Confined space rescue

Confined space rescue is a subset of technical rescue operations that involves the rescue and recovery of victims trapped in a confined space or in a place only accessible through confined spaces, such as underground vaults, storage silos, storage tanks, or sewers.

Confined space rescues can be technically challenging due to the environment in which they occur. Confined spaces are often narrow and constricting preventing easy access by rescuers. They are usually either unlit or poorly lit so rescuers must provide their own light source. Finally, confined spaces often contain hazardous materials in liquid or gas form which can be harmful or fatal to humans.

These hazards can be fatal as they create a limited window in which to perform a rescue. The general rule is that after four minutes without oxygen, a person in a confined space will likely suffer asphyxia resulting in either brain damage or death. The urgent need to rescue someone from a confined space often leads to ill-prepared rescue attempts. Two-thirds of all of deaths occurring in confined spaces are attributed to persons attempting to rescue someone else.

Confined space rescue categories
There are three categories of confined space rescue: self rescue, non-entry rescue and entry rescue.

Self rescue
In a self-rescue, much as the name suggests, the individual who recognizes a critical condition or symptoms of exposure and exits the space on his or her own. This is the preferred rescue method as confined space hazards can quickly incapacitate or kill an individual. An individual can almost always exit a confined space in far less time than it takes to wait for someone to come in and retrieve them.

Non-entry rescue
A non-entry rescue involves attempting to extricate an incapacitated person without having anyone else enter the confined space. This can be done via a safety line attached to the personnel in the confined space or by grabbing the personnel with a rope, strap or pole and pulling them to safety.

Entry rescue
This is a last resort option as having more personnel enter an area that has already incapacitated one or more persons places the rescuer at considerable risk. Entry rescues must be carefully planned and executed to avoid creating more victims in need of rescue. Rescuers need to be aware of their surroundings and must reevaluate their plans immediately if there is any change in the conditions of the confined space.

In the event of an entry rescue, standby rescuers are recommended in the event that the initial entry rescuer(s) encounter trouble.

Rescue equipment
Due to the unique nature of confined space rescues, there is specialized equipment necessary to perform a safe and successful rescue.

One of the initial pieces of equipment employed in a confined space is a method of ventilation to disperse collected hazardous gasses and introduce fresh air into the environment.

A wristlet is often the first item used to actually perform the rescue, as opposed to the ventilator which is used to prepare the environment for a rescue. A wristlet is a cloth strap that is used to cinch tightly around the wrist or ankle of an incapacitated person. Once the strap is looped around a hand or foot, its attached rope is pulled by rescuers, tightening around the arm or leg and pulling the victim out of the confined space.

In the event that an entry rescue must be performed, rescue personnel will wear protective clothing appropriate for the situation. This may include a self contained breathing apparatus (SCBA), protective headgear and the use of explosion proof lighting (to prevent igniting any gases). The rescuer may also wear a full body harness with an attached safety line, especially if a vertical descent is required. To assist in vertical descents, a mechanical winch and tripod may be set up over the access point, if the bottom of the confined space is more than five feet from the entrance.

The rescuers may also carry monitoring equipment by which they can ascertain the quality of the air in the environment. Even if the air quality reading does not indicate any hazardous conditions, it is still recommended that rescuers wear SCBA.

Rescue training
Agencies that oversee workplace safety require that persons qualified for confined space rescue operations complete rescue training and exercises annually, at the least, and recommend more frequent training.

Numerous agencies in the United States have facilities for technical rescue training and often have a confined space training area.

In the USA, confined space rescue is covered under the National Fire Protection Association (NFPA) 1670, and under 29 CFR 1910.146 and 29 CFR 1910.147, and often is managed according to the Incident Command System.