Thesis (Ph. D.)--Columbia University, 1945. / Vita. Bibliography: p. 71-75.

Thesis (Ph. D.)--Cornell University, 1988. / Typescript. Vita. eContent provider-neutral record in process. Description based on print version record. Includes bibliographical references (leaves 295-309).

Thesis (Ph. D.)--University of Washington, 1988. / Vita. Includes bibliographical references (leaves [160]-166).

This thesis deals with a comparative economic analysis of the truck, rail and water modes of transporting raw wood in the British Columbia Forest Industry. The thesis is directed toward establishing general guidelines for the determination of the optimal mode or combination of modes for transporting wood from the forest to consuming plants. Companies holding large tracts of timber find it necessary to do a comparative analysis of each transportation mode for their own specific situation before designing a transportation network. Since the location of wood-using plants has considerable effect upon transportation networks, this topic is also included in the thesis. The first part of the thesis shows the importance and the variety of transportation methods employed in the British Columbia Forest Industry. The largest portion of logging costs is directly attributable to transportation. Improved technology has led to several important changes in forest transportation in recent years. These are mainly the change-over from private logging railways to truck transport, and the complete change from Davis rafts to self-loading and self-dumping barges. A large portion of the thesis is concerned with a graphical comparison of transfer rates for raw forest products over distance for each of the transportation modes. Break-even distances between modes were calculated graphically. This portion of the study was accomplished by gathering province-wide transfer rates for raw wood from the Canadian National Railways, the Canadian Pacific Railway, the Pacific Great Eastern Railway, the Motor Carriers Branch of the Public Utilities Commission, various trucking firms, tugboat companies, forestry firms, and the British Columbia Forest Service. Rates for various distances were plotted for each mode and forest product. Curves and intersections were analyzed. In the transfer of logs, it was found that water rates are the lowest even at short distances. This is unlike transfer rates for other commodities where at short distances, water transfer rates are higher than both truck and railway rates. The buoyancy and ruggedness of wood make it naturally suited to low cost forms of water transport, especially by flat raft where investment in vessels is minimal . Average log transfer rates for truck and rail indicate a break-even distance between these modes of about 15 miles. When considering that most log hauls originate by truck, the cost of transshipping to rail cars causes the actual break-even to occur at about 70 miles. A similar analysis was carried out for chip and lumber transfer rates. A comparison on a common per hundredweight basis is made of transfer rates for logs, chips, and lumber by all modes. A comparison of average transfer rates indicates an economic line-haul distance for logs of about 90 miles by truck, 270 miles by rail, and 1,000 miles by barge when $12 hauling allowance remains after gathering logs at transportation terminals. Actual hauls throughout the province rarely exceed the above distances. Many other economic aspects of the above modes besides rates, are of considerable importance and are considered in some detail in three separate chapters. For example, the construction of private roads or roads of higher standard may favorably affect costs, depending upon the volume of timber to be hauled. Since timber is heavy and bulky, and experiences a large weight loss upon conversion, mills have tended to be raw-material oriented rather than market oriented. However, on coastal British Columbia, mills tend to be more centralized, with the resource being gathered over a wide area by using cheap water transportation. Future technological developments may result in the use of pipelines, helicopters, and conveyor belts in the transfer of raw forest products. / Business, Sauder School of / Graduate

The purpose of this study was to evaluate the effectiveness of steam conditioning immediately after drying to reduce internal checking resulting from high-temperature drying of Pacific Coast hemlock lumber. Three different levels of conditioning time, 2, 4 and 6 hours, were carried out on 2 inches wide by 4 inches thick by 3 feet long (51 mm by 102 mm by 0.91 m) , and on 4 inches wide by 4 inches thick by 3 feet long (105 mm by 105 mm by 0.91 m), specimens. For comparison purposes, controls of both sizes of specimens were also high-temperature dried without conditioning. Analysis of the results indicated that internal checking was not significantly reduced by steam conditioning and was more likely to develop afterwards during storage at room temperature, and that total degrade observed in the "4x4" specimens was more excessive than that in the "2x4" ones. The defective "4x4" specimens were found over-dried (below the targeted 12% moisture content) with high core-shell moisture content differences. More internal checking was found when the specimens' final moisture content ranged from 7 to 8%. / Forestry, Faculty of / Graduate

A 10 GHz microwave bridge measurement system has been developed to automatically measure the electromagnetic field parameters transmitted through a dielectric material. These parameters are used to calculate the complex dielectric constant with the free-space transmission technique. The system is used to measure the field parameters transmitted through dimension lumber and a correlation is made with two strength determining factors of lumber: specific gravity and moisture content. Hemlock and Douglas Fir wood samples were tested and a grading technique was implemented. The system is capable of estimating the specific gravity to ±0.05 accuracy and the moisture content to ±3.0% accuracy. / Applied Science, Faculty of / Electrical and Computer Engineering, Department of / Graduate

The intersection of decreasing resource size and increasing population and its associated demand creates a pressing need to develop products that act as alternatives to solid sawn lumber. Engineered composite lumber is one such alternative. The product described herein utilizes a modified form of sawn lumber as the raw material. The objective of this research was to manufacture, mechanically test, and evaluate a novel type of engineered lumber. Non destructive evaluation of raw materials and finished beams, and final mechanical testing to determine mean strength and stiffness values as per ASTM 5456 were used. The mechanical property data was converted into design values for fiber stress in bending (Fb) and stiffness (MOE). These design values was compared to those published by the U.S. (NDS) for wood construction. Pine logs were reduced into cants and further processed into matched symmetrical trapezoids. Symmetrical trapezoids were then non-destructively evaluated via E-computer and Director, and sorted by results. Next, the sorted trapezoids were matched into pairs and assembled into bowtie beams. Polyvinyl acetate adhesive was used throughout. Stiffness of the manufactured beams was nondestructively evaluated too. Then the beams were mechanically tested. The information from the E-computer was correlated to the strength and stiffness for each beam. The design strength and stiffness was compared to the values of sections of equivalent depth and maximum width as shown in the NDS. Also, non destructive test values were compared and correlated to those from the destructive tests. Finally, the design strength and stiffness values were respectively multiplied by the sectional area or the moment of inertia. This produced a strength efficiency factor and a stiffness efficiency factor. These factors were compared to factors derived from multiplying the design strength or design stiffness values (from the NDS) times the area or the moment of inertia of a rectangular section of equivalent depth and maximum width. It is found that the mechanically efficient bowtie section produced an increased strength and stiffness efficiency as compared to that of solid sawn material.

Thesis (Ph. D.)--University of Washington, 2001. / Vita. Includes bibliographical references (leaves 313-344).

Hardwood sawmills must become more efficient to remain competitive. One way to increase efficiency and competitiveness is to increase the value or lumber volume produced from logs. While methods to maximize value and volume recovery exist for round logs, little information exists on how to maximize these outcomes for logs with ellipticality. The goal of this research was to determine the impact of low and high degrees of ellipticality on green lumber grade and volume recovery for red oak logs under current sawing methods. Logs of low and high ellipticality were selected and processed at four Appalachian area sawmills. Processing variables and lumber output were tracked for all logs. It was determined that there was no significant difference in overrun, lumber volume, lumber value, and lumber grade between low and high ellipticality logs when comparing the log output at all four sawmills. It was determined that how an individual sawmill processes logs affects the outcome between logs with high and low ellipticality. None of the sawmills produced more value for high elliptical logs than for low elliptical logs and it was possible to produce more lumber volume and value with low elliptical logs. Highly elliptical logs required more processing time than low ellipticality logs in terms of log turns, total elapsed time at the headrig, and number of sawlines at the headrig. The increased processing time results in increased processing costs which were estimated to be $1.28 to $11.33 per log. These costs were not offset by an increase in lumber volume nor lumber value; therefore, highly elliptical sawlogs are less desirable to process than low elliptical logs using current sawing methods. / Master of Science

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