Table Of ContentTREE HARVESTING TECHNIQUES
FORESTRY SCIENCES
Baas P, ed: New Perspectives in Wood Anatomy. 1982. ISBN 90-247-2526-7
Prins CFL, ed: Production, Marketing and Use of Finger-Jointed Sawnwood. 1982.
ISBN 90-247-2569-0
Oldeman RAA, et al., eds: Tropical Hardwood Utilization: Practice and Prospects. 1982.
ISBN 90-247-2581-X
Den Ouden P and Boom BK, eds: Manual of Cultivated Conifers: Hardy in Cold and
Warm-Temperate Zone. 1982. ISBN 90-247-2148-2 paperback; ISBN 90-247-2644-1
hardbound.
Bonga JM and Durzan DJ, eds: Tissue Culture in Forestry. 1982. ISBN 90-247-2660-3
Satoo T and Magwick HAl: Forest Biomass. 1982. ISBN 90-247-2710-3
Van Nao T, ed: Forest Fire Prevention and Control. 1982. ISBN 90-247-3050-3
Douglas J, ed: A Re-appraisal of Forestry Development in Developing Countries. 1983.
ISBN 90-247-2830-4
Gordon JC and Wheeler CT, eds: Biological Nitrogen Fixation in Forest Ecosystems:
Foundations and Applications. 1983. ISBN 90-247-2849-5
Hummel FC, ed: Forest Policy: A Contribution to Resource Development. 1984.
ISBN 90-247-2883-5
Duryea ML and Landis TD, eds: Forest Nursery Manual: Production of Bareroot Seed-
lings. 1984. ISBN 90-247-2913-0
Manion PD, ed: Scleroderris Canker of Conifers. 1984. ISBN 90-247-2912-2
Tree harvesting techniques
by
K.A.G. STAAF
College of Forestry
Swedish University of Agriculture
Uppsala, Sweden
and
N.A. WIKSTEN
Canadian Executive Overseas
Montreal, PQ, Canada
SPRINGER-SCIENCE+BUSINESS MEDIA, B.V. 1984
Library of Congress Cataloging in Publication Data
Staaf, K. A. G. (K. Anders G.)
Tree harvesting techniques.
(Forestry sciences)
A condensed edition of the original Swedish version
of 1972.
Bibliography: p.
1. Logging. I. Wiksten, N. A. (N. lke) II. Title.
III. Series.
SD538.S82155 1984 634.9'82 84-14692
ISBN 978-90-481-8282-4 ISBN 978-94-017-3592-6 (eBook)
DOI 10.1007/978-94-017-3592-6
Copyright
© 1984 by Springer Science+ Business Media Dordrecht
Originally published by Martinus Nijhoff Publishers, Dordrecht in 1984
Softcover reprint of the hardcover 1st edition 1984
All rights reserved. No part of this publication may be reproduced, stored in a
retrieval system, or transmitted in any form or by any means, mechanical,
photocopying, recording, or otherwise, without the prior written permission of
the publishers, Springer-Science+Business Media, B.V.
Contents
Preface 13
Introduction 17
TREE HARVESTING - GENERAL 19
Tenninology 19
Fonns of production 20
Rationalization of the various forms of operation 21
General objective 22
Tree harvesting a secondary form of production 22
Thinning and final harvest 22
PLANNING OF TREE HARVESTING 23
Objectives and means of planning, 23 Planning requirements 23,
Data required 23, Collection of stand data 24, Requirements of
labour and machines 24, Preparation of the tree harvesting plan
24, Planning for low costs of tree harvesting 25, Maps 25,
Planning in general - Land and Labour 28
Various forms of cooperation 28, Population and labour 29, Areas
and centres of labour 31, Forest guard (ranger) district A 31,
Forest guard (ranger) district B 33, Forest guard (ranger) dist-
rict C 34, Growing stock and volume of timber harvested 35, Prob-
lems are solved in general and in detail 36, Trends 36,
Planning in detail 38
Planning for various seasons 40, Division of the areas of treat-
ment into parcels for felling and transport 40, Road systems and
other routes of transport 41, Planning of roads 42.
ENVIRONMENTAL FEATURES INFLUENCING TREE HARVESTING 43
General features of environment 43, Geographic location and ex-
tent of the work area 43.
Climate features 44
Air temperature 44, Precipitation 44, Winds influence the fell-
ing of trees 45, Wind felling 45.
6
Terrain features 46
Classification of terrain 46, Dominant terrain features 47, Carry-
ing capacity of ground 47, Surface structure 47, Minor obstacles
48, Major obstacles 48, Statistics on micro-terrain features 48,
Slopes 49, Ground conditions 50, Surface structure 50.
The trees 50
Diameter 51, Crowns 51, Limbs 52, Weight of trees 52, Density of
wood, center of gravity in trunks and statistics on bark 53, Units
of timber handling 55,
The forest stands 56
Relationship between cost of harvesting and volume of timber 57,
Thinning 58, Clearcutting 58,
TREE HARVESTING TECHNIQUES 59
Partial operations 59
FELLING 60
Choice of felling object 61, Felling year-round 61, Direction of
felling 61, Directed felling 61,
Tools and means of felling 62
Working and holding positions 62, Preparations 63, Guiding cut and
felling cut 63, Some safety rules at felling 64, Use of felling
pad 66, Calculation of shearing forces 68, Cracking caused at fell-
ing by means of clipping and shearing tools 69, Felling saws 70,
Circular saws for felling 70, Feller-buncher with circular saw 71,
Felling head with two circular saws 73, Alternative solutions 76
Felling patterns 76
Felling along strip roads 76, Parallel felling and felling in
swaths for the tree length trunk method 77, Parallel felling for
the tree method 79, Delimbing and topping before felling 79, Ex-
traction of trees in vertical position 80, Felling of whole trees
81, Lifting of whole trees 82, Trees felled with cut root systems
82, Felling or collection of several trees simultaneously 82
Manual felling 84
Manual felling with mechanized processing 84, Alternative tree
part method in thinning operations using grapple saw on crane with
long boom 85
Mechanized felling 87
Feller- a small skidder with straight boom 87, Feller mounted on
a tracked vehicle with short boom 88, Feller 89, Feller-buncher
90, Feller-skidder (buncher) 91, Feller-delimber-buncher 91,
Feller-delimber-bucker 92, Some performance data 93, Un-manned
machine without operator seat in the cabin 94, Small machine for
felling and bunching in thinning operations 96, Trends 98
7
DELIMBING 98
Manual delimbing 98, Mechanized delimbing 99, The tree limb as an
object of work 100, Whorls and internodes 100, Frequency of limbs
100, Diameter of limbs 100, Height to crown base 101, Resistance
to shearing force at delimbing by means of cutting tools 101,
Weight of limbs 103
Tools and means of delimbing 104
Various tools and machines for delimbing 105, A presentation of
some machine types 105, Trunk embracing knives and stepwise feed
105, Removal of slash 105, Tree harvester 106, Processor 107,
Pulpwood harvester 107, Trunk embracing knives and roller feed
108, The Garp Rake 08, Trunk embracing knife track and stepwise
feed 109, Trunk embracing knife track and roller feed 109, Fixed
cutters (or corresponding) and roller feed 110, Tools with screws
111, Most common delimbing tools 111
Conduct of delimbing 113
Some views on mechanized delimbing 114, Relationships between
feeding rate, feeding capacity and infeed power 115
Manual and motor-manual methods of delimbing 104
Motor-manual methods 121, The leverage technique 122, Some safety
rules at delimbing 124, Delimbing of standing trees 125
Mechanized delimbing 126
Delimbing of felled trees in horizontal position at the stump 126
Delimbing of trees in vertical position after separation at the
stump 127, Method of work 128, Process of delimbing 128, Output
of machine 131
Delimbing integrated with other harvesting operations 131
Mechanized delimbing, bucking and bunching at strip roads 131,
Work procedure of the machine 131, Delimbing tools 131, Mecha-
nized delimbing and bucking at landings 132, Delimbing depot 132,
Felling and transport to the delimbing depot 132, Output 133,
Principle of delimbing 133, Bunch delimber 133, Work procedure
of the bunch delimber 134, Output 135
Trends in delimbing 135
Some views on the weight of delimbing machines 135, Increased
mechanization of delimbing can be expected 135
BUCKING 142
Importance of bucking 142
Tools and means of bucking 142
Manual tools 142, Motor-manual tools 143, Mechanized bucking 143,
Advantage of machine power 144
Various methods of bucking 145
Stationary bucking equipment 145, Mobile bucking equipment 145,
Moving bucking equipment 146, Interrupted or continuous sequence
8
of bucking 147, Bucking of single or several trees 147
Manual and motor-manual bucking 148
Bucking at the stump 148, Bucking at various tension conditions
149, Bucking at strip roads 150, Bucking at landings 151
Mechanized bucking 151
Mechanized bucking at the stump 151, Mechanized bucking at strip
roads 152, Method of bucking by means of the grapple saw 152,
Method of bucking by means of a very rapid chain saw 153, Pro-
cessor A 154, Method of felling 154, Various partial operations
155, Terrain travel 155, Processor B 155, Work procedure 156,
Design of the machine 157, Processing of timber 157, Mechanized
bucking at truck roads or industrial landings 158, Bucking of
partial trunks 158, Bucking of trunks in the tree length method
159, Bucking of trunks in the tree method 159, Processor C 159,
Output and costs 160, Mechanized processing of tree length
trunks at industry or terminal 160, Main components of the estab-
lishment 161, Bucking-scaling 161, Mechanized processing at mo-
bile and semi-stationary establishments 162, Partial operations
in the analysis 164, Infeed 164, Delimbing 164, Scaling and buck-
ing 164, Sorting 165, Handling of timber in a processing estab-
lishment 165
Trends in bucking 166
Increased mechanized bucking 166, Automatic scaling and bucking
167, Application of electronics 167, photo-cells 167
DEBARKING 168
Purposes of debarking 168, Debarking in the forest 168, Debarking
at the industry 168, Choice of location for debarking 169, Some
physiological features of bark 169, Various layers of bark 169,
Cambium 169, Inner bark 169, Outer bark 170, Cohesion between bark
and wood 170
Tools and means of debarking 172
Manual debarking in the forest 172, Motor-manual debarking 173,
Mechanized debarking 173, Debarkers with knives 173, Debarkers
with cutters 173, Debarkers with rings or rotors 173, Working
principles of a debarking machine 175, Pressure of the debarking
tools 176, Procedure of debarking 176, Hydraulic debarking in the
forest 178, Chemical debarking in the forest 178
Debarking integrated with other harvesting operations 179
Factors influencing the result of debarking 179, Reasons for inte-
grated debarking 179, Types of debarkers 181, Stationary debarkers
181, Semi-mobile debarkers 181, Mobile debarkers 181, Most common
forms of organization at debarking by means of small units 182,
Debarker mounted on tractor 182, Debarker mounted on tractor-
trailer 182, Mobile debarker 182, Debarking of pulp-wood in troughs
183, Development trends in debarking 163, Relationship between the
cost of manual work and degree of mechanization 184, Cost of labour
climbs faster than machine costs 185, Investments required 185,
Trends in concentration 186
9
BUNCHING 187
Manual bunching 187, Bunching by means of horses or tractors 187,
Purpose of bunching 187, Work techniques and equipment 189,
Manual bunching 189, Bunching by means of winch 189, Bunching
by means of crane 189, Bunching by means of processing machines
189
Various fonms of bunching 190
Manual forms of bunching 190, Bunching of bucked timber 190,
Bunching of tree length trunks 190, Bunching in combination with
delimbing 190, Bunching in combination with bucking 191, Bunching
of trees 191, Bunching in combination with transport 191, Bunch-
ing in combination with processing of trees 191, Bunching in com-
bination with processing of bunches 191, Bunching integrated with
other harvesting operations 191, Trends in bunching 191, Descrip-
tion of a machine for bunching-delimbing of trunk sections- 1983
model, 192
CHIPPING 194
Needles, bark and cones 194, What is chips? 194, Chipping -
fuelwood 195, Types of chipping machines 195, Chipping with por-
table chippers 196, Chipping in the forest 197, Chipping of re-
sidues from thinning operations (tops and limbs for fuel) 200
Tractor mounted chipper 200, Chipping of energy forests and tree
harvesting residues requires efficient equipment 201
Coordination of the various partial operations 202
Coordination 202, Rational coordination 203, Objective of pro-
duction 203, Various modes of production 204, Systems of various
modes of production 205, Continuous systems with parallel coup-
ling 205, Costs of capital and operation 206, Utilization of
equipment 207, Production 207, Integration of partial operations
in harvesting machines 208.
TRANSPORTS OF TIMBER IN TERRAIN 211
Costs of transports 211, Some transport concepts 212, Transport
in terrain and transport on roads 212, Short transports and long
transports 213, Driving and terminal work 213, Forest roads and
timber terminals 213, Most common types of forest roads 213, Ter-
minal locations 214
Forwarding 214
Choice of transport method in terrain 215, The horse 215, Expand-
ing truck road systems in the forests 215, Tractors for tree har-
vesting 216, Current transport infrastructure 216
Objects of transport 216
Volume, weight and shape of timber 216, Quantity of transports
216, Volume of timber 217, Costs of tree harvesting 217, Size of
the clearcut areas 218, Dimensions of the transport objects 218,
Piling of the transport objects 218, Weight of timber 219
10
Routes of transport 219
Various routes of forwarding 219, Patterns of strip road systems
and road net density 220, Various patterns of road systems 220,
Optimum density of the road systems 222, Length of strip roads
222, Relationship between strip roads and the truck road 224,
Terminals 224, Various types of terminals 225, Terminals on ice
225, Preparation of ice 226, Various methods of ice preparation
226, Quality of ice 227, How is watering done? 227
Means of transport 227
Means of transport on land, water and in air 227, Transports on
land 228, Transports on water 228, Transports below the water
surface 228, Transports by aircraft 228
Live means of transport 229
Conditions for transport by horse in general 230, The performance
of a horse in haulage 230, Traction 230, Minimum possible loss of
power 230, Final harvest operations 232, Thinning operations 233,
Other tree harvesting operations 234, Harvest of fuelwood from
cleaning operations 235, Manual winches 238, motor powered win-
ches 239
Tractor as a means of transport in harvesting operations 239
Development of the tractor 239, The forest tractor 240, Require-
ments of the tractor 240, Ability to travel in terrain 241, The
tractor wheel 241, Improved knowledge of wheels and wheel combi-
nations is needed 241, Difference in resistance to rolling be-
tween twin wheels and single wheels 242, Standardization of
tractor wheels 243, The wheel is the cause of biological concern
243, Damages to the ground 243, How can rutting be counteracted?
244, Improvement of traction 245, Minimizing losses of motor
power 245, Forces acting around a wheel 245, What is to be gained
by larger wheel diameter and wider tires 246, obstacles 246,
Slopes in terrain 247, Carrying capacity 247, High hauling capa-
bility required 247, Practical hauling capability 248
Cranes and winches 248
Cranes 249, Knuckle boom cranes 249, Characteristics of the crane
249, Steering levers 251, Winches 252
Methods of transport in terrain 253
Skidders and forwarders 253, Methods of transport by means of
tractors 253, Transport of trees by means of tractor 255, Trans-
port of whole trees to strip roads within 100 m distance 255,
Transport of whole trees within a distance of 400 m 255, Skidders
equipped with winch 256, Skidders equipped with clam bunk 256,
Skidders equipped with grapple 258, Transport of tree length
trunks 258, Skidding by means of winch 259, Skidding by means of
clam bunk 259, Transport of assortments or timber bucked into
multiple length 260, Wheel forwarders 260, Track forwarders 260,
A 16-wheel forwarder for difficult terrain 261, High load capa-
city 262
