We are willing to listen to feedbacks from our end users, which allow us to continuously improve our products and services. If you have any questions about ASAT, please send email to info@asatsafe.com.
Questions related to RD2 descender.
Q: What’s the slippage load on RD2？
A: First, RD2 has certified to EN 12841 type C, the minimum working strength of type C device is 3 kN for 3 min. That means the locking performance of the descender should hold 3 kN for 3 min（maximum slippage of 300 mm）. The rope sample is Teufelberger Vulcanus 10.5 and Beal Raider Tactic 11mm.
However, there’re different usage conditions in real life, such as tensioning a highline, falling on a descender. So we do more slippage tests on RD2.
Static pulling test:
|
Models |
Note |
Load starting to slip |
|
Teufelberger Comes 11 mm |
Old rope polyester/nylon (sheath/core) |
5.7 kN |
|
Teufelberger Patron Plus 11mm |
New rope nylon/nylon (sheath/core) |
4.7 kN |
|
Sterling HTP 11 mm |
New rope polyester/polyester (sheath/core) |
4.5 kN |
We’ll continue to use other rope models and ropes in different conditions to do this test.
Note : Due to ASAT semi-static rope is manufactured by Teufelberger, most of our device is designed based on Teufelberger rope.
Dynamic test:
3m rope, falling height：1m，fall factor: 0.33
|
Models |
Note |
Peak force |
Slippage distance |
|
Teufelberger Comes 11 mm Mass: 200 kg |
New rope polyester/nylon (sheath/core) |
4.90 kN |
935 mm |
|
Teufelberger Patron Plus 11mm Mass: 150kg |
New rope nylon/nylon (sheath/core) |
5.16 kN |
770 mm |
Q：Why does rope slip in descender?
A: If the rope is completely locked in descender, it will generate huge impact force or cut the rope during falling or other high-tension use. So when we’re designing a descender, we will let the rope slip intentionally within a range of 6 kN，because this value is also the maximum force required for fall impact in EU and Chinese standard.
Q: Why did I find the rope slipping in RD2?
A: It’s possible, because your load is too high, reaching the slippage load. And this slippage load mainly depends on the rope diameter, conditions, icy or wet… And also the wear condition of your RD2.
We’ve received several cases about rope slippage in rescue load (around 180kg). And it’s more likely happened on Beal 10.5mm rope. We found that in the same diameter, Beal‘s rope is lighter than other rope(nylon core and sheath), which means Beal’s rope is slightly thinner.
The EN 1891 allows the manufacture have a ±0.3mm in rope name diameter.
Q: What can I do if I find rope slippage in working?
A: You could tie off the RD2. As pictures show below, and after the work, check your rope, consider to change a different rope.
Q: What the precautions in a long heavy descent?
A: The heavier load+ the higher speed+ the longer distance+ the thinner rope=the harder to control the rope.
ADD an additional friction on heavy use. For example:
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