Rescue planning and emergency response

Every confined space entry must begin with a simple question: if something goes wrong, how will we get this person out, alive, quickly? If there is no good answer, the entry does not go ahead. Rescue planning is not an afterthought; it is a condition of entry in every Canadian jurisdiction and under OSHA. This lesson explains the types of rescue, retrieval systems, how to judge whether a rescue service is fast enough, what a rescue plan contains and why drills matter.

Why rescue must be planned in advance

Confined space emergencies move fast. A worker overcome by low oxygen, hydrogen sulfide or carbon monoxide may suffer brain damage within about four to six minutes without breathable air, and an engulfed worker may suffocate even faster. A rescue service that takes 20 or 30 minutes to arrive, find the space, assess it and set up equipment will often be too late. At the same time, untrained people who rush in without breathing apparatus are often killed, as lesson 1 described. The only answer is to plan the rescue before the entry, have the right equipment set up at the space and have trained rescuers available within a time that matches the hazards.

The rescue hierarchy

Rescue methods are usually ranked from safest to most dangerous:

• self-rescue: the entrant recognizes a problem, such as an alarm or symptoms, and leaves on their own before they are incapacitated. Training, continuous monitoring and clear evacuation rules make self-rescue the most common and most successful kind;
• non-entry rescue: the attendant or rescuers retrieve the entrant from outside, without entering, usually using a retrieval system attached to the entrant's full-body harness. It is fast and does not expose anyone else, but it only works when the line runs straight and unobstructed;
• entry rescue: trained and equipped rescuers enter the space to reach and remove the entrant. It is the most complex and hazardous form of rescue, and requires supplied-air respiratory protection where the atmosphere is or may be hazardous, a backup team and specialized training.

A good plan provides for all three, with non-entry rescue set up wherever it is feasible and entry rescue available as backup.

Retrieval systems

A retrieval system usually consists of a full-body harness worn by the entrant, a retrieval line attached to the harness at the back or shoulders, and a mechanical device, such as a winch on a tripod or davit arm, that lets the attendant lift the entrant out. For vertical entries, the retrieval line also acts as fall protection. Some systems combine a self-retracting lifeline with a retrieval winch.

Canadian rules require rescue equipment suitable for the space to be readily available, and many require harnesses and lifelines where they would assist rescue. British Columbia, for example, sets out requirements for lifelines, harnesses and lifting equipment (sections 9.42 to 9.44), including their use where a worker could not otherwise be rescued.

Retrieval lines can become a hazard in some spaces. In a horizontal space with turns, baffles or obstructions, the line can snag and prevent retrieval or injure the entrant. Near agitators or moving parts, the line can become entangled. The assessment decides where retrieval systems help and where other rescue methods are needed.

Mechanical advantage

A rescuer cannot lift a person straight up a manhole by hand for long. Winches and rope systems use mechanical advantage (MA) so a small force lifts a large load. With an ideal MA, the force needed is the load divided by the MA. Friction in pulleys and winches reduces the real advantage, so practical calculations include an efficiency factor.

Retrieval equipment must be rated for the load, inspected before each use, set up and anchored before entry, and operated by people trained to use it. The tripod or davit must be stable and positioned so the line runs straight down to the entrant.

Is the rescue service fast enough?

Many employers rely on an outside rescue service, often the local fire department or a specialized contractor, rather than training their own team. This can be acceptable, but only if the service is able and available to respond in time with the right skills and equipment. Asking these questions before entry is part of the plan:

• Has the service agreed to provide confined space rescue for this site, and do they know the spaces and their hazards?
• Do they have the training and equipment for this type of space, including supplied-air respirators and rope rescue?
• How long will it take them to be notified, travel to the site, find the space, set up and reach the entrant?
• Will they be available during the planned entry, or could they be committed to another call?
• How will they be summoned, and has the method been tested?

Canadian rules require the employer to ensure that rescue can be carried out effectively. Ontario requires on-site rescue procedures to be ready for immediate implementation (s. 11). Alberta prohibits entry unless an effective rescue can be carried out. British Columbia requires the employer to provide rescue persons, equipped and trained, with practice drills at least annually.

The rescue plan

A written rescue plan for each space or type of space typically covers:

• the rescue method or methods: self-rescue, non-entry retrieval and entry rescue;
• who will perform the rescue, their training and how they will be summoned;
• the equipment at the space: harnesses, retrieval systems, tripods, supplied-air respirators, gas detectors, stretchers or rescue litters, lighting and first aid equipment;
• how the rescuers will reach and remove a casualty, considering the size of the openings and the shape of the space;
• the call protocol, including who calls the rescue team, emergency services and the supervisor, and what information they give;
• first aid and medical care, including CPR, oxygen and safety data sheets for any chemical exposure to go with the casualty to hospital;
• how others will be kept away so they do not become victims.

Rescue team training and drills

Rescuers need training in the hazards of confined spaces, the use of supplied-air respirators, rope rescue and retrieval systems, patient packaging in tight spaces, first aid and CPR, and the specific spaces they may have to enter. Skills fade quickly without practice, so rescue teams must practise regularly on real or representative spaces.

British Columbia requires a practice drill at least annually, and Quebec's revised rules require periodic exercises. Many employers and CSA Z1006 recommend more frequent practice, especially for spaces with unusual access or high hazards.

Drills often reveal problems that look obvious afterwards: a tripod that will not fit over a manhole, a stretcher that will not fit through an opening, a radio that does not work at the bottom of a tank, or a rescue service that takes far longer to arrive than expected. Each problem found in a drill is one less problem in a real emergency.

What to do in an emergency

For people outside the space who are not trained rescuers, the actions are simple and should be practised until they are automatic:

• do not enter;
• raise the alarm and call the rescue team and emergency services using the agreed method;
• if you are the attendant and a retrieval system is attached, begin non-entry retrieval if it is safe to do so;
• keep the ventilation running if it is safe, unless the plan says otherwise;
• keep other people away from the opening;
• when rescuers arrive, tell them how many people are inside, where they are, what happened, the latest gas readings and the hazards of the space;
• once the casualty is out, give first aid and CPR if trained, and send the safety data sheets and permit information with the casualty to hospital.