Webbing, slings, cow's tails & lanyards

Wire rope slings

Where there is a risk of abrasion at anchorage points, wire rope slings should be chosen over textile webbing slings. Slings can be manufactured to any length but would generally have a min. Ø of 7 mm.

Wire rope slings should conform to EN 795 B or have a SWL of 500 kg (Factor of Safety 5:1).

Webbing

Webbing-based equipment — slings, harnesses and lanyards — should be chosen so that any damage (through abrasion, cutting, excessive loading, heat, UV etc.) will become immediately visible before significant loss in strength occurs. Structural stitching is of a contrasting colour to that of the webbing to aid inspection.

Anchor slings made from textiles should:

• Have sewn joints.
• Have a minimum rated static strength of 22 kN.

Slings should conform to EN 566, EN 795 B or BS EN 1492-2, and lanyards to EN 354.

Cow's tails

Individually marked cow's tails connect the operative's harness to the safety or working rope (via the appropriate knots and attachment points). They should be able to withstand any dynamic forces they may be subjected to — including those that may occur as a result of a failure within the suspension system.

Generally this requires them to be made from dynamic rope conforming to EN 892 (UIAA 1) Full Rope, min. 11 mm Ø.

The length of the cow's tail should be kept as short as possible and limited to the limit of the operative's reach when under tension.

How long can a cow's tail be?

If the longest cow's tail were 0.6 m in length, with a maximum Fall Factor of FF1 and no shock absorption allowed for, the maximum impact force generated with a 100 kg mass would be 6 kN (600 kg).

Energy-absorbing lanyards

Energy-absorbing lanyards are used to connect an operative's fall arrest harness to a suitable attachment point on the structure. In the event of a fall the lanyard:

• Limits the fall height.
• Reduces impact forces on both the operative and the structure to below 6 kN.

The lanyard's webbing or rope construction should have a minimum rated static strength of 22 kN. The longest length available is 2 m; however lanyards should be chosen which reduce the potential fall distance to an absolute minimum.

Single vs double lanyards

• Single energy-absorbing lanyards protect a worker while entering a small hazardous area via a pre-installed safety harness eyebolt or temporary anchor strop. Also for connecting to a permanent fall arrest system such as a Latchway continuous wire system.
• Double energy-absorbing lanyards are required where progress around a structure is needed — ensuring continual attachment while progressing.