with limited vehicle access. This puts many victims outside of the reach of timely responses, adequate technical resources and quick care from nearby trauma centers.
If this environment isn’t daunting enough, consider the personnel and their operation. These holes are often being filled with rebar framework, casings or pipes and concrete. There are often two to four workers around the hole during the drilling operation.
Once the auger is pulled out, the hole is maintained by inserting casing or pipe or by filling it with slurry to produce hydrostatic pressure against the walls and prevent cave in.
This is a dicey operation. The slurry mix does exert pressure against the walls, but it also start the erosion process, which greatly increases the potential for soil cave in.
When a worker falls in
I have assessed several of these sites and have never seen one that places ground pads and bridging around the hole. If the hole were to cave in, there is virtually nothing to prevent workers from riding a topside sluff into the hole.
Most of the workers who are in close proximity to the hole are on retractable leashes with shock arrestors and full-body industrial harnesses. If the hole was intact and a worker simply fell in, his fall would be arrested within a few feet of the lip.
However, these workers are often anchored to portable and independent anchors that are usually with 10 to 20 feet of the lip. If the surface soil breaks into the hole, there is a high probability that the anchor and the rescuer will end up in the hole — rendering the set up useless.
Because of the great depth of the digs, there are additional hazards such as soil type changes, sub-grade sinkholes or pockets that were not identified, atmospheric hazards and water hazards. All are challenges in and of themselves.
Here are some additional requirements and standards for trenches and excavations. At 4 feet deep, begin continuous atmospheric monitoring with a minimum of a four-gas meter. Sampling should be continuous and within a 4-foot radius of any and all entrants.
In most of these operations, there are no entrants. That is, until a worker ends up in the hole and we show up. Now we have entrants. Ventilation should be applied where unfavorable natural or mechanical ventilation exists.
The game changer
These are requirements that we can tackle proficiently and with confidence. The next one, however, is a whole new ball game. Anything deeper than 5 feet requires shoring and shielding based on tabulated data charts.
This is not just a challenge of depth and the tremendous resources that a hole with a worker that’s 75-feet deep presents, it is the challenge of shoring and shielding a circle.
This is where our problem-solving wheels start spinning. We can always start with the most readily available and simplistic solutions. If the victim is within a manageable distance from the lip (anything less than 20 feet), place ground pads and bridging and then deploy some simple measures.
Deploy a ladder from the opposite lip and direct it towards the sidewall that the victim has come to rest against. These victims will rarely be anywhere other than against the wall if they are on a fall-arrest system because they typically use lateral anchors without high directionals.
The feet of the ladder should be controlled with lines from the topside and placed just below the victim and secured topside. Coach the victim to self rescue and climb the angled ladder.
If the victim is beyond the reach of the ladder, another option is to deploy a retrieval system with a remote attachment component. The CMC sure clip is an example of this application. This will also require a high directional anchor and the anchor most readily available may simply be an appropriate rigging point on the drill rig or other heavy equipment located at the hole.
More complexities
Rig a simple system with a progress capture device such as a CSR2, extend it out to the necessary length, then clip an auto-locking carabiner into the remote attachment device. These devices have extension poles that can be extended to the victim.
Secure the carabiner and retrieval system to the victim, duplicate the entire process with a belay if appropriate and haul the victim up. Notice that both of these applications were conducted from the topside of the hole without making entry.
Now let’s add the more complex wrinkles. If the victim is in the bottom of the trench or beyond reach with remote access devices or ladders, we are now facing the grave possibility of entry.
If we are going to enter this hole, we have to address the shoring and shielding requirements. The vast majority of all fire and rescue services will not have the equipment or expertise to start attempting a shoring operation.
If the casing or pipe is on scene but not in the hole, can the drill rig operator install it so we can enter and effect the rescue? A big concern is the position of the victim. These victims, if suspended, are most likely against a wall, which places them in the direct path of the pipe.
If their fall-arrest system was center mass from a high directional or if it failed and they are on the bottom of the hole, then they may be away from the walls. This would improve the possibility of a life saving casing installation.
But, there are some very significant and unforgiving hazards associated with this choice. It would put a massive hazard above the victim and the placement process can increase the likelihood of a cave in until it is at depth and secure. These would both normally make this selection a no go. Here are three options.
1. High-angle rescue
We can enter in a high-angle rescue application, package the victim and the haul them out completely dismissing the possibility of a cave in and all of the standards and guidelines that we are trained to adhere to.
2. Attempt shoring
We can attempt a shoring operation. Hit the brakes. There are probably only a handful of organizations across the country that have the equipment and training to even make a significant dent in shoring up a 9-foot-diameter hole with a 75-foot depth.
3. Attempt a dig out
Attempt a dig out to create lateral access to the victim through basic benching models to alter the hazard state of the hole. This would be a massive and time-consuming operation requiring the movement of unimaginable amounts of soil. Additionally, it would potentially compromise the integrity of the hole during the process and might cause a cave in or collapse.
These are the worst-case scenarios and I would not pretend to have all of the answers. These are the rescue problems with no easy answers. And so we devote ourselves to finding them.
I have done a lot of work with these drilling companies over the past few years and I can very honestly tell you it has been an incredibly humbling process in which we are still working on solutions. The goal with this is to increase awareness and open the dialogue to get all rescue professionals considering different courses of action. Get your wheels turning and weigh in with your thoughts.
