1. Field of the Invention
This invention relates to a skyline logging carriage for yarding logs in a logging operation.
2. Prior Art Relating to the Disclosure
Aerial cable logging systems utilizing skyline carriages are used for logging operations in the Pacific Northwest area of the United States. Skyline carriages generally include a winch drum which may be powered by a diesel engine mounted on the frame of the carriage. The engine drives the winch drum through a clutch or direct mechanical connection. U.S. Pat. No. 3,083,839, for example, employs a centrifugal clutch to transmit power between the engine and the winch drum, effective only at accelerated speeds of the engine. U.S. Pat. No. 3,022,747 employs disc clutches, with the driving members of the clutches directly powered through a gear case by the engine. Skyline carriages, such as those disclosed in the above patents, pose severe maintenance problems. Additionally, such mechanical drives limit the location of the winch drum on the carriage frame. This presents problems of locating the fairlead in relation to the winch drum to obtain proper level winding of the cable about the winch drum.