I was able to do a trellis test section a couple weeks back. On the end and center brace posts I mounted a five foot oak 3×3 with 10 inch J bolts to extend the post between 9 and 10 feet. I braced the end and center posts and installed a high tensile wire a 3 and 5 feet. Eventually I will double back and put wires at 7 and 9 feet as well.
In between the brace posts I hand drove oak 5 foot 3×3’s at 30 foot intervals and attached a ten foot steel post using 4 inch bolts. I used the center brace posts to start a new section of wire to the end posts, so each wire was a total of 150 feet long. After putting a strainer on each wire, the trellis was nice and tight with just a little bit of give to it, but not so much that it strained the hand driven posts. Here is a picture of my help, working hard to stay warm.
