Here is a short vid. of the creeper and me plantin' strawberries last month! (Nov.)--kind of shows it in action and how I operate it!
The irons sticking out on the left side, just above the peddle line can be used to carry a few things if you want!--plant trays, ( I usually just slide the tray along in front of me, but carry the second one up there), small tools,(our ground is mellow enough that I don't have to use a pick-ax for a hoe!--just use hands or the little flower bed tools!), and harvest containers while pickin'! you can attach a platform where it would be the handiest for you to reach and make a size to fit your needs, too!
I have been on this thing for many hours at a time and the spine is not supporting your whole weight like in the stand/bend position! (I can't even bend to put my shoes on, and have limited head turn range),---by being able to alternate from sitting to laying helps too!--sitting on this still dosen't put a great strain on the spine, and you can kind of help walk yourself along and use the ratchet at same time.
The steel track model will have a hydraulic system with 2 hyd. motors, one on each track to drive/steer the unit.--I know hydro. systems require LOTS of hp, I am starting with a new 6.5 hp B & S motor---may have to up that after a test run, as I don't have and specs to go by!--just the knowledge learned from other projects that I have made!
some of the hydraulic experience comes from when I built the excavator before I had a real back-hoe!
If you have other questions, ask, and I will try to answer them for you! thanks :sonny