[Oliver]

...  putting an inground barrier between you and those JA's ...

This is an excellent idea.  It just never occured to me - the other neighbour did the inground barrier thing when he put up his chicken shed - about 18 of corrugated iron in the ground, the rest as a 'wall' before he put the chicken wire to stop the foxes digging their way in.  Worked a treat!

Need to figure out a way to get the corrugated iron cut in half (we have stacks on our plot).

Thanks!  

[WG.]

Need to figure out a way to get the corrugated iron cut in half  

Corrugated iron sounds like an accident waiting to happen.  Have you nothing more child-friendly?

[muntjac]

grinder with the safety goggles .  cut to size . get 2 inch battens and drill and bolt them to the top and ends of the sheets to cover the corners .......

[Smudgeboy]

Thoughts on allotment etiquette:

Never drive your combine harvester over your neighbours plots

Never get caught on all fours, munching through your neighbours brassicas

Never use the site for that retro-90s "illegal rave"

Never surround your plot with triple thick layers of electrified barbed wire and a watchtower with armed guards

Never start renting out your neighbours potting shed to the local gang of glue-sniffers

Never - no matter how annoying they may be - NEVER dead-head your neighbour!