One thing about concrete posts - they are unbelievably heavy - two
man job to install.
FWIW Supreme now do a range of lightweight concrete posts.
http://www.supremeconcrete.co.uk/default.asp?page=235

Buildbase list them and sometimes have them in stock. I can confirm
they make it a doddle for one (weak and winded) person to handle 2.36m
posts. But the concrete is *very* different from the (smaller)
conventional posts I installed 25 years ago: lots of what looks like
clinker (to keep the weight down) and voids (to make them even
lighter?). So I may survive to see them crumble.
--
Robin