Tighten rope without turnbuckles?

Question

I have two 4-ft x 4" x 4" wood posts, and each post has a screw eye. There's 12 feet of distance between each post.

How can I tighten a piece of 1/2" diameter rope that goes through each screw eye and it's stretched tightly without having to buy turnbuckles?

There has to be a knot just for this.

Answer 1

Use a simple cinch loop (a.k.a. trucker's hitch):

1. Connect to the first eye and tie a small loop about 2/3 the way across the span.
2. Run the tail through the second eye and back through the loop.
3. Pull the tail toward the second eye to create the desired tension and pinch the tail to maintain position.
4. Tie off the tail at the loop.

_Source

The key here is the pulley effect, which compounds the user's strength, and the friction of the assembly, which helps hold position while tying.

Turnbuckles are a poor way to tighten rope. Most rope has far too much stretch for the range of adjustment a turnbuckle offers.

Answer 2

Tautline hitch is what we used in the Boy Scouts (also suggested by Ed Beale in comment above). Worked well, held when wet (with ordinary rope, including nylon; probably works with polypropylene too, but I've never tried). Does not work with monofilament, but you're not using that...

Answer 3

Why not make your own "turnbuckle"? Instead of a single strand, connect the two screw eyes with a loop. Then insert a piece of scrap lumber and twist until the desired tension is achieved. You'll need a way to tie off the wood to keep it from untwisting.

As the rope stretches, it should be easy enough to re-tighten.

Granted, this will be more functional than attractive

Answer 4

Tight is not a very specific goal. A slackline with a tension of 200 daN would be a tight slack line, which seems like an oxymoron. If you are looking at achieving a tension just under what the 4x4s can handle, you might want to look at some slackline pulley kits. Most use webbbing, but many of the same principals apply to using rope.