Abstract: The ditcher is provided with two engines. The first engine powers the hydraulic system which rotates the digging wheel. The second engine powers the hydraulic system which actuates the wheel lifting cylinders, the conveyor system and the track driving means. The two hydraulic systems are selectively interconnected so that, in the event that the second engine fails, the first engine can be used to actuate the wheel lifting cylinders and track driving means. As a result, the ditcher's wheel can be lifted to the travelling position and the tracks driven to move the ditcher off the pipe line right-of-way and enable it to return to a base camp for repairs.

Abstract: A multi-phase drive system is provided in a ditcher having a non-axially supported digging wheel comprising spaced rim assemblies. Each rim assembly carries a double segment of teeth. A pair of double sprockets drive each rim assembly. The land of each double sprocket functions as a bearing to support the digging wheel. The drive systems for the rim assemblies are interconnected by a common shaft. The system functions to drive an unusually large and heavy digging wheel.