I opted for the KISS approach and went with a rail-on-rail subframe. It is a simple, proven and low maintenance design. I like that it does a solid job of keeping all 4 tires on the ground, contributes little to overall height (keeping the center of gravity low) and has essentially no moving parts to grease or maintain. I also like that the vast majority of the time the weight is evenly distributed along the chassis rails, that is until it is time to go to work. Then, as it maintains a flat sturdy platform for the habitat, it favors one rail over the other while allowing the truck chassis to flex.
This system is also commonly used for tanker trucks and has similar characteristics to a dumptruck. It is fixed in the rear and allows for the rails to increasingly separate towards the cab.
It is very difficult to see the system with the storage boxes mounted so this older picture will have to do. It was taken the day I brought home the Total Composites panels back in 2016. To save cost we shared a shipping container with a guy who was building on the unimog platform. The video of us leaving camp does a pretty good job showing the system in motion.
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