GD, click on that link above in my last post and read my build thread.
You must have a center support for the first 3-4 arches. Scaffolding works well, or you can build anything that is about 6'x4' at the top that the first arches can rest on. Ropes staked to the ground will prevent the panel from getting knocked or blown off the scaffold until other panels are added.
Any noticeable amount of wind on the day of erection is bad. Single panels can catch the wind like a sail and pretzel. Once they are bolted together with other panels they are very stable and strong. Setting the first few arches is where everybody runs into trouble
Most use ropes to stand up individual arches by hand. I used my tractor with a front end loader and a homemade boom. I used straps to make a 4 point sling so I could pick up a assembled arch all the way off the ground, drive it down the foundation and hold it in place next to the last arch. Once the sling is removed, add bolts and repeat. I have done two buildings using my boom...works like a charm and makes positioning the arches easy.
