What is Trench Rescue?

Trench rescue is the process of rescuing individuals buried due to excavation collapses or landslides. The goal is to conduct the rescue while stabilizing the surroundings to prevent further collapse and secondary disasters.

In the United States, approximately 1,100 workers are seriously injured, and around 100 workers die each year from trench or excavation-related accidents.

Definition of a Trench

A trench is defined as follows:

“A depression, hole, ditch, or earth wall that is 4 feet or more deep, created either artificially or naturally.”

Trench collapses typically occur due to a combination of unstable soil conditions and improper or inadequate construction.

Removing soil or debris, adding weight to the edges of the opening, vibrations (such as from vehicle movement), rain, or simply the passage of time can all cause a collapse during rescue operations.

Collapsed trenches or excavations have more than a 50% chance of collapsing again while rescuers are digging. This potential for secondary collapse makes response difficult, especially when combined with factors like bad weather, gas release from ruptured lines, and broken water pipes.

Activity Overview

Preparation

1. Prepare equipment (plywood, pipe supports, shovels, etc.).
2. Since the activity might extend into the night, prepare lights and generators.
3. Personal protective equipment (PPE).

Initial Response

1. Keep fire trucks at least 30 meters away from the accident site to minimize vibrations (trenches can collapse with even slight vibrations).
2. Identify witnesses and ask them about the victim’s location and number of victims. If possible, assess the victim’s condition.
3. Establish a hot zone (danger zone) at least 10 meters away from the site with traffic cones. Secure the site and prohibit entry to anyone except rescue teams.
4. Confirm the number and location of victims.
5. Place equipment outside the hot zone.
6. Evacuate all unnecessary civilians to at least 50 meters away from the collapse site.
7. In this stage, rescue team members should not enter the trench.

Approaching the Trench

1. To stop ground vibrations, shut down all excavation equipment operating within 100 meters of the collapse site (this also prevents colleagues from trying to “rescue” the victim themselves).
2. Get information from relevant agencies about gas pipes and water pipes buried underground.
3. If possible, approach from both ends of the trench.
4. Look for unseen hazards like cracks and unstable piles of soil.
5. Evaluate soil piles for inappropriate resting angles or overall instability.
6. Remove tripping hazards around the trench.
7. Use gas detectors to measure the environment.
8. Lay ground pads around the trench to distribute the load and prevent trench collapse (leave small gaps to monitor the collapse extent).

Guard Panel Installation

1. Wear appropriate PPE such as dust masks or respirators.
2. One team member enters the trench using a ladder and sets guard panels from the victim’s position.
3. Install ladders for entry and exit from the trench; place at least two ladders.
4. Ensure the entering team member can evacuate quickly in case of an emergency.
5. Decide on the support system to use (e.g., hydraulic support, pneumatic support, wooden support).

Approaching the Victim

1. A team member descends using a ladder and starts digging out the buried victim’s head and chest first by hand.
2. If the victim can walk, help them move to the safety zone on their own; avoid entering the trench unless necessary.
3. Use a shovel if the distance to the victim is significant.
4. Once the victim is dug out to below the diaphragm, assess their condition.
5. If there are fractures or a possibility of crush syndrome, get medical personnel to provide treatment.

Rescue

1. Use equipment like Arizona Vortex, ladder cranes, or rescue vehicle cranes to rescue the victim.
2. Pipe supports can obstruct rescue, making it difficult.

Clean-up

1. Remove tools, equipment, and trench support systems from the trench.
2. In case of a fatality, consider leaving everything as is until the investigation process is complete.

Important Notes

• Trench collapses with even slight vibrations, so minimize vibrations as much as possible.
• Do not let team members without rescue skills enter the trench.

Reference page: Learn essential rope rescue techniques, including anchor systems, knots, and rappelling methods. Discover the differences between low, steep, and high-angle rescues, and understand key equipment, safety measures, and edge management for efficient and secure rescue operations.

Related posts:

Ladder Escape – Head First Building Rescue Rescue in an Irrigation Canal Rescue from Manholes (confined space) Arizona Vortex Breaching Tower Rescue Rope Rescue Equipment Mechanics Rope Rescue System Using Cranes in Rescue Operations High-Angle Rescue