A bit of a pita access wise...so filled dumper up on truck at yard with sand/gravel/cement and take to job so we can drive it straight round.
Materials arrived 8ish
Got some of them in reach of digger when its at bottom
Trench started and got a few in, took a few to get a system going and the digging side on in the slate/shale was steady as needed ripper/bucket combo.
70cm concreted in ground with 100cm/120cm above should be sufficient for a backfill of washed stone.
Could well look decent when we get different heights going etc.