Remembering we are talking cm accuracy not mm accuracy, here are some shots of my more agricultural solution.
The whole rig,
A section of 23mmx23mm (radio transparent) plastic stake with a nut set in the top.
A section of 25mm external diameter steel box section with a nut set in the bottom.
A piece of metal sheet with a hole drilled in it to replace the tribrach.
The plastic stake can be dropped into any piece of 25mm box section, so my permanent reference stations are, you guessed it, 25mm box section. I can just turn up on site and drop the Reach base station in. Some are bolted to the roofline of buildings, some to structures, some longer sections just hammered into the ground. A cheap, but repeatable way to move precise positioning from the domain of the surveyor into the farmyard. The land owners like this, as my permanent infrastructure is clearly low cost, robust AND accurate. I think the phrase is 'fit for purpose.
