Safety net防墮網

 Anchor point 

Anchor points

Safety nets are attached with tie ropes or karabiners to the supporting structure or to specifically-designed anchor points on the structure.

Based on a maximum fall height of 6 metres and an assumed load angle of 45° to the horizontal, each anchor point should have a 6 kN minimum load-carrying capacity– see Figure 10. The combined load-carrying capacity of the supporting structure applied over three adjacent anchor points should be at least 4 kN, 6 kN, 4 kN.

Figure 10: Minimum load-carrying capacity of anchor points.

The maximum distance between anchor points according to BS EN 1263-2 is 2.5 metres but WorkSafe NZ recommends installing anchor points at between 1.5 and 2.0 metre centres.

According to the standard EN 1263-2, the net should be suspended with ropes. When doing so, pay attention to:

• fixed suspension points at maximum distance of 2,50 metres
• resistance of each suspension point to a load of at least 6 kN at an angle of 45°
• advice for a max. distance of 100 mm between the edge of the net and the supporting structure
• a minimum tensile strength of 30 kN (single rope) or 15 kN (double rope)
• the securing of rope ends to prevent fraying
• a containment of the edge rope of the net
• use of a self-locking knot, such as a clove hitch
• sufficient distance without obstacles under the net, for the deformation during a possible impact of falling persons

Installation:

Tips from concretefastener

Do. For M10 bolt:

Minimum Embedment depth:

40mm

Hole be 12 mm(1/2 inch) deeper than bolt

TSB M10 w/ hook

Option A:

Using M10 drill bit, hole too tight, bolt sleeve easily deform when hammering. Sometimes bolt head also deform

Need at least 40 hits to get the bolt in.

bolt without sleeve. Expansion cone / Nut need to screw in 5 to 10mm. Hammer until  thread 5 to 10mm protruding, tighten with screwdriver or similar.

Option B:

Using M11 drill bit, tighten the bolt expansion cone, as the left bolt. Hammer as normal

Tighten with screwdriver or similar, by rotating 7 to 10 turns

How to remove anchor:

Option C:

M12 drill bit. Too loose. Not suitable 

Reference:

 Worksafe nz

Hsewebsite

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