wow that is some nice equipment and what the heck is that giant thing bx23barry.
I've always known them as "land planes". It really are a big box scraper (blade) suspended on a solid long wheelbase frame. Used for leveling fields for row crop/flood irrigation (if if ain't irrigated it ain't growing). Very common here in the valley. I bet there are more land planes than moldboard plows around here.
Had a chance to use my 60" box scrapper alot the last 2 days cutting a drain swale thru the wooded part of my yard, have not had much experience with it in the past but one thing I learned quickly is that it's much more forgiving than a rear blade or even a front bucket for level cutting into the ground, I tried the rear blade and made such an uneven mess in short order. Same with the front bucket, once you ride over a little bump your digging in one side more than the other and then it's just down hill from there, I mean I had this little swale so messed up that the tractor almost tipped in otherwise level terrain.
With the box scraper it levels as it digs making things much easier, even though it may take less bite in each pass in the end it's a better job done
