Could you post a picture? I'm very interested in seeing a example
I described a free-standing setup in anticipation that most folks don't have a practical alternative as I do. In my case, I have a two story home facing just east of due south with decks on both levels. And blessed with a very supportive spousal unit, I can pretty much do whatever it takes to get things done
So I erect 10' risers on the upper level and string 3/8" nylon support lines between them, passed through eyebolts lagged into the risers, and long enough that I can lower the line down to easy reach from the upper deck. I then hang coir drops all the way down to tent stakes in the beds. Discounting the sag, from the top of the risers to ground level is just shy of 25'.
This picture was taken mid-season (June 15) of last year, and shows my four Chinook and four Centennial crowns (all 2nd year in 2012) doing their thing (my four Cascade crowns are out of view to the left). That big bushy beast in the middle is actually a trumpet vine that I work around (its twin is near the Cascades).
I veed two drops per crown at the upper railing to give the upper parts of the bines (where nearly all the cones develop) more space to soak up the sun.
This picture was taken a month later and shows the bines reached the suspension line and were then trained along it. You can see one of the risers at the far end - as well as a length of 1/2" conduit I use to prop up the sag in the middle of the suspension line.
The separation of the two beds is about 6', but I still make sure that runners don't cross the divide.
I didn't know you could grow them up then back down
Yes, you can do this, but it takes planning in advance to set up something that makes that a viable option, and late in the season when the bines are toughening up and getting "woody" you do run the risk of them snapping when bent under load. Basically you set up your drops long enough so you can lower them periodically, bunching the bines downward while giving the leaders more drop to climb up. But folks do this with success, so it's definitely in the "hop grower's play book"...
hth!
Cheers!