What safety nets do
Safety nets can limit the consequences of a fall through deformation of a textile system and its supports. They are not equivalent to debris-retention mesh. They must be selected for people, the work geometry and the fall trajectory to be intercepted.
Related concept: Collective protection.
Preventing and arresting a fall
A guardrail prevents a person reaching the drop; a fall-arrest net acts after a fall has begun. This distinction explains why installing nets does not justify removing protection that prevents falls. The decision must follow assessment and consider installation, transitions and subsequent tasks.
Clearance and anchorages
The net must be able to deform without the person striking a slab, machine or the ground. Positioning it closer to the working level reduces the fall but does not remove the need to check clearance below. Supports, connections, dimensions and layout must correspond to the intended system, without improvised ties or incompatible components.
Installation and condition
Installation, modification and removal require competent personnel and a safe access method. The completed installation must be checked, and the net kept free of material that could injure someone falling into it. Environmental exposure, cuts, abrasion and building modifications may alter its protective capacity.
After a fall
Work involving the affected system must stop, the planned rescue must be carried out and competent review must take place before reuse. An apparently intact net does not establish that fibres, connections and anchorages retain their performance. The rescue procedure must be prepared before work begins, not after an accident.
Example and limitations
In a hypothetical example, a correctly installed net over a courtyard becomes ineffective when pallets are stacked beneath it. The problem is not net strength but loss of deformation clearance. System instructions and checks take precedence over visual rules such as “there is plenty of space” or “we have always installed it this way”.
