Retractable fall arrester
What is a Retractable fall arrester?
A retractable fall arrester is Personal Protective Equipment designed to arrest a fall and to limit the impact generated by the deceleration, without causing injuries to the user's body.
How does a Retractable fall arrester work?
The retractable fall arrester mechanism is similar to that of a car safety belt. It allow the cable or webbing to extend or retract to take up slack in order to always be "taut". However, a sudden extension of the line caused by a heavy impact, activates a locking mechanism which blocks the fall.
The impact of the fall must be blocked smoothly in order to prevent injury to the worker. The idea is therefore to arrest the fall and to absorb the shock, thereby transferring smaller loads to the user's body, which can be withstood without suffering injury.
What standard regulates retractable fall arresters ?
The operation of retractable fall arresters is regulated by EN 360.
Those retractable fall arresters which are also used for other purposes such as retrieval or descent, must also be compliant with EN 1496 and EN 341 respectively.
Retractable fall arrester
As far as the actual retractable fall arrester is concerned, EN 360 establishes that it must:
- Halt the fall with a maximum arrest force of 6kN.
- For this purpose, it establishes that the fall arrest must occur within a maximum distance of 2 metres.
- The impact absorption can be achieved through:
- A means of dissipation inside the retractable arrester
- An energy absorber incorporated in the line.
It is important to make it clear that, for this point, the standard only demands minimum requirements. Any improvements in provisions is therefore based on the technical capability of the system manufacturers.
With regard to the retractable anchor device, the standard allows it to be made of:
- Metal cable, they are normally made of galvanized steel
- Synthetic fibres. Rope.
- Textile strap. We understand that this could be any textile strap such as that used as anchorage points.
With regard to the retractable anchor device, the standard allows it to be made of:
- Metal cable, normally galvanized steel
- Synthetic fibres. Rope.
- Textile strap. We understand that this could be any textile strap such as that used as anchor points.
Retractable fall arrester with retrieval system EN 360 and EN 1496
In addition to functioning as a retractable fall arrester and complying with the provisions of EN 361, these retractable blocks must meet the provisions of EN 1496 for rescue lifting devices.
With regard to rescue lifting, we would point out that the EN 1496 standard distinguishes between:
- Class A: When the device raises the person from the current position to a higher one.
- Class B: When, in addition to the lifting set out in section A, it is also possible to lower the person.
For both cases, the standard indicates that the retrieval can be performed by the suspended worker himself or by a third person located in other place.
Classes of retractable fall arresters:
Fall arrester with a retrieval winch
These are mounted on tripods or Davit arms as retrieval systems for confined spaces. It is important to emphasise that, in order to use them in the event of a fall, they need to be secured to a fixed base to prevent them from moving. These are the most convenient retrievers to use.
Fall arrester with a chain retrieval system
These are more versatile given the fact that, in addition to the possibility of mounting them on tripods or Davit arms, they can also be installed on anchorage points or fall protection systems.
On the other hand, with regard to retrieval, it should be pointed out that they are not as easy to use as the winch systems.
Retractable fall arrester with controlled descent: EN 360 and EN 341
In the same way as the retractable fall arresters with retrieval systems, retractable devices with controlled descent must also comply with two standards:
On the one hand EN 360 on retractable fall arresters and, on the other hand, with the provisions for descender devices set out in EN 341.
With regard to the EN 360 standard, the provisions have already been indicated above. While, concerning the EN 341, standard, it establishes that:
That obviously the evacuation is by descent:
- By the same person who is at risk
- Or by a third party who is not in the same place.
That they can be made from:
- Rope; of sheath and core construction.
- Metal cable; braided galvanized steel wires.
- Webbing: at least the same material as the rope.
How to perform the load tests for these devices.
Retractable fall arrester
for elevating work platforms
The ACB 1.8 safety device is a webbing retractable fall arrester designed for fall protection on elevating work platforms and, particularly, for the double edge of platforms with square guardrails. Length 1.8 metres
