Having considered the sometimes controversial topic of cut-away rescues (see Part 1, Part 2 and Part 4) we now turn to a similar technique that doesn’t involve sharp objects! A common video on rescue training courses shows the unfortunate results of someone using a knife incorrectly in a rescue context:
Poor “Goob”. He probably wasn’t expecting to end his day like that! And to be honest people were putting pressure on him to rush, which is never a good idea. But either way, cutting that rope wasn’t ideal!
So, while shears and cutters do have their place in certain contexts there are other, potentially better ways to rescue a casualty hanging in free space on fall arrest lanyards.
One of the main issues of rescuing a casualty hanging on fall arrest lanyards is the fact that all their weight is hanging on one point. In order to lower them down, with or without the rescuer, their weight must be released. In a cut-away rescue their weight is released from their original attachment by cutting through their lanyard, leaving the casualty hanging on the rescuers system. There is another way to achieve this effect. It’s always nice to keep ropes away from knives and shears when we can!
There are lots of different names and variations for this kit: Crackers, Inchworms, Set of fours, Fast Fours, self-contained hauling systems… and that’s without looking at the manufacturers names!
Basically they are all pre-assembled pulley systems which can be deployed quickly. They are usually 4:1, 5:1 or 6:1 mechanical advantage systems, depending on orientation and design.
On the left we can see a Skylotec’s “Safety Roll” system. On the right we see A “DIY” system. A prussic could be added allowing the system to be locked.
These are massively useful bits of kit that can be used for a number of different applications, not just pick-offs. For our purposes though we’re considering here the use of them in a pick-off rescue, where the rescuer abseils down to the casualty, clips themselves on to the casualty, detaches them and then descends.
The whole focus of these devices in a pick-off rescue is on lifting the casualty a short way to allow their fall arrest lanyards to be detached. If you can’t picture this in your head the pulley system is usually placed in this kind of position:
Rock Exotica’s Aztec system
What’s the process (Briefly)
The casualty is positioned under the rescuer, with the pulley system usually attached to the screwlink or similar under the rescuers descender (see picture above).
Rescuer clips pulley system on to casualty. Where necessary rescuer clips on a back-up lanyard between them and the casualty.
Rescuer lifts casualty with pulley system to take load off fall arrest lanyards.
Rescuer either locks pulley system or lowers casualties weight a short way on to an additional sling/ lanyard (in situations where the pulley system is not rated/ secured).
Rescuer descends with casualty attached to them, hanging on pulley system or where necessary a sling.
Simple setup where pre-assembled pulley systems are used. Handing a rescuer a bag of loose rope, pulleys and krabs would be a different picture though…
No cutting of ropes or webbing (hear the collective sigh of relief from many!)
The entire system can be reversed where necessary eg. wrong attachment point being used etc (unlike a rope which has been cut, which is more terminal…).
Less shock-load on the system than is sometimes the case with cut-aways.
Position of casualty can be adjusted by rescuer with some systems, possibly leading to easier descents.
Pulley systems can be employed in a range of different rescues and are not tied in to one particular scenario.
Rescuer can accompany casualty on the way down, avoiding obstacles, monitoring casualty and even administering first aid.
Equipment can be expensive in comparison to shears or cutters.
Potential for some pulley systems to be tangled when removed from the bag (some manufacturers get round this by encasing the ropes in a fabric sleeve).
Care must be taken in the selection of pulley systems. Some systems are not rated for lifting people, or do not have any kind of “locking function” to prevent them unravelling when the user releases the tail rope.
Increased load can be placed on the rescuers system due to the presence of the “pulley effect”, in particular momentarily during jerky, uncontrolled hauling.
How easy is it to remember?
It’s essential that techniques are easy to recall, especially under pressure. This system does pretty well on this, although due to the presence of extra equipment I think it’s going to be a little harder than cut away for the average tower worker who doesn’t play with ropes very often. Therefore this scores:
There are lots of different techniques to be considered, and as we move through this series we’ll be looking at possible approaches from a range of perspectives. What systems are you using to rescue an unconscious casualty hanging on a fall arrest lanyard in free space?
These articles are designed only to provide an overview of certain approaches to rescue. They should not be used as a substitute for proper training, in person, by professionals. Very conveniently, that is exactly what we do!
Reax provide training in work at height, confined space, rope rescue and many other disciplines. Please contact us for more information or call us on 01253 767775.