Fall Protection

The Complete Guide to Fall Arrest Systems

Posted by Ralph Balbaa M.Eng., P.Eng. On July 18, 2022

Do you provide services that require employees to work at heights?

According to the Occupational Health and Safety Act and Regulations, it is the employer’s responsibility to ensure that their workers are protected when working in an environment with potential fall hazards. These hazards include:

Falling for more than three metres
Falling into operating machines
Falling into a body of water or any liquids

Falling is one of the top causes of injury in industrial and construction sites. If your employees regularly work at a height, having a fall protection system should be part of your safety protocol.

Here is our guide to fall arrest systems and how you can keep your employees safe while at work.

What is fall arrest?

Fall arrest is a type of fall protection system that safely stops a person from falling at a height. Other methods of fall protection include:

Fall guarding: Safety gates or guardrails to prevent the worker from entering a fall hazard area.
Fall restraint: A system to restrict a worker’s travel along an elevated surface.

Fall arrest equipment is designed to stop a fall that has already happened. There are two major types of fall arrest: general and personal.

Both forms should keep the free fall distance as short as possible and protect the person from hitting other surfaces while falling.

Their design should also keep the forces of the fall on the person minimal and protect the person from pendulum or swing falls.

Keep in mind that fall arrest should only be used when other fall protection methods are not available or possible.

The best fall protection plan is one with multiple fall protection systems.

What are the personal fall arrest system components?

Every personal fall arrest system should have a full-body harness, a connecting device, and an anchor point.

Full Body Harness

A full-body harness is the wearable component of the fall arrest system. It connects the person to the anchorage point and prevents them from hitting another object if they fall.

The harness distributes the forces of a fall throughout the body and ensures that the person is suspended upright.

Connecting Device

The connecting device, as suggested by the name, is the means by which the full-body harness is attached to the anchor point.

This device determines the length of the person’s potential fall and should always be worn, connected, and anchored while working at an elevated height.

There are two main types of connecting devices: a lanyard and a self-retracting lifeline.

A lanyard is a short but flexible line of rope or webbing strap that often includes an internal or external shock absorber to reduce the force exerted on the person in the event of a fall.

A self-retracting lifeline also connects the harness to the anchorage point, but it retracts automatically to limit the free-fall distance rather than allowing the person to hang freely.

Anchorage Point

The anchorage point is what holds the weight of the person during a fall. Typically, this is attached to a steady structure, such as a steel member, where work is being done.

Any bolts and washers used for the anchorage point must be routinely inspected and evaluated to ensure that their load-bearing capabilities are intact.

What should be considered when using a fall arrest system?

When setting up a fall arrest system, you should assess any potential hazards the worker may be exposed to if they fall.

The three main elements include bottoming out, the pendulum effect, and suspension trauma.

Bottoming Out

Bottoming out is when a worker hits the ground, or any material, equipment, or the lower level of a building before the fall is stopped by the protection mechanism.

This can happen when the “total fall distance” is greater than the distance from the work site to the level below or any other hazard.

The total fall distance is the distance from the ground or hazard below to the anchorage point. Important factors to consider when determining this distance include:

Length of the lanyard
Deceleration distance
Worker’s height
Safety factor distance

The Pendulum Effect

Also known as a swing fall, the pendulum effect describes when the person swings from side to side after the fall has been arrested. Swinging poses a danger to the worker, as they might hit the ground or other structures.

The bigger the swing, the more significant the impact would be if the worker hits an object in their path. The movement can also cause the lanyard or lifeline to break if they are caught against rough or sharp edges.

The anchorage point should be positioned directly above the worker to reduce possible swinging.

As work progresses, workers should be able to change anchor points so that the lanyard or lifeline is always perpendicular to the ground.

Suspension Trauma

Suspension trauma can occur if the worker is held upright with limited movement for some time.

Pressure from the body weight in the harness can cause blood pooling in the legs, causing unconsciousness, serious injury, or even death.

An effective rescue plan should be in place to limit the time the worker spends suspended vertically.

Make sure to take any fallen worker to a hospital for examination as soon as possible. Inform the emergency medical staff how long the worker has been suspended, so they can help the worker as needed.

At HITE Engineering, we offer complete custom design of fall protection systems and turnkey services by experienced professionals.

From design and installation to inspection and testing, we are here to ensure your fall arrest systems are structurally safe, functional, and compliant with government requirements.