If I do unattach the other end that in the above picture will happen and that is just not cool. I had some nylon band left from the sun sail project and then I bought snap fasteners to make a strap that is easily opened and closed. I tested how long strap I need and then cut two bands.
Nylon or any plastic band or rope is the easiest to tie off by melting the ends. It will easily burn so you need to be careful with it. Also if it starts to burn the edges will turn yellow or brown and that's not nice on a white rope.
Then I sewed on the fasteners. That was perhaps the most time consuming part of the whole project.
Once the straps were finished I removed the wall end of the laundry lines and stapled the straps on the back of the wood.
Then I rescrewed the wood end to the wall. This is how it looks when the laundry lines are rolled to the other end.
Sorry about that one loop from the rope, it just wouldn't stay put, I didn't roll it very well I guess. Then here is how it looks open. The loose straps seem a bit odd, but I'll get used to them.