So you are saying the poles are every fifth row at a 30' increment?
The question you are asking is very difficult to answer. There are many variables involved in the answer:
- What is the size/strength of the poles?
- What is the size/strength of the wires and cross wires?
- What's your hill spacing? Expected vegetative load?
- What are you planning for end poles/anchors/additional bracing?
- What's typical steady state wind load? What's going to be your peak wind gust and at what angle to the vegetative blanket?
Honestly, I'm not trying to be a prick. I just want to point out how many variables there are in this selection. In our first acre, we did poles for every row at about 50' spacing. Our newest field is much less poles and more wire but after we finished our calculations, I handed them over to a buddy that designs electric transmission systems for a living.
The best advice I can give is check the source of the drawing you have. Is it someone else's idea? Or is there a field someplace that is standing with this design. Then copy it exactly, including all the hardware detail. Don't skimp on any point or you may regret it when you have thousands of pounds of hop bines laying on the ground.
