Three numbers for impact force

If you go to the link below and click on "Details", there are three numbers listed for "Impact force". They could refer to the measured impact force for the three different tests listed for UIAA falls. However, if this is the case, it's weird that the 55kg impact force is larger than the 80kg impact force. Anyone have any ideas to what these three impact forces mean? I figured I'd get a faster response here than emailing Mammut.

mammut.ch/US/en_US/B2C-Cate…

Bob Johnson wrote:If you go to the link below and click on "Details", there are three numbers listed for "Impact force". They could refer to the measured impact force for the three different tests listed for UIAA falls. However, if this is the case, it's weird that the 55kg impact force is larger than the 80kg impact force. Anyone have any ideas to what these three impact forces mean? I figured I'd get a faster response here than emailing Mammut. mammut.ch/US/en_US/B2C-Cate…

Wouldn't you rather get a BETTER response directly from the manufacturer, rather than a QUICKER response from a bunch of assholes on the internet?

two thoughts: A) a typo B) that because of the greater mass the rope stretches more, so lower maximum force, but greater force over time.

Email them and get the right answer. Because mine are pure speculation.

Single/double/twin

That all da phat beah growled

;)

First number is with 80kg tested as a single on a single strand. Second number is with 55kg tested as a half on a single strand. Third number is tested on two strands as a twin.

bearbreeder wrote:Single/double/twin

What bearbreeder said. The impact force values correspond to the different "UIAA-falls" tests beginning two rows down. Unfortunately they seem to have put the impact force ratings in single/half/twin order and the fall tests in half/single/twin order. Confusing! Put it all together in proper order and you get

• UIAA-falls (1 strand 55 kg): 17–18 falls, 6.3kN
• UIAA-falls (1 strand 80 kg): 5 falls, 8.4kN
• UIAA-falls (2 strands 80 kg): > 20 falls, 9.7kN

Brian Abram wrote:First number is with 80kg tested as a single on a single strand. Second number is with 55kg tested as a half on a single strand. Third number is 80kg tested on two strands as a twin.

Yup Yup Yup

shoo wrote: Wouldn't you rather get a BETTER response directly from the manufacturer, rather than a QUICKER response from a bunch of assholes on the internet?

Yes, I would! I was putting a presentation together last minute where I talk about some hard numbers and time was of the essence. I'll let you know how they respond.

People,
I'm sure I should know this, but when it says:

dynamica elongation: 31 %

is that in the standard drop test? or something else?

Thanks

David Coley wrote:People, I'm sure I should know this, but when it says: dynamica elongation: 31 % is that in the standard drop test? or something else? Thanks

It's the rope's working elongation as determined by the first UIAA fall w/ 80kg. On the first drop test they determine both the dynamic elongation and the impact force. All subsequent falls are solely to determine the number of UIAA falls held. I am not sure how they measure the dynamic elongation though. I always assumed there was a slider on the test weight rail which stops once the weight springs back up at the end of the fall.