Gear Question

How much weight can this Hold

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How much weight can this Hold

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Rope is rated by force not weight.
For example, a rope that is rated for 8.8kN of force can hold about 900kg (1980lbs) if and only if the weight is not moving. If the 900kg object were to be falling the force would exceed 8.8kN and break. This is because the force would increase due to the short stopping time at the end of the rope. Below I showed how I got the 900kg weight, remember that it is assumed the object is suspended by the rope and not moving.

Proof:
8.8kN = 8800 (kg m/s^2)
8800/9.8 = 897kg (divided be gravity 9.8 m/s^2)

Responded on

The maximum impact force required to break the rope on a first fall is not specified. However, Sterling's "Guide to Rope Engineering, Design, and Use (Volume 1)" states: "There are no document cases of a rope breaking under "normal use"." They do indicate that ropes can be damaged by chemical exposure or by being cut.
The 8.8kN impact force specification is derived from a UIAA 101 drop test. A 80kg weight is dropped about 4.8M. The specification only measures the maximum force this weight generated on the rope during the first drop test of a new rope. It does not directly measure the force required to break the rope. The drop test is repeated until the rope breaks. The maximum impact force is not measured on subsequent drops. The UIAA falls specification indicates how many falls the rope withstood before breaking. That would be six for this rope. A new rope can obviously support larger weights. If tested, a slightly larger impact force and dynamic elongation would be measured. Note the drop test simulates a factor 1.7 fall (A fall onto the anchor on a multi-pitch climb). If you are enormous and leading a multi-pitch climb with a hairy run-out after the anchor, just lower the belay. Bail off the route if you keep falling on the anchor. The rope will not break as long as you maintain it and retire it if it is overly worn or old.