Manual on Introduction to Forest Roads and Considerations for Reduced Impact Logging

Foreword

The renewable nature of forests can be conserved indefinitely provided stakeholders act responsibly their interventions in forest resources. One vital and critical aspect of forest management, whatever the objective of management, is the construction of roads and trails. The harvesting of timber in particular leads to a higher density of roads (km/ha) and in addition skid trails at the rate of about 1- 2.5km/100ha; roads are essential for conveying production inputs (machines, fuel, rations, logging rigs, personnel) to the areas targeted for harvesting, for the removal of logs from forest concessions to processing locations, and for concession monitoring purposes. Poor road design and road construction lead to higher truck maintenance costs and deterioration of logs in transit. Roads are therefore intrinsically linked to the viability of forest enterprises. Good roads also reflect environmental responsibility. This manual is for loggers. Its intention is to sensitise loggers to the key considerations guiding road location, road construction and road maintenance within the context of reduced impact logging. a) It does not in any way attempt to replace the excellent manuals on roads available in stores and on the internet. This manual does not attempt in any way to detract from standard engineering criteria for road location and construction. The objectives of the manual are to: provide loggers with enough information in a simple format to encourage the logger into taking road construction and maintenance more seriously; b) help the logger identify any specific problems and to seek expert technical assistance as required; c) help logger articulate their road construction and road maintenance plans within their forest management plans and their annual plans of operations. For the Guyanese forestry sector, it is anticipated that this manual will complement the prescriptions of the Code of Practice for Timber Harvesting. (In fact, much of the prescriptions on roads in the Code of Practice have been reproduced in this manual). 

Table of Contents

Foreword 2

Acknowledgement 6

Glossary 7

Module 1: Introduction to Forest Roads 11

Module 2: Soil Properties & Forest Roads 13

2.1 Soil particles 13

2.2 Organic matter 14

2.3 Soil Moisture 14

2.4 Important soil characteristics 14

Module 3: Location of Forest Roads 16

3.1 Introduction 16

3.2 Basic considerations 16

3.2.1 The P-Line 16

3.2.2 Grade 16

3.2.3 Slopes 17

3.2.4 Obstructions 17

3.2.5 Distance from Waterways 17

3.2.6 Waterway crossings 17

3.3 Methods of Locating Roads 18

3.3.1 Introduction 18

3.3.2 Preliminary location of the road (P-Line) by a two man crew 18

3.3.3 Use of grade and slope stakes 19

Module 4: Road Construction 20

4.1 Basic Considerations 20

4.2 Clearing and Grubbing 20

4.3 Earthworks 20

4.4 Road Surfacing 21

4.5 Horizontal curves 22

4.6 Vertical curves 22

4.7 Erosion control 22

4.8 Drainage structures 22

4.8.1 Introduction 22

4.8.2 Culverts 23

4.8.3 Bridges 23

4.9 Other considerations 24

4.9.1 Choice of road construction equipment 24

4.9.2 Water management 24

4.9.3 Compaction 25

Module 5: Recommended design and drainage standards for Guyana 28

Introduction to Forest Roads And Considerations for Reduced Impact Logging FTCI February 2010

5.1 Road classification 28

5.2 Road Planning 29

5.2.1 Road location 29

5.2.2 Surveying requirements 30

5.3 Road Construction 30

5.3.1 Timing of construction 30

5.3.2 Roadway Development 30

5.3.3 Side slopes 31

5.3.4 Road grades 32

5.3.5 Road width 32

5.3.6 Curves 35

5.4 Drainage 36

5.4.1 General Considerations 36

5.4.2 Methods of Drainage 36

5.4.3 Additional requirements 37

5.4.4 Spacing between drains 37

5.4.5 Drain outflow 38

5.5 Water Crossings 40

5.5.1 Types of crossings 40

5.5.2 Construction of Crossings 41

5.5.2.1 Location of crossings 41

5.6 Earthworks 42 5.7 Bridges 42

5.8 Culverts 44

5.9 Low level watercourse crossings (fords) 46

Module 6: Road Maintenance 47

6.1 Introduction 47 6.2 Road surface failure 47

6.3 Road surface deformation 47

6.4 Road way drainage maintenance 48

6.5 Drain and culvert maintenance 48

6.6 Waterway crossing structures 48

Module 7: Swamps 49 7.1 Definition 49

7.2 Swamps and forest roads 49

7.3 Methods of crossing swamps 50

Module 8: Road Safety Practices 51