Paracord - is it worth it?

shpshooter said:
If you want something stronger than dental floss go down to your local walmart and pick up some braided spiderwire. There is one type that is very close to thick sewing thread in size and how it ties, yet it is rated for 60lbs. I carry that too since it is small enough for sewing, yet strong enough for lashing, and 200' of it takes up little room.
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Spiderwire is great- i have the 80 lb test in my kit- and its still about as thin and flexible as regular heavy duty thread- so it would be perfect for sewing repairs - plus its 80lb test...
 
I've been a professional climber for 2 years now and been rapelling for 18.If you should find yourself in dire straits and need to use parachute cord to rapell with, descend VERY slowly. The friction on such a small area of the caribiner could cut it(the biner). Saw it happen to a guy who was using 3/8 rope on a 250ft. very fast rapell.
 
John35 said:
I've been a professional climber for 2 years now and been rapelling for 18.If you should find yourself in dire straits and need to use parachute cord to rapell with, descend VERY slowly. The friction on such a small area of the caribiner could cut it(the biner). Saw it happen to a guy who was using 3/8 rope on a 250ft. very fast rapell.
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he cut the caribiner in half with 3/8 rope? thats reasonable size rope, 9 or 10mm. I guess he had the rope straight onto the caribiner (ie italian hitch or something)
 
I'm no expert on rope so I'll phrase this as a question rather than a suspiscion. What is the difference between slowly loading a rope up to it's maximum load as opposed to suddenly loading it?

For instance I weigh 193 lbs, theoretically well within the load limit of seven strand paracord if I let my weight settle on the cord gradually. What kind of load spike would be expected on that cord if I were to fall suddenly about 10 feet and have the cord arrest my fall? Will that load spike over the load limit and snap the cord?

UNQUALIFIED SUSPISCION - I "only weigh" 193lbs but I'm pretty sure that my falling body can generate enough force to break a single strand of paracord. Maybe it won't break as I gradually go over the edge but what happens 20 feet down after I slip and have to suddenly commit my total falling weight and falling inertia to that cord?

I carry paracord in places with lots of "verticality" and have never considered trusting my body weight to it for this reason. Am I wrong in this? Mac
 
If youre travelling at speed then the rope has to absorb a lot more energy when it takes your weight than if you were moving very slowly.

Say you were travelling at virtually zero m/s the kinetic energy the rope had to absorb would be virtually zero, if you were moving at a greater speed the energy the rope has to absorb is much greater

for the purposes of this I have to work in kg so your weight of 193lbs is approximately 90kg

Kinetic energy = 1/2 mv^2
where m = mass in kg and v = velocity in m/s

so if you were loading the rope very slowly your velocity may be 0.05 m/s and the energy the rope had to absorb would be

1/2 * 90 * 0.05^2

= 0.11 Joules of energy the rope has to absorb

If you were to fall 20 ft onto the rope (20ft = approx 6m) the energy the rope would have to apsorb much more energy. To make it easy to calculate I'm going to use a height of 10m (approx 36ft) to fall onto the rope, because if you were to fall 10m on earth the acceleration due to gravity would mean when you hit the 10m mark you would be travelling at approx 10 meters per second (earth gravity accelerates at 9.8 meters per second per second)

now the energy the rope has to absorb after a 10m fall is

1/2 * 90 * 10^2
=1/2 * 90 * 100
=4500 Joules

You can see a relatively small fall puts a huge amount more strain on the rope. Thats why 'full size' climbing gear typically can take an effective weight of something like 22,000 Newtons (over 2000 metric tons) because if a human falls a long way their effective weight on the gear is many many times more than their actual stationary weight

Obviously you should make your own choices as to what you consider safe but if I were in a situation where I may fall onto a rope I wouldnt trust anything less than full thickness climbing rope (ie 10 or 11 mm) If I were rapelling I wouldnt trust anything less than 6mm and preferably at least 8mm unless it were an emergency.
 
bladefixation2 said:
If youre travelling at speed then the rope has to absorb a lot more energy when it takes your weight than if you were moving very slowly.

Say you were travelling at virtually zero m/s the kinetic energy the rope had to absorb would be virtually zero, if you were moving at a greater speed the energy the rope has to absorb is much greater

for the purposes of this I have to work in kg so your weight of 193lbs is approximately 90kg

Kinetic energy = 1/2 mv^2
where m = mass in kg and v = velocity in m/s

so if you were loading the rope very slowly your velocity may be 0.05 m/s and the energy the rope had to absorb would be

1/2 * 90 * 0.05^2

= 0.11 Joules of energy the rope has to absorb

If you were to fall 20 ft onto the rope (20ft = approx 6m) the energy the rope would have to apsorb much more energy. To make it easy to calculate I'm going to use a height of 10m to fall onto the rope because if you were to fall 10m on earth the acceleration due to gravity would mean when you hit the 10m mark you would be travelling at approx 10 meters per second (earth gravity accelerates at 9.8 meters per second per second)

now the energy the rope has to absorb after a 10m fall is

1/2 * 90 * 10^2
=1/2 * 90 * 100
=4500 Joules

You can see a relatively small fall puts a huge amount more strain on the rope. Thats why 'full size' climbing gear typically can take an effective weight of something like 22,000 Newtons (over 2000 metric tons) because if a human falls a long way their effective weight on the gear is many many times more than their actual stationary weight

Obviously you should make your own choices as to what you consider safe but if I were in a situation where I may fall onto a rope I wouldnt trust anything less than full thickness climbing rope (ie 10 or 11 mm) If I were rapelling I wouldnt trust anything less than 6mm and preferably at least 8mm unless it were an emergency.
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And if I worked it out right, that equals about 3319 ft-lbs of force. A lot of force from a fall.
 
Good Answer!

So, according to my public school education I conclude two things.

#1. I don't want to fall off of stuff.

#2. I won't use paracord to try to avoid #1 unless I have alot of it connected to a parachute.

That does it for me. Mac
 
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