Fall arrest PPE is widely used in a number of jobs carried out at height. The basic principle of such equipment is to prevent the user hitting an injurious object by catching them at an earlier stage – namely, before the energy associated with the fall reaches terminal levels (either when hitting the floor or due to decelerations that are likely to cause death). However, one factor that is quite often overlooked in such systems is how the user is likely to be recovered once he or she suffers a fall.
This is especially important where fall arrest is used, as the potential for permanent injury and possibly fatal consequences will increase the longer the user is left suspended following a fall. As well as the need for treating any injuries sustained in a fall, there is the effect of suspension trauma (constriction of blood vessels and pooling of blood in the limbs) to consider, which can have fatal consequences if the pressure on the user is not released within good time. The need for suitable training is therefore important, to ensure that operatives are able to carry out the rescue in as short a time as possible. In such training, the worst-case scenario should be considered, where the user who has fallen has lost consciousness. In such circumstances, they are often referred to as the ‘casualty’.
When a CE mark is required
In Europe, equipment intended for rescue only is generally outside the scope of both the current outgoing PPE Directive and the new PPE Regulation, which applies from 21st April 2018, and therefore does not usually need CE marking. There are exceptions to this rule, such as where rescue equipment is integrated into fall arrest equipment. As an example, a retractable fall arrester which includes an integrated rescue winch facility would require CE marking, as would a rescue harness intended to be worn when commencing work and which incorporates other fall protection attachment points.
The new PPE Regulation will apply to connection systems that connect PPE worn by the user to mobile, reliable anchorage points or devices.
There are a number of systems and methods available for the rescue or recovery of a user whose fall has been arrested, including both systems integrated into a fall arrest device and standalone products. The system and method in use will depend on the location, type of work and the type of fall arrest equipment in use and should, therefore, be tailored to each individual job.
A number of European standards exist for typical equipment available, although the need to tailor individual systems will inevitably mean that not all products on the market will fall into the scope of a standard. Even in such circumstances, it is essential that complete systems are subject to suitable tests. These tests should include overload conditions using suitable safety factors to ensure that they are safe for use.
EN 1496:2017 details requirements and test methods for rescue lifting devices. These devices are designed to lift users from their place of rest up to a safe location after a fall, and are divided into ‘type A’ (lifting only) and ‘type B’ (lifting and limited lowering) devices. Rather than intended for lowering users down to the ground, type B devices are used for lifting casualties upwards, and for lowering over short distances of less than 2 metres, in order to negotiate obstacles. The standard includes design and material requirements for the device, including any ropes or wires used alongside the device. It also includes requirements for the strength of the device, which are defined as at least ten times the maximum rated load, with a minimum of 12kN test force (120kg user mass). This ties in with the requirements for man-riding devices under normal lifting and lowering conditions (LOLER in the UK). The standard also includes a test for the function of the device in overload conditions. The device should be capable of lifting and holding a mass equal to 1.5 times the maximum rated load of the device. An ergonomics test is also included – the device must be able to be operated under a maximum applied load (for example, to the lifting handle) of 250N.
A dynamic performance test is carried out on type B devices. The device must be capable of arresting a mass equal to the maximum rated load after a 600mm freefall, with a maximum force applied to the mass of 6kN. This is included as a provision for if the device becomes snagged in use, leading to a small amount of freefall when the casualty is released. The maximum allowed force of 6kN ensures that the user is not subjected to excessive forces in such cases. Practically, this would usually mean that a lifting and lowering device would need to include a system for energy absorption or use rope with some inherent stretch (such as dynamic rope).