How can the automatic cable tension system be realized?

Question

Physics

Actually there is a cable on which the load will be suspended. (up to 100 kg. for example).
From time to time, you will need to change the length of the cable.
Length difference: 2-3 meters.
I can't figure out how to implement its tensioning mechanism, considering:
1. The cable is stretched and tensioned without load.
2. The mechanism must be compact.
3. The rope tensioned in the mechanism must withstand the load.
The cord from the vacuum cleaner comes to mind: it needs to be longer - pulled it out, it needs to be shorter - I pressed the button and it was tightened. The only thing is that it can't take the load.
Another adjustable leash for dogs, but again the problem with the load.

Answer 1

There are such coils on barges / ships and in industry. All you need is a proper stopper to hold the load. I suggest using two metal pins/loop and some sort of marine knot.
Well, and accordingly, train a sailor, who will tighten and stretch the cable))
By the way, from the first page of Google tyts tyts

Answer 2

And for a large mass, you don’t have much options. Winch and stop not the cable, but the coil. The old, but reliable way - to put the coil on the ratchet - will definitely not break and it will be possible to pull it up. But with stretching without load, this is already difficult. The ratchet must be released and this is done either manually or with the ratchet turned upside down - as in the block of the inertial seat belt. But then there will always be problems with tension - they let go of the tightness and it spins up again.
So I think it is necessary to broadcast an electric winch with a ratchet and a relay with an electromagnet to release the ratchet when free rotation in both directions is required.

Answer 3

Yes, there is a winch with a gearbox.
It is not entirely clear where the load will be located on the cable, is it tied to the end of the cable, or is the load hung in the middle of the stretched cable?
If the latter, then it is possible to weight the second end of the cable through the roller with an additional load, the mass of which is greater than the maximum mass of the main load.