This study evaluated the impact of using a rubber-tired skidder to keep the landing clear by sorting and decking the logs along the road prior to loading by a self-loading truck. The evaluation was accomplished through detailed time studies conducted on a Koller K-300 yarder, a Crown Super 3000 self-loader,...
An extension of the sensitivity analysis of linear programming, called parametric programming is used in determining optimal sawtimber logging system mix. The five logging systems under study are manual log-length, system, log-length processor and harvester systems, manual tree-length system and tree-length harvester system. In conditions where it is not exactly...
Tension relationships were determined in steel cable passed through a stump notch and anchored to another object. Tensions were measured in the cable coming into and leaving the notch with one full wrap on the stump. Data was collected from two sites with two test stumps (15.7 to 37.5 inches...
This paper describes a study done on swinging and processing whole tree, tree length and log length pieces in a smallwood Douglas-fir thinning. Two machines were evaluated, a 70 horsepower rubber tired skidder and a hydraulic loader mounted on a 6 x 4 live tandem truck.
The study took place...
The use of mechanized harvest equipment has been
increasing as an economical method to harvest small diameter
timber. While the use of this equipment is increasing,
little is known about associated soil compaction. In
particular, little information exists on soil compaction
caused by feller--bunchers.
This study measured soil compaction caused...
This paper shows how ten easy-to-use linear skyline thinning production rate equations were obtained by transforming existing but more cumbersome turn time equations using the THIN simulation model [11). The equations provide reasonable approximations of delay-free hourly production for several cable yarders operating skyline thinnings under a variety of conditions....
This paper describes a mathematical formulation and computer
programs for use on hand-held programmable calculators to analyze
the load carrying capacity of skyline systems, including the effects
of log drag. The actual physical characteristics of the load and
the ground geometry are used in the analysis of the payload capacities...
Cable yarding of first thinning size material from plantations of Pinus radiata in South Eastern Australia 15 simuiated using a computer model. Production rates, expressed in cubic metres per hour and production cost, expressed in dollars per cubic metre were derived using the model to simulate cable yarding under set...
Shovel logging is a relatively new ground-based method of yarding tinther. It involves moving logs from stump to landing by successive swinging with a hydraulic excavator modified into a log loader by replacing the shovel bucket with a grapple. Loaders used in shovel yarding can weigh in excess of 100,000...
The peat swamp forests of Sarawak are an important
resource in the context of the socio-economic development
of the state. Logging is the main activity in these forests.
In the absence of an economical mechanized system, the
method of harvesting has evolved into a highly organized
effective manual system. Though...
The Pulp and Paper Industry in the Pacific Northwest is
obtaining an increasing share of its fiber supply by
chipping small diameter trees from thinnings, insect damaged
stands, and stand conversions. Since most of the mills
require pulp grade fiber to contain less than 0.5% bark, the
timber must be...
This paper was written to serve as an introduction to instructional video production for tiraber industry officials. Discussed herein is the applicability of video to the timber industry and the development steps required to produce a scripted, edited instructional video. The focus of the paper is on content development and...
The principles of mobility are applied to the forest setting to
simulate the movement of logs with a rubber tired-skidder. A computer
program was written to perform the analysis . Vehicle-terrain and logterrain
interactions are the resistances which must be overcome by
the available vehicle power. The rate at which...
The objective of this paper is to develop a methodology for determining running skyline yarder performance based on the mechanical characteristics of the yarder and its interaction with the load and the terrain. A code for implementing this procedure on the HP-9020 will be prepared .
The purpose of this paper is to determine the dynamic tensions that occur in the guylines and pendulum lines of a tethered logging balloon. A scale model was used to represent the tethered logging balloon.
During the swinging of payloads, line tensions followed a very predictable sinusoidal curve. It was...
This paper includes a literature review of the methodologies invoked to surmount difficulties inherent with aerial photograph mensuration. The synopsis of early achievements is followed by a more intensive examination of experimental studies of the last decade, particularly the work on controlled scale photography.
This report on the pursuit of...
In the Pacific Northwest, loggers are faced with the problems of changing from logging old growth to second growth. This is due to the shrinking old growth timber supply and increased entry into the· second growth stands. Beuter (1 980) indicated that in western Oregon 70.2 percent by volume of...
In this paper the extent of the steep slope brush conversion problem will be estimated. Potential solutions and development should be commensurable with the extent of the problem. The state-of-the-art of steep slope site preparation and conversion will
be described. Feasible alternatives to these limited options will be developed.
LOCCOST is an interactive computer program that
predicts stump to mill logging costs, stumpage and net
present value of a harvest based on stand data, pond value
and logging parameters, entered by the user. The program is
intended for use by foresters to evaluate the economics of
different stand management...
This paper describes the results of a study of log
truck travel speeds in three locations in Western Oregon on
favorable grades and curves. Independent variables of grade,
curve radius, width, ditch depth, superelevation, sight
distance, time of day, and maximum engine braking horsepower
were regressed against speed. Only grade...
The sale of raw logs from the Pacific Northwest (PNW) was at first
considered a desirable market for the sale of unwanted logs. It became
a rapidly growing market, and with its growth also came demands from
some in the PNW for restrictions against exporting logs. Some believed
that the...
This paper documents the development of a model which determines multiple stump anchor system displacement as a response to skyline load for four anchor rigging configurations: 1. Series multiple, 2. Tieback, 3. Elevated tieback, and 4. Equalizer block. It also documents the field testing of four two stump anchors rigged...
This paper presents an evaluation of the cable loading
support capacity of red alder, Alnus rubra Bong., Sitka
spruce, Picea sitchensis (Bong.) Carr, and western hemlock,
Tsuga heterophylla (Raf.) Sarg., tail trees. Capacity is
measured in terms of combined stress resulting from
compression and bending, rather than the traditional methods...
Western hemlock and Sitka spruce are relatively thin-
barked species and susceptible to damage during thinning
operations. Damage to the wood allows decay-causing fungi
to enter resulting in loss of merchantable volume at the
time of final harvest. Cable yarding systems are needed for
much of the thinning because most...
This project was one of several studies conducted during the summer of 1981 that were part of the Smallwood Harvesting Research Program administered through the Department of Forest Engineering, Oregon State University. The study looked·at the feasibility of falling and yarding whole trees as a combined activity in a cable...
This paper represents preliminary engineering analysis on the pendulum swing balloon system. It also describes an
analysis of measurements taken in the summer o.f 1982,
during a field test of a 37,000-foot3 balloon used as a
prototype model under static conditions. This work
established the influence of important variables on...
The Northwest timber industry is in a transition to a smallwood harvest environment. As the Northwest moves to smaller average diameter stands log values have decreased and harvest costs have increased. In an effort to increase profitability, Northwest loggers are beginning to "mechanize". The profitable operation of a mechanized harvest...
An analysis of forces on two tree intermediate supports is presented. The analysis is in two parts:
The maximum force that the support jack will experience. The movement and forces created in the two tree support by the skyline and carriage. The maximum force on the support jack occurs when...
A computer program package to estimate cable yarding
payload capability was made. The package was intended to
expand applicability of existing packages and to be user
friendly. It has six system options: live skyline, standing
skyline, running skyline, slackline, multispan and highlead.
In the standing skyline and multispan analyses, load...
Small, independent logging contractors can benefit
from cost control and cost planning. This report
details the labor and equipment cost components of a
logging crew. Records, both required and available for
determining costs, are discussed. Recommended costing
procedures are illustrated. Although the study took
place in the Pacific Northwest, the...
The calculation of optimum setting dimensions and road standards simultaneously on a timber sale is a common problem in uniform terrain. Analysis usually begins by evaluating certain road standards under various road spacings and profile geometries. Linear costs, single period entry and simplified skidding patterns are often assumed to permit...
The use of partial cutting in the western conifers has become popular in the last decade. This has resulted in an increase in the amount of damage to the residual stand due to skyline logging. The purpose of this study is to provide models to predict the percent of a...
This paper is a compilation of most of the recent cable yarding
production equations generated by the Forest Engineering Department
at Oregon State University. Additional production equations found
in the literature review have also been included. Background
information for each of the studies involved has been summarized.
Data is basically...
This paper describes the results of a time-study conducted
near Grand Ronde, Oregon, to determine the production
rates and total harvesting costs of a cable thinning in a
young stand. The stand had a species mix of 48 percent
western hemlock (Tsuga. heterophylla- (Raf.) Sarg.), 45 percent
Douglas-fir (Pseudotsuga meuziesil...
Time studies of logging equipment are important to determine
production rates, calculate logging costs and locate operating inefficiencies. However, using present time study techniques, they are also costly and time consuming to complete. This project will develop a new data gathering and storage technique using the HP-75
portable computer to...
The objectives of this paper are to: (1) describe the structure and output of SHRUB and RMS8O, (2) evaluate their respective ability to satisfy the needs of a state level timber assessment, and (3) demonstrate their application to forest planning using the state of California as the focus of a...
A model is presented which predicts the net present
value of a stand level multi-entry harvest plan. The model
accounts for potential volume losses due to harvest-related soil compaction. The goal of this project was to answer five economic questions about the issue of soil compaction in forestry. The five...
In this paper, a catenary analysis of static skyline, mainline and haulback cable tensions just prior to an unsuccessful attempt by a carriage to pass an intermediate support jack is presented. Field tests were conducted for a range of skyline deflections and span chord slopes. Data collected during the field...
The selection of a road standard is a complex decision involving consideration of design, construction, maintenance, and vehicle operating costs. The first step in any analysis involves a definition of the physically feasible alternatives. In the Oregon Coast Range, a combination of steep topography and sensitive soils influence the type...
Some results of a study conducted in the Sierra Nevada
Mountains west of Lake Tahoe are reported. The study measured
soil impacts resulting from the use of a Caterpillar Tractor
model D6D, a John Deere wheeled skidder model JD-640, and an FMC
Corporation model FMC 21OCA logging vehicle. The three...
This paper discusses the development of a computer simulation program for the operation of a log landing for the proposed Helistat airship. The first part of the paper describes the time study used to develop production rates for the chasers, buckers, front-end loaders, and skidders to be used on the...
Time study data was collected for two horsepower classes of rubber tired skidders from field operations controlled by Associated Pulp and Paper Mills, Ltd., Tasmania, Australia. A wide range of site and logging conditions were used to produce both production per hour and cycle time predictive equations.
The resultant equations...
The purpose of this paper is to compare the estimated production of the pendulum swing logging system to the production of a conventional balloon logging system. Cycle Time is established for the conventional system by time study techniques. A combination approach is used to model the pendulum system. A computer...
A semi-empirical mobility model is presented which predicts tracked vehicle performance in timber harvesting applications. The interactions between the log load and the
terrain, the log load and the vehicle, and the vehicle and the terrain cause resistances for the vehicle. The mobility
model calculates these resistances, comparing them to...
There is much interest in the State of Vermont in cable harvesting. Since there are no time studies available for cable harvesting with various machines in Vermont, it is necessary to arrive at production and cost levels by a different method.
The method chosen for this paper is made up...
The prescription presented covers two stands of timber, designated Stands A and B, owned by the Wolf family. The owners seek a management plan which will coordinate activities between the stands to yield a continuous flow of wood products and income.
This paper describes a computer program developed for the Hewlett
Packard 9830, which analyzes and computes costs and engineering
data for paper plan timber harvest road networks. The program will
accept up to 110 road segments. Each segment is analyzed individually
based on digitized data from a contour map and...
Whole tree and tree length thinning are two alternatives which are likely to be more productive and may prove to be more cost effective
than conventional log length thinning. The purpose of this study was to evaluate and compare log length, tree length, and whole tree thinning techniques in terms...
As the population in the United States and the world grows, the demand for wood products, recreation opportunities, clean air and water, and other primary and derived forest resources will grow. Opportunities to realize each of the forest resources in a given area may be mutually exclusive, and their production...