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Tech
Tip: Ascenders won't catch you!
At
Ropeworks we field technical questions from customers daily.
One that pops up frequently is: “Is it OK to use a handled
ascender for your backup rope?” In a word, NO! In rope access,
the backup device should only come into play when a primary
support fails. This type of fall can subject the backup device
to a considerable shock load. A handled ascender typically
has an aggressive toothed cam that grabs the rope with no
slippage when it’s loaded. This can result in a shock load
tearing the sheath and cause failure of the back-up system!
This is no urban myth, we have tested it! Read
more…
The
backup device chosen should dissipate energy if dynamically
loaded in a fall. There are many “rope grabs” in the market
that do this. We tested several of them, combining different
ropes and devices to find the best “real world” solution.The
truth is there is no perfect device for all applications.
The standard Ropeworks Kit comes with a Petzl Shunt as a backup
device for rope access. The Shunt also happens to be the most
commonly used device in rope access world-wide. We chose the
Shunt because, in our testing, it delivered a reliably mild
“catch” to a falling load. It achieves this by slipping a
certain amount along the rope and absorbing energy as it goes,
in a manner that doesn’t damage either the rope or the device
if used correctly. It is important to note the Shunt should
only be used by trained and certified rope access technicians.
It should not be used in standard fall arrest applications
by unqualified workers! Some basic reminders on how to properly
use the Petzl Shunt in rope access applications will be the
subject of the next issues’ tech topic.
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