A comparison of two full tree harvesting systems employed by Valley Forest Products Limited Nackawic, New Brunswick

Abstract

The purpose of this study was to determine, through sound engineering practices, the optimum choice between two mechanical harvesting systems to be used by Valley Forest Producst Limited of Nackawic, New Brunswick. The harvesting system being utilized at the time of this study was the Koehring Feller Forwarder Model KFF (KFF) and the Morbark Chiparvester Model 22 (Chipper). The system that was used for comparison consisted of International Harvester Feller Bunchers, a Morbark Chiparvester and Clarke Ranger 667 Grapple Skidders. In order to acquire the data necessary to prepare this report, the authors spent a total of five days in the field observing the KFF system in operation. A sample of thirteen (13) loads, eight for operator one and five for operator two, was obtained for the Koehring Feller Forwarder and a sample of seventeen (17) loads was obtained for the Morbark Chiparvester. The authors initiated a time and motion study of the.KFF system by employing stop watches and two Bolex 16 mm time and motion cameras. These cameras operated, one on a synchronous drive and the other on an impulse drive. Functions, performed in short time intervals such as the time to shear a tree, were observed and accurately recorded by these cameras. Stop watches were used to record larger time intervals such as total cycle time per KFF load. It was determined that the KFF averaged 6,440 centiminutes (cmin.) to acquire a load averaging 11.4 cunits and the chipper averaged 2,650 cmin. to chip one van load, averaging 7.25 cunits. The machine system comparison was made on the basis of the cost per cunit of wood produced at roadside. Because the volume per tree of the KFF system was 7.71 merchantable cubic feet (ft3) and that of the previous system was 4.56 ft3 , the cost was determined for the area of study and then converted to cost in the stand with trees of smaller volume. It was determined that the KFF system cost $14.24 per cunit in the study in which tree size was 7.71 ft3. This became $18.13 per cunit after adjustment for operation in the smaller volume stand. The Feller Buncher system cost was well documented, therefore a cost of $34.47 per cunit was obtained from Valley Forest Products Limited. On a cost per cunit basis, the KFF system proved to be the most favourable. When road construction cost per cunit was balanced against variable forwarding cost per cunit, an optimum forwarding distance of 500 ft. was obtained. It was determined that the KFF system should be operated under hot logging conditions, based on this 500 ft. forwarding distance.