How can you measure the strength of a hanging setup without using a weight?

[ASp4E]

This is for long-drop hanging from a building or other large height, so it isn't very easy to use your own body for testing before the attempt. Using something like a sandbag of the same weight would also draw a lot of attention, and since you're also testing the rope this way, you would presumably need to untie the sandbag and reuse the rope for yourself. I'm not sure how you could do that safely without intervention. So that's why I'm wondering about any alternative methods, like maybe a tool to tighten the rope and measure the tension?

By the way, if using a building I'm thinking of using the metal supports you might find for water tanks, solar panels, etc. In case that is relevant for any advice. A second concern would be whether the rope snaps on the corner of the building's roof, which is roughly 90 degrees.

 

[Nuance]

A comically large anvil

 

[Neowise]

A comically large anvil

This is what I immediately had in mind.

Edit: ahh, sorry for the necro. I didn't realize the post was a month old already.

 

[QueerMelancholy]

Couldn't you test the rope elsewhere first? Use some kind of weight and then test it again on the building by pulling on it after you attach it to w/e you're attaching it to.

 

[locked*n*loaded]

If you wanted to go all out, you could get yourself a load cell (transducer) and attach it inline with your rope and some kind of pulling mechanism, like a winch. Tie the rope onto something very sturdy, the other end to the winch/load cell, and then run the winch until the rope breaks (hopefully), and then observe the reading on the load cell. That will tell you the ultimate breaking load of the rope in tension, although it won't tell you what impact load would contribute to it. Also, this assumes you have some extra money to spend on the necessary equipment for the test.

I suppose you could get creative and attach your rope to something stationary, again, very sturdy, and the other end to your car. I'm not going to look them up right now, nor do any math, but there are formulas that will allow you to calculate the pulling force of a vehicle at a given velocity/acceleration (kps, mph, k/s², mph/s², ft/s², etc). You'd have to not allow your tires to spin, though, which might be very difficult.

What does the manufacturer of the rope say are its strength specifications?

 

[ASp4E]

Edit: ahh, sorry for the necro. I didn't realize the post was a month old already.

No need to apologize. I'm grateful you revived it, since I still didn't have any answer.

If you wanted to go all out, you could get yourself a load cell (transducer) and attach it inline with your rope and some kind of pulling mechanism, like a winch. Tie the rope onto something very sturdy, the other end to the winch/load cell, and then run the winch until the rope breaks (hopefully), and then observe the reading on the load cell. That will tell you the ultimate breaking load of the rope in tension, although it won't tell you what impact load would contribute to it. Also, this assumes you have some extra money to spend on the necessary equipment for the test.

I suppose you could get creative and attach your rope to something stationary, again, very sturdy, and the other end to your car. I'm not going to look them up right now, nor do any math, but there are formulas that will allow you to calculate the pulling force of a vehicle at a given velocity/acceleration (kps, mph, k/s², mph/s², ft/s², etc). You'd have to not allow your tires to spin, though, which might be very difficult.

What does the manufacturer of the rope say are its strength specifications?

Thank you for the details, and winches sound like the kind of thing I was looking for. I'm unfortunately still not sure what rope to choose, or where to buy it. Maybe Kevlar since I've read it's fairly inelastic, high strength, and longer-lasting than something like Zylon?