The steel trailer concept is not that new. As a truck driver I drove containers with removable floor pieces and an included collapsible tent to transport steel rolls. When empty, the containers can be folded and stacked, so 1 container can carry 10 steel containers. They also drove with tank-containers that could stay at 85 degrees Celsius by connecting the tank circuit to the truck's cooling circuit. Therefore, you did not need an extra power unit to keep the product warm in the tank. They were very innovative back then.