The purpose of this paper is to discuss some of the theory of Boolean matrices and apply this theory to construct contact networks by using algebraic methods.
The first section of this paper (Chapter I to III) describes Boolean algebra and its properties, the theory of Boolean matrices, and the...
Stem form development of trees in response to wind has been established in the literature to be a response to stem sway induced by the wind. The response is manifested in modifications to height and diameter growth which strengthen the stem against wind stresses. Experiments in the literature show that...
This paper describes the analysis of data from a three-year gross time study of skyline, balloon, and helicopter yarding systems operating in Western Oregon. Data collection activities were designed and supervised by the Pacific Northwest Forest and Range Experiment Station, U.S.D.A. Forest Service. The specific logging systems studied were running...
As the demands for forest products increase, additional timber harvesting operations can be expected on steep mountainous terrain, The resulting disruption of natural slope stability by man's disturbances (roadbuilding, logging and vegetative manipulation, etc.) may also accelerate mass movement processes in this terrain. Swanston (1969) defines mass movement as ".,...
The popularity of gravity-return skyline logging systems is now increasing in the Western United States. Simplicity seems to be the basis for their success. While two drum yarders are most commonly used, ·some systems, such as the Wyssen, use only a single drum for yarding. Carriages commonly used with these...
Commercial thinning young growth forests is an increasingly
important silvicultural technique for improving second growth
management of Douglas-fir stands. Research aimed at advancing the
efficiency of skyline logging operations in small wood timber stands
is essential in order to make thinning these young stands economical.
The purpose of this study...
This paper describes the results of a time study conducted on the
Sierra National Forest to determine production capacity of the Madill 044
Skyline Yarding Crane operating in a partial cut situation for old-growth
mixed conifer stands. The yarder was rigged in the running skyline configuration
and used a Danebo...
Environmental concerns have prompted the need for reviving an old art: controlled felling. The methods currently used, jacking and lining, present new and varied problems for the faller in today's environment. One of the major concerns of the faller is the purpose of this paper what kind of forces are...
The preparation of suitable sites for planting and growing of tree seedlings following logging is recognized by British Columbia Forest Service as a major silvicultural problem in the Central and Northern Interior regions of the province. Over the past few decades, scarification trials have been made with various types of...
Results of a recent production study indicate that a four man
crew thinning young growth Douglas-fir [Pseudotsuga mensiezii (Mirb.)
Franco] with an Iglarid-Jones Trailer Alp can produce 1360 to 1460
cubic feet (38 to 41 cubic metres; 8160 to 8750 bd. ft.,) per eight
hour day on slopes of 10...
In recent years, inflation and a growing concern for soil compaction and environmental damage have affected both the forest manager and the logger. Balloons, helicopters, and skylines have been used to harvest timber and the results have been promising
(Dykstra, 1975, 1976). However, the high cost of using these aerial...
In order to appraise timber, it is necessary to estimate logging costs with reasonable accuracy. The purpose of this study is to provide a rethod for estimating log loading costs in the Intermountain Region. Nine different log loaders were studied loading from cold decks on six USDA. Forest Service timber...
In recent years considerable work has been done in the development of improved logging machinery. The word improvement may bring to mind entirely new or improved systems which offer the logger greater mobility and efficient use of manpower. Logging has generally been labor intensive, however, "The need to achieve greater...
The comercial thinning of second-growth stands in the Pacific Northwest is becoming increasingly important for satisfying the demand for timber. Cable logging will require the rigging of smaller intermediate support trees rather than those utilized on old-growth timber sales. This paper reports on the results of a study designed to...
In northeast China, logging has three stages; timber
harvest, transportation and the operations inside a timber
yard. The timber yard is an intermediate transhipment point between truck transport and rail transport to manufacturing centers. The transhipment capacity of the timber yard is often the limiting acitivity in the logging chain....
Gradeability of log trucks is limited by either
vehicle rimpull or ground-tire adhesion. The analysis presented shows that log trucks in current use in the Pacific Northwest are limited by tire-slip gradeability rather than by rimpull. Analytic techniques were used to determine that gradeability is greatest for piggyback and least...
Potentially large savings can be realized within the forest industry by improved machine scheduling, labour scheduling, machine investment, inventory management, and the maximization of wood value. Forecasting must change within the forest industry from Ttguesstimatesll to more efficient production forecasting models. Much work needs to be done with data collection...
Intensive forest management requires efficient logging techniques
to remain economical. Commercial thinnings and shorter
rotations increase piece count inversely to piece size. Continued
research aimed toward effective log handling processes is essential.
The purpose of this study was to evaluate one case of a self-loading
log truck (integral loader and...
This paper describes the results of a study conducted in the
Sierra Nevadas located in California to determine the production rates,
s.kidding costs and the extent of soil disturbance and compaction on two
partial cut units harvested with a Caterpillar D-7F. A harvest unit
with preplanned skid trails and winching...
Surface and subsurface data are combined to determine the structure of the western half of the Simi fault system in the Las Posas and Camarillo Hills area. Cretaceous to Eocene sedimentary rocks, present only in the subsurface, are overlain by late Eocene to early Miocene nonmarine stata (Sespe Formation) and...