HSE: Industrial rope access - investigation into items of personal ...

This standard has two categories, or types, A and B. Only type A ropes are recommended for
work purposes. Both types of rope have low extension during normal working procedures, but
they have sufficient stretch to dissipate the type of forces likely to be generated by the
progression of operatives along them, up to those generated by a fall from the anchor point.
(This severity of fall, where the distance travelled before arrest equals the length of rope
arresting the fall, is known as fall factor 1).
The sheath on low-stretch ropes is generally thicker than that of dynamic ropes, specifically to
withstand the wear and tear of rope adjustment devices.
Type A ropes, to BS EN 1891, can be from 10 mm to 16 mm in diameter. However, the industry
‘norm’ is 10.5 mm, and so three different ropes of this diameter were chosen for the tests:
Table 1
Details of the Type A low stretch ropes used in the tests
Manufacturer Rope name Diameter
(mm)
(nominal)
8
Weight
(gm/m)
Static
strength
(kN)
Sheath/core
ratio
(%)
Beal Antipodes 10.5 65.0 27.0 38/ 62
Edelrid Softstatic 10.5 67.0 29.9 41/ 59
Marlow Static 10.5 69.7 32.9 37/ 63*
All figures are from manufacturer’s data sheets except where marked*- this was measured
during the project.
All were soaked in tap water and dried (conditioned) before use, according to the
manufacturers’ instructions.
In certain applications, where greater elasticity is required, the appropriate rope will be a
dynamic rope complying with BS EN 892 4 . This standard specifies single, half and twin ropes.
Only single dynamic rope is generally applicable to work purposes. It should be deployed in
circumstances where a fall greater than Factor 1 could be encountered – in simple terms a fall
from above the position of the anchor. In practical terms this means where ropes are used for
lead climbing or to make cow’s tails, a type of attachment lanyard or link.
Single dynamic ropes on the market vary in diameter from 9.4 mm to 11 mm. A rope at the
upper end of this size range is recommended for work use. The following table shows the rope
which was chosen as being reasonably representative of this type of rope:
Manufacturer
Rope
name
Table 2
Details of dynamic rope used during the tests
Diameter
(mm)
(nominal)
Weight
(gm/m)
Impact force
(FF2, 80 kg mass)
(kN)
Sheath/core
ratio
(%)
Beal Apollo 11 78 7.4 30/ 70*
All figures are manufacturer’s stated except where marked*- measured during the project.
(FF2 means fall factor 2)
4 BRITISH STANDARDS INSTITUTION
BS EN 892: 1997 Mountaineering equipment - Dynamic mountaineering ropes - Safety
requirements and test methods