BS 8411:2019 pdf download – Safety nets on construction sites and other works – Code of practice
4 Layout and applications
4.1 Layout
4.1.1 General Safety nets may be used by themselves or in combination with other fall arrest and fall protection systems to mitigate the consequences of a fall at openings or edges, or where working over or near fragile materas. Safety nets of various sizes may be linked together (see Z33) so as to span large areas Nets may be used in the form ofa protection fan (eg BS EN 1263-1:2014, Figure 2). enhanced where required by placing debris netting over the safety nets to prevent smaller debris from flling through the net. The debris netting should be able to withstand the type of material likely to fall in to it, and gaps should be avoided at edges and around service ducts so that debris is not permitted to pass through. In order to minimize the risk of injury to those who might fall into safety nets, nets should be capable of deforming and deflecting suficienty under impact to largely absorb the energy of the fllig person; this deformation and delflection being possible through the net cords slipping and tightening (knotted nets) or net meshes (knotless nets) deforming or stretching through plastic deformation.
The ropes and border ropes might also stretch under load, so absorbing some of the flling energy Safety nets should have sufficient clearance below them in order to allow for this deflection while ensuring that the person flling does not strike any object.
NOTE. 1 Generally. the greuter the fall height and the smaller the net areu, then the greater the enengv absorption capecity per unit area that is required to sjely contain the Jull (for further information see denexA). A workable rescue plan with the required equipment and skills to effect it should be in place before any works are carried out above the net.
NOTE2 Industrialy regnized training is anuilable on the subject of rescue planning.
NoTE 3 While sjety nets are designed to catch people, they com also be ursed to retain or control debris, although debris within the net can also injure anyone subeequendy Jling into it The fect of debrir in the net depends on the mass, shape, nuture and flling height of the debris. The lkelihood of debris flling into the net and not being regularly cleared should be assessed by a competent person, who may recommend additional safety measures if this is anticipated to be an issue.
In particular, this assessment should establish the likelihood of the net being overloaded, causing excessive deflection and tension in the net, tes and anchorages, and/or the risk of material bouncing out of or being deflected from the net, to the danger of anyone in the vicinity. Safety nets used with or without containment nets as protection fans (system “Tshould not be used to catch materials deliberately thrown into them or for storing debris or materials. Following the impact of any heavy objects into the nets, the nets should be taken out of service for checking, and repair when necessary (see Clause B].
Damaged nets should be immediately taken out of service. However, as an immediate short-term measure, damage of up to three adjacent meshes should be repaired with a tie rope by a qualified rigger. There should be not more than two temporary repairs in a single net. Once the immediate work is complete the damaged net should be either repaired fully before reuse (see Clause 8) or destroyed.
No persons, materials or machinery should be permitted within the area of maximum deformation asdefined within BS EN 1263-2:2014, Figure 4.
It should not be possible for anyone to enter the area below the safety nets when persons are working above them, unless there is no risk of them being struck by flling objects.
Classification of safety nets
NOTE 1 Safety nets conforming to BS EN 1263-1:2014 are classified according to mesh size and energy absorptioncharacteristics, as shown in Table 1. Two energy absorption capabilities are referenced, each in two mesh sizes.