Trench Training: A Careful Balance Between Realism and Safety
by Dennis O' Connell, Director of Training/Chief Instructor
This IPhone video captured at a recent training exercise is being posted here solely to illustrate the powerful nature of a trench collapse. Instructors were aware that a collapse was imminent and a “safe zone” was established along with other measures that will be discussed in this article. It’s important to note that all students were cleared from the area prior to releasing the struts for the collapse. This video is presented with the intention of helping trainers and rescuers achieve greater safety awareness during training events.
You’ve probably heard the saying “train as you play, and play as you train” many times. However, for rescuers, this training mentality is essential! Rescuers should have the ability to handle a wide variety of events, but must also appreciate the dangers of the job.
This behavior needs to be practiced but must also be balanced with safety as the #1 priority. To avoid injuries, a risk analysis must be conducted and carefully reviewed. This will help in planning the training exercises and in determining possible hazards where students may be most at risk. Everyone involved in the training exercises (including observers) should be informed of the dangers as well as control measures and safety requirements. Everyone should be aware that they have the ability to stop an evolution immediately should a safety concern be detected.
In order for this to happen, an established rescue plan should be devised for each element of training. An example in high angle training would be an “instructor’s line.” A designated instructor/rescuer, an additional line, and equipment should be staged and ready for a rescue, just in case. Teaching stations should also be set up in close proximity to allow for the use of the equipment from one station to another.
In our quest for realism, we need to constantly re-evaluate as the training proceeds. Risk vs. reward…is this training exercise worth the risk?
Now, let’s take a look at some common techniques used to increase pressure for rescuers and evaluate performance during a “simulated” rescue. Time limits are often used to increase stress levels while performing skills. In rope rescue training, knot tying and patient packaging are good examples where time restraints are a useful tool. On the other hand, if you set time restraints or implement a “speed reward” for how fast you can rappel down a building or perform a rescue, it can lead to unsafe actions that can cause injury or even death.
Here’s a deadly example of speed rewards during training. There was a video of tree trimmers taking their final exam. In the video, they were required to climb a ladder into a tree, anchor themselves off and hook up to a rappel line, rappel down to a simulated victim, and then lower themselves to the ground. In the video, the student is being timed, while being offered a reward for speed. In the process of doing so, the student missed a connection, as did the instructor, and fell to his death.
Another interesting means of rescuer stress or pressure that can develop unexpectedly during training is “peer pressure.”
In the same tape, students can be heard encouraging, for lack of a better word, individuals to beat the clock. If used in the correct manner, this friendly competition can be useful, but if not exercised properly, it can be dangerous. Competitive training exercises should be used only within the design of the class. If it develops unexpectedly, it should be shut down. Otherwise, it can quickly create a dangerous learning environment.
Again, the instructor needs to keep the safety of the students in mind and evaluate all potential consequences.
Span of control is “the number of people one can effectively manage.” The more technical or hands on a training course is, the smaller the number of people a single instructor can safely control.
In rope training, techniques (and teaching) may occur at multiple levels on a structure. For example, pick-off techniques or patient packaging in a simulated confined space rescue exercise. Certain techniques may require additional instructors at various levels to monitor students “going over an edge” and at the “pick-off” level. Or, with a confined space scenario, it may require an additional instructor to be physically located in the space to make sure patient packaging connections are correct prior to raising or life-loading the line.
Sometimes with in-house training, personnel can become complacent with double-checking all systems or having that extra set of eyes from an uninvolved participant. That’s why it is so important that every training exercise is carefully planned and followed through in all areas.
When training a group of your peers, it can often be difficult to prevent “freelancing” and to keep everyone on the same page. A well-planned training session will include a review of safety issues at the start – every time! The briefing should explain what will be covered (and allowed or not allowed) during the training. This will help students to understand that it’s more than just a “play” session, and will hopefully reduce the temptation for freelance activities.
It’s important for trainers and rescuers alike to watch this video. The training is being conducted in a live trench, which is definitely more realistic and more real world than setting trench panels between two containers. It is also more dangerous! The instructor ratio, training, and skills must be competent for the task. Acceptable conditions must be re-evaluated constantly and discussed between instructors. In some cases, like this one, a dangerous condition can be presented when students remove trench panels and equipment. This is the time to stop a class and halt all operations.
During this particular session, there was a large crack or separation in the dirt, which made the weight of the dirt unstable. As you will see, this caused the collapse of a large portion of the trench wall. In this particular situation, it was simply not worth trying to recover the trench panels at the cost of safety. The students were informed of the danger, how it was detected, and how it could be resolved.
Just remember… no piece of equipment or gear is worth injuring a student or instructor!
After everyone was informed of the danger of an impending collapse, the decision was made to let the wall collapse and to video it as a learning tool for that class and future classes. This video will give you a very clear picture of the speed and force that can occur in a trench collapse.
As you can see, the proper precautions were taken during this exercise in order to demonstrate the incredible power of a trench collapse.
An emergency plan was developed. A safety officer designated areas of safety as well as areas of dangers for students, instructors and observers. In order to maintain the stability of the opposing trench wall, a decision was made to keep a couple of other trench panels in place. A backhoe was used to slope sections of the trench and create a “safe zone” for the instructor to remove the struts, which in turn let the wall collapse. The force of the dirt was so powerful that it snapped a ¾-inch shore form panel and a 2" x 12" strongback like a toothpick.
What you won’t get from the video is the sense of force or vibration that was felt when the trench wall collapsed. It’s something the students will take away from the training along with a much greater respect for the power of a trench wall collapse.
Again, we stress that constant re-evaluation of conditions during technical rescue training is critically important for the safety of all involved. Instructors must have the ability to perceive any differences in the training environment or situation, be able to identify unacceptable conditions, and to take quick, corrective action. Students should also have the ability to stop a training evolution if they perceive danger or have concerns. It’s always best to stop and re-check everything!
Many times, it’s as simple as letting the students know if they see something that they think is dangerous or not quite right, or if they don’t quite understand, just yell, “STOP!”
This video is a great learning tool that illustrates what can happen during “live trench” training. It dramatically demonstrates the speed and force of a trench wall collapse. However, it also affirms that with proper attention to the training environment and changing conditions, injury can be avoided.
It’s similar to personnel who have been exposed to swift water rescue in real world environments. They take away a much greater respect for the power of moving water, and it cannot be simulated in a swimming pool. Or, with high angle training, while it’s the same technique, rappelling from height versus a one-story building is a totally different experience.
As instructors, we must develop training that will give our students the experience and skills needed to perform their jobs safely. But we also need to keep them safe during training as well. Use this video and the story behind it to emphasize safety and proper planning during training sessions. It also helps us to realize that being a trainer or instructor comes with great responsibility. For me, it’s a constant battle between two thoughts: “No one should get injured during training,” versus “let no man’s ghost return to say his training let him down.”
The need to develop safety plans and perform risk analysis during training is an important part of our job as instructors, and student safety is our #1 priority.