Lanyards for climbing
Investigating the legislation that covers fall arrest lanyards used to provide protection when working at height.
A typical fall arrest system consists of three main components:
- a harness (in the case of industrial-type fall arrest, a full body harness is essential), to be worn by the user
- an anchor point, fixed to a structure, intended to remain stationary in the case of a fall
- connecting components, such as lanyards and karabiners, used to connect the harness (and, therefore, the user) to the anchor point.
The ideal set-up for this type of system is to keep the user connected to the anchor point throughout the task, for which anchor rails or vertical anchor lines are typically used. However, there are often situations where access or cost implications render the use of rails or anchor lines unsuitable. The user must disconnect from one anchor point in order to connect to another, such as when climbing a ladder or traversing a structure.
In such cases, the user needs a device with two lanyards, which can allow movement between anchor points without ever being disconnected from an anchor point. The use of two single lanyards can be dangerous, due to the possible scenario in which the user falls while both lanyards are connected. If each lanyard has a separate energy absorber, a fall on both absorbers at the same time (in ‘parallel’) would result in a doubling of forces applied to the user. To avoid this risk, twin-tailed (or twin-legged) lanyards are commonly used.
|Assessing twin-legged lanyards|
Twin-legged lanyards are assessed using a combination of EN 355:2002 and VG11 sheet 63 – a ‘recommendation for use sheet’ – drawn up by the vertical group of Notified Bodies dealing with PPE against falls from height, and covering additional tests relevant to twin-legged lanyards, as well as EN 354:2010, which includes a requirement that lanyards are subjected to a strength test in all possible configurations and directions of use. In practice, this means that a twin-legged lanyard will need to withstand a force of 22kN applied between the harness connector and anchor connector, and between both anchor connectors. The most common option is to use a combination of EN 355:2002 – relating to the performance of the whole lanyard (including legs and energy absorber), and EN 354:2010 – relating specifically to the lanyard legs.
Such lanyards typically include a single energy absorber – often a tear webbing type, where two stitched layers of webbing are pulled apart in the case of a fall. This slows the descent of the user and reduces the energy of the fall. The energy absorber is attached to the harness and connected to two lanyard sections (legs or tails), each intended to be attached to an anchor (for example, a ladder rung). The intention of these lanyards is that the user can leave one leg attached to a suitable anchor while he or she detaches the other leg to move it to another anchor. This means that the user is constantly attached to the structure. The single energy absorber design ensures that the energy absorption properties of the lanyard are consistent in the case of a fall, whether one or both of the lanyards are attached. Twin-tailed lanyards without energy absorbers can be used for the same process, provided the user attaches a suitable energy absorber to the correct attachment of the lanyard – the intersection between the two legs (not one on each leg).
However, with the use of such lanyard designs, additional hazards can be introduced due to the way in which these lanyards can be used (or misused). For instance, there is a possibility that the user attaches the two legs at the lanyard’s full span horizontally, creating a three-point ‘Y’ configuration loading. This can generate significantly larger forces on the lanyards and connecting components (the closer the lanyard is to full stretch horizontally, the higher the loading in the case of a fall). Therefore, these lanyards require additional consideration for testing and, hence, EC type-examination, than was originally included in EN 355:2002 – the standard used for single energy absorbing lanyards.
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