New hydraulic circuits, providing superior efficiency, have been designed making innovative use of existing and new pumps, motors and controls. Applied in demanding mining applications, these circuits and components also show considerable promise for application on other mobile equipment.The mining environment dictates three primary design objectives: 1.) Use limited space most efficiently; 2.) Maximize horsepower efficiency; 3.) Assure that varying system horsepower demands are kept within the capability of the prime mover.These same objectives are gaining importance in all mobile applications, as higher energy and manufacturing costs cause equipment designers to strive for lower machine costs and more energy-efficient operation.