Digging the holes is the worst bit espcially if there are loads
of old stones, bricks and tree roots in the way - it can labour even
the strongest man. A quicker way (although I have not tried it) is to
hire a petrol hole digger - I intend to try one the next time.

HSS do a large cantilever model - but it won't touch my land, good for soil
or sub-soil, but not for very rough made up ground - loads of very large
stones.

But would be great for earth.