OPERATIONAL EFFICIENCY IN FORESTRY VOL. 2: PRACTICE

Transcription

1 OPERATIONAL EFFICIENCY IN FORESTRY VOL. 2: PRACTICE

2 FORESTRY SCIENCES Baas P, ed: New Perspectives in Wood Anatomy ISBN Prins CFL, ed: Production, Marketing and Use of Finger-Jointed Sawnwood ISBN Oldeman RAA, et ai., eds: Tropical Hardwood Utilization: Practice and Prospects ISBN X Den Ouden P and Boom BK: Manual of Cultivated Conifers: Hardy in Cold and Warm- Temperate Zone ISBN Bonga JM and Durzan DJ, eds: Tissue Culture in Forestry ISBN Satoo T and Magwick HAl: Forest Biomass ISBN Van Nao T, ed: Forest Fire Prevention and Control ISBN Douglas J: A Re-appraisal of Forestry Development in Developing Countries ISBN Gordon JC and Wheeler CT, eds: Biological Nitrogen Fixation in Forest Ecosystems: Foundations and Applications ISBN Nemeth MV: The Virus-Mycoplasma and Rikettsia Disease of Fruit Trees. ISBN Duryea ML and Landis TD, eds: Forest Nursery Manual: Production of Bareroot Seedlings ISBN Hummel FC, ed: Forest Policy: A Contribution to Resource Development ISBN Manion PD, ed: Scleroderris Canker of Conifers ISBN Duryea ML and Brown GN, eds: Seedling Physiology and Reforestation Success ISBN Staaf KAG and Wiksten NA: Tree Harvesting Techniques ISBN Boyd JD: Biophysical Control of Microfibril Orientation in Plant Cell Walls ISBN Findlay WPK, ed: Preservation of Timber in the Tropics ISBN Sam set I: Winch and Cable Systems ISBN Leary RA: Interaction Theory in Forest Ecology and Management ISBN Gessel SP: Forest Site and Productivity ISBN Hennessey TC, Dougherty PM, Kossuth SV and Johnson JD, eds: Stress Physiology and Forest Productivity ISBN Shepherd KR: Plantation Silviculture ISBN Sohlberg Sand Sokolov VE, eds: Practical Application of Remote Sensing in Forestry ISBN Bonga JM and Durzan DJ, eds: Cell and Tissue Culture in Forestry. Volume 1: General Principles and Diotechnology ISBN Bonga JM and Durzan DJ, eds: Cell and Tissue Culture in Forestry. Volume 2: Specific Principles and Methods: Growth and Developments ISBN Bonga JM and Durzan DJ, eds: Cell and Tissue Culture in Forestry. Volume 3: Case Histories: Gymnosperms, Angiosperms and Palms ISBN (Set Vols. 1-3: ISBN ) Richards EG, ed: Forestry and the Forest Industries: Past and Future ISBN Kossuth SV and Ross SD, eds: Hormonal Control of Tree Growth ISBN Sundberg U and Silversides CR, eds: Operational Efficiency in Forestry. Volume 1: Analysis ISBN Silversides CR and Sundberg U: Operational Efficiency in Forestry. Volume 2: Practice ISBN

3 Operational Efficiency in Forestry Vol. 2: Practice by C.R. SIL VERSIDES Prescott, Ontario, Canada and U. SUNDBERG Swedish University of Agricultural Sciences, Garpenberg, Sweden SPRINGER-SCIENCE+BUSINESS MEDIA, B.V.

4 Library of Congress Cataloging in Publication Data (Revised for vo]. 2) Operat;iona1 efficiency in forestry. (Forestry sci.ences ; 29: v. 1; 32: v. 2) Edi tors' names in r'everse order in v. 2. Bibliography: p. Contents: v..i. Ana1ysi" -- v. 2. Practice. 1. Forestry efficiency. 2. Forests and forestry- Lalxlr productivity. 3. Forestry engineering. 1. Sundberg, U. (Ulf) II. Si1versides. C. R. Ill. Series: Forestrv sciences; v. 29:' v. 1; 32: v. 2, etc. SD387.E ' 338.1' 6 /i/i-294u ISBN ISBN (ebook) DOI / nd printing 1996 All Rights Reserved 1989 by Springer Science+Business Media Dordrecht Originally published by Kluwer Academic Publishers in 1989 No part of the material protected by this copyright notice may be reproduced or utilized in any form or by any means, electronic or mechanical including photocopying, recording or by any information storage and retrieval system, without written permission from the copyright owner.

5 PREFACE It is our conviction that professional skill in forestry will develop more readily and more efficiently if forestry students are presented with a clear understanding of the impact of the physical factors that both enhance and inhibit forestry activities. Part I is analytic, written as a basic text for undergraduates in courses such as logging, transport, forest engineering and even forest management. It deals with the fundamentals of technology in forestry as determined by the physical environment. The analytic approach serves two purposes, to bring about a clear understanding of the real world of the forest and to develop tools through which efficiency and productivity can be explored, understood and improved. The principal author of this volume was Prof. Ulf sundberg. Part II discusses in some detail a wide variety of practical problems encountered by foresters. It describes harvesting systems and the principles of management and control of forest operations. The influence of the forest on operations is described at length, the terrain, topography, forest soils as well as the engineering characteristics of trees and forest stands. It also considers the impact of operations on the forest. The principal author of this volume was Dr. Ross Silversides. Chapters 11, 12 and 13 were written by-prof. Sundberg. With these two volumes our aim has been to produce a text with the essential technological knowledge that we consider every forester should have. The professional profile even of those specializing in biological and environmental subjects, should include an understanding of the technology of forest operations. No detailed descriptions of equipment are given as these are readily available elsewhere. In this period of mechanization of harvesting operations obsolescence is a dominant factor as new concepts for systems and system components appear and disappear at a rate unheard of pre-world War II. Both authors wish to acknowledge the tremendous assistance afforded us by Gunvor Harrysson, Agneta Krohn, Kerstin Tordmar, and the illustrators, Britt Lindblad-Sundberg and Sigge Falk. Professor Per Olov Nilsson, Professor of Forest Energy systems at Garpenberg, is sincerely thanked for permitting the use of the facilities of his department. We are indebted to the Central Fund for Employees in Forestry and Forest Industries for a grant which greatly assisted in the preparation of these volumes. Finally we would like to acknowledge the devoted support given by our wives, without which the volumes would not have materialized. Prescott, ontario and Krylbo, Sweden, 1988 C.R. Silversides and Ulf Sundberg v

6 CONTENTS PREFACE LIST OF FIGURES, Vol. 1 and 2 LIST OF TABLES, Vol. 1 and 2 1. INTRODUCTION 2. OPERATIONAL EFFICIENCY 3. WORLD FOREST RESOURCES 4. FOREST MECHANIZATION 4.1 Harvesting Systems Shortwood Tree length Full tree Unlimbed tree sections utilization of logging residues Impact of marketing on logging systems 4.2 Cutting Axes Saws Shears Circular saw and cutting disc devices 4.3 Concept and Performance Reliability 4.4 Equipment Acquisition Through Ownership, Leasing or Rental Ownership Leasing Rental 4.5 Depreciation straight line depreciation Sum of digits depreciation Diminishing balance depreciation 4.6 Equipment Replacement Repair costs Unavailability productivity Fuel Loss in salvage value 4.7 Relifing Forestry Machines v x XVI

7 Vlll 5. CONTROL IN WOODLANDS OPERATIONS 5.1 Control Function 5.2 Principles Governing the Control Function Principle of uniformity Principle of comparison Principle of utility Principle of exception 5.3 systems Approach or Outlook Harvesting systems 5.4 Wood Inventory Control 6. INFLUENCE OF THE FOREST ON OPERATIONS 6.1 Effect of Stand and Tree Characteristics Upon Operational Function Effect of stand volume upon feller buncher productivity Effect of tree size upon feller buncher productivity Effect of obstacles and rough terrain on skidder productivity Effect of tree size upon wheeled skidder productivity 6.2 Range of Tree Size 6.3 Uniformity of Tree Size 6.4 Spatial Distribution of Trees 6.5 Tree Characteristics Tree branching habits 7. FOREST SOILS 7.1 Fine Grained Soils 7.2 Coarse Grained Soils 7.3 Organic Soils 7.4 Aspects of Soil Strength Cohesion Friction Moisture content of soil 7.5 Bearing Capacity of Soils 7.6 Relationship of Rubber-Tired Vehicle to Soil Tire contact area Relation between tire and soil under static conditions Relation between soil and tire in motion Rolling resistance Tires versus tracks 8. TERRAIN

8 IX 9. TOPOGRAPHY 9.1 Slope Gradient Relief Length 9.2 Ground Roughness 10. SOIL COMPACTION 11. EARLY THINNINGS 11.1 Harvesting Small Wood 11.2 Manual Handling of Wood 11.3 Harvesting with Mini-Skidders 11.4 Thinning with Single Grip Harvester 12. HARVESTING BIOMASS FOR FUEL 12.1 Scandinavian Experiences 12.2 North American Developments 12.3 Energy Plantations 13. FOREST ROADS IN A STAGGERED OWNERSHIP SETTING 13.1 Legislation. Right of Way 13.2 Classification of Forests with Regard to Road Utility 13.3 Location 13.4 Cost Distribution 13.5 Road Maintenance Cost 13.6 Concluding Remarks REFERENCES

9 FIGURES Volume 1 Page Example on the wood flow of a forest enterprise 3 Hypothetical isoquants for A and B 6 Labour productivity and the development of mechanization in Swedish forestry 8 The material flow for the Swedish forest enterprise A 9 Examples on production forms and vertical integration in forestry 16 Main logging systems 20 Graphs illustrating the influence of the tempo of work on the physical work load 33 Typical correlation between tree size and rate of production 35 Polygons giving full coverage of an area 60 Area divided by infinite, parallel roads 61 Locations of landings 65 Distribution of the area in distance zones 69 Measurements of distances from random points for establishing "V" and "T" factors 70 Stereometric properties of a log 72 Graph illustrating the break-even points for three modes of transport 78 Break-even point for two modes of transport 80 optimal road spacing 82 Optimal road standard 87 Determining "a" and "b" through plotting of observations 96 Break-even points for different modes of transport 101 Direct construction cost of forest roads 112 Expected annual plant yields as a function of annual solar irridation 122 ECE region: energy flows in the forest industries in the mid 1970's 124 The flow of energy and matter in the forest sector in the ECE region 125 Energy system for a charcoal burner at Basttjarn 126 Example on system boundry of energy analysis of transport system 129 Levels indicating system boundaries of energy analyses Energy consumption in Swedish forestry in 1972 Graph indicating how fuel and embodied energy is used Energy balance for the entire fuelwood trajectory Fuelwood energy trajectory for heating Colorado State Forest Service greenhouses A generalized fuelwood energy trajectory x

10 xi Total removals from the forests of Europe in 1980, by end uses Example on the energy consumption in a Swedish sawmill Example on energy balance for kiln drying of lumber Production function for deriving optimal level of mechanization The neoclassical flow model of economic production Economic production from an energy perspective In Appendices to Volume 1. The winding coefficient for the legs of a rightangled triangle The winding coefficient for the periphery of a circle Derivation of winding coefficient for a curve Uniform patterns of roads Average transport distance for a square Efficiency of roads in square pattern Deriving transport distance for a triangle with two equal sides Logging areas of congruent form from one point Template of transparent material Area configuration and graph for determination of transport distances Geometry of rectangular area, two way yarding Upper right-hand quadrant of rectangular harvest setting Graph exemplifying the relative value of R/Q The composition of wood The calorific energy value of wood at different moisture content Wood quantity to replace 1 m3 of oil Comparison of power ratings Mussel diagram for a diesel engine Volume 2 Page 1. Flow charts of various harvesting systems Logging methods of limit wood in eastern Canada, , in percent (%) of total harvested volume Comparison of productivity of cable and grapple skidders based upon 8-h day (Sarles and Luppold, 1986) Production in off-road transport, grapple versus clambunk skidder. Average load: grapple skidder 5,9 m3, clambunk skidder 13,5 m3 (Mellgren, 1987) Kinetic energy in Nm generated in axes of different mass Pattern of SUbstitution of cutting tools in eastern Canada 21

11 xii 7. The function of raker tooth saw in soft wood with large feed and in hard wood with lower feed, showing the adapt ion of the depth gauge setting to wood properties. Note that the rear point of the raker rides on uncut wood, causing a lift or compression of the wood Relative values sawing manually with bowsaw and with powersaw Sawn area of wood in cm2/s as function of powersaw power in kw cutting times for different log diameters: full lines - for sawchains of various capacities, in cm 3/s, time proportional to d2; dotted lines - for various sawchain speeds, in mis, time proportional to d Shear blade with triangular ribs (McLauchlan and Kusec, 1975) a) Operating principle for vibration shear blade b) Cutting force without vibration and with vibration in feeding direction Reliability exponential relationship. The probability of an item surviving an operational time equal to its MTBF (mean time between failures) is 0, Machine availability versus operation competence (Kurelek, 1976) Cost of purchase or rent for 5 years at various annual usage. The chart is based upon a machine costing $70 000, a rental rate of 8% of purchase price per month, a trade-in value of the purchased machine of 10% and a machine life of 5 years Various methods of calculating annual depreciation (Spanjer, 1968) The "bathtub" curve. Normal development of the failure rate over machine life. The failure rate is approximately constant during the period of useful life Flowchart of a self-controlling communication system. Actual performance is compared with goal. If it does not reach desired performance, a control mechanism acts to correct the actual performance until it meets the required standard Production control chart Flow process from raw material to end product systems that utilize the advantages offered by the Canadian forest resource (Boyd, 1977) Effect of tree size on various stages of tree harvesting (Conway, 1977) comparison of shear productivity, accumulator versus single tree (John Deere 544 Feller Buncher with Rome accumulator shear) Mean fell and bunch time in seconds/tree versus DBH, cm for 1, 2, 3, and 4 trees per cycle, Timbco system (Gonsior, 1986) 77

12 xiii 25. Machine productivity with various size trees, in m3 per productive machine hour (m3/pmh) Koehring Shortwood Harvester (Newnham, 1971) Distribution of log sizes, Ivory Coast, by log diameter (A) and by log volume (B). Average log length 6,5 m and average log volume 4,8 m Relationship between productivity and tree diameter squared. Feed speed in example is 45 m/min Load capacity of knuckle boom loader as function of lifting radius a) Various ranges of tree size around common mean diameters for stands of same volume. b) Standard deviation showing that 68% of stand lies within 1 standard deviation from mean and 94% of stand lies within 2 standard deviations Use of cumulative curves to assist in sizing harvesting machines Spatial patterns of trees in different stands a) uniform, b) random, c) clumped (Newnham, 1971) Minimum skidding or forwarding cost as related to speed: graph A trail construction cost, graph B direct cost of transport, top graph total cost with optimum speed Turning patterns a) Machine with point of articulation at centre and with extended wheelbase and point of articulation ahead of centre: b) Influence of location of point of articulation on on wheel slip, at various turning angles Obstacle raised side of vehicle with large single wheel higher than if equipped with tandem bogie (Bredberg and Wasterlund, 1983) Effect of slope and or obstacles upon the operating width of a forwarder Effect of rearranging obstacles, minimum spacing unchanged (Addor, 1963) A vehicle can usually tolerate a mean spacing of obstacles down to 1,4 times its width Vehicle speed in km/h as related to the ratio: mean obstacle spacing (MOS) to width of vehicle (WV) Physical characteristics of coniferous and deciduous trees Average number of branches and average stub area in cm2/m sections of the bole located at various distances downward from the top cut at a diameter of 7,5 cm, jackpine Distribution of tree crown for jackpine Example of the classification of trees by crown length Variation in branch size in relaltion to tree diameter for Scotch pine and Norway spruce in southern Finland (Hakkila, 1971) Distribution in percent of small, medium and large branches in relation to tree size for short leaf pine (P. echinata) and yellow poplar 102

13 xiv 45. Relationship between branch length and tree size Distribution of branches and branch stub area around tree stem per 0,305 section of crown. Distance between successive circles represents one branch or 6,5 cm2 (one square inch) of branch stub area. (Drolet et ai, 1971) Chart indicating combinations of basic soils, sand, clay and silt Soil strength: a) Mechanical friction between soil particles; b) Cohesion between soil particles; c) Friction and cohesion acting together Soil parameters which affect the safe load of a vehicle A) Cross section of tire indicating overall width at widest point, in example 18 inches. B. Side view of tire showing diameter of rim, 25 inches. such a tire is referred to as an 18,00 x 25 size tire or the equivalent in centimeters (Anon, 1961) Rolling resistance encountered by wheel on soft ground Tires versus tracks Skidding with crawler tractor (Bendz and Jarvholm, 1970) Typical load sizes with crawler tractors (Bendz and Jarvholm, 1970) Skidding productivity with wheeled skidder. Load size will depend upon log size but will not exceed m3 in most cases comparison of crawler tractor and wheeled skidders Slope shape or relief Classification of terrain difficulty according to frequency of slope gradient (Leffler, 1984) Example: With easy terrain 90% of the surface area has a gradient of approximately 30% or less, with difficult terrain 50% of the surface area has a gradient greater than about 30% Relationship of increase in soil density to seedling height growth (Rollerson and Kennedy, 1984) Example of the relative time consumption for the felling and conversion of small trees Production rate for the manual dragging of logs of different weights The influence of log size on the production in piling of wood Thinning with mini-skidder a) Single grip harvester which can fell and process a tree without releasing its grip upon it; b) Double grip harvester which transfers felled tree to processing mechanism mounted on the base machine (Courtesy: Forest Operations Institute, Stockholm) 138

14 xv Thinning with a single grip harvester The two harvesting systems compared in Table 26 Forwader loading unlimbed tree sections in the stand after bucking the trees with the powersaw mounted in the grapple utilization in thinnings, in percent of total biomass above felling cut. Left: Traditional system - slash not utilized Right: Modified full-tree system - unlimbed tree sections Forwarder collecting logging residues for transport to roadside comparison of machine energy requirements Example of the cash flow for an energy plantation (Sydkraft, 1985) The type scheme on stand development

15 TABLES Volume 1 Page The forests of a Swedish compay 2 The cost distribution of a Swedish company 4 Gross data for some forest enterprises 5 Staff and labour force 5 Revenues per employee 6 Costs and cost distribution on main activities 7 Capital investments - roads and machines - wage rates 7 Output for felling and extraction to roadside 8 Scheme for the choice of off-road transport method in temperate forests 21 Labour supervision requirements in field operations 26 Daily energetic cost during rest and in some occupations 29 Energetic cost of some forest jobs 29 The grading of the heaviness of work 31 Expected output in starting up logging and transport op~rations 41 Work study techniques 46 Example from a work study of production rates as related to tree size 48 Examples of capacities of modes of wood transports ' Example on variable transport costs Average transport distance at different ratios short/long side Approximate ratios of variable (distance) transport cost Example on volume of transport for which costs break even Example of tariffs of transport Estimate of optimal spacings of gravel depots Example of break down on road standards for forest road nets Heat and work conversion factors Average-to-good annual yields of dry matter production Inputs of energy and outputs Energy contents in some fuels Approx. economic energy values for fuels Estimates of EROI for some fuel supply technologies, USA Energy balance in the forest sector in the united states in 1980 Input of labour and energy in Swedish forestry in 1956 and 1972 Energy consumption by the sawmilling sector in xvi

16 XVII 4.10 Matrix for the adjustment of a uniform machine rate Matrix (in table 4.10) as modified by Svanqvist (1985) 147 In Appendices to Volume Examples on body weights of rural workers Limits of tolerance to heat stress in forest work Grading physiological work load acc. to sweating rate Time consumption or reduction of productivity due to heat stress Common diseases in tropical countries Energy content of fuels and other inputs Energy transmission for a passanger car in urban driving Fuel consumption per kwh at maximum power rating 209 Volume 2 Page la. World forest area (FAO) 5 lb. Annual rates of deforestation and plantation in tropical regions, lc. World forest resources 7 2. Relative characteristics of rubber-tired forwarders and skidders Nutrients and bark/wood ratios, averaged for all species Energy consumption in chopping Reliability of six harvesting machines (Mellgren, 1978) Estimated operational efficiency for tree harvesting machines - % Calculation of straight line depreciation Sum of digits depreciation Calculation of depreciation on a diminishing balance Average equipment purchase prices for various years ($000) Level of workflow rigidity (Legendre, 1973) Numerical and volumetric percentage of trees with diameters exceeding the design one, in the major logging regions of the USSR (Nemtsov, 1975) Example of an asymmetric distribution of trees for a typical spruce stand in Canada Grapple skidder versus choker skidder (Sarles and Luppold, 1986) Skidding tree lengths over bulldozed trails and unprepared trails (McGraw and Hallett, 1970) Relative above-ground portions of coniferous and deciduous trees (Thomas, 1981) 97

17 xviii Coefficients of density of slash piles 104 Coefficients of cohesive resistance (c) and angle of internal friction for various soils (Anon, 1929, Hogentogler, 1937) 110 Relation between service conditions, tire loading and tire inflation pressure (Goodyear, 1970) 115 Coefficients of traction for various ground conditions (caterpillar, 1976) 116 Drawbar pull (kg) required to overcome log skidding resistance - log lengths (Caterpillar, 1976) 117 Values (E) for losses due to friction in gears and axle 117 Key for trafficability (Nataraj, 1969) 125 Slope classes and gradient values (Leffler, 1984) 126 Classification of ground roughness (Leffler, 1984) 128 Comparison of traditional utilization of pulpwood and full-tree logging (unlimbed tree parts) in the thinning of a forest stand with DBH 10 cm o.b. 141 Road network located on forest land in Sweden 150 Traffic indices (TI) for the grading of the present worth traffic volume per unit area of a forest stand 155 Correction factors Fz for the grading of the crosswise function or a road with regard to the crosswise location of the stand (unit area) 156