Shoulder yokes are available commercially from Lehmans, but they are solid wood and would require some padding to be tolerable. The spinal compression
of carrying a load this way is not good for your body...... but of course the same is true or worse carrying two five gallon jugs in your hands.
As a backpacker, I can say that carrying a heavy pack from the shoulder straps is not good for your body either, and we long ago learned that a good hip strap should transfer the load to your hips, bypassing the spine completely, and using the shoulder straps only to balance the load.
It would be worth doing a bit of "development" in this area if you routinely carry cans of water or gas or diesel
, and can't for some reason use a wheeled cart. I personally would start with a good quality frame pack with an excellent padded hip strap. Kelty is my personal preference with their welded aluminum
frame. 'The pack frame could support the yoke, transferring the load to where your body can handle it. My big concern would however be designing the rig so I could get away from it quickly if for example I fell off a dock
. A "ripcord" if you will........... If shoulder straps were not used... which would be better, and you simply hand held whatever suspended the load as with an ordinary yoke, the safety
could be a simple break away... if the frame tipped away from your body so many degrees, the strap would release, like a break away stirrup on a saddle...... a real life saver by the way...
Just an off topic aside about break away stirrups:
I'm one of the very few people who have survived being dragged behind a horse, without anybody around to help. Thanks to snow, and being very fit, I managed to release myself by main force, actually climbing my leg (insulated coveralls), hand over hand until I could grab the stirrup strap, at which point I was completely off the ground under the horse, and hanging by one hand from the strap, flipped it off my lug sole boot. All while the horse was running, and I was being dragged through sagebrush, and bounced off rocks, etc. I was as good as dead, and I knew it! The strength of adrenalin and the knowledge that I was going to die if I didn't succeed, and my powerful survival instinct saved me. I've never heard of anybody else surviving this experience except in cowboy boots by turning over. I spent enough time afoot that I had to wear lug boots in those conditions.
As a result, I'm an huge advocate of break aways. Not just stirrups, but anything where you are in danger
of getting hung up.