Fall-Arrest Systems

Fall-arrest systems are designed to prevent a worker or materials that has fallen from an edge, making contact with the level below.

These systems include:
• Catch platforms.
• Safety nets.
• Individual fall-arrest systems.

Catch Platforms and Safety Nets

Catch platforms and safety nets are temporary structures installed below a work area to catch a worker if they fall or to catch falling objects.

They should be strong enough to take the impact of people, equipment, and materials.

Industrial safety nets are sometimes used as an effective means of fall protection for those working at heights where it is not practicable to provide scaffolds or temporary guard railings.

When combined with overlay nets of finer mesh size, they can also be used to contain falling debris.

• Anchorages.
• Lifelines and static lines.
• Inertia reel.
• Lanyard of fixed length.
• Retractable lifelines.
• Rope grabs.
• Wire grabs.
• Rail system.
• Shock absorbers, both personal and industrial.
• Harness.
• Snap hooks (double or triple action to prevent rollout).
• Karabiners (double or triple action to prevent rollout).
• Rescue equipment.

Always select compatible components (parts) whenever preparing for work at heights.

The use of non-compatible components may lead to malfunction of the equipment, resulting in accidents, injury, or death.

If you are not sure if the components of a fall-arrest system are compatible you should check with the manufacturer.

Anchor Points

Each anchorage point should comply with the requirements in AS/NZS 1891:4 Industrial fall-arrest systems and devices – selection, use and maintenance.

Anchorages are required, under AS/NZS 1891.4, to have a minimum breaking strength of 15kN (1500kg) for 1 person attached.

An anchorage rated to greater than 21kN (2100kg) is suitable for use by no more than 2 people.

All anchorages should be tested and approved by a competent person before use – a visual inspection may not reveal the structural integrity of the anchor point (i.e. the bolt may have failed below the concrete surface).

Lifelines and Static Lines
Lifelines and static lines are horizontal or substantially horizontal lines to which a lanyard may be attached, and which is designed to arrest a free fall.

These provide a suitable anchor point for a fall-arrest system, while still allowing a limited range of movement along the path of the line.

These lines must be installed and checked regularly by a competent person and must only be used in accordance with the manufacturer’s specifications, including limits relating to the number of workers connected to the line at one time.

Wherever possible lifelines and static lines should be as high as the situation safely allows to limit the free-fall distance of workers connected to it.

Life and static line anchors must be rated appropriately for the situation and number of workers.

Fall-Arrest Harnesses
In most cases of working at heights a full body harness should be worn.

Harnesses must be correctly fitted in accordance with manufacturer’s instructions to ensure effectiveness.

Workers should connect the fall-arrest line to the attachment point on their harness (dorsal attachment point in the middle of the back, or the chest connection) that will provide the best protection in the situation it is being used.

Safety harnesses must meet the requirements of AS/NZS 1891 Industrial fall-arrest systems and devices.

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Lanyards

There should be a minimum of slack in the fall-arrest lanyard between you and the anchor point, which should be as high as the equipment permits.

The length of the lanyard should restrict the fall distance to a maximum of 2 metres before the fall arrest system takes effect.

Avoid work above the anchor point, as this will increase the free fall distance in the event of a fall, resulting in higher forces on the body and greater likelihood of the lanyard snagging on obstructions.

To reduce injuries caused by a fall, energy absorbers should be used as part of the lanyard.

Inertia Reels

Inertia reels provide a worker with a relatively free range of movement or extra reach compared to a lanyard, with the added safety feature of being able to lock in the event of a fall, arresting the descent of the worker.

Inertia reels should not be used in the following situations:
• While working on a sloped surface (e.g. a steeply pitched roof) or any other surface where a fall may not be a quick vertical one.
• Locked as a constant support for a worker during normal work.

In conjunction with a lanyard.

Inertia reels must comply with AS 1891.3 Fall arrest devices.

Swing Down and Swing Back – The Pendulum Effect

If a worker who is using an individual fall-arrest system falls from an edge, the system may act as a pendulum.

This may result in the worker hitting the ground (called ‘swing down’) or swinging back into the building or structure (called ‘swing back’).

These situations may also be referred to as ‘the pendulum effect’.

Swing down can occur if the lanyard slides back along the perimeter edge of the roof as a worker falls, until it is vertical.

When this happens, the worker may hit the ground (or lower level), or the lanyard may break from being dragged across the edge of the roof.

The code of practice ‘Managing the risk of falls at workplaces’ lists the following measures to address ‘swing down’:
• The installation of guard rails.
• Placing the anchorage point at a right angle to the position of the lanyard at the perimeter edge (for example, by using a mobile anchorage).
• The installation of a second anchorage point and belay devices (intermediate anchorages).