What is a crawler truck crane? A rubber-tired truck crane? Or a caterpillar-track crane?
It occurs to me that with the rubber tired version, contact pressure would be somewhat related to tire pressure. IE, neglecting tire stiffness, the contact pressure IS the tire pressure, and as load increases, the contact area must increase accordingly.
On the track-type machines, P/A + MC/I should get you fairly close.
While in motion any vehicle will apply its load to the supporting track or tires based on the center of gravity. The next consideration will be the contact area which will be based on tires or tread and air pressure. When the crane is in use the loading will be based on first the CG of the load and outrigger configuration if used. You would also have to assume a flat level surface.
4-wheeled articulating tractors are an example of reducing soil compaction. When the tractors are built and shipped they are usually equipt with single tire/wheels while in operation they utilize double wheels/tires. In special load compaction application triple wheels and tires have been used.
Gross weight at load divided by track area in square inches equals PSI ground pressure. This is a common figure known on most earthmoving equipment so that you know if the equipment is too heavy for a soil type.
