Moderator: Tim White
Yes - personal preference can also change as a result of the experience of others, if you keep an open (but somewhat critical) mind.
hunter wrote:I decided to never use the tibloc as a regular ascender.
hunter wrote:I'm curious, does anyone have access to destructive testing info on the tibloc under extreme load?
hunter wrote:<snip>
The diagrams seems to say that given a static load the tibloc strips the sheath off of any rope at 6-7kn. This means that with the proposed burly scenario a tibloc used as a main haul ascendor would strip the sheath if the system stuck and you got 7kn.
With a dropped weight scenario the dynamic ropes do ok but I read the diagram as saying the sheath is stripped at 5-6kn on static ropes. I read this as meaning, if you had the tibloc as a PCD and you shockloaded it over 6kn you would strip the sheath.
Also of note, it shows 8mm ropes as being cut but nothing thicker.
I don't remeber all the force stuff but my gut feeling is that these forces are way to low to be using the tibloc in a rescue pulley system even in a crunch. Personally I think carrying some prussik cord or building some part of your system out of prussik instead of webbing would be much safer.
hunter wrote:Hank,
Thanks for the pointer, after some deciphering I think this is what I was after.
someone correct me if I'm reading these diagrams wrong)
The diagrams seems to say that given a static load the tibloc strips the sheath off of any rope at 6-7kn. This means that with the proposed burly scenario a tibloc used as a main haul ascendor would strip the sheath if the system stuck and you got 7kn.
With a dropped weight scenario the dynamic ropes do ok but I read the diagram as saying the sheath is stripped at 5-6kn on static ropes. I read this as meaning, if you had the tibloc as a PCD and you shockloaded it over 6kn you would strip the sheath.
Also of note, it shows 8mm ropes as being cut but nothing thicker.
I don't remeber all the force stuff but my gut feeling is that these forces are way to low to be using the tibloc in a rescue pulley system even in a crunch. Personally I think carrying some prussik cord or building some part of your system out of prussik instead of webbing would be much safer.
James
volica wrote:It is gonna be pretty tough to open bottle of beer with Prusik knot. Ttibloc is perfect for that.
OK, seriously now. You will have to pay lot of attention to not shred shed of rope using tibloc.
volica wrote:It is gonna be pretty tough to open bottle of beer with Prusik knot. Ttibloc is perfect for that.
OK, seriously now. You will have to pay lot of attention to not shred shed of rope using tibloc.
cob wrote:In another post you said you had seen where prusiks had torn the sheath from a rope??? This is news to me (not being sarcastic, seriously, I have never heard that). I thought the main advantage of a prusik was it could NOT damage the rope (in that way at least).
NZcaver wrote:cob wrote:NZcaver wrote:Dude - if your haul cam cuts your rope, there is no load for the PCD to capture!
Dude, correct me if I am wrong (it has been 10 yrs) but does the PCD go above or below your haul system???
Oh - OK. Yes the PCD can go below the haul system, but if so it usually needs to be tended. In fact now that I think about it, haul systems are often (usually?) taught this way - good call. Personally, I prefer to have it riding by the first pulley above the haul cam - but your preferences may vary.
hank moon wrote:Prusiks can cause coreshots, but I have not seen this happen outside of severe drop tests conducted with rescue loads.
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