The cart should be prepared to screw on the floor. The floor beams and the bottom of the floor shall be built into the undercarriage. On the underside there should also be L-shaped iron to attach the vertical posts.
The wagon should have double axes sitting on a bogie but stable to a certain gradient, then it can bend to a certain level. The level should be as a logarithmic curve, here we have the form that controls the function. Advantages of two different solutions, dual axles can rest steadily when the wagon rests freely and is neutral on the dragon when the ground is flat, boggie can swallow oil roughness in the terrain and be relatively neutral on the dragon and the wagon remains in the wave. However, considering the distance between the wheels in the boogie, determine the size of the obstacle it can swallow. On a forest wagon they are made to roll over a stump.
Ability to adjust the platform in a wave. Any form of killing system that presses the bogie. Possibility to lift one wheel in the boogie pair when you need to turn. Possibility of moving the center of gravity on the trolley to distribute the weight correctly, moving the wheel pairs.
Think of any kind of suspension with a low center of gravity. Have thought that a shock need not be caught by a long suspension. You can divide the shock into different small parts, such as microscopes that have a frequency that matches the mass and gravity. The frequency may be quick first to ebb out.