Shady suggestions?

Hi all,
 We are not blessed with a full size allotment, so space is valuable. I always see the space inbetween rows of beans as a waste, especially as i always dig a deep trench, so there are loads of nutrients there too. When this years beans are gone, i am putting a 4x4 post in each corner of the bed (16ftx6ft) 8ft high.

Im then going to connect the posts at the top with a tight wire, then at intervals, run twine down from the wire to pegs in the ground to grow the beans up (hope your still with me)

This will mean that the beans are growing straight up, leaving a pathway of about 3-4ft between the rows. This should also mean that the inside of the plants (usually shaded by themselves) will get lots of sunlight through the gap now left at the top, and that hopefully i could make use of the space in the middle by growing some semi shade loving veg that can also feed from the trench.

Does this sound ok? any recommendations?

All replies appreciated
Totty

Yes the plan is to be able to walk in between the rows in order to harvest the beans and whatever other veg grown, this will be on scaffold planks placed in between. Any other ideas on things we could grow in between? the rows will be n/s facing and due to the fact the beans wont be meeting at the top of any joining canes, the entire 'roof' area will be letting in the sun

Totty