Weeding in the Forest: a Work Study Approach
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Forestry Commission ARCHIVE The front cover shows hand weeding with a reap hook, chemical weeding with a knapsack sprayer, and mechanical weeding with a tractor powered narrow gauge brushcutter. FORESTRY COMMISSION BULLETIN No. 48 Weeding in the Forest: A Work Study Approach By W. O. WITTERING, M.I.W.S.P., A.M.B.I.M., M.Inst.For. Work Study Branch Forestry Commission A Membership Thesis for the Institute of Work Study Practitioners London: Her Majesty’s Stationery Office 1 9 7 4 ABSTRACT la 1959, when the Forestry Commission’s annual expenditure on weeding in the forest exceeded £1 million for the first time, the Work Study Branch was instructed to study the problem in all its aspects. Work was initially concentrated on hand weeding and the tools associated with it. Later studies of chemical and mechanical methods have resulted in the Commission adopting techniques which have given very substantial savings in costs. At the end of eleven years of intensive effort, i.e. in 1970, the weeding account stood at £0 7 million. In real terms, allowing for the decreasing value of money resulting from inflation, a true saving of 44% overall (7-2% compound per annum) had been achieved. Costs of the various methods of weeding are given together with advice on how to select the most suitable method. Protection of the worker is dealt with in detail. New methods, such as ultra low volume spraying, which are being studied at present, are discussed. © Crown copyright 1974 ISBN 0 11 710140 0 FOREWORD A Disclaimer This Bulletin is aimed principally at the practical man, the man whose job it is to plan and supervise weeding in the forest. His attention is drawn to specific makes of equipment, and details of suppliers are given, with an indication of the cost. The mention of such products and services does not however constitute an official recommendation, endorsement or approval of any product or service to the exclusion of others which have not been mentioned and may be equally suitable. It is important to note that the Standard Time Tables and Output Guides in Appendix II were produced by the Forestry Commission especially for their conditions. The Commission can therefore accept no responsibility for any losses arising from their use (or misuse) in circumstances outside the Commission’s jurisdiction Enquiries About Products The prices in this book were checked with manufacturers and were correct as far as it is possible to be on 1 August 1972. They do not include Value Added Tax. The Forestry Commission can accept no responsibility for any errors which may arise or any consequential losses arising from such errors. Readers are strongly advised to check all details with manufacturers before placing an order. Enquiries about products mentioned should be addressed to the firm concerned and not to the Forestry Commission. Metrication The Forestry Commission adopted metric measures on 15 February 1971 but it is appreciated that many other organisations have not done so. The principle adopted in this publication is as far as possible to give both measures, the ruling measure coming first, i.e. where a pressure gauge is graded in pounds per square inch, this measure precedes the metric equivalent. Similarly where planting has been carried out at 21 m spacing between the rows, the metric measure comes before the imperial. Forestry Commission standard time tables and output guides are produced in metric measures only. These tables (which are reproduced in Appendix II) and the costing data based on them in Chapters 21 and 22, are therefore given in metric terms only. ACKNOWLEDGEMENTS The work on which this Bulletin is based was carried out by many people between 1960 and 1972. The Author gratefully acknowledges the part they played in producing the information on which this Bulletin is based. The photographs were taken as follows: Plate 1 by courtesy of Amateur Gardening-, Micron Sprayers Ltd, Plates Nos 58, 62 & 64; Cooper, Pegler & Co Ltd, Plate No 37; National Institute of Agricultural Engineering, Silsoe, Beds, Plate No 12; The Forestry Commission’s Photographic Section, Plates Nos 5, 20, 44 and colour plate No 3; Mr W. E. Powell, Plates Nos 2, 3, 41, & 42; Mr F. B. W. Platt, Plates Nos, 8, 10, 11, & 32; Mr G. Bland-Flagg, Plates Nos 38, 40, 77, 78, & 79; Mr E. V. Rogers, Colour Plates Nos 1 and 2 and Plates Nos 39, 51, 55, 59, & 60; M r D. H. Wallace, Plates Nos 14, 15, & 16; Mr J. Laurie Muir, Plate No 50; Mr D. J. Howard, Plates Nos 19, 22, & 25. All other photo graphs, including the colour pictures on the front cover and Colour Plates 4 & 5, were taken by the author. The diagrams were redrawn by Alan Crow Associates from sketches by Work Study staff. Mrs J. Anderson and Miss J. J. Sleigh typed the drafts. CONTENTS Page A b s t r a c t ii F o r e w o r d iii A cknowledgements iv PART A: BASIC CONSIDERATIONS PARTB: HAND WEEDING C h a p t e r 1 T o o l s 2 General .... 2 Tools Employed . 2 Hooks and Scythes . 2 Suppliers of Hooks and Scythes 3 C h a p t e r 2 T o o l M a in t e n a n c e 4 Cutting Edge ....... 4 Gauge ........ 4 Sharpening Stones ...... 4 Carrying Frog ....... 4 Supplier of Tool Maintenance Equipment 4 Replacement of Worn Hooks and Sharpening Stones 4 C h a p t e r 3 F a c t o r s A f f e c t in g t h e J o b . 5 Training ........ 5 Producing a Standard Timetable .... 5 Factors Affecting Working Time .... 5 Constant Factors ................................................................. 6 Introducing a Piecework Scheme .... 6 Weed Types not covered by Hand Weeding Table . 6 Winter Weeding and Cleaning .... 6 PARTC: WEEDING WITH MACHINES C h a p t e r 4 G e n e r a l 7 Introductory ...... 7 Scrub Clearance and Cleaning . 7 Types of Machines ..... 7 Types of Cutting Head .... 7 The Place of Machines in the Weeding Armoury 8 v Contents continued Page C h a p t e r 5 P o r t a b l e B rushcutters 9 Description .......... 9 Machine Tests .......... 9 Types of Driving Shaft ........ 9 Direction of Rotation of B la d e ................................................................. 9 Blade Types .......... 9 The Machine .......... 9 Blade G u ard s ........................................................................... 9 Cutting Climbers ................................................................................................. 12 Recommended Uses of Portable Brushcutters . .... 12 M ethods of W o r k in g ...................................................................................... 12 Protection of the Operator ........ 13 Care of the Machine ......... 13 Machine Maintenance ......... 13 Simple Crate for Carrying Brushcutter Fuel, Tools, Blades and Spares 14 Standard Time Table ......... 14 C h a p t e r 6 P e d e s t r ia n C o n t r o l l e d M a c h in e s 16 General ....... 16 Types of Machine Available. 16 Reciprocating Blade Machines (Autoscythes) . 16 Rotating Blade Machines .... 16 Flail Machines ...... 17 C h a p t e r 7 T r a c t o r P o w e r e d W e e d in g M a c h in e s 18 Types of M ach in e ................................................................. 18 Plantation Layout ....... 18 Tractors for Tractor Powered Weeding Machines 18 Modifications to the Tractors ..... 18 Tractor Tools ........ 19 Tractor Power Take O f f ...................................................... 19 General Points Relating to the Operation of Brushcutters 19 Brushcutter Maintenance ...... 20 R e a r M o u n t e d H orizontally R o t a t in g C h a in M a c h in e s 20 General 20 The Wolseley Swipe 20 Dimensions 20 Tools and Spares 20 R e a r M o u n t e d H orizontally R o t a t in g B l a d e M a c h in e s 20 G e n e r a l ...................................................... 20 Standard Gauge Machines . 20 The Bush Hog ..... 21 Modifications to the Bush Hog 21 The FES Standard Brushcutter 21 Output of Standard Gauge Machines 21 Narrow Gauge Machines . 21 Tractors for Narrow Gauge Machines 22 Brushculter Tools and Spares . 22 vi Contents continued Page R e a r M o u n t e d V e r t ic a l l y R o t a t in g F l a il M a c h in e s . 22 Description . 22 F r o n t M o u n t e d H orizontally R o t a t in g B l a d e M a c h in e s . 23 General .... 23 The Tractor . 23 The Brushcutter ... 23 Problems Found During Trials . 23 O utput .... 24 Conclusions ... 24 R o l l e r s 25 G e n e r a l ................................................................................................. 25 The Mark I Roller ........ 25 The Mark II Roller ........ 25 The M ark III R o l l e r ............................................................................ 26 O u t p u t ................................................................................................. 26 Organisation of the Job: Plantation Layout .... 26 Time of Rolling ......... 26 Tree Visibility ......... 26 Job Planning ......... 26 Filling the Roller with Water, etc... 26 Tools. .......... 26 Roller Maintenance ........ 26 Varying the Width of Roll ....... 26 Ground Compaction ........ 26 Mulching Effect ......... 26 Limitations of Grass Rollers ................................................................. 27 Tractor for Rolling in Narrow Gauge Plantations . 27 Conclusions ......... 27 PARTD: WEEDING WITH HERBICIDES C h a p t e r 8 I ntroduction t o H e r b ic id e P r a c t ic e .