That depends on the material of your saddle, and most importantly your fall factor. Are you falling 3’ on a 3’ length of rope (is your waist even with your girth hitch with 3’ of slack) or are you say climbing until your waist is 1.5’ above your girth hitch on a 1.5’ rope. Believe it or not how far you fall isn’t nearly as important as your fall factor when dealing with force generated with ropes
That page didn't help me understand it than.
Here is a simple fall factor calculator. It will theoretically do static vs dynamic. Not sure how accurate, but it at least will give you a grip on the forces being displayed.
Hey Cooter you are right that fall factors are not the major deciding factor for generated force of static ropes because they do not stretch as much. However this has been a topic of debate because there’s only limited numbers of tests and studies on it. A Cave rescue organization did some testing and reported it is not the major factor, the way it is the biggest factor for dynamic. That is because dynamic ropes need to stretch to absorb force. It does though play a factor because all ropes have some stretch. It would also play a factor because screamers stretch as they break away. In most static work operations, they state if you expect a fall with a fall factor of greater than .25:1 that a dynamic rope should be used instead. So you are right to a large degree but it does play a factor
That’s a great tool. Notice that even though it calculates static, it still asks for a fall factor (length of the rope (slack) distance from anchor. Because all that does in fact matter just not to the degree it would on a dynamic line. Again thank you for posting this so that everyone has a tool to calculate the potential force of a fall
Yes sir, falling on static is never ideal. There were a few small studies but nothing ever that made definite rulings. Fall factors do play a role just not the same degree as dynamic ropes do. I am glad these threads have everyone reading up on it. It might not change anyone’s mind but we all will be more informed from the research!
I ran the numbers you gave 185 lbs and a 3’ fall meaning you are even with your anchor point which is a 1:1 fall. It calculates you generate 9.4 kN which is around 1900 lbs. that same fall on a dynamic line says 4.7kN… I then changed the fall factor to 1.5 by saying you only had 2 foot of rope and 1’ above your anchor point, the force generated in that calculation was 14kn even though the distance fallen would still only be 3’ on a static line. Just as a reference. So I still dare say that dynamic rope would most likely absorb more force than a screamer but again these are all theoretical without one of us doing 3rd party testing
Check out Bluewater ropes. They have both and they make some amazing ropes
Not being a smart a$$ but I think you’re catching on sir. Just remember the “distance from anchor” is how high your extended bridge is above where your tether wraps. So if you have your bridge short and it’s like bellybutton height, then distance is how much higher your belly button is above your tether. If it’s longer, that distance will be longer.So using a dynamic rope with a screamer to one-stick would be better according to the calculator with a 3 foot fall and a 3 foot rope it cuts the falling force in half
A twin rope has to be used as a two rope system. You want a single
