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UBC Theses and Dissertations

Skyline thinning production study. Hemphill, Dallas Campbell 1970

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SKYLINE THINNING PRODUCTION STUDY b y DALLAS CAMPBELL HEMPHILL B . S c , U n i v e r s i t y of Au c k l a n d , 1967 A THESIS SUBMITTED IN PARTIAL FULFILMENT OF THE REQUIREMENTS FOR THE DEGREE OF MASTER OF SCIENCE i n the Department of FORESTRY We accept t h i s t h e s i s as conforming t o the r e q u i r e d s t a n d a r d THE UNIVERSITY OF BRITISH COLUMBIA August, 1970 3 In presenting th i s thes i s in pa r t i a l f u l f i lment o f the requirements fo r an advanced degree at the Un ivers i ty of B r i t i s h Columbia, I agree that the L ibrary sha l l make i t f r ee l y ava i l ab le for reference and study. I fu r ther agree that permission for extensive copying of th i s thes i s fo r scho lar ly purposes may be granted by the Head of my Department or by his representat ives. It is understood that copying or pub l i ca t i on of th i s thes i s f o r f i nanc ia l gain sha l l not be allowed without my wr i t ten permission. Department of F o r e s t r y  The Univers i ty of B r i t i s h Columbia Vancouver 8, Canada Date August 18, 1970 i i . ABSTRACT Supervisors: Professprs_L. ,Adamovich and .C-.UJ. Boyd Thinning i s r a p i d l y gaining importance i n the P a c i f i c Northwest as old-growth timber reserves approach exhaustion. In the past, t h i n n i n g s have, been e x t r a c t e d by wheeled or tracked machines, but the need f o r reducing s o i l disturbance, while operating i n any kind of t e r r a i n , has l e d to the de-velopment of a number of s k y l i n e systems. Two of these systems were s t u d i e d , a Washington Model 98 Skylok yarder r i g g e d with a running s k y l i n e , and a West Coast Tower using a standing s k y l i n e . Both systems are des-c r i b e d i n d e t a i l . A time study was done on seven s k y l i n e "roads" f o r the West Coast Tower, and on two "roads" f o r the Washington Model 98. The c o n s t r u c t i o n of a computer s i m u l a t i o n model of the yarding process i s d e s c r i b e d . The v a r i o u s elements of the logging process were modelled i n s e v e r a l ways, and the t h e s i s shows how the model could be used to make g u i d e l i n e s f o r planning l o g g i n g l a y o u t s , f o r s e n s i t i v i t y analyses, f o r cost and time p r e d i c t i o n , f o r methods improvement, to a s s i s t i n equipment s e l e c t i o n , to help a l l o c a t e machines, and to show the a p p l i c a b i l i t y of s k y l i n e t h i n n i n g to an area o u t s i d e of the P a c i f i c Northwest. E x t e r n a l yarding d i s t a n c e , over a wide range, was i i i . f o u n d t o be u n i m p o r t a n t i n d e t e r m i n i n g y a r d i n g c o s t s . S t o c k i n g was an i m p o r t a n t f a c t o r . I t was s h o w n t h a t t h e r e was an o p t i m u m r o a d w i d t h f o r a g i v e n l e n g t h a n d s h a p e o f s k y l i n e " r o a d " . P o t e n t i a l s a v i n g s w e r e shown i n l o a d i n g a n d y a r d i n g p r o c e d u r e s . The s t a n d i n g s k y l i n e was f o u n d t o h a v e no a d v a n -t a g e i n d e f l e c t i o n , a n d i t was more e x p e n s i v e t o s e t up t h a n t h e r u n n i n g s k y l i n e . I m p r o v e m e n t s i n t r e e m a r k i n g p r o c e d u r e a r e . s u g g e s t e d . L o a d i n g was f o u n d t o h a v e c o n s i -d e r a b l e p o t e n t i a l f o r c o s t r e d u c t i o n . S u g g e s t i o n s a r e made f o r f u t u r e r e s e a r c h , and t h e l a c k o f some v e r y b a s i c k n o w l e d g e i s n o t e d . T h e r e i s a b u n d a n t r o o m f o r , a n d a g r e a t n e e d o f , an e x t e n s i o n o f t h i s a n a l y s i s . IV. TABLE OF CONTENTS Page ABSTRACT i i TABLE OF CONTENTS... i v LIST OF FIGURES v i i ACKNOWLEDGEMENTS x i CHAPTER I INTRODUCTION 1 CHAPTER II DESCRIPTION OF THE OPERATIONS STUDIED 4 STAND DESCRIPTION, AND MARKING TREES FOR EXTRACTION 4 FALLING AND BUCKING 5 YARDING ......... 7 West Coast Tower. 7 The rnachine 7 The r i g g i n g system 10 The working method 14 Washington Model 98 Skylok Yarder 20 The Machine 20 The r i g g i n g system... * 21 The working method 23 LOADING 25 CHAPTER III COLLECTION OF DATA 3 0 CHAPTER IV MODELING THE OPERATIONS 36 REASONS FOR MAKING A SIMULATION MODEL H THE- FUNCTIONAL FORM OF THE COMPONENTS OF THE MODEL 41 V . TABLE OF CONTENTS ( c o n t ' d ) Page Y a r d i n g C y c l e . . . . . 41 Road C h a n g i n g . . . . . . 55 I d l e T ime. . 57 THE STRUCTURE OF THE MODEL 57 Methods Improvement. . . 61 LIMITATIONS OF THE MODEL 6 5 VERIFICATION OF THE.MODEL 67 CHAPTER V USING THE MODEL 70 COST CURVES ... 7 0 U5ING THE COST CURVES. 8 6 CHAPTER VI DISCUSSION OF NON-SIMULATED FACTORS 9 3 DEFLECTION CONSIDERATIONS 9 3 MARKING 9 7 LOADING 9 9 CHAPTER V I I SUGGESTIONS FOR FURTHER RESEARCH . 1 0 2 CHAPTER V I I I CONCLUSIONS 1 0 6 REFERENCES CITED 112 APPENDIX I 113 APPENDIX I I 116 APPENDIX I I I l l 7 APPENDIX IV . . .118 APPENDIX V I 2 0 APPENDIX V I . I 2 2 APPENDIX V I I 1 2 5 APPENDIX V I I I 1 2 7 APPENDIX IX . . . . 132 v i . TABLE OF CONTENTS ( C o n t ' d ) APPENDIX X 134 v i i . LIST OF FIGURES FIGURE PAGE 1. S e t t i n g t o be yarded, Road 1602 6 2. Thinned D o u g l a s - f i r s t a n d , near Headquarters camp 6 3. D e s i r a b l e f a l l i n g p a t t e r n 7 4. The West Coast Tower y a r d i n g t h i n n i n g s 9 5. The West Coast Tower, w i t h tower r e t r a c t e d , moving t o a new l a n d i n g 9 6. S k y l i n e system employed on the West Coast Tower 10 7. A t h r e e s p r i n g L a r s e n c a r r i a g e , s i m i l a r t o the two s p r i n g v e r s i o n d e s c r i b e d i n the t e x t 11 8. A t h r e e s p r i n g Larsen c a r r i a g e , showing the s l a c k - p u l l i n g drum top c e n t e r geared t o the s p r i n g s on the l e f t 11 9. O p e r a t i o n o f the La r s e n s l a c k - p u l l i n g c a r r i a g e 12 10. B u t t r i g g i n g used on both y a r d e r s 13 11. Crop t r e e being uprooted d u r i n g y a r d i n g 16 12. R i g g i n g a t a i l t r e e 16 13. Changing r o a d s , f o r t h e West Coast Tower 17 14. Washington Model 98 e x t r a c t i n g t h i n n i n g s 22 15. Shamley c a r r i a g e and r u n n i n g s k y l i n e 22 16. Changing r o a d s , f o r t h e Washington y a r d e r . . . . . 24; 17. F r a n k l i n s k i d d e r t a k i n g l o g s from the s k y l i n e deck t o the p r e - l o a d bunk 26 I B . Grapple s k i d d e r l o a d i n g the bunk 26 L i s t of Figures (cont'd) v i i i . FIGURE PAGE 19 Taking t r a i l e r o f f truck 28 20 T r a n s f e r r i n g a load to truck 28 21 Bunk ready f o r the next load 29 22 A yarding c y c l e i n a s k y l i n e t h i n n i n g operation ?7 23 P u l l i n g slack from the Shamley c a r r i a g e . . 38 24 S e t t i n g chokers 38 25 Breaking out a turn 39 26 Chaser unhooking a turn 39 27 The geometry of a s k y l i n e road ^0 28 Example of raw data: P u l l Slack times f o r Road 5 42 29 Example of raw data: Return times f o r Washington Model 98 •. .. . f*U-30 Real cumulative d i s t r i b u t i o n f u n c t i o n , and f i t t e d approximation f o r Untangle times 46 31 Simulation flowchart 58 32 Schematic r e p r e s e n t a t i o n of pre-choking method 63 33 Comparison of a c t u a l and simulated turn t times f o r a road 600 f e e t long, 160 f e e t wide at the back, converging on the l a n d i n g . . 68 34 Comparison of cumulative d i s t r i b u t i o n p l o t s of turn times, a c t u a l and simulated f o r a road 600 f e e t long and 160 f e e t wide at the back, converging on the l a n d i n g 69 35 Comparison of simulated productive and road change times f o r the West Coast Tower and the Washington 98 71 LIST OF FITURE5 (Cont'd) i x . FIGURE PAGE 36 Comparison of simulated logging costs f o r West Coast Tower, with and without t a i l t r e e r i g g e d . Roads converging at lan d i n g 72 37 Comparison of simulated logging costs f o r West '-oast Tower, f o r various road widths. Width at la n d i n g 40 f e e t 73 38 Comparison of simulated l o g g i n g costs f o r West Coast Tower, f o r roads of various widths. Roads 80 f e e t wide at l a n d i n g . . 74 39 Comparison of simulated logging costs f o r West Coast Tower, f o r various road widths. Width at landing 120 f e e t . . J 5 40 Comparison of simulated l o g g i n g costs f o r West Coast Tower, f o r various road widths, Width at landing 1 6 0 f e e t 76 41 Comparison of simulated l o g g i n g costs f o r West Coast Tower, with and without t a i l t r e e r i g g e d . P a r a l l e l roads 77 42 Comparison of simulated l o g g i n g costs f o r Washington Model 9 8 , f o r various road widths. 78 43 Comparison of simulated l o g g i n g costs f o r West Coast Tower with and without t a i l t r e e , and Washington Model 9 8 . P a r a l l e l roads •••• 8t-1 44 Comparison of simulated yarding costs f o r West Coast Tower and Washington Model 9 8 , assuming "optimal" l o a d i n g method 81 45 Comparison of simulated l o g g i n g costs f o r West Coast Tower, f o r present work method and pre-choking 82 46 Comparison of simulated yarding costs f o r Washington Model 98 and West Coast Tower, using present and "optimal" l o a d i n g methods.. 83 LIST QF FIGURES (Cont'd) x FIGURE PAGE 47 Comparison of simulated yarding costs f o r West Coast Tower, using present and "optimal" l o a d i n g methods 84 48 Comparison of combined road c o n s t r u c t i o n and yarding c o s t s , f o r West Coast Tower and Washington Model 98, yarding one and both ways ....'. 85 49 Comparison of simulated l o g g i n g costs f o r West Coast Tower and Washington Model 98 at Kaingarpa, New Zealand.... 87 50 Comparison of simulated l o g g i n g costs f o r West Coast Tower f o r 120 f e e t wide p a r a l l e l roads, removing 113 and 200 pieces per acre 51 D i s p e r s i o n of simulated times about the f i t t e d curves 92 52 S t a t i c f o r c e s and running s k y l i n e c a r r i a g e 98 53 Two haul road patterns f o r u p h i l l l o g g i n g . . . . 104 x i . ACKNOWLEDGEMENTS The author wishes t o express h i s thanks and appre-c i a t i o n t o the f o l l o w i n g : Dr. CW. Boyd, Mr. L. Adamovich, Mr. G.G. Young, and Dr. D.D. Munro of the F a c u l t y of F o r e s t r y at the U n i v e r s i t y of B r i t i s h Columbia, f o r t h e i r encouragement, c o n s t r u c t i v e c r i t i c i s m , and h e l p f u l s u g g e s t i o n s at a l l sta g e s of the s t u d y . Tom Boyd, John Z i n g g , Jim A x e l s o n , R.Q. B o h l i g and the DT6 and DT7 crew members of the Weyerhaeuser Company at Longview, Washington, f o r t h e i r c h e e r f u l a s s i s t a n c e i n g a t h e r i n g the d a t a . Lou Skudder, Tony H a r r i s , Bob B o y l e , and C B . Douglas of the New Zealand F o r e s t S e r v i c e , who s u p p l i e d me w i t h l o c a l d a t a . Jim S p i e r s , a l s o of the F o r e s t S e r v i c e , arranged f o r me to work w i t h Weyerhaeuser. E. Hogl and J . Raven, of the I n t e r s t a t e T r a c t o r Company and Washington I r o n Works r e s p e c t i v e l y , f o r s u p p l y -i n g me w i t h data on t h e i r p r o d u c t s . D.B. Malmberg, of Crown Z e l l e r b a c h , S e a s i d e , Oregon, f o r i n f o r m a t i o n on h i s company's o p e r a t i o n s . Dr. P.G. Haddock of the U n i v e r s i t y of B r i t i s h x i i . Columbia, for helpful advice on s i l v i c u l t u r a l aspects of the study. Mrs. Waldron, for typing the manuscript. F i n a l l y , I would l i k e to express special appre-ciation to my wife Nori, for her patience and understand-ing, and assistance in the l a t t e r stages of manuscript preparation. 1 CHAPTER I INTRODUCTION Commercial t h i n n i n g of the second-growth f o r e s t s of the P a c i f i c Northwest i s experiencing a r a p i d expansion, as old-growth reserves approach exhaustion and the market f o r small logs i n c r e a s e s . Improving the economics of ex-t r a c t i o n i s important not only f o r the immediate e f f e c t on l o g g i n g c o s t s , but f o r the greater f o r e s t resource that becomes f i n a n c i a l l y a t t r a c t i v e f o r t h i n n i n g , and f o r s i l v i -c u l t u r a l improvement. Thinning i n c r e a s e s the wood y i e l d over a r o t a t i o n , improves q u a l i t y i n the f i n a l crop, pro-vides an e a r l i e r f i n a n c i a l r e t u r n , and gives b e t t e r pro-t e c t i o n from f i r e , i n s e c t s , and disease (Malmberg, 1968; Worthington and S t a e b l e r , 1961). Rubber-tired skidders and crawler t r a c t o r s have replaced the horses used twenty years ago ( S p i e r s , 1956; Adamovich, 1962), but there has been a need f o r machines that could yard t h i n n i n g s with minimal s o i l disturbance and stand damage, on any kind of t e r r a i n . Adapting t r a d i -t i o n a l c l e a r c u t yarding methods has u s u a l l y been u n p r o f i -t a b l e . T h i s heavy, comparatively immobile machinery, when used f o r t h i n n i n g , was expensive to set up, and damaged r i g -ging, l o g s , and r e s i d u a l t r e e s . Lower volumes per piece and per acre, and the s u s c e p t i b i l i t y of standing t r e e s to damage, have r e s u l t e d i n the recent development of sky-l i n e systems i n Washington and Oregon (O'Leary, 1969; Adamovich, 1968, 1969; Bink l e y and Williamson, 1968). The l o g g i n g systems developed must be subjected to an economic and engineering a n a l y s i s f o r optimal use, to compensate f o r the present lack of experience. Equipment i s s t i l l e v o l v i n g and a c o n t i n u a l r e - e v a l u a t i o n of methods i s needed to take advantage of i n n o v a t i o n s . The w r i t e r was employed by the Weyerhaeuser Company i n the summer of 1969 i n s k y l i n e t h i n n i n g operations on St. Helens Tree,Farm, Longview, Washington. Old-growth timber on the Tree Farm w i l l bB cut out i n l e s s than f i f -teen years; there are vast areas of second growth on land logged f o r t y to s i x t y years ago, which are now economically e x p l o i t a b l e . D o u g l a s - f i r (Pseudotsuga m e n z i e s i i (Mirb.) Franco) makes up most of the stands c u r r e n t l y being thinned, with l e s s e r volumes of western hemlock (Tsuqa  h e t e r o p h y l l a (Refn.) Sarg.), western red cedar (Thuja  p l i c a t a Donn.) and a l d e r (Alnus rubra Bong.). The topography v a r i e s from gently r o l l i n g to 3. mountainous, but i s generally steep and broken. The region i s favored by a well-developed t r a n s p o r t a t i o n network, constructed to log the old-growth f o r e s t . A Weyerhaeuser Company r a i l r o a d connects western points of the f o r e s t to the m i l l complex at Longview, while truck roads r a d i a t e from the various r o a d - r a i l reloads, many of them along old r a i l r o a d grades. Two s k y l i n e t h i n n i n g systems were studied; the ob-j e c t of the a n a l y s i s was not to demonstrate that any ma-chine was better than another, but to i n d i c a t e the condi-t i o n s to which each was. adapted. Time study data was used to construct a computer simulation model, with seven uses of the model i n mind: 1. Constructing guidelines f o r planning logging layouts 2. Studying the s e n s i t i v i t y of each system to change i n v a r i a b l e s such as yarding distance, s k y l i n e road width, and stacking 3. Constructing a set of curves to p r e d i c t pro-duction times and costs f o r a given layout 4. Experimenting with changes i n working methods 5. A s s i s t i n g equipment s e l e c t i o n 6. Deciding how to a l l o c a t e various machines to d i f f e r e n t conditions 7. Studying the a p p l i c a b i l i t y of the systems to New Zealand c o n d i t i o n s . A glossary of logging terminology may be found i n Appendix I. 4 CHAPTER II DESCRIPTION OF THE OPERATIONS STUDIED Two t h i n n i n g operations were s t u d i e d i n the Road 12 area on St. Helens Tree Farm: f i r s t l y , on Road 1602, i n h i l l y t e r r a i n at 900 to 1200 f e e t e l e v a t i o n ; secondly, near the Headquarters camp on gentle slopes at 700 to 800 f e e t e l e v a t i o n . (See Appendices II and I I I ) . STAND DESCRIPTION, AND MARKING TREES FOR EXTRACTION T o t a l stand f i g u r e s were u n a v a i l a b l e f o r e i t h e r area. There were about 250 stems per acre, with a volume of 6000 to 7000 cubi c f e e t per acre. About 65 percent of t h i s volume was D o u g l a s - f i r , 20 percent hemlock, 5 percent cedar, and 10 percent a l d e r . The Road 1602 area had been logged and burned about 1910, with a few t r e e s dating from that year; most of the f i r and hemlock were about 56 years o l d . The Headquarters area had been logged and burned about 1920, most of the t r e e s dating from then. A marking t a l l y taken on Road 1602 showed 47 stems per acre marked f o r removal which were 45 D o u g l a s - f i r , and 2 hemlock. Alder and down volume was not i n c l u d e d i n the 5. c a l c u l a t i o n s . Alder patches, i n the v a l l e y bottoms, were c l e a r c u t ; "down" c o n s i s t e d mainly of very d e f e c t i v e - o l d -growth snags, which could not be c r u i s e d a c c u r a t e l y and which were u s u a l l y not e x t r a c t e d . About 15 stems of a l d e r were cut per acre. The marked t r e e s had an average d i a -meter breast height of 11.1 inches, with a range of 7 to 23 inches. According to the t a l l y , 1473 cubic f e e t (6543 board f e e t ) per acre were to be e x t r a c t e d ; 96 percent of the cubic footage was D o u g l a s - f i r , and 4 percent hemlock. Alder would have i n c r e a s e d t h i s volume to about 1820 cubic f e e t per acre. The marking t a l l y was misleading, s i n c e a f t e r the stand had been marked according to s i l v i c u l t u r a l p r i n c i p l e s , s k y l i n e "roads" 12 f e e t wide were cut, probably accounting f o r an extra 1000 c u b i c f e e t per acre. Further volume would have been e x t r a c t e d from^uproots*, 1 e s p e c i a l l y cedars, and from t r e e s cut a f t e r being e x c e s s i v e l y damaged during yard-i n g . In any case, the v a l i d i t y of the c r u i s e was question-able; i t accounted f o r none of the cedar which occurred. Probably the marking t a l l y gave a 50 percent underestimate of the t r e e s removed, and twice the number of stems per acre, that i s 94, was more r e a l i s t i c , iffor both areas. Trainee f o r e s t e r s marked the stands with white p a i n t , to a uniform d e n s i t y . They chose crop stems f o r form and Figure 1. S e t t i n g to be yarded, Road 1602. Large gaps were crea t e d by c l e a r c u t t i n g a l d e r patches. Figure 2. Thinned Douglas f i r stand, near Headquarters camp* 7. dominance, not being t i e d to a q u a n t i t a t i v e s i l v i c u l t u r a l p r e s c r i p t i o n . The engineering crew followed, marking s k y l i n e roads ten or twelve f e e t wide with ri b b o n , and chopping " X n i 8 i n the t a i l t r e e s they chose. Figure 1 shows part of the Road 1602 area, before the f a l l e n timber was yarded. Note the c l e a r c u t areas of a l d e r , F i g u r e 2 shows a thinned area of n e a r l y pure D o u g l a s - f i r , near the Headquarters camp. FALLING AND BUCKING Two f a l l e r s worked together, a month or two i n ad-vance of y a r d i n g . They t r i e d to f a l l the t r e e s i n a her-ringbone p a t t e r n , that i s , at 45 degrees to the s k y l i n e "roads", f o r easy e x t r a c t i o n . ( S e e F i g u r e 3). direction of yarding Figure 3* D e s i r a b l e f a l l i n g p a t t e r n . 8. A l l t r e e s w e r e l e f t i n t r e e l e n g t h s , e x c e p t f o r a f e w o l d - g r o w t h l o g s w h i c h w e r e b u c k e d i n t o s i z e s m a n a -g e a b l e by t h e s m a l l t h i n n i n g r i g g i n g . YARDING W e s t C o a s t T o w e r The m a c h i n e . The West C o a s t T o w e r i s a p o r t a b l e s y s -t e m f o r s k y l i n e y a r d i n g w i t h an e x t e n d a b l e s p a r , m o u n t e d on a G e n e r a l M o t o r s c r a w l e r t r a c t o r ( F i g u r e s 4 a n d 5 ) . The T e r e x t r a c t o r m o t o r , w h i c h a l s o p o w e r s t h e y a r d e r , i s a 239 h o r s e p o w e r D e t r o i t D i e s e l , c o u p l e d w i t h a t h r e e - s p e e d A l l i s o n t r a n s m i s s i o n . The t o w e r i s a s t e e l b o x s e c t i o n 32 f e e t l o n g , t e l e s c o p i n g t o a f u l l h e i g h t o f 49 f e e t . The,,, b a s e o f t h e t o w e r i s m o u n t e d on t h e r i g h t t r a c k f r a m e . No o u t r i g g e r s a r e r e q u i r e d ; t h e r e a r e t w o h y d r a u l i c a l l y p o w -e r e d g u y l i n e d r u m s , w i t h a t h i r d o p t i o n a l . I t i s a d a p t e d t o s k y l i n e t h i n n i n g i n s e c o n d g r o w t h t i m b e r , a n d i s a p p l i e d i n t h i n n i n g i n W a s h i n g t o n a n d O r e g o n , as w e l l a s on some c l e a r c u t s . Two w e r e i n u s e a t t h e R o a d 12 o p e r a t i o n s ; t h e y w e r e u s e d f o r t h i n n i n g most o f t h e y e a r . F r o m A p r i l t h r o u g h J u l y t h e y w e r e t r a n s f e r r e d t o c l e a r c u t s i n s m a l l t i m b e r s i n c e a t t h i s t i m e l o o s e b a r k on t h e t r e e s made t h e m s u s c e p t i b l e t o i n t o l e r a b l e s c a r r i n g ^ d u r i n g t h i n n i n g . F o r a d e t a i l e d m e c h a n i c a l d e s c r i p t i o n o f t h e West C o a s t T o w e r , s e e A p p e n d i x I V . Figure 4. The West Coast Tower ya r d i n g t h i n n i n g s i Figure 5. The West Coast Tower, with tower r e t r a c t e d , moving to a new l a n d i n g . 10. The r i g g i n g system. The West Coast Tower s t u d i e d operated a t i g h t s k y l i n e system, with a Larsen s p r i n g -powered s l a c k - p u l l i n g c a r r i a g e . F i g u r e 6 i l l u s t r a t e s the r i g g i n g system. cariage _ 5 l a c ^ E U l l i B a J i n e — nnainjine v\/ J-drum springs haul back Figure 6 . S k y l i n e system employed on the West Coast Tower . The Larsen c a r r i a g e i s a Weyerhaeuser-built pro-duct. Figures 7 and 8 show another, three s p r i n g , Larsen c a r r i a g e ; the c a r r i a g e i n the operation had only two springs, but worked on the same p r i n c i p l e . The two sheaves on top of the c a r r i a g e support i t on the s k y l i n e . The s l a c k - p u l l i n g l i n e , which p u l l s up to 150 f e e t of mainline through the c a r r i a g e , i s wound on a drum on the c a r r i a g e . This drum i s powered by two springs extending the length of the c a r r i a g e . 11. Figure 8. A three s p r i n g Larsen c a r r i a g e , showing the s l a c k - p u l l i n g drum top center geared to the s p r i n g s on the l e f t . 12. I t s mode of ope r a t i o n , i l l u s t r a t e d i n Figure 9, i s as f o l l o w s : Going ahead on the mainline p u l l s the s l a c k - p u l l i n g l i n e o f f the drum. As the drum r e v o l v e s , i t t e n s i o n s the s p r i n g s . Then, when the mainline i s "slacked" the springs cause the s l a c k - p u l l i n g l i n e to be r e e l e d i n , p u l l i n g the mainline i n . A f r i c t i o n sheave feeds the mainline through the c a r r i a g e and down to the ground. tight mainine 2 slack mainlie F i g u r e 9. Operation of the Larsen s l a c k - p u l l i n g c a r r i a g e . 13. The r i g g i n g c o n s i s t e d of 2000 f e e t of 1-ineh sky-l i n e , 1500 f e e t of 5/8-inch mainline, 2600 f e e t of 1/2-i n c h haulback, and 3000 f e e t of 5/16-inch s t r a w l i n e i n 10Q foot s e c t i o n s . The two o u t s i d e guys were 3/4-inch, the center one 7/8-inch. The butt r i g g i n g c o n s i s t e d of a b u l l hook shackled on the mainline eye and a s l i d i n g hook shackled over the l i n e so that i t could s l i d e along the l i n e but waspprev^en-ted from s l i d i n g o f f the end by the butt hook. (Figure 10). Each hook c a r r i e d one, two, or three chokers. " B u t t e r f l i e s " which could be turned to open or c l o s e the t h r o a t s of the hooks kept the chokers from f l y i n g o f f . The chokers were 1/2-inch. Figure 10. Butt r i g g i n g used on both yarders. 14 The working method  S e t t i n g up; The engineering crew should have c l e a r l y marked the c o r r e c t p o s i t i o n of the yarder, e s p e c i a l l y at the conver-gence of r a d i a t i n g s k y l i n e roads. Otherwise, the yarder may be s i t e d o f f the center l i n e of the s k y l i n e road, r e -s u l t i n g i n excessive "hangups" on crop t r e e s (Figure 11). On the yarder a s i n g l e - s t a g e h y d r a u l i c c y l i n d e r , set i n s i d e the boom base, extends the tower; the two s t i f f l e g braces extend with the tower, and are locked i n place with two p i n s . Each guy l i n e runs through two 10-inch blocks and fastens to a shackle on the tower head. Guys with poured f e r r u l e s hook onto the blocks, and are tig h t e n e d by the winch drums. In some i n s t a n c e s , f i n d i n g s u f f i c i e n t anchor-age f o r the guys among small second-growth stumps i s pro-b l e m a t i c a l . The yarder can be kept more or l e s s l e v e l with b i t s of wood under the t r a c k s , but both t r a c k s must bear the weight of the machine. The study on the West Coast Tower came to an end when the tower buckled at the base. This could be t r a c e d to improper " s e t t i n g up"; the guy-l i n e s had been taken up so f a r as to l i f t the ri g h t ( t o w e r ) 15. s i d e o f f the ground. The bending moment of t h i s system was greatest near the base of the tower. Tension i n the s k y l i n e , while " f i g h t i n g a hangup" tended to p u l l the tower forward. When the mainline was slacked, the guys jerked the tower back, bending i t at the base. Changing "roads"; The most e f f i c i e n t procedure f o r changing roads was as f o l l o w s : (See Fig u r e 13): The hooker p u l l e d the s t r a w l i n e down the road about to be logged, and r i g g e d a t a i l t r e e i f necessary, with the help of the cho k e r s e t t e r ( f o r job d e s c r i p t i o n s of these men, see page 19 ). The un i t hooker continued s e t -t i n g chokers. Figure 12 shows a t a i l t r e e being r i g g e d . A f t e r the l a s t t urn on the o l d road, the haulback was disconnected from the c a r r i a g e and p u l l e d the straw-l i n e out, and the s k y l i n e s l a c k e d . A b i t s t r a p i n the haulback eye was used to p u l l s l a c k s k y l i n e so that i t could be unhooked from i t s anchor. Then the haulback p u l l e d the s t r a w l i n e through the t a i l b l o e k , and a few f e e t past the corner block. The two l i n e s were separated, andi back-l i n e a c t i v i t i e s became independent of those on the l a n d i n g . The c h o k e r s e t t e r and un i t hooker next took the ol d corner block t o i t s new p o s i t i o n as the new t a i l b l o e k . The s t r a w l i n e was a l s o p u l l e d over to the new t a i l b l o e k Figure 11. Crop t r e e being uprooted during yarding 17. Figure 13. Changing roads f o r the West Coast Tower. 18. and connected to the s t r a w l i n e that had been p u l l e d out on the new road. At t h i s stage, s t r a w l i n e went i n a loop from the l a n d i n g along the new road, through the s k y l i n e block i n the case of a t r e e r i g , across to the o l d road, and back to the l a n d i n g . The s k y l i n e anchor s t r a p was moved to a s u i t a b l e anchor. On the l a n d i n g , the yarder might have to be moved up to 160 f e e t . Guys had to be loosened and p o s s i b l y moved to new stumps. Us u a l l y the yarder was not i n p o s i t i o n to l o g the new road before the u n i t hooker s i g n a l l e d "go ahead straw". When the yarder was p o s i t i o n e d , the straw s e c t i o n s were hooked up, and the haulback p u l l e d around the o l d road and the new. It then p u l l e d out the s k y l i n e , along with the s t r a w l i n e . Before reaching the t a i l t r e e , the r i g g i n g was stopped and the straw taken o f f . The haulback p u l l e d the s k y l i n e through the s k y l i n e block and i t was anchored. In the meantime the chokersettex p u l l e d the s t r a w l i n e back to the s k y l i n e anchor so i t could be hooked to the h a u l -back. The l a t t e r was p u l l e d to the landing and hooked to the c a r r i a g e . (The c a r r i a g e had remained hanging from the tower). A f t e r the "wraps" i n the l i n e s were taken out ( i n v a r i a b l y the haulback crossed the s k y l i n e and burned 19. i t ) l o g g i n g could proceed. I d e a l l y road changing took 40 minutes but could take an hour and a h a l f . Where d e f l e c t i o n did not d i c -t a t e the use of a t a i l t r e e , about 14 minutes were saved: about seven minutes when anchoring the s k y l i n e and p u l l i n g straw out to the haulback, and seven more i n longer choking times f o r one man while the c h o k e r s e t t e r helped the hooker r i g the t a i l t r e e * . Yarding c y c l e : A f i v e man crew was employed f o r y a r d i n g : a hooker, who supervised and set up r i g g i n g , and sometimes helped set chokers; a chaser; who unhooked logs at the l a n d i n g and kept the r i g g i n g i n order; a u n i t hooker, who super-v i s e d c h o k e r s e t t i n g and set chokers; a c h o k e r s e t t e r ; a yarder operator. A f t e r a turn had been unhooked on the l a n d i n g , the mainline was taken up, t e n s i o n i n g the s l a c k - p u l l e r . Ten-s i o n on the haulback r e l e a s e d the c a r r i a g e brake. When the c a r r i a g e reached the next t u r n , " s l a c k i n g " the haulback a p p l i e d the c a r r i a g e brake. The mainline was " s l a c k e d " u n t i l the chokers hung j u s t above the ground, so they could be untangled from each other. E i t h e r two chokers per hook w e r e " f l o w n o r three on one and one on the other. On n e a r l y l e v e l s e t t i n g s , the s l a c k - p u l l e r was not strong 20. enough to p u l l slack past about 900 f e e t . The i n a b i l i t y of the Larsen c a r r i a g e to l o g down steep h i l l s i s a big disadvantage. Adding an extra s p r i n g was not the answer; t h i s was done on the c a r r i a g e i n Fig u r e 7, but i t l e t the r i g g i n g down too v i o l e n t l y , with a r e s u l t i n g t a n g l e . One man p u l l e d out the butt hook, the other man the s l i d i n g hook, and the chokers were set on logs which had been s e l e c t e d by the u n i t hooker. Both men c a r r i e d T a l k i e Tooter r a d i o w h i s t l e s . When the turn was choked and the men were clear, they . s i g n a l l e d " T i g h t l i n e " ; the haulback remained s l a c k , brak-ing the c a r r i a g e ; the turn was yarded out of the t r e e s onto the s k y l i n e road. Hangups on standing t r e e s f r e q u e n t l y occurred at t h i s stage. Once the turn was on the road, t e n s i o n i n the haulback r e l e a s e d the brake, and the c a r r i a g e and l o g s suspended beneath i t t r a v e l l e d up to the l a n d i n g . Washington Model 98 5kylok Yarder  The machine; The Model 98 i s a mobile, three-drum, 180 horse-power yarder which provides s t e p l e s s c o n t r o l of haulback t e n s i o n and speed. I t has two mainlines f o r running sky-l i n e or grapple y a r d i n g , a 40 foot boom.with independent swing, and a crawler undercarriage (Figure 14). 21 Haulback ten s i o n regenerates power i n t o the main drums by i n f i n i t e l y v a r i a b l e i n t e r l o c k i n g . The yarder has h y d r a u l i c a l l y operated g u y l i n e s ; there are no o u t r i g g e r s . The 98 i s used f o r t h i n n i n g and c l e a r c u t s i n small timber. It i s operated e i t h e r with chokers or a grapple ( i n c l e a r c u t s ) , on a running s k y l i n e . One was acquired f o r the Road 12 operations i n J u l y , 1969* For a mechanical d e s c r i p t i o n of the yarder and i n t e r l o c k i n g system, see Appendices V and VI. The r i g g i n g system: The Washington 98 s t u d i e d operated a running s k y l i n e system, i n which the haulback ran through the Shamley c a r -r i a g e sheaves to f u n c t i o n as a s k y l i n e (Figure 15). The Shamley c a r r i a g e was designed by the Weyerhaeuser d i s t r i c t superintendent at Cosmopolis. The two i n - h a u l drums on the yarder, synchronized, act i n opposing d i r e c t i o n s to pay out s l a c k on the mainline to which the butt r i g g i n g i s attached, to yard the turn of l o g s from the s i d e to the c a r r i a g e . The , main and s l a c k - p u l l i n g l i n e s work together to p u l l the c a r -r i a g e and turn to the l a n d i n g . The c a r r i a g e i s e a s i l y con-verted to grapple yarding, and can operate e q u a l l y w e l l up-h i l l and d o w n h i l l . The r i g g i n g c o n s i s t e d of 1000 f e e t each of 5/8-inch main and s l a c k - p u l l i n g l i n e , 2100 f e e t of 3/4-inch haulback, 22 Figure 14. Washington Model 98 e x t r a c t i n g t h i n n i n g s . s l a c k p u l l i n q line mainline h a u l b a c k t a i l b l o c k Figure 15. 5hamley c a r r i a g e and running s k y l i n e . 23. and about 2500 fe e t of 5/16-inch s t r a w l i n e i n 100-foot s e c t i o n s . 7/8-inch guys were used. The butt r i g g i n g was the same as on the West Coast Tower. The working method;  5 e t t i n g up; The yarder s t u d i e d had a tank undercarriage which lac k e d maneuverability Ci . > the f o u r - a x l e v e r s i o n should be more maneuverable, but o u t r i g g e r s must be s e t . S e t t i n g up the Model 98 i s s i m i l a r to, but e a s i e r than, s e t t i n g up the West Coast Tower: there i s no tower to t e l e s c o p e , the machine does not have to be a l i g n e d p e r p e n d i c u l a r to the s k y l i n e road, and there i s l e s s need to block up the t r a c k s . I f the i n - h a u l l i n e s need to be synchronized (e.g. when put-t i n g on new l i n e s ) t h i s may take some time. The boom al s o buckled on t h i s machine, when the topping l i f t was a c c i d e n -t a l l y set i n motion. Changing roads: It took about 15 to 30 minutes to change roads by the f o l l o w i n g procedure: The hooker p u l l e d s t r a w l i n e down the new road and back again, and rigged a t a i l t r e e with the help of the c h o k e r s e t t e r , while l o g g i n g continued on the o l d road. When the o l d road was f i n i s h e d , the haulback was unhooked from the c a r r i a g e , and taken through the blocks and back to the l a n d i n g . Then the yarder moved to the 24 l i n e s brought In to landing from road 1 i i Figure 16. Changing roads, f o r the Washington yarder. 25. next road (guys being unhooked and slacked as necessary); the haulback was p u l l e d through the new t a i l b l o e k and to the landing by the s t r a w l i n e , connected to the c a r r i a g e , and l o g g i n g could s t a r t again. Delays mainly occurred at the l a n d i n g — w a i t i n g f o r logs to be removed so the yarder could maneuver, f o r i n s t a n c e . The procedure i s i l l u s t r a t e d i n Figu r e 16. Yarding c y c l e ; The same working method was followed as described above f o r the West Coast Tower, without the p e c u l i a r i t i e s of the Larsen c a r r i a g e of course. LOADING The l o a d i n g system c o n s i s t e d of a F r a n k l i n 170 P5 skidder with a 42-inch Esco grapple, swinging logs to a Nelson Batson highway model pre-load bunk. The grapple skidder grabbed logs about three at a time from the s k y l i n e deck, and skidded them 100 to 300 f e e t , and sometimes much f u r t h e r , to the bunk. This d i s t a n c e was to allow room f o r segregated p i l e s of hardwoods and softwoods, which then had to be skidded forward to be loaded onto the bunk. Figures 17 and I B show the process. When a load was i n the bunks and a truck ready, the bunk was jacked up h y d r a u l i c a l l y , the truck backed F i g u r e 18 Grapple s k i d d e r l o a d i n g the bunk 27. under, and the bunk lowered. Figures 19, 20 and 21 show the l o a d i n g p r o c e s s — t h e skidder takes the t r a i l e r o f f the t r u c k , the truck backs under the l o a d , and l a s t l y the bunk i s empty. The pre-load bunk c o n s i s t e d e s s e n t i a l l y of a frame-work with four stakes, which could be r a i s e d h y d r a u l i c a l l y . It had r e t r a c t a b l e rubber wheels f o r m o b i l i t y ; the pump was powered by a g a s o l i n e motor. The highway model weighed 18,000 pounds and could l i f t 60,000 pounds. In the systems s t u d i e d , l o a d i n g and yarding produc-t i o n r a t e s were roughly equal. Sometimes the skidder had to wait on the yarder, i n which case i t was used to s k i d l o g s adjacent to the road. West Coast Tower landings often became plugged while the skidder was p u t t i n g a l o a d on the bunk. The operation of the Washington yarder was almost independent of the skidder, except that sometimes yarding was delayed f o r s a f e t y while the skidder f i n i s h e d grabbing a turn from the l a n d i n g . On West Coast Tower landings atop steep r i d g e s , f r e q u e n t l y logs could not be unhooked unless the skidder held them from s l i d i n g d o w n h i l l . 28. Figure 19. Taking t r a i l e r o f f t r u c k . Figure 20. T r a n s f e r r i n g a l o a d to t r u c k . 2 9 . Figure 21. Bunk ready f o r the next load 30. CHAPTER III COLLECTION OF DATA The data was c o l l e c t e d by one man, who had the advantage of having set chokers and chased f o r a couple of months p r i o r to the time study. This work experience was v a l u a b l e , both to gain f a m i l i a r i t y with the system and i t s p e c u l i a r i t i e s , and to e s t a b l i s h good r e l a t i o n s with the crews being s t u d i e d . Data on road change times was gathered at t h i s stage, to provide a l a r g e r sample. Both systems were s t u d i e d by continuous timing over a peri o d t o t a l l i n g 10 days. 233 turns were timed f o r the West Coast Tower and 75 f o r the Washington Model 98. The West Coast Tower was s t u d i e d on Roads 1602 and 1603, yarding on easy country on the f i v e roads on Road 1602, and across an eighty foot canyon on two roads on Road 1603. The Washington 98 Skylok yarder was s t u d i e d on 2 roads near the Headquarters v i l l a g e , where i t operated on gentle u p h i l l s l o p e s . The 13 elements as defined below, were timed to the nearest second, using one stopwatch. Rating was not employed, as the,crews worked at a normal r a t e throughout the study. Rating i s s u b j e c t i v e i n any case and was not 31. j u s t i f i e d i n t h i s study. The yarding c y c l e was broken i n t o the f o l l o w i n g elements: Element Instant b e q i n - f i n i s h Element Des-c r i p t i o n 1. Return 2. Drop r i g g i n g 3. Untangle chokers Carriage enters stand Stop w h i s t l e Stop slack w h i s t l e Carriage returns f o r next t u r n . Mainline dropped t i l l chokers j u s t above ground. Untangle chokers from each other. Each man takes two. Slack w h i s t l e 4. P u l l slack 5. Set chokers 6. Get c l e a r 7. Breakout Stop slack w h i s t l e Last log choked Tight l i n e w h i s t l e (two toots) Mainline p u l l e d l a t e r a l l y out to t u r n . Delay as men get c l e a r of t u r n . Yarding from with -i n stand onto sky-l i n e road. Go ahead w h i s t l e (three toots) 32. Element Instant b e g i n / f i n i s h .Element des-c r i p t i o n 8. Yard Yarding along s k y l i n e road. Carri a g e reaches edge of stand 9a. Chase A Turn decked and chokers unhooked. Chaser leaves deck 10. Wait f o r Skidder Skidder departs 9b. Chase B U s u a l l y does not o c c u r — d e l a y while waiting f o r skidder to c l e a r l a n d i n g , e t c . Chokers unhooked. Chaser leaves deck 11. Raise Rigging Carri a g e enters edge of stand 12. Road Change During Yarding Minor adjustments to b u t t r i g g i n g , p u t t i n g on extra choker e t c . ; r a i s e butt r i g g i n g to c a r r i a g e . Time spent at any part of yarding c y c l e on road changes, e.g. sending b a c k r i g g i n g to the l a n d i n g . 13. Rig Major r i g g i n g r e p a i r s . 33. For each t u r n , the h o r i z o n t a l yarding distance (gauged from ribbons set 100 feet a p a r t ) , number of chokers set, number of l o g s , and i n c i d e n t a l remarks, were recorded. The loading component was n o n - c y c l i c a l and did not lend i t s e l f to continuous time study, unless f o r a week or so. L a t e r a l distance ( i . e . the h a l f width of a s k y l i n e road) was obtained from operational maps. 'Road' Change Elements; Instant b e g i n / f i n i s h West Coast Tower; Element Last turn unhooked 1. Move blocks at backline S i g n a l straw 2. F i n i s h moving yarder Lines s t a r t moving 3. Backline r i g g i n g — ( s h a c k -l i n g s k y l i n e to anchor) A l l l i n e s hooked up 4. Rigging D e l a y — ( t a k i n g out wraps i n l i n e etc.) S t a r t logging 5. Wait f o r s k i d d e r — u s u a l l y does not occur: waiting to get logs o f f landing so yarder can manoeuvre. Washington 98; 1. Bring l i n e s i n Move yarder Hook l i n e s u p — ( c o n n e c t haulback to straw, p u l l guy o u t ) ! Take l i n e s o u t — ( H a u l b a c k taken down road and back, hooked to c a r r i a g e ) 5. Rigging Delay 6. Wait f o r skidder 34. Last turn unhooked Haulback eye reaches la n d i n g and a l l guys unhooked Yarder ready at next landing Haulback s t a r t s to move Haulback hooked to c a r r i a g e . Ready to l o g Turn volumes were not s c a l e d , and t h i s must be seen as a major l i m i t a t i o n of the a n a l y s i s . D i r e c t s c a l i n g on the l a n d i n g was impossible; an attempt was made to photo-graph turns, using known dimensions of the s k y l i n e c a r r i a g e to s c a l e the l o g s . It was found t h a t , i n t h i s method, part of each turn was obstructed, so volume determination was very i n a c c u r a t e . The sample of turns photographed, which 35. could be s c a l e d , proved to be s m a l l , and the only c o n c l u -sion that could be reached was t h a t , w i t h i n the range of turn volumes measured i n t h i s way (30-150 cubic f e e t ) volumes did not have a marked e f f e c t on c y c l e time. There-f o r e , the s i m u l a t i o n was b u i l t f o r turn volumes "the same s i z e as being yarded i n the study". The photographic study was used to estimate breakage, the percentage break-age being assumed equal to the percentage of tops and chunks. 36. CHAPTER IV MODELING THE 0PERATI0N5 Figure 22 i l l u s t r a t e s a yarding c y c l e . Times t ^ through t ^ ^ cover the f o l l o w i n g a c t i v i t i e s : The c a r r i a g e returns to the woods ( t ^ ) , the r i g g i n g i s dropped ^ 2 ) , and the chokers are untangled ( t ^ ) . Then the men p u l l slack mainline out to the turn ( t ^ ) (Figure 23), set some or a l l of the chokers ( t ^ ) (Figure 24), and get c l e a r of danger ( t g ) . The turn i s "broken out" onto the center of the road (ty) (Figure 25) and yarded to the 1 l a n d i n g ( t g ) . The turn i s "chased", that i s , unhooked (t^) Figure 26), the r i g g i n g i s r a i s e d i n t o the a i r ("tj^ )» a|">d the c y c l e s t a r t s again. These a c t i v i t i e s are subject to i n t e r r u p t i o n s — t h e chaser may have to wait f o r the skidder to grab some logs from the landing ("t^g), o r there may be some major r i g g i n g r e p a i r s such as s p l i c i n g a l i n e ( t j ^ ) * B a ckrigging may have to be brought up to the landing and other road changing a c t i v i t i e s c a r r i e d out during the yard-ing of a road (^^3^* Figure 27 shows the geometry of a p a r t i c u l a r s k y l i n e road. Given the width at the la n d i n g and at the b a c k l i n e , and the len g t h of the road or the e x t e r n a l yarding d i s t a n c e , Figure 22 A yarding c y c l e i n a s k y l i n e t h i n n i n g o p e r a t i o n . 38 Figure 24. S e t t i n g chokers. 39 F i g u r e 26. Chaser unhooking a t u r n . 40. f «» width at l a n d i n g b = width at b a c k l i n e th = yarding d i s t a n c e f o r k turn w^  = width of the road at d i s t a n c e y^ th y^ + ^ y ^ =» yarding d i s t a n c e f o r (k + l ) turn w^  + .^w^  = width at d i s t a n c e (y^ + ^y^) 1 « e x t e r n a l yarding d i s t a n c e , i . e . , l e n g t h of road Figure 27. The geometry of a s k y l i n e road. i t i s p o s s i b l e to f i n d the width at any p o i n t . REASONS FOR MAKING A SIMULATION MODEL T y p i c a l data as shown i n Figure 28 i s too widely d i s -persed to be s u i t e d to a d e t e r m i n i s t i c model. Simulation provides a convenient means of changing v a r i a b l e s one or a few at a time, to see how they a f f e c t the t o t a l system. Some elements occur only at random i n t e r v a l s , i n d i c a t i n g the use of a p r o b a b i l i s t i c model. While i t may be p o s s i b l e to obtain an expression f o r each element as a f u n c t i o n of various stand, machine, and geometric parameters, the v a r i a t i o n of geometry-dependent elements wit h i n a road can-not be adequately solved d e t e r m i n i s t i c a l l y . Various con-s t r a i n t s and ideas can be b u i l t i n , that would be d i f f i c u l t to i n c o r p o r a t e i n t o a d e t e r m i n i s t i c model. The main disadvantage of si m u l a t i o n i s the time and expense of w r i t i n g and running computer programs. Also, cause-and-effect r e l a t i o n s h i p s cannot be abs t r a c t e d i n t o a simple formula; r a t h e r ; e f f e c t s are to be seen as a d i f f e r -ing output which h o p e f u l l y can be r e l a t e d to d i f f e r e n c e s i n the i n p u t . THE FUNCTIONAL FORM OF THE COMPONENTS OF THE MODEL Yarding Cycle The r e l a t i o n s h i p s d e s c r i b i n g the elements are shown •1*2. --v ~\ \ i r V <j -1 s J \ V J ( t I \ f, t V V J -\ 1 t *i c / \ J } \ f /• V \ -; V / V •1 r t / \ L V A / I i \ 9 t —( \ > * < • r-i i \ d t ) 1. J p r , ^  i p\ ) \ J f 1, j KJ V c (D i 1 /• ~r ™r i • P t \ t \ V t s r I vo ami f \ V J \ J \ —• r *"1 r-< t \ J t c ) ^ \ \ V i — / \ 1 I A r J f fl-( J J V •\ V •<-A i 4 J (i W i r 0 Q V \ J t t SI H -—i h -* * V ) , O / < \ c U Q) V, ? ( i u UJ _ i e f-i < D p» V fl1 i \ L> < >-\ J 1 / \ < -t i 1 V J / 1 i J c > J t-, ( i •J 4 4 / •\ J ; \ r T vU i_\ V J t—1 1-^  I W r/i V o\ p Ti f hr—t c i 0 iTl I K y c p • ( J I. c J c 1 1 \ /I I n i T II i r, T 1 V •—i i n r i ; 1 43. below; the time i n minutes f o r each element, t.,, i s e i t h e r i • a constant or a f u n c t i o n of one or both of: 1. y^* the yarding d i s t a n c e i n fe e t 2. n. ., the random number used to simulate 1 , K the i ^ n element f o r the k*~ t u r n . Where a primed time, t ^ , i s used, separate r e l a -t i o n s h i p s were found f o r the two yard e r s . The prime r e -f e r s to the Washington yarder. A l l elements were assumed to be s t a t i s t i c a l l y independent, except f o r P u l l Slack (t ^ ) and Breakout ( t y ) . For each r e l a t i o n s h i p , the root mean square, RMS, of the curve. or mean f i t t e d to the data, and the number of observations, l\l, on which the r e l a t i o n s h i p i s based are given. The root mean square i s not given where 5 or fewer observations were made. Return, t ^ . The data i n d i c a t e d that Return time could be handled as a l i n e a r r e g r e s s i o n f u n c t i o n of d i s -tance (Figure 29). Deviations from the l i n e a r f i t were greatest at the l a s t f i f t y f e e t of a road, where the oper-ator reduced speed to stop the c a r r i a g e from h i t t i n g the t a i l t r e e . The equations are: West Coast Tower: t, = 0.06 + 0.00065.y. ; (RMS - 0.09, N = 192). Washington 98: t j - 0.08 + 0.0015.y k ; (RMS = 0.10, N= 68). Drop Rigging. t~.« This was a small element and comparatively constant, so the mean, - 0.09, (RMS = 0.03, N - 225) was used f o r both yarders. Untangle Chokers, t j . These times were widely d i s p e r s e d . A polynomial approximation to the i n v e r s e of each cumulative d i s t r i b u t i o n f u n c t i o n over the e n t i r e range of times tended to give a poor f i t below the p r o b a b i l i t y l e v e l of about 80 percent. Therefore, the i n v e r s e s of the cumulative d i s t r i b u t i o n f u n c t i o n s were approximated by l e a s t squares polynomials over most of t h e i r ranges, with l i n e a r i n t e r p o l a t i o n s over the longer times (Figure 30). Separate r e l a t i o n s h i p s were found f o r 3 or 4 chokers flown: Three chokers flown: t 3 = 0.03+0.75.n3 k+3.70.(n 3 k ) 2 - 1 2 . 1 6 . ( n 3 k ) 3 +13.62.(n 3 k ) 4 - 4 . 9 1 . ( n 3 k ) 5 ; (RMS = 0.03, i\l = 22). Four chokers flown: |~-0.07+5.06.n3 k-25.62.(n 3 k ) 2+76 .61. ( n 3 k ) 3  3 '-117.56.(n 3 j k) 4+87.19.(n 3 k ) 5 - 2 3 . 9 4 . ( n 3 ^ k ) 6 , f o r n 3 k $ 0 . 9 6 ; (RMS - 0.02; N - 181). s29.00.n 3 k-26.40, f o r n 3 k>0.96; (RMS=0.10, N=7). Values obtained f o r t 3 that were l e s s than zero, were set equal to zero. 1. -z -d -r c i 1) • -1 • i {' \ n i. r -\ Hi L r p * z p * J S I- u • ro 4 - u \ • * I H A -1 • V - i c 1 M • 0 l< I H P r H U P . 1 a 'Ji u \ V H •> J b r IS -» > H P OS H c 5 -» > • t J r c a 1 y - •< i OC + s <L i a ) r I t U > Li • y V s C 4-<D >H ! P * h. ] 1 C » k i . E< • \ i L 1 JL. J J t b ' » C ) ZJ •A T T -t a 47., P u l l Slack, t ^ . The a c t u a l length of mainline p u l l e d to the s i d e f o r k**1 turn could not be measured, but the road width w^  could be. P u l l Slack times were widely d i s -persed, f o r any given road width. They ranged from zero f o r turns taken beneath the c a r r i a g e , to long times f o r p u l l i n g s l a c k f a r out. The f o l l o w i n g i n v e r s e s of the cumulative d i s -t r i b u t i o n f u n c t i o n s were found, f o r 0 to 40 f e e t , 40 to 80 f e e t , 80 to 120 f e e t , and 120 to 160 f e e t width c a t e g o r i e s : West Coast Tower: Width 0 to 4Q f e e t : t„ = 0.01+0.47.n„ .-0.48.(n. . ) 2+0.31. (n. , ) 3 f (RMS-0.01, 4 4 , K 4 , K 4 , K N - 3 8 ) . Width 40 to 80 f e e t : t 4 = 0.03-0.76.n 4 > ( <+12.43. ( n 4 > | < ) 2 - 4 9 . 9 6 . ( n 4 > | < ) 3 +93.79.(n. .) 4-83.26.(n. ,) 5+28.32.(n„ .) 6;(RMS=0.01 4,k 4,k 4,k N-72), Width 80 to 120 f e e t : t 4 = - 0 . 0 8 + 2 . 6 0 . n 4 ^ k - 1 2 . 6 l . ( n 4 > k ) 2 + 3 3 . 1 1 . ( n 4 > k ) 3 9 -38.90.(n 4 k) 4+17.21. ( n 4 > | < ) 5 ; (RMS = 0.02, N == 28). Width 120 to 160 f e e t : t 4 = 0.03-0.01. n 4 k+0.81. ( n 4 > ( < ) 2 ; (RMS - 0.02; N = 17). Washington 98: Width 40 to 80 f e e t : 0.01+0.27.n4 k+1.20.i(in4 k ) 2 - 3 . 31. ( n 4 ^  k ) 3+2.40. ( n 4 k * 4 = f o r n 4 k * r 0 . 8 5 ; (RMS = 0 . 0 6 , N = 22). 8.27.n 4 k-6.63, f o r n 4 k >0.85; (N = 3). 4 8 . W i d t h 80 t o 120 f e e t : t 4 = 0 . 1 4 + 1 . 8 3 . n 4 k - 4 . 5 2 . ( n 4 > ( < ) 2 + 4 . 2 3 . ( n 4 > | < ) 3 ; (RMS _ 0 . 1 1 , N t . 1 1 ) . V a l u e s o b t a i n e d f o r t 4 t h a t w e r e l e s s t h a n z e r o , w e r e s e t e q u a l t o z e r o . S e t C h o k e r s , t - . S e p a r a t e p o l y n o m i a l i n v e r s e s o f t h e c u m u l a t i v e d i s t r i b u t i o n f u n c t i o n s w e r e d e r i v e d f o r 1 , 2 , 3 , o r 4 c h o k e r s s e t : One c h o k e r s e t : t _ ( 4 , 4 7 , n 5 k " 1 * 5 1 , f o r n 5 k ^ 0 * 4 0 ; ( N : = 3 ) * . 0 . 2 0 . n g k + 0 . 2 0 , f o r n g k*> 0 . 4 0 ; ( N - 2 ) . Two c h o k e r s s e t : t . = 0 . 0 7 + 0 . 2 3 . n 5 ^ k + 3 . 9 4 . ( n 5 > | < ) 2 - 3 . 0 3 . ( n 5 ^ k ) 3 ; (RMS = 0 . 2 0 ; N = 8 ) . T h r e e c h o k e r s s e t : " 0 . 4 0 + 0 . 9 3 . n _ k , f o r n & k 4 0 . 9 4 ; ( R M S = 0 . 0 4 , N - 3 3 ) . *5 " 1 7 3 . 3 3 . n 5 k-67.71 f f o r n - J q . 9 4 j ( N - 2 ) . F o u r c h o k e r s s e t : * 5 ^ 0 . 2 4 + 6 . 3 4 . n _ k , - 4 0 . 4 4 . ( n 5 k ) 2 + 1 4 8 . 3 3 . ( n 5 R ) 3 - 2 6 6 . 1 5 . ( n - k ) 4 + 2 2 5 . 2 4 . ( n 5 > | < ) 5 - 7 1 . 0 4 . ( n 5 j | < ) 6 , f o r n - k ^ 0 . 9 1 ; (RMS = 0 . 0 6 , N = 8 5 ) . 1 9 . 5 5 . n - k - 1 5 . 6 7 , f o r n _ k > 0 . 9 1 ; (RMS = 0 . 0 9 ; N 49. Get C l e a r , t ^ . The mean of these times, tg = 0.32 (RMS = 0.09, N = 8) was used f o r t h i s comparatively s t a b l e element. In areas of d i f f e r e n t ground v e g e t a t i o n , t h i s might not be a good estimate. Breakout, t - . A long P u l l Slack time f r e q u e n t l y i n d i c a t e d a long Breakout time, f o r example, i f a turn was a long way out to the s i d e . For t h i s reason the same random number used i n the P u l l Slack s i m u l a t i o n was used to simulate Breakout, using the f o l l o w i n g i n v e r s e cumulative d i s t r i b u t i o n f u n c t i o n s f o r the various width c a t e g o r i e s : West Coast Tower: Width 0 to 40 f e e t : -1.13+18.62.n 4 > k-96.13.(n 4 > | <) 2+236.13. ( n 4 ^ k ) 3 -272.72.(n. .) 4+119.89.(n. . ) 5 , f o r n. . <0.74;(RMS=0.07 4,k 4,k 4 , K . N=20). 2.15.n 4 > k-0.87, f o r n 4^ k>0.74; (RMS - 0.05, N « 7). Width 40 to 80 f e e t : " - 0 . 0 3 + 3 . 1 0 . n 4 > k - 1 8 . 2 4 . ( n 4 > k ) 2 + 5 7 . 4 3 . ( n 4 > k ) 3 - 8 2 . 8 2 . ( n 4 > k ) V +44.03.(n 4 k ) , f o r n 4 k ^ 0 . 8 0 ; (RMS = 0.02, N = 52). 21.20.(n 4 k ) - l 6 . 2 4 , f o r n 4 k>0.80; (RMS = 0.08, N = 13) Width 80 to 120 f e e t : t ? = -0.06+3.26.n 4 > k-13.17.(n 4^ k) 2+32.31.(n 4 > k) 3-42.05.(n 4^ k) +22.50.(n 4 k ) 5 5 (RMS = 0.01, N _ 54). 50. Width 120 to 160 f e e t : t 7 H 0 . 0 4 + 2 . 7 7 . n 4 > k - l 6 . 2 5 . ( n 4 f k ) 2 + 5 4 . 5 9 . ( n 4 ^ k ) 3 - 8 6 . 3 7 i n 4 ^ k ) 4 +51.48. ( n 4 f k ) 5 ; f o r n 4 k ^ 0 . 8 0 ; (RM5=0.05,N=48). 17.00.n 4 k-12.00, f o r n 4 k>0.80; (RMS-0. 09 , l\l=12). Washington 98: Width 40 to 80 f e e t : 22.00.n 4 k ~ l 6 . 4 0 , f o r n 4 k>0.80. t ?=,0.07+0.18.m 4 k+24.58.(n 4 k ) 2 - 1 7 5 . 8 5 . ( n 4 k) 3+509.28.(n 4 k -655.75. (n 4 > | <) 5+310.72. ( n 4 k ) 6 , f o r n 4 k$Q.B0; ^ 5 = 0 . 0 5 , ^ 4 0 ) . Width 80 to 120 f e e t : t 1 • ^18.74.n 4 k-12.08, f o r n 4 k>0.76; (N=5). -0.02+0.55.n 4 k+21.61.(n 4 k ) 2 - 1 4 9 . 5 9 . ( n 4 k) 3+402.06.(n 4 k -472.35.(n 4 k) 5+204.94.(n 4 k ) 6 , f o r n 4 > k$.0.76; (RMS=0.05 N=16). • Values obtained f o r t y that were l e s s than zero, were set equal to zero. Yard, t g . T h i s element was modeled by l i n e a r r e -gr e s s i o n , unless a hangup was simulated. The p r o b a b i l i t y that a hangup would not occur was 0.98 f o r the West Coast Tower, and 0.95 f o r the Washington 98. When a hangup occurred, the Yard time was increased by a uniform random value averaging 30 percent f o r both yarders. When a hangup was not simulated, Yard time was given by: 51. West Coast Tower: t Q = 0.10719 + 0.00126.y k; (RMS = 0.18,N = 164). Washington 98: tg = 0.17199 + 0.00209.y k; (RMS = 0.24,N = 72). When a hangup occurred, tg was m o d i f i e d : West Coast Tower: tg = (0.10719+0.00126.y k).(1.00+0.60.n Q^ k); (N=4). Washington 98: tg - (0.17199+0.002D9.y k$.(1.00+0.60.n 8 k); (N=3). Chase, t g . The elements Chase A and Chase B of Chapter I I I were merged, and the f o l l o w i n g f a m i l y of i n v e r s e cumulative d i s t r i b u t i o n f u n c t i o n s d e r i v e d f o r 1, 2, 3 or 4 chokers s e t : One choker s e t : t 9 - 0.16 + 0.56.n g k ; (RMS = 0.02, N = 7). Two chokers s e t : * 9 -0.24 + 0.21.n g k , f o r n g R 0.57;-(-N = 4 ) . ,1.67.nQ k - 0.59, f o r n g k>0.57; (N = 3 ) . Three chokers s e t : r0.14+5.45.n q k-26.14.(n g k ) 2+61. 28 . (n- k ) 3-66 . 68. ( n g ki *9 = +27.70.(n g k ) 5 , f o r n g k<0.90; (RMS-0.14,N=26). 10.00.n g k-7.76, f o r n g k>0.90; (N = 3). Four chokers s e t : t Q = 0.15 + 3.49.n Q ,-7.06.(n Q . ) 2+5.43.(n q , ) 3„RMS-0.04. 9 y . k y , k y , k N _ 1 1 2 ) < 52 Wait f o r Skidder. t^~« This element had a value of zero with a p r o b a b i l i t y of 0.85 f o r the West Coast Tower, and 0.87 f o r the Washington 98. When the element did occur, i t s value was given by the f o l l o w i n g expres-sions : West Coast Tower: 325.00.n 1 Q k-315.00, f o r n 1 Q k>0.98; (l\l=l). t 1 Q =- 12.50.n 1 Q k-8.70, f o r 0 . 8 2 < n 1 0 k<C0.98; (N=5). 1.83.n 1 Q k , f o r n 1 Q k ^ 0 . 8 2 ; (RMS-0. 08 ;N=2B ). Washington 98: 0.15, f o r n 1 Q | < ^ 0 . 4 0 ; (l\l=3). no -0.45, f o r 0.40 < n 1 Q k ^ 0 . 7 0 ; (N=4). 0.75, f o r 0 . 7 0 < n 1 Q ^ 0 . 9 0 ; (N=3). 1.05, f o r n 1 Q k>0.90; (N=l). Raise Rigging, t j ^ . The f o l l o w i n g i n v e r s e s of the cumulative d i s t r i b u t i o n f u n c t i o n s were found: West Coast Tower: 1.00+6.00. n.^ k , f o r n 1 J L k>0.87; (RMS=0.22,N=15). 5.00.n i : L k-4.00, f o r 0.84 < n 1 1 k4"0.87; (IM-5). t l x = -|0.58.ni:L k-0.10, f o r 0.63 < n x l k ^ 0.84 0.18.n i : L k+0.18, f o r 0.10 <r>±1 k £ 0 . 6 3 0.10+0. 83. n A 1 k , f o r k-*j0.10; (RMS-0.04, N-12) . (RMS=0.06,N=25) (RMS=0.05,N=57) 53. Washington 98: 0.70+3.00. n x l k , f o r n u k>0.90; (N=4). t| 1=,0.18+0.14.n J L 1 k , f o r n ± 1 k ^ 0 . 7 7 , (RMS=0.03,N=32). 2.86.n 1 J L k - 2 . l 6 , f o r 0.77<n i : L k $ 0 . 9 0 ; (N=5). Road Change During Yarding, t ^ This element had a value of zero with p r o b a b i l i t y 0.97 f o r the West Coast Tower and 0.95 f o r the Washington 98. When i t did occur, the means of the observed times were used f o r the two yarders: t 1 2 = 3.72 (RMS=0.27, N-6) f o r the West Coast Tower, and t ^ _ =4.19 (N=4) f o r the Washington 98. Rig, tj^-j. This element had a value of zero with a p r o b a b i l i t y of 0.95 f o r the West Coast Tower and 0.97 f o r the Washington 98. When i t d i d occur, i t s duration was given by the f o l l o w i n g expressions: West Coast Tower: *13-10.00.n 1 3 k , f o r n 1 3 k>0.83; (N=2). 6.00.n 1 3 k , f o r n 1 3 k ^ 0 . 8 3 ; (RMS=0.28 , N=10) . Washington 98: t j 3 = 5.00.n 1 3 k ; (l\l=4). T h e o r e t i c a l l y , the model could have been b u i l t by convolving the frequency d i s t r i b u t i o n f o r the geometry-independent elements, d e r i v i n g a frequency d i s t r i b u t i o n f o r the other elements by s i m u l a t i o n , and combining these two by c o n v o l u t i o n . The method of s i m u l a t i n g a l l the 54. elements was chosen f o r convenience. P h y s i c a l parameters, which v a r i o u s o f the above elements depended upon, were computed f o r each t u r n . The w i d t h of a road at y a r d i n g d i s t a n c e y k was giv e n by w. . ^k^. ( b - f ) + f k 1 The average a r e a , a, occu p i e d by a t u r n was given by a = 43,56D.p t/p g square f e e t where p^ = average number of p i e c e s per t u r n p a = average number of p i e c e s per a c r e . The l o g s were assumed t o be u n i f o r m l y d i s t r i b u t e d along the roa d . In p r a c t i c e , they would be more c o n c e n t r a t e d i n can-yons . Given the area o c c u p i e d by a t u r n and the widt h of the road at t h a t p o i n t , i t was. p o s s i b l e f o r the y a r d i n g d i s t a n c e y k to be i n c r e a s e d by A y k f o r the ( k + l ) ^ t u r n : 2.a=(wk+wk+ A w k ) . A y k S u b s t i t u t i n g f o r wk +/\wk l e d to the f o r m a t i o n of a quadra-t i c e q u a t i o n 2.a= A y k . (w k+y k, | b - f | / l + f) + ( 4 y k ) 2 . ( b - f l / l f o r b g r e a t e r or l e s s than f . There was one r e a l s o l u t i o n , Ay k = -wk +/w k + 4.a. \ b-f | /2.1 f o r the i n c r e a s e i n y a r d i n g d i s t a n c e . 56. Washington Model 98. The element times were based on only two observations. Bring l i n e s i n . t | . Uniformly d i s t r i b u t e d times of 5 to 10 minutes were used. Move yarder. t i , . Uniformly d i s t r i b u t e d random times of 0 to 10 minutes were used. Hook l i n e s up. t ^ . Uniformly d i s t r i b u t e d times of 7 to 17 minutes were used. Take l i n e s out, t ^ . Uniformly d i s t r i b u t e d times of 5 to 8 minutes were used. Rigging delay. tA. This time was zero below the 87 percent p r o b a b i l i t y l e v e l , and a uniformly d i s t r i b u t e d random time of 5 to 11 minutes above the 87 percent pro-b a b i l i t y l e v e l . the 95 percent p r o b a b i l i t y l e v e l , and a uniformly d i s t r i -buted random time of 0 to 10 minutes above the 95 percent p r o b a b i l i t y l e v e l . Wait f o r s k i d d e r . t l This time was zero below The road changing time was found by summing these times: u=5 u u=l f o r the West Coast Tower, and u=6 T r u=l f o r the Washington Model 98. 57. I d l e Time The only i n f o r m a t i o n a v a i l a b l e on i d l e time, T , cl was the y e a r l y average f o r each machine recorded by the company. I t was assumed to be uniformly d i s t r i b u t e d , with a range of • to 32.6 percent of the t o t a l turn time f o r the West Coast Tower, and 0 to 22.2 percent of the t o t a l turn time f o r the Washington 98. . THE STRUCTURE-.OF .THE MODEL A flowchart of the s i m u l a t i o n i s presented i n Figure 31. Turn time, T^, was found by summing the i n d i v i -dual elements: 13 T k = X V i = l The piece count was found, by adding a simulated i n t e g e r to the number of chokers s e t . A f t e r each t u r n , the sum of turn times on the road, T , was brought up to s date, the yarding distance incremented byAy^, and the next turn simulated. P r o v i s i o n was made f o r p r i n t i n g out information every 100 f e e t along a road. When the yarding d i s t a n c e equalled the e x t e r n a l yarding d i s t a n c e , idle, time, T , was simulated f o r the whole road, as a percentage of t o t a l turn time: I n i t i a l i z e I Increment ext'l y a r d i n g d i s t a n c e 1QD f t . Increment number of roads H Increment yard i n g d i s t a n c e -Generate number of choker3 set Generate each element i n c y c l B Generate p i e c e count  [Turn time =» sum of element times Summarize times F i t q u a d r a t i c curves to mean times f o r 10 roads F i g u r e 31* Si m u l a t i o n f l o w c h a r t . 59. T = T .ran a s o where mg = a uniformly d i s t r i b u t e d random number, range 0 to 0.326 f o r the West Coast Tower or 0 to 0.222 f o r the Model 98. Road change time was simulated, and the t o t a l time f o r the road was found by summing t u r n , road change, and i d l e times: T T = T + T + T T s r a where T_ = t o t a l time to l o g the road. Basic output from the s i m u l a t i o n c o n s i s t e d of the time to l o g a thousand square f e e t of ground, T^, which was found by d i v i d i n g the t o t a l time by the area A of the road: T M = T_/A . 1000 where A = (f+b).1/2 that i s , TM " T k + T r + T i ] / A k=l where d = number of turns on a road. This procedure was repeated f o r ten roads. F i n a l output c o n s i s t e d of a summary of the time to l o g a thou-sand square f e e t of ground, the standard d e v i a t i o n of t h i s f i g u r e over the ten roads, and a p a r t i a l breakdown of times. Then t h i s was repeated f o r a road a hundred f e e t longer, up to a maximum of a thousand f e e t . The mean times per 61. thousand square f e e t were approximated by an orthogonal l e a s t squares quadratic curve, chosen because i t would give the s i n g l e minimum value i n t u i t i v e l y expected, from the t r a d e - o f f between road changing and yarding times. Logging various road shapes and s i z e s with or without a t a i l t r e e was thus simulated, and a s e r i e s of curves could be drawn f o r each yarder. Once the model had been const r u c t e d as described, i t was programmed i n FORTRAN IV and run on the IBM 360/67 computer using the G compiler at the U n i v e r s i t y of B r i t i s h Columbia. A program l i s t i n g and a t y p i c a l output are shown i n Appendix V I I I . Methods Improvement Two improvements were i n d i c a t e d i n the systems s t u d i e d . F i r s t l y , l o a d i n g was expensive and sometimes l i m i -ted production from the West Coast Tower. When the skidder was occupied p u t t i n g a l o a d on the bunk, the l a n d i n g could be q u i c k l y plugged, not i n f r e q u e n t l y f o r h a l f an hour. It was assumed that any a l t e r n a t i v e l o a d i n g method, f o r the West Coast Tower, could not reduce the "Wait f o r Skidder" time below that of the Washington 98, the operation of which was nearly independent of l o a d i n g . I d l e time f o r the West Coast Tower, i t was estimated, would be reduced 62. from 16.3% to 13.5% s i n c e "Wait f o r Skidder" was recorded i n the f i e l d as idle,, time when i t exceeded ten minutes. For the Washington yarder, wait time i n the s i m u l a t i o n was e l i m i n a t e d , but i d l e time was not a l t e r e d . This s i -mulation was intended to show the e f f e c t of the l o a d i n g method s t u d i e d on the yarding c y c l e , compared with minimal i n t e r f e r e n c e from an"optimal"loading method. Secondly, the choker s e t t e r s were i d l e most of the time. Could t h i s time have been used more p r o f i t a b l y by prechoking? In t h i s method, two sets of chokers are flown; while one set i s on a turn being yarded, the other set of four i s being set on the next t u r n . When the r i g -ging returns to the woods, one man takes the chokers o f f of the hooks, p u l l s the mainline out to the p r e v i o u s l y choked t u r n , and hooks the chokers on. In the meantime the other man takes the chokers to the other s i d e of the road and begins to set them f o r the next t u r n . Obviously the method cannot work s a f e l y f o r logs on the s k y l i n e road. Figure 32 shows the method s c h e m a t i c a l l y . Determining the time saving, and the extent to which the r i g g i n g returned before a turn had been prechoked was not easy i n the absence of a time study of prechoking. However, the i n v e s t i g a t o r had set chokers i n t h i s way on a s i m i l a r o p e r a t i o n , and estimated the c y c l e as f o l l o w s : 63. Untangle ( u n i t hooker) (chokersetter) P u l l Slack Carry Chokers Hook Chokers Set one choker (Get Clear) (Breakout) Set remainder of chokers (Rigging Returns) Figure 32. Schematic r e p r e s e n t a t i o n of pre-choking method. 64. Return, Drop Rigging, P u l l Slack, Get Cl e a r , Breakout, Yard, and a l l l a n d i n g element times were u n a l t e r e d . Taking the chokers o f f the hooks, the Untangle time, was estimated to be twenty seconds. P u l l i n g s l a c k took about the same time as with chokers on, since i n the usual (not prechoking) method, one man took each hook, or one man a l l the chokers; and t h i s i n turn was about the same time as i t took the cho k e r s e t t e r to reach his next t u r n . A f t e r one man had p u l l e d the mainline out and hooked the chokers on, often the other man had j u s t f i n i s h e d s e t t i n g one choker. Thus the time f o r Set Chokers was about the same as f o r one choker, or two men s e t t i n g two chokers. Hence the c y c l e time was computed as usual except that the time f o r two men to set two chokers was s u b s t i t u t e d f o r the re g u l a r Set Chokers element. In t h i s way the reduc t i o n i n turn time could be s t u d i e d . Another question was whether the men had enough time to set a turh before the r i g g i n g returned from the l a n d i n g . I f i n t e r f e r e n c e occurred, they could e i t h e r hook on as many log s as had been choked, or continue to set a l l four chokers. T h i s was t a c k l e d by s i m u l a t i n g the time needed to set the remaining chokers, given that f o r s a f e t y the men could not work during Get Clear and Breakout. This 65. time was compared with the t o t a l of a l l the i n t e r v e n i n g elements u n t i l the r i g g i n g returned to the woods, and any i n t e r f e r e n c e noted i n the output. A t h i r d m o d i f i c a t i o n to the s i m u l a t i o n was made to t e s t the a p p l i c a b i l i t y of the systems s t u d i e d to a stand of D o u g l a s - f i r at Kaingaroa Forest, New Zealand, f o r which r e l i a b l e data was a v a i l a b l e (see Appendix IX). Climate, piece s i z e , species composition, and r e s i d u a l stand c h a r a c t e r i s t i c s were s i m i l a r to the Washington s i t u a t i o n ; however the topography was much steeper, and many more stems per acre were removed. Breakage was assumed to be greater because of the l a t t e r two f a c t o r s ; piece s i z e was conse-quently s m a l l e r , so the piece count per turn was adjusted to keep the same turn volume as before. S e t t i n g chokers on more pieces was assumed not to take more time, because of the extreme density of logs on the ground. The times f o r the Yard and Return elements were increased by a 10 percent slope f a c t o r . LIMITATIONS OF THE MODEL The f o l l o w i n g l i m i t a t i o n s can be l i s t e d , and they should be borne i n mind when i n t e r p r e t i n g the r e s u l t s of the s i m u l a t i o n : 1. Some of the r e l a t i o n s h i p s d e s c r i b i n g the yarding c y c l e elements were based on a small number of o b s e r v a t i o n s . 66 2. Topographical f e a t u r e s , which can a f f e c t most of the elements by decreasing clearance or making work harder f o r the men, were not i n c o r p o r a t e d i n t o the model. 3. Landing s i z e was not considered, as a l a r g e r sample would be needed to model i t . Landing s i z e e f f e c t s the Wait f o r Skidder and Chase elements. 4. The road change times f o r the 5kylok yarder came from a sample of two o b s e r v a t i o n s . The range of times was estimated. 5. There was i n s u f f i c i e n t data to set up a simu-l a t i o n f o r the Washington yarder f o r roads wider than 120 f e e t , which l i m i t e d the compari-son of the two y a r d e r s . 6. Allowance was not made f o r downtime or non-productive man-time, that would not have been recorded as i d l e time. 7. The e f f e c t of turn s i z e was not considered e x p l i c i t l y . 8. The longest road s t u d i e d i n the f i e l d was 600 f e e t long. The e x t r a p o l a t i o n to 1000 f e e t i s t h e o r e t i c a l ; any of the r e l a t i o n s h i p s d e s c r i b -ing elements which i n v o l v e moving l i n e s may 67. have become non - l i n e a r at t h i s d i s t a n c e . 9. The logs were assumed to be uniformly d i s -t r i b u t e d on the ground. VERIFICATION OF THE MODEL The model was t e s t e d by superimposing turn times from the s i m u l a t i o n output which was based on data from s e v e r a l roads, on a p l o t of raw data, f o r a road 160 f e e t wide at the back, 600 f e e t long, converging at the l a n d -ing (Figure 33). The high p r o p o r t i o n of long times past 400 f e e t i n the r e a l case was due^ to an e x c e p t i o n a l number of hangups. Cumulative d i s t r i b u t i o n ' p l o t s were compared f o r the r e a l and simulated times (Figure 34). The d i f f e r -ences were small and were not considered to d e t r a c t from the r e a l i s m of the model. As f a r as turn times are con-cerned, the model appears to be quite r e a l i s t i c . » t * ni \fc> 1 *-> c C 3 P 1 «0 ,i T 1 i T3 rri "i VO O T / \ 1 1 v. ) T rrt VO C > f - i cl 1" I c J 1 r\ r \ J Q H to ' * • / \ *f r — it— i—j n f » I I r v » = >— L ) i " t I -* ri •\ c ;, J > i • , i f /• 1 t t~ v. —' ?-c •t 1 v: 1 \ *» h i t L J •rt f~ J T • V 1 y * -f ~ T -y > J c > i D =*• ri f T— > { D " 1 n < ) (" \ H s C3 L I u t~ 1 •rt -f W ( D -1 r» < rf i IU 5 1 + ~r 2^  «• ^  r 0 i I <_ 1 I 'i 5 ml "1 v. ill. <L r 4 VO T | \ v. 1 l \ I -1 •\ V s»- m t TO i t i ) *r M 7 (—* Ji m i - i r J J t \ 4 V. . •r W -* l i J 1 1 I > H J V . 1 " f - T VO — 4 i C > ni 0 ~1 C ri T •+• -< Ly r-1 rH -> \ 1 a*-0 •> •\ _ } r* ni r 1 u> 111 r —\ |(_ r _v © C > " i •+ &~ — •+- K r T T i "i IT T T r T T n T —1 4 L L A V L LA A. . i il 1 t/ 1 i =H -1 -• rY \ 7 4_ Q 1 r ,s ; f 1 c | • i rr ) n 0,1 i i 4-f= n j rl >-n rr t i r i \ > r< iH | ft i .[ 1 n, 33 n i m r i ( i P i _^ 1 H i ti 1 X. •3 y i j -; K -> \ H ri l > > w r N "1 • * 41 > fl n n i -i *-( '1 —. ( Q ii — |\ ? r I H •) •p f1 H ij fti $ -< r T 1 T T" -J < r1 ) » 0 -i c f r "1 H L. x t i H •4 I f. 5 "> o 0 j fll 1 I . r tt 11 L -t fl • rt H ,r « -) •> H j-4 c ) n r ) • • • b 0 f ti nS { r 0 I) H i rrt n I i ri i •> H H D r > b -4 •-f c > $\ t c 0 ( — =? ft T 1 T r 1 ll 1 \' L I 4 70. CHAPTER V USING THE MODEL Figure 35 compares the road changing and produc-t i v e times f o r the two yarders. The high road changing time of the West Coast Tower must be seen as a disadvan-tage, while the productive times of the Washington Model 98 i n d i c a t e that low l i n e speeds make turn times too long. COST CURVES Const r u c t i n g the Cost Curves Times to l o g a thousand square f e e t were converted to cost per c u n i t , and the r e s u l t i n g cost curves p l o t t e d . The hourly machine and l a b o r rates are given i n Appendix X. For the purpose of comparing systems, 120-foot-wide roads were chosen as r e p r e s e n t a t i v e of a t y p i c a l l a y o u t . Simulated costs per c u n i t were p l o t t e d against e x t e r n a l yarding distance as f o l l o w s : 1. Yarding and l o a d i n g costs i n the Longview s i m u l a t i o n were p l o t t e d f o r various widths and shapes of roads (Figures 36 through 42) (pages 72 through 78 ). 2. Costs f o r the Washington yarder were com-pared with those f o r the West Coast Tower, -—,— I \ o \ \ \ \ I \ \ \ \ i \ — \ % \ \ — o Q — \ c 1 1 \ 1 \ — \ R1 a J G \ £ h •P 1 r. •5 I i p I « I C G 1 1 I 1 I ( j. / c r in / | 4. £ 1 j ~i ft H) 1 / i ' <L ( t/ 0) / 1 c| It f 1 r' IP f ;i / — ) r. i / r 1 i f N ) j / / —i p (U h 1 ( i —< o ( •\ / n I , / f, —• m n c i / i • fi ) [ ct ^ Q i • / *— 03 f Q t-3 -1 jl r -i &• ffl E3 n -] '£) y < V r* ^> I "0 rr~ — ^= d ,1 4- i L ) \ / u IH s / SH 0 £• H ( i r-( u C y / U r j \ / / n o '0 fll f. i y < f. r ct | i / / y ffl rH p / i r r f ^ o c i c ,r S QJ l r j 17™ { P i •i t-^  1 i Q c - rr [ V •0 t D 1 "1 • ri -< r \ L> 1- | i -< C I ±^ 1 -i »• \ t( i j c 1 f c ; 1 o o h, ) 1 > -4 ,r 1 J -* 1 n r n i r i ~ V H H r 4- > \ \1 n / h • n " P ?, I n i r T r W t -1 i d i - -i I T r -l l t J -I )1 L" L 1 3 V L I ill X. i l • < ;< i A si Ll \ >( ) 3 L' >U i a . o r :i 1 3 -V • L 3 1 V H ?< I 3 3< ) : i H >\ L< V / r? K P L ? J i i i l i . L< 1 1 >< ) r P L H O r I 1 V ) 70 1 • L( J 0 _> t - T > U ' J *H < Si 1 r r 1 I f ) i K If 1 i K )( ) •>( ) r '( )( \ \{ )( 1 r ir I r H V \ *> ^  1 V r 1 . ^  11. ) V 1 •4 rr T •H r + r - j i 1 . 1 •. '1 Ic M 'C .1 i r > i ll' t i !C !T f 1 1 1 1 i 1 T f i i \ 1 y 1 r J ki" 1 L )\ 1 J r D LJ X L i > 1 _» -> Li 3 • L C 2. 3 1 LJ i 1 1 L > T | | p ;/ •> P 1 - -\ ad ,r \ v 1 L L 1 1 I pi L I t n 1 b A > 1 2 J I L V C p 1 1 £ i -i o n f t" i. T J. u f 1 1 u i o h r. s Q I b/ 0 f r u I * K I' C > 1 o n f t* n n 1 1 Q 1 L. X u 1 -A J -bl J i 1 « , J 1 a fa J £. 1 x: 1 r 5 > i h> r 3 ) 4 ) ) s ) ) ) ) / ) ) rl ) ) ) 1 T' D y \ • n I.- n r» f > C D - ; A. C L 1 i . X X. i zr l • 79. with and without a t a i l t r e e r i g g e d (Figure 43, page 80) . . Costs f o r "optimal" l o a d i n g and prechoking were compared with the systems s t u d i e d (Figures 44 through 47, pages 81 through 84 ). Haul road c o n s t r u c t i o n and logging costs were p l o t t e d to f i n d the "optimal" yarding d i s t a n c e . (The idea that t h i s d i s t a n c e i s found where yard-ing and road costs are equal was di s c a r d e d . T h i s i s only true when the two curves have equal but opposite slopes at t h e i r point of i n t e r s e c t i o n ) . The costs of yarding to one or both s i d e s of a haul road were compared. A p a r a l l e l haul road system was assumed (Figure 48, page 85). The prac-t i c e i n many companies i s to charge the e n t i r e cost of road c o n s t r u c t i o n against current l o g g i n g ; t h i s was assumed i n d e r i v i n g the curves. In Washington, a road c o n s t r u c t i o n cost of $200 per s t a t i o n was taken to be r e p r e s e n t a t i v e . Costs might be lowered by d e p r e c i a t i n g a road over an e n t i r e r o t a t i o n , de-pending on whether the road .was i n use that long, the costs of maintaining and upgrading the road between c u t t i n g s , and the i n t e r e s t r a t e charged on the road. 86. 5. Cost curves were const r u c t e d f o r the New Zealand s i t u a t i o n (Figure 49, page 8 7 j • 6 . Cost curves were compared f o r e x t r a c t i n g 113 pieces per acre and 200 pieces per acre at Longview (Figure 50, page 88), assuming the same volume per p i e c e . USING THE COST CURVES Two questions a r i s e on the i n t e r p r e t a t i o n of the cost curves. F i r s t l y , how are the simulated times f o r l o g -ging a thousand square f e e t , and t h e i r means, dis p e r s e d about the curve f i t t e d to the means? Secondly, how should the curves be compared? Figure 51 shows the d i s p e r s i o n s of times about two curves p l o t t e d f o r the West Coast Tower and the Washington 98, l o g g i n g 120-foot-wide p a r a l l e l roads. Logging costs are d i r e c t l y p r o p o r t i o n a l to these times. The f o l l o w i n g p o i n t s may be noted f o r each curve: 1. On roads longer than 300 f e e t , e x t e r n a l yard-i n g d i s t a n c e has l i t t l e e f f e c t on l o g g i n g times. The high times f o r roads 200 f e e t long cause a s l i g h t l y u n r e a l i s t i c " d i p " to be formed i n the parabola f i t t e d . <\ T Li q I-. "ll i • rv r •y 1 f i a - ,1 -** T T i 7 ~> T r •f :• q • T r r 1 =*- =H — . J " 3 1 1 0 r \ • .T -I • 7 ^ 1 1 -1' i • 1 , V 1 P" n ft a 3 1 1'. D. 1 •1 1 L S y a. 1 r V 3. » 7 Bl. L. y- J. • J-I 1 L. JL L Ji X. • ) -T /, =?, a' 1 w ^ i 1 t L ... J + 3" H y 1 ''r [ 5 • 1 3 -cp-1 fl 1 =1 1 |' t rl R r t ty M1 1 If •V i 1 '•V U' rt •L | 4- t 0 L 1 "\ p T -c lr t" 7- I i. |-'<-•i; •ts )• i, 4- • 7 3 V--£= •CC L. n >- Vv 3 5 1 1 '1 p J 1 1 L j .i 1 ? ~\ f 1- '.T T ir t- rr" ±H I, • 5 u > r\ r\ "•( L) J 4- 3 3 3 3 J 3 3 3 J 3 J j 3 1 J J J H! L rt; V 1 Y i \ rr I") 1 h f >— - -' . a t ) , -t > r> 11 1 1 r J c 1 T c •> V c i T \ c b i c i c 5 P — 4 a. f ~l <P i t w 1 (1 1 CD r r *~ Q ) r r-1 C 5 *-> c 1 f \ s a 1 c If b f \ J > \ w z\ rt • n l D 1 r 1 1 u (J 1 -«p T T r 1 1 be [) o) i ) n ") c \ Is 1 Ctf c a < w ^ a N F hi p" C 5 o + i i 4 ri ri t T to c 1 ( o • p 1 crt 4- ( w -i T ( o ( o < X ry v i iiiT » ,i r > 1 _> c 1 C. .1 31 j\ 71 1 r T 1 H r c _ fee cc p 1 4 > r; ci c ( zi H CD CV ; < ? T O E • -> 1 Zl f-i M r% n n rt r '!» if 1 1 r 1 .•> P a rt) j Vi L> VJ v. r' F f T r ) n is Ft •i i) 1 H c; rl <i H • -> F-i L3 •k f c( 4- r ri 11 CO V 3) •1 -> CC J -< c i [fl f i c_ r H J r rt s 50 1 l r 1 j i i w P u •*< *i •1 r fl 0 4- F> ( V/ pi H < V ( > r a ! 0 „ < H -< 0 H a r r ) ? rt rt a ft Q .if Til iii — pi HO r ) -i \J u %j '\ J -zi c H f X) lj a a 0 -< 10 4- • • H J o \ H 4- C ) 11 1 -) T, 1 i i "> c- t •i c > r f r > x< • e i cn rt ' J r r ri —1 a 0 U "iii r r> 4 i 4- C ) 1) C ) p 4- <<-•* Ui r-c c > 4 0 r i 1 cc r •\ r > r t f, } 1 i / i 1 i o 3 P \ JL I T tr I X \ n t Tl II [ i 1 ] "E He T T • r iT c 1 T , T u J t 1. • I U 1 •90. %i\ Tb© tiraee to jLog a thouaafid square feet as?© widely diaparaad* A road 100 foot long could conceivably ba logged at the same rate as on©. 1000 fast lohcjo The r&nga of tiroes for a given length of road i s t y p i c a l l y one to two minutes a. thousand squar© fa©t»»®-differenca of ZQ to 40 percent.botween a«trasaa values.. 3. The curves are quits w a l l ' f i t t e d to the mash, tifaasp and are useful to i l l u s t r a t e p r i n c i p l e s * They ar© less useful for predicting eoata or tirasa on an operational basis. 4 0 The tiwo© appear to ba normally distributed about t h a i r means/* About two-thirds of thera i i o within a half minute af the eurva? that i s within a 10 percent rang© of ti©©. Comparing the two curves of Figure 51 ©haws, the fallowings io. About f.0- percent of the ind i v i d u a l time© over- ' • lap for th© two" yar-dsra-^ Zo Nona of th© moans overlaps. 3.* About 10 percent of th© ind i v i d u a l tifaaa o w * • lap tha curve for th© other yardor, . 4». Tha distance ©©parstina. tha two curved c l o s e l y approximate® the separation of th© r a ~ • spactive. means* • • , S'.». Visually* thasa curves appeared well enoufb att>azrfit.*«l to conclude that, ana yatd©* 'lagged. " . f a s t e r than the other for a l l road lengths*. . A e t e t i a t i c a l analysis to' confirm t h i s was. hat carried out*' •Sema .factMe which depend, on. th© particular i o c a * 'tistft war© wet included i n the. ©amputation, of the curva®* such ae noh^pxoductive man-timet moving to a new aettiftf.* •the .eest. oiP 'downtime* overheads* and ee an. Sam© oaesa*-' ^ i tosa w i l l went, -to 'la-'dii .insurances,. tsxe&( and interest t« the machine' rates"-* ' \ • Minima and intersection© on curves should not ba thought af-as l y i n g on a car tain .point, but within a ear* rahfe* The purpose' ©f the curves far planning pur* pases i© i l l u s t r a t e trend®;,' In practice, i t i a usually not peaaibla to plan roads af exactly the length oorr©*» • spending to, the minima an the Curves, because ©f topogra* phi©; and'mechanical l i m i t a t i o n s . , Curves far the two yerdars should ba compared with caution. Costs are affected by variables that war© not . found'to be'quantifiable* also,, 120-foot-wide road® may' nat- always he the beat basis for comparison. Far-' a given external yarding distance, 120 feet sway be the optimum tisad width far ana yarder, -hut not for the other. The pe*tieul&£ values assumed' i n da»iv£n.g thie' zmt® should be bd»n@ i n ffllnd*-ve>iut«e pm &&m9_ p&$m # i f % %*»*» e i * » t , l^b©* mtm± haul read construction and so on* 93. CHAPTER VI DISCUSSION OF NON-SIMULATED FACTORS DEFLECTION CONSIDERATIONS Time s t u d i e s of a producing lo g g i n g operation are ge n e r a l l y unable to q u a n t i f y the d e f l e c t i o n p r o p e r t i e s of s k y l i n e s . Mechanical a n a l y s i s can p r e d i c t the l i f t or clearance a v a i l a b l e , but the only way to p r e d i c t the exact e f f e c t on yarding c y c l e times of varying amounts of d e f l e c t i o n i s by c a r e f u l l y c o n t r o l l e d experimentation. depends on the tension i n the l i n e . Given a d e f l e c t i o n of 5 percent, what are the r e s p e c t i v e load c a r r y i n g c a p a b i l i t i e s of the two systems? T h e s B may be c a l c u l a t e d by the procedure shown i n the S k y l i n e Tension and D e f l e c t i o n Handbook (Lysons and Mann, 1968). 1-inch standing s k y l i n e : The d e f l e c t i o n of the s k y l i n e f o r a given load D e f l e c t i o n 5 percent Span 5 s t a . Slope 0 percent D i a . 1 i n c h . Weight 1.85 #/ft. Breaking strength 103.4 kips Safety f a c t o r 2. Safe working load 51.7 k i p s . 94. C a r r i a g e Weight 3 kips Cable Tension C a p a b i l i t y : Tension due to cable 0.85/k/sta/#/ft x 5sta x 1.85 #/ft Remaining cable t e n s i o n c a p a b i l i t y Gross Load C a p a b i l i t y : Remaining ten s i o n c a p a b i l i t y 49.4 Tension/kip load 5 C a r r i a g e Payload C a p a b i l i t y 3/4-inch running s k y l i n e : D e f l e c t i o n Span Slope Maximum Tension Weight 1.04 #/ft Tension due to cable 0.25 k/sta/#/ft x 5 s t a x 1.04 #/ft Remaining cable t e n s i o n c a p a b i l i t y Gross Load C a p a b i l i t y Remaining tension c a p a b i l i t y 27.3 Tension/kip load 5 Carriage Payload C a p a b i l i t y = 2.3 kips 45.4 k i p s = 9.9 kips -3.0 kips  -6.9 kips 5 percent 5 s t a 0 percent 28.0 kips 1.3 kips 26.7 kips = 5.3 kips -3.0 kips  2.3 kips 95. The s a f e t y f a c t o r of 2 i s an extreme, beyond which wire rope i s subject to permanent damage. The maximum haulback te n s i o n i n the Washington 98 i s h a l f the breaking s t r e n g t h of the haulback, so f o r comparison purposes a s a f e t y f a c t o r of 2 was assumed f o r both s k y l i n e s . A s a f e t y f a c t o r of 3 to 5 i s more commonly used f o r dynamic l o a d i n g . In the computation f o r the running s k y l i n e , i t was assumed that the upper part of the haulback c a r r i e d a l l of the l o a d ; the l i n e of a c t i o n of the lower part of the haulback, which was not l i f t e d i n t o the t a i l t r e e , was such that i t balanced the mainline t e n s i o n without c o n t r i b u t i n g to the l o a d - c a r r y i n g a b i l i t y of the system (Figure 52, page 98). The payload c a p a c i t y f o r t h i s manner of r i g g i n g i s i n f e r i o r to t hat of the standing s k y l i n e . I f the lower part of the haulback i s passed through a block on the t a i l t r e e (Figure 52), i t s t e n s i o n i s exerted not downward on the c a r r i a g e , but upward. The t e n s i o n c o n t r i b u t i n g to the gross load c a p a b i l i t y i s doubled, and the payload c a p a c i t y becomes 7.6 k i p s . For l i t t l e e f f o r t and the cost of an extra block or one with two sheaves, the running s k y l i n e can have clearance p r o p e r t i e s s u p e r i o r to those of the standing s k y l i n e . Does i t pay to r i g a t a i l tree? to r i g the t r e e takes the hooker an hour or two of otherwise non-productive 96. time, but he needs help from the c h o k e r s e t t e r f o r 30 to 45 minutes, reducing e f f i c i e n c y i n s e v e r a l yarding c y c l e s . Also i t takes s e v e r a l more minutes to change roads to a t a i l t r e e than to a stump. The t o t a l extra time i s about fourteen minutes. On the plus s i d e , extra c l e a r a n c e en-ables f a s t e r y a r d i n g , and f r e q u e n t l y makes a longer road p o s s i b l e . Where good topographic maps are a v a i l a b l e , a d e f l e c t i o n l i n e should always be run i n d o u b t f u l cases to decide whether to r i g a t a i l t r e e . T h i s can be done at f a r l e s s cost than running a whole s i d e f o r an e x t r a fourteen minutes. Where good maps are not a v a i l a b l e and clearance i s d o u b t f u l , the engineering crew, when l a y i n g out a sky-l i n e road, should p l o t a p r o f i l e of the c r i t i c a l part (us-u a l l y the l a s t hundred f e e t or so) from Abney l e v e l s , s t a r t -ing from the t a i l h o ld. A f t e r f a l l i n g , the e l e v a t i o n of the t a i l - h o l d should be e s t a b l i s h e d from the l a n d i n g s i t e , and the p r o f i l e checked f o r c l e a r a n c e . L o c a l c o n d i t i o n s would determine whether the saving i n r i g g i n g stumps where tr e e s would otherwise have been ri g g e d , outweighs the ex-t r a engineering c o s t . I f the engineering crew decides a stump r i g i s f e a s i b l e , they should a l s o consider the e f f e c t s of r i g g i n g a t a i l t r e e to lengthen a road. Clearance should not be too great, e i t h e r . Then, the r i g g i n g i s harder to "spot'; and not enough l i n e can be 97. p u l l e d through the c a r r i a g e . A r u l e of thumb would be f o r the s k y l i n e height plus h a l f the road width at that point to be l e s s than the maximum length of l i n e p u l l e d through the c a r r i a g e . I t i s always p o s s i b l e to s l a c k the s k y l i n e , but t h i s i n c r e a s e s c y c l e time. MARKING The marking system adopted i n the areas sudied was to mark uniformly over the area, and cut roads through t h i s . An improvement would be to mark the stand f o r t h i n n i n g a f t e r the roads had been cut. F i r s t l y , hangups and uproots would be reduced, as t r e e s l i a b l e to cause these along the s i d e of the road could be marked f o r removal. Secondly, there could be a gradation i n t h i n n i n g i n t e n s i t y , from heaviest near the center of a road to l i g h t e s t at the s i d e s . The gradation i n t h i n n i n g i n t e n s i t y across a road i s more f u l l y d i scussed by Adamovich (1968). Advantages from the o p e r a t i o n a l point of view would be reduced times f o r p u l l i n g s l a c k and breaking out, and fewer hangups. Less damage should be caused to r e s i d u a l stems. The i n t e n s i t y of t h i n n i n g could a l s o be v a r i e d according to the width of the s e t t i n g , i . e . the pr o p o r t i o n of timber c l e a r c u t on the center of the s k y l i n e road. For the New Zealand Forest S e r v i c e marking p r e s c r i p t i o n i n s k y l i n e t h i n n i n g , see Appendix VII. 98 h a u l b a c k — upper A gure 52. S t a t i c f o r c e s on a s i m p l i f i e d running s k y l i n e c a r r i a g e . 99. S t r i p t h i n n i n g , where a l t e r n a t e s t r i p s are c l e a r -cut, i s beyond the scope of t h i s t h e s i s . I t has been done i n the Northwest and l o g g i n g c o s t s should be lower than f o r uniform t h i n n i n g . LOADING The l o a d i n g system s t u d i e d , the grapple skidder and pre-load bunk des c r i b e d e a r l i e r , cost $17.16 per hour (see Appendix f o r the determination of t h i s and other l o a d -ing c o s t s ) . Loading could be seen as two a c t i v i t i e s — r e -moving logs from the s k y l i n e deck to prevent the l a n d i n g from being plugged, and the l o a d i n g operation i t s e l f . At Kaingaroa, New Zealand, c o l d decks can be loaded f o r $4.92 per hour with a Priestman Bison c l a m s h e l l l o a d e r . In Washington, i f the machine were a v a i l a b l e at the same p r i c e , the cost would be $7.40 per hour, assuming the loader worked between two s k y l i n e s i d e s . T h i s method would be an obvious choice under c e r t a i n c o n d i t i o n s , bearing the f o l l o w -ing i n mind: 1. Two s i d e s would need to be c l o s e . 2. Cold decking would not g e n e r a l l y be f e a s i b l e with the West Coast Tower. 3. The hooker on the Washington yarder s t u d i e d s a i d that one road could be cold-decked s a t i s f a c t o r i l y . A num-ber of roads converging to one l a n d i n g would give 10.01., problems unless l o g s were loaded out d a i l y . 4. Access f o r r e p a i r s would be r e s t r i c t e d . 5. Species could not be segregated as e f f e c t i v e l y . 6. Close s u p e r v i s i o n would be needed to see the loader was i n the r i g h t place at the r i g h t time, f o r exam-p l e , to prevent the yarder from being trapped by i t s own logs at the end of a spur. 7. Bucking would present problems. In the operations s t u d i e d , t r e e lengths were loaded where p o s s i b l e ; the skidder operator bucked and headed o f f . The chaser would have a hard time bucking on a c o l d deck. I t would p o s s i b l y pay f o r the f a l l e r s to do a l l the heading o f f . I f only some logs needed bucking, the chaser could handle t h a t . C u t t i n g to c l o s e l y s p e c i f i e d lengths could make c o l d deck-ing i m p r a c t i c a b l e . In the case of a West Coast Tower, a machine i s needed to move logs from the s k y l i n e deck. A loader i s cheaper to operate than a s k i d d e r . A P r e n t i c e D-100 hy-d r a u l i c l oader can be operated f o r $13.50 an hour, plus $1.98 f o r a pre-load bunk (using the loader f o r l o a d i n g trucks would probably i n c r e a s e i t s cost by an amount ex-ceeding that f o r the bunk). A Priestman Bison loader costs $14s80- per hour. The saving would be i n c r e a s e d by de-creased i n t e r f e r e n c e with the yarding c y c l e . However, 101. standing t r e e s near the lan d i n g mean that the P r e n t i c e loader cannot heel l o g s . The Bison does not heel l o g s , but f o r slewing the logs should be c l e a r of the ground. This might or might not be achieved on i n d i v i d u a l l a n d i n g s . The skidder can save costs i n other d i r e c t i o n s , however. , I t can s k i d l o g s from easy t e r r a i n when not need-ed on the la n d i n g ; and i t can save road c o n s t r u c t i o n c o s t s . Probably, 700 foot swings are p r a c t i c a b l e , on roads b u i l t to only a low standard. Where the grapple skidder i s used f o r l o a d i n g , the l a s t few hundred f e e t of each spur should be designed to low standards, s u f f i c i e n t only to get the yarder i n t o p o s i t i o n and to allow the skidder to operate. Because of the many a l t e r n a t i v e methods and the l a r g e p o t e n t i a l savings, the economics of l o a d i n g should be c a r e f u l l y looked at f o r each s i t u a t i o n . Where s e v e r a l sky-l i n e t h i n n i n g s i d e s are operated, a s i n g l e l o a d i n g system i s not enough to cope with varying c o n d i t i o n s . 102. CHAPTER V I I SUGGESTIONS FOR FURTHER RESEARCH Further research i s needed at three l e v e l s : f i r s t l y , i n t o the costs of men, machines, and fi n a n c e ; secondly, on improving the log g i n g operation; and t h i r d l y , i n t o how l o g -ging costs are r e l a t e d to the t o t a l wood co s t , present and f u t u r e . Some suggestions are l i s t e d below. (a) B a s i c Costs i . A survey of company records would r e v e a l the best time to dispose of a machine, how much i t c o s ts t o operate and maintain, l a b o r c o s t s , and how much these things vary, i i . Haul road d e p r e c i a t i o n i n the s u s t a i n e d - y i e l d f o r e s t needs more study, i i i . A standard economic procedure f o r c a l c u l a t i n g the cost of finan c e i n the l o g g i n g i n d u s t r y i s needed. (b) Improving the Logging Operation i . Loading methods should be s t u d i e d , compared, analyzed, and optimized, i i . The mechanics of changing drum speeds and/or c o n f i g u r a t i o n s on yarders, and the e f f e c t of t h i s on c o s t s , should be looked i n t o . 103. i i i . The economics and p h y s i c a l f e a s i b i l i t y of using a tractor-mounted t a i l s p a r should be s t u d i e d . i v . I t might be p o s s i b l e to put stronger, but c o n t r o l l a b l e , springs on the Larsen c a r -r i a g e f o r downhill l o g g i n g . For short yard-ing d i s t a n c e s , to prevent the butt r i g g i n g from being thrown down i n a t a n g l e , one s p r i n g could be disengaged from the s l a c k -p u l l i n g drum, v. Pre-choking should be subjected to a time study. v i . A way should be found to i n c o r p o r a t e v a r i a -t i o n s i n topography i n t o the model, v i i . The e f f e c t of s t o c k i n g on yarding costs should be more c l o s e l y s t u d i e d , v i i i . The c o s t s of, and savings due t o , l a r g e r l a n d -ings should be c a l c u l a t e d , i x . The e f f e c t of varying the turn volume should be i n c o r p o r a t e d i n t o the model, x. Wider roads should be s t u d i e d i n the f i e l d , f o r both yarders, and the degree of dependence of optimum road width on e x t e r n a l yarding d i s -tance found. 104 . x i . The economics of swinging logs with a grap-ple skidder on low standard roads should be computed, x i i . The i d e a l haul road p a t t e r n i s not known. Ii i t b e t t e r , f o r i n s t a n c e , to b u i l d roads along both s i d e s of a wide r i d g e , or one road down the center served by truck or skidder spurs (Figure 53)1 Figure 53. Two haul road patterns f o r u p h i l l l o g g i n g . 105. (c) T o t a l Wood Cost i . A s i l v i c u l t u r a l study could be done on the e f f e c t s of d i f f e r e n t r i g g i n g systems and s k y l i n e road patterns on t r e e damage and the area taken out of wood f i b e r p roduction. i i . What are the economics, over a r o t a t i o n , of c l e a r c u t t i n g narrow a l t e r n a t e s t r i p s as a method of "thinning"? i i i . I t i s not known how decreased yarding costs a f f e c t the t o t a l wood c o s t — f o r i n s t a n c e , i f a company's truck f l e e t i s sa t u r a t e d , i n -creased yarding p r o d u c t i v i t y might not pro-duce cheaper logs at the m i l l . A cheaper l o a d i n g method might r e s u l t i n l o g s being bucked to un d e s i r a b l e l e n g t h s . i v . The usefulness of the haul road system used f o r t h i n n i n g , f o r l a t e r cuts i s a matter of s p e c u l a t i o n , but i t should be considered. 106 . CHAPTER VIII CONCLUSIONS Operation of the West Coast Tower at Lonqview: i . Wider roads were cheaper to l o g , up to 120 f e e t wide. i i . There i s l i t t l e cost d i f f e r e n c e between roads 120 f e e t and 160 f e e t wide, i i i . T h i s cost d i f f e r e n c e , i f any, decreases with i n c r e a s i n g e x t e r n a l yarding d i s t a n c e ; t h e r e -f o r e , s h o r t e r roads should be wider. i v . The cheapest logging i s on roads 700 f e e t to 850 f e e t l o n g , v. Logging costs are comparatively i n s e n s i t i v e to changes i n e x t e r n a l yarding d i s t a n c e past 300 f e e t f o r wide roads and 500 f e e t f o r nar-row ones. v i . The cost of r i g g i n g a t a i l t r e e i s l e s s no-t i c e a b l e on a road 160 f e e t wide, than on a narrower one. v i i . Where a t a i l t r e e i s r i g g e d , the optimum road width may exceed 160 f e e t , v i i i . Costs on narrow roads are most s e n s i t i v e to changes i n the e x t e r n a l yarding d i s t a n c e . 107. i x . For roads converging at the l a n d i n g , the o p t i -mum width at the b a c k l i n e probably exceeds 160 f e e t . x. Where topography d i c t a t e s a r a d i a l yarding pat-t e r n no more expense i s i n c u r r e d i n moving the yarder 40 f e e t i n s t e a d of allowing the roads to converge on the l a n d i n g , f o r roads under 400 f e e t l o n g . T h i s i s d e s i r a b l e to avoid c r e a t i n g gaps i n the r e s i d u a l stand. Operation of the Washington Model 98 at Lonqview: i . Up to about 700 f e e t , 120-foot-wide roads are cheapest. i i . Beyond 700 f e e t , narrow roads would produce approximately the same c o s t , i i i . Roads 600 f e e t to 700 f e e t long are cheapest to l o g . i v . The cost d i f f e r e n c e between d i f f e r e n t road widths decreases with i n c r e a s i n g e x t e r n a l yarding d i s t a n c e . Therefore s h o r t e r roads should be wider, v. The optimum road width may exceed 120 f e e t f o r roads l e s s than 500 f e e t l o n g . v i . Logging c o s t s are comparatively i n s e n s i t i v e to changes i n e x t e r n a l y a r d i n g d i s t a n c e w i t h i n s e v e r a l hundred f e e t of the t h e o r e t i c a l optimum. 108, (c) Prechoking: 1. Prechoking i s cheaper, f o r a l l yarding d i s -tances, by about 300 or 40(2 per c u n i t . i i . I n t e r f e r e n c e was r a r e — t h e chokers were almost always set before the c a r r i a g e r e t u r n e d . (d) ^Qptimal"Loading; i . There i s a co n s i d e r a b l e p o t e n t i a l saving i n yarding costs i f l o a d i n g and yarding can be made nea r l y independent, f o r the West Coast Tower. i i . There i s some p o t e n t i a l saving i n yarding c o s t s i f l o a d i n g and yarding can be made nea r l y i n -dependent, f o r the Washington yarder. i i i . * Optimal'"loading made costs more s e n s i t i v e to e x t e r n a l yarding d i s t a n c e . (e) The Two Yarders Compared: I. As p r e s e n t l y operated, the Washington yarder i s cheaper to operate on 120-foot-wide roads under 850 f e e t long; past t h i s p o int, the West Coast Tower i s cheaper, i i . The cost d i f f e r e n c e i s greatest f o r short yarding d i s t a n c e s , i i i . The West Coast Tower operates best on roads wider and longer than those best f o r the Washington Model 98. 109. i v . Because of i t s a b i l i t y t o swing, the Washington yarder has the greater p o t e n t i a l f o r reduced l o a d i n g c o s t s , and smaller landings are necessary than f o r the West Coast Tower. v. The Washington 98 i s a more v e r s a t i l e yarder, except f o r long yarding d i s t a n c e s . Kainqaroa S i m u l a t i o n ; i . Logging c o s t s are q u i t e i n s e n s i t i v e t o changes i n e x t e r n a l yarding d i s t a n c e , i i . Road width i s not important, because of the high volume to s u s t a i n each set-up. i i i . Yarding was cheapest on roads 300 f e e t long f o r the Skylok yarder, and 600 f e e t long f o r the West Coast Tower, i v . Because of the low l a b o r cost (and higher p r o p o r t i o n a t e machine cost) and high volume to s u s t a i n each set-up, the West Coast Tower got logs cheaper than the Washington yarder on roads over 500 f e e t l o n g . 110. (g) Loading; i . The Washington 98 should cold-deck where con-d i t i o n s permit, i i . A c l a m s h e l l loader and a grapple skidder are competitive cost-wise; the choice would de-pend on l o c a l c o n d i t i o n s . The grapple skidder can save haul road c o n s t r u c t i o n c o s t s , and do some logging i n f a v o r a b l e t e r r a i n when not needed on the s k y l i n e l a n d i n g . (h) Rigging Systems: i . Turn times were sh o r t e r f o r the West Coast Tower, r e f l e c t i n g i t s greater l i n e speeds, i i . Road change time was f a r greater f o r the t i g h t s k y l i n e ; t h i s , and a s s o c i a t e d i d l e time, could be s u b s t a n t i a l l y reduced by r e a r r a n g i n g the drums on the West Coast Tower f o r a running s k y l i n e system, i i i . The Shamley c a r r i a g e i s more v e r s a t i l e than the Larsen c a r r i a g e , and i t s r i g g i n g needs l e s s r e p a i r . i v . The West Coast Tower should be modified to a running s k y l i n e , with the standing s k y l i n e r e -t a i n e d as an option f o r areas with a prepon-derance of long yarding d i s t a n c e s . 111. v i . L ine speeds and drum c a p a c i t i e s could pro-f i t a b l y be i n c r e a s e d on the Washington Skylok yarder. S k y l i n e Road Layout Procedure: i . I t i s worthwhile to run d e f l e c t i o n l i n e s i n do u b t f u l cases, i i . The d e s i r e d l o c a t i o n of the yarder should be c l e a r l y marked, e s p e c i a l l y on converging roads, i i i . The engineering crew should be aware of the cost trends shown by the s i m u l a t i o n , i v . Care should be taken to a l l o c a t e each yarder to the most s u i t a b l e t e r r a i n , v. Tree marking should wait u n t i l a f t e r the roads are c u t . v i . A layout should be made f o r a p a r t i c u l a r s y s -tem; that i s , d i f f e r e n t l o g g i n g systems should be f i t t e d to d i f f e r e n t topographic c o n d i t i o n s , v i i . The engineering crew should have d e t a i l e d c r u i s e maps, to adjust road width: to s u i t s t o c k i n g . Volume per acre e x t r a c t e d : i . 1 Denser volumes lower c o s t s , e s p e c i a l l y f o r roads under 600 f e e t l o n g . 112 REFERENCES CITED Adamovich, L. 1962. "Problems of Thinning and Small Log Handling i n Second Growth Western Hemlock Stands." Unpublished Master's t h e s i s , U n i v e r s i t y of B r i t i s h Columbia. 157 pp. ________________ 1968. Problems i n Mechanizing Commercial Thinnings. American S o c i e t y of A g r i c u l t u r a l Engineers Paper No. 68-127. Mimeo. 24 pp. ______________ 1969. In Thinning and Mechanization. IUFRO Meeting, Royal College of F o r e s t r y , Stockholm, Sweden. 173 pp. Bi n k l e y , V.W., and R.L. Williamson. 1968. S k y l i n e E f f e c t i v e f o r Thinning Douglas F i r on Steep Slopes. For. Ind. 95 (2). 2 pp. Lysons, H.H. and C.N. Mann. 1967. S k y l i n e Tension and D e f l e c -t i o n Handbook. U.S. Forest Serv. Res. Pap. PNW-39, 41 pp. P a c i f i c Northwest Forest and Range E x p e r i -ment S t a t i o n , P o r t l a n d , Oregon. Malmberg, D.B. 1968. " P r o f i t a b l e High Lead Thinning Methods." Paper presented to Redwood Region Logging Confer-ence, Eureka, C a l i f o r n i a , March 14-15, 1968. Mimeo. 6 pp. O'Leary, J.E. (ed.). 1969. S k y l i n e Logging Symposium Proceed-ings.. School of F o r e s t r y , Oregon State U n i v e r s i t y , C o r v a l l i s , Oregon. 100 pp. S p i e r s , J.J.K. 1956. "5ome Considerations i n Planning a Mobile Logging Operation." Unpublished Master's t h e s i s , U n i v e r s i t y of B r i t i s h Columbia. 99 pp. United States Department of the I n t e r i o r , Bureau of Land Management. 1967. Logging Costs Manual. Schedule 15. P o r t l a n d , Oregon. 189 pp. Worthington, N.P. and G.R. S t a e b l e r . 1961. Commercial T h i n -ning of Douglas f i r i n the P a c i f i c Northwest. U.S. Dept. of A g r i c . Forest S e r v i c e . Tech. B u l l . No. 1230, 124 pp. 113. APPENDIX I Glossary of Logging Terminology There are two major lo g g i n g methods i n the P a c i f i c Northwest today: f i r s t l y , t r a c t o r or skidder l o g g i n g , where a crawler t r a c t o r , or a r u b b e r - t i r e d a r t i c u l a t e d v e h i c l e , a s k i d d e r , " s k i d s " logs behind i t ; secondly, cable y a r d i n g , where a s t a t i o n a r y u n i t , the yarder, "yards" logs by means of cables to a c e n t r a l " l a n d i n g " , where the l o g s are loaded on t r u c k s . Haul roads connect the landings to a sawmill or p u l p m i l l . A s k y l i n e system i s a form of cable yarding i n which an a e r i a l cableway allows the " t u r n " of l o g s to be l i f t e d c l e a r of o b s t a c l e s . At the l a n d i n g the s k y l i n e i s suspended from a s t e e l tower; at the " b a c k l i n e " i t i s f a s t -ened to a stump, or to a " t a i l t r e e " where more l i f t i s r e q u i r e d . A s k y l i n e "road" r e f e r s to the area of ground from which the logs are yarded to any one s k y l i n e " s e t -up". When a l l the l o g s on a road have been yarded, the road i s "changed", that i s , the s k y l i n e i s moved to a new t a i l t r e e or stump, and the yarder may a l s o be moved to a new l a n d i n g . In t h i n n i n g with a s k y l i n e , a l l t r e e s i n the center ten or twelve f e e t of a road are cut by the " f a l l e r s " , to make a path f o r e x t r a c t i o n . Over the r e s t of the area, 114. Appendix I (cont'd) only c e r t a i n "marked" t r e e s are f a l l e n . The tower on the yarder i s held up s t r a i g h t by "guys". At a new l a n d i n g , " s e t t i n g up" i n v o l v e s p o s i t i o n -i n g the yarder, t a k i n g out the l i n e s , and "anchoring" the guys to stumps. A l i g h t l i n e , the " s t r a w l i n e " , i s p u l l e d around the road manually; i t i s hooked back onto the yarder and used to p u l l out the heavier l i n e s used i n y a r d i n g . These terms are i l l u s t r a t e d i n Figure (L ; the te x t and i l l u s t r a t i o n s of Chapter II w i l l serve to f u r t h e r c l a r i f y the s i t u a t i o n to the layman. F i g u r e 1. Logging Terminology, Road 1602 Study Area Map Headquarters Study Area Map APPENDIX IV West Coast Tower S p e c i f i c a t i o n s APPENDIX IV 119. CARRIER: Engine—Series 6-71 Diesel 239 gross vehicle horsepower ra 2100 r.p.m. 6 cylinder, 4 l/,"x5" (108 mm x 127 mm). Torque Converter—Allison—GM hydraulic (no clutch) Transmission—(Power Shi(l) Allison GM 3 speed Track—7 track rollers each side, 43 shoes, 78" track gauge. GENERAL DIMENSIONS Width-13' 9" track extended Height—11' 3" top of cab Length— 45': Weight Approx. 75,000 pounds. HOIST: Air controlled; self-aligning lifetime bearings, all clutches and brakes mounted outside of yarder frame for easy maintenance with quick release valves, air set dogs; = 100—1 Vi" .pitch chain. TOWER: 16" x 16" formed steel box section 32' with hydraulically con-trolled extension to 49'. Rubber-mounted slifflegs, 4" hy-draulic cylinder for boom extension. TOWER BASE: 1- beam construction and pin mounting for easy removal. POWER GUYLINES 2— Gearmatic No. HE hydraulic winches, cab-controlled, power in and power out, 11,000= pull each, 74' per min. line speed, bare drum (3rd guyline drum optional). AIR SYSTEM Bendix—Westinghouse 12 cu. ft. compressor, SAEJ1402 fit-tings and hoses. HYDRAULIC SYSTEM: Gear pump—35 g.p.m. @ 2000 lbs. p.s.i. Standard SAE100R2 fittings and hoses. Tank capacity 35 gallons. FAIRLEADS 2 Young Model 814—main and haulback. 1 Young Model 385—bullseye type—strawline. 4 Young Model 826 10" Blocks—guylines. 3 Young 821 8" TSA Sheaves—main, haulback and slackline. FUEL TANK 180 gallon capacity. STANDARD EQUIPMENT Fully-enclosed, rubber-mounted, full-visibility cab of all-bolted steel construction, 4 sliding windows, hinged roof panel, heater, defroster, windshield wiper, adjustable bucket seat, electric air horn, 35 amp. alternator, 24 volt starting system. Slackline Main Drum Haulback Strawline Line Capacity 2700'—ys" 2000'—1" 1600'—1 Ve" 1800'—%" 1800'—%" 3600'—5/,c" 5000'—1,4" Clutches Wichita ATD 214 Disc Wichita ATD 218 Disc Wichita ATD 214 Disc Wichita ATD 114 Disc Brakes 7" Air Band 3" 136%" Wichita ATD 118 Water Cooled Disc Wichita ATD 118 Water Cooled Disc 3"x21>/2" Band-Manual Shafts 3'5/16" 4140 heal treated 37/,o" 4140 heal ticated 4140 heal treated 3' 5/l6" 4140 heat treated Model WC6S-3 SPECIFICATIONS LINE SPEED Manulaclured, Sold and Serviced by: I1TE1STIIE T U T U 111 PORTLAND PORTLAND EUGENE MEDFORD 2855 N.W. Front Ave., 97208 • 2320 H.E. Columbia Blvd. 97211 1041 Highway 99N • Box 192 • 97401 5100 Crater Lake Ave. 97501 228-2333 2820017 688-7321 779-5255 1 2 0 . APPENDIX V Washington Model 98 Skylok Yarder S p e c i f i c a t i o n s APPENDIX V Specifications MODEL 98 SKYLOK Yarder Oowler mounted DIMENSIONS 4 AXLE TANK A Mox. height over "A" Frame 35' 8" 35' 8" B Mox. height to machinery house 12' 8" 12' 8" C Minimum swing clearance 4' 10" 4' 10" D Minimum ground clearance 12" 23" E Toil swing topping drum 14' 0" 14' 0" F Tail swing machinery deck 12' 0" 12' 0" G Top main sheave to haulback sheave 3' 0" 3' 0" H Boom length 40' 0" 40' 0" 1 Boom height to ground at 20° 44' 9" 44' 9" J Carrier height without Mono-race 4' Ah" 4' 7-3/4" K Length of tracks on ground 15' 4" L Overall carrier length 24' 2Yi" 19' 10-1/2" M Height over operator's cab 14' 11" 14' 11" N Width of operator's cab 3' 6" 3' 6" 0 Mox- width of machinery house 8' 0" 8' 0" Pi Width from center 6' 5" 6' 5" Pz Width from center 4" 0" 4' 0" Q Boom pin to ground 6' 9" 6' 9" R Center to center track Ireod — — 92" S Width of track tread 2' 0" T Width over outside tracks U Ovoroll width of carrier 10' 0" V Centers af front & rear tandems 54" w Center to center of outriggers 12' 2" Wheel Base 13' 6" Y Width over outside tires 8' 8" z Width of rear track 80" AA Width of steering track 90" BE Mox width of retracted jacks 11' 0" CC Center to center of retractable jack 14" 0" LINE PULLS, SPEEDS and CAPACITIES Main Drums Reor Front Haulback Max. line pull (lbs.) Ful l drum 60,000 18,000 11,100 Bare drum 70,000 22,800 16,750 Max. Line speed (fpm] Ful l drum 904 904 713-1,363 Bare drum 712 712 471-903 Line size 5/8" 5/8" 3/4" Capacity 1,000' 1,000' 2,100' OTHER DATA Swing speed, 4.8 rpm Travel speed, 0 to 10.4 mph Tank 13.4 M.P.H. 4 Axle Gradeability, 25% Tank 25% 4 Axle Washington "Var i - l ok " drive assembly is covered by U.S. patent nos.: 3,300,188; .3,282,569; 3,002,385. Other U.S. and Canadian patents pending. W ® mmm. w 1500 Sixth Avenue South Seattle. Wail, SSI34 . Tel. (206) 623-1292 PRINTED IN U.S.A. 1966, WASHINGTON IRON WORKS APPENDIX VI I n f i n i t e l y V a r i a b l e I n t e r l o c k i n g I N F I N I T E L Y V A R I A B L E I N T E R L O C K I N G J i m E. Raven Sales Manager, Logg ing D i v i s i on Wash ing ton I ron W o r k s Seat t le , Wash ing ton W A S H I N G T O N I R O N W O R K S H A S P R O D U C E D Y A R D I N G M A C H I N E S O F I N T E R L O C K I N G D E S I G N fo r the past 5 years. The design m a y best be desc r ibed as " s t e p " o r " s h i f t " ' i n t e r l o c k i n g , where a de f i n i te step in gears is made by sh i f t i ng , to e i t he r increase o r decrease the speed o f the reced ing l ine and , as near l y as poss ib le, to s ynchron i ze it w i t h the i nhau l i ng l ine. A l t h o u g h this is the s implest o f i n t e r l o c k i n g designs, it is d i f f i c u l t for the opera to r s to understand. I n te r l o ck i ng yarders have proven to have m a n y advantages o v e r c o n v e n t i o n a l yarder s , once the opera to r has learned h o w to take advantage o f t hem. I N F I N I T E L Y V A R I A B L E I N T E R L O C K I N G IS N E W . It has been d e v e l o p e d b y the Eng inee r i ng D e p a r t m e n t o f i Wash ington I r on W o r k s under the d i r e c t i o n o f Rus se l l T h o m p s o n , C h i e f Eng ineer o f the Logg ing D i v i s i on . Its deve lopment w a s a ided b y pat ience and c o o p e r a t i o n f r o m the owners o f the f i r s t few mach ine s p r o d u c e d . T h e f i rst a pp l i c a t i o n o f this s y s tem was in the design o f the ba l l o on ya rde r that was • made f o r B o h e m i a L u m b e r C o m p a n y 4 years ago. A new and larger b a l l o o n ya rder w i t h t h i s sy s tem is n o w be i n g manu fac tu red fo r the same c o m p a n y . I n f i n i t e l y var iab le ! i n t e r l o c k i n g has been app l i ed also in o u r S k y l o k Y a r d e r M o d e l s - 108 and 98 . T h e f irst S k y l o k M o d e l 108 was de l ivered to Weyerhaeuser C o m p a n y at V a i l , W a s h i n g t o n , in Janua ry , 1968. Since tha t .da te we have de l i ve red twe lve units that are w o r k i n g in A l a s ka , B r i t i s h C o l u m b i a , Wash i ng ton , Oregon, and C a l i f o r n i a (F igure 1). T h e sma l le r S k y l o k , M o d e l 98, is n o w on o u r assembly l i ne . We are also m a n u f a c t u r i n g for an O regon l u m b e r company, . a - l a r g e s k y l i n e , yarder. w i t h an in f in i te ly , var iable ' i n t e r l o c k i n g s y s tem. I p o i n t ou t these app l i c a t i on s mere ly to impress u p o n y o u that the s y s tem o f i n f i n i t e l y var iable F igure I. M o r e than a d o z e n un i t s o f the S k y l o k Y a r d e r M o d e l 108 w i t h i n f i n i t e l y var iable i n t e r l o c k i n g are w o r k i n g on the West Coast f r o m A la ska to C a l i f o r n i a . i n t e r l o c k i n g is not a d ream, not an e xpe r imen t , bu t a design pu t i n to pract ica l app l i c a t i on w i t h successfu l results. Because we are interested spec i f i ca l l y in the i n f i n i t e l y var iable i n t e r l o ck i n g sys tem, I w i l l not discuss deta i l s o f the c omp l e t e mach ine , but jus t how the system powers and c o n t r o l s the set o f drums. T h e main source o f p owe r is a De t r o i t Diesel M o d e l 8 V - 7 1 , 318-hor sepower engine. A t t a c h e d to the f l y wheel hou s i n g is a cha in case w i t h a h yd r au l i c - pump dr ive. A t t a c h e d c o a x i a l l y to this c ha i n case is a T w i n D i sc , single-stage to rque conve r t e r that dr ives a T w i n Disc, fu l l - revers ing, four-speed, power - sh i f t , t ransmiss ion. Power is t r an smi t ted f r o m the t ransmi s s i on t h rough a drive l ine i n to a bevel p i n i o n and ring-gear hous ing . The ring gear dr ives the shaft and bu l l p i n i o n that p o w e r the d rums (F igure 2 ) . I have so far descr ibed the f l o w o f p o w e r f r o m the d ie se l engine to the dr ive p i n i o n for the main d r u m . N o w , r e tu rn to the d iese l engine f l y w h e e l and f o l l o w the power t ra in f r o m the h y d r a u l i c drive o r pumps to the h y d r a u l i c m o t o r that dr ives the p lanetary c on t r o l p i n i o n . T h e h y d r a u l i c m o t o r is a t t ached t o a reducing-gear b o x that gives the p r ope r rat io and power . T h e power o f the diesel engine is d i v i ded i n t o t w o con t ro l l ab l e power trains, one mechan i ca l and one h y d r a u l i c . Each o f these powe r t ra ins has c o n t r o l l i n g levers w i t h i n the ope ra to r ' s cab. T h e power-sh i f t t ransmiss ion is c o n t r o l l e d b y a speed and d i r ec t i on se lector; the h y d r a u l i c power t ra in has a single con t ro l lever. E i t he r set o f con t ro l s can d e t e r m i n e t h e ' t o rque and speed o f each o f the two trains. The m e c h a n i c a l train is con t ro l l ed th rough the t ransmiss ion and conve r te r b y sh i f t i ng . The h yd r au l i c train is c o n t r o l l e d th rough i n f i n i t e chang ing o f h yd r au l i c pressure b y valv ing w i t h a range f r o m n o pressure to m a x i m u m pressure and vo l ume . T h e key assembly between the two d r i ve p i n i on s is s i m p l y a p lanetary arrangement s im i l a r to that o f the Hy s t e r two- speed w i n c h o r a Western Gear Torq-Master . T h e main d i f f e r ence in this p lanetary is that w'c do not use a b rake to make the change in speed rat io. In place o f the b rake ring we use a gear, a nd in place o f the brake bund we use a pinion. T h i s p i n i o n , because it is i n f i n i t e l y con t ro l l ed and powered by the h yd r au l i c s y s t em, not o n l y can exceed the e f f i c i e n c y o f brakes but also can be i n s tan t l y reversed to give i n f i n i t e c o n t r o l in e i ther d i r e c t i o n o f r o t a t i o n . The main dr ive p i n i on is d r i v i ng the large s k y l i n e gear, w h i c h drives the s ky l i ne d r u m th rough a set o f p l ane ta r y p in ions . The h yd r au l i c dr ive p i n i o n can accelerate o r dece lerate and c o n t r o l the speed ra t i o th rough the p lanetary p i n i o n i n t o the s k y l i ne d rum. Whatever the speed o f the main l ine may be, the ra t i o w i th in the p lanetary can be adjusted to s y n c h r o n i z e the s k y l i ne w i t h the main l ine. 82 124 Figure 2. Schematic drawing of the power (rain of the Skylok Yarder Model 108 with infinitely variable interlocking. The ability of Ihe hydraulic drive to reverse makes possible the raising or lowering of the skyline while the logging carriage is traveling in cither direction. In other words, the skyline drum can be put instantly into rotation in either direction. The hydraulic drive also permits the operation of the skyline drum independently, with the main drum disengaged. In high-leading, this ability to reverse also permits the operation of the haulback und the main drum as a conventional yarder; that is, having both lines inhauling at the same time to permit picking the rigging directly off the landing or picking a turn directly out of a hole. Another advantage of the hydraulic system is that the maximum pull available on the line is predetermined. Washington Iron Works has found, by experimenting and experience, the maximum tension required in a skyline. We have also found that with brakes, the tension on these lines can be much greater than necessary. This over-tensioning shortens the life of the table and rigging without a gain in production. The gear for Ihe main drum is interlocked with the gear for the skyline drum. The main shaft is splined for the driven gear, and driving gear, driving sprocket, and the Twin Disc air-actuated plate clutch that powers the drum. The drum is bushed for free wheeling on the shaft. The assembly includes a split, cast-iron brake ring that holds up the rigging when it is not in motion. The third drum, located directly in front of the main drum, is powered by either a gear identical in size to the one on the main drum, or a sprocket also identical in size to the sprocket on the main drum. The front drum is thus interlocked to the main drum. Because the front drum is identical in dimensions to the main drum, both lines will travel at the same speed. The gear and sprocket run on anti-friction bearings and each is connected to the shaft by clutches. The drum is also splined to the shaft; whichever clutch is engaged at the time will drive the shaft and, in turn, drive the drum. When the gear is engaged, the-rotation of the drum will be opposite to that of the main drum. With engagement of the sprocket clutch, the gear clutch will automatically disengage and the drum will rotate in the same direction as the main drum. This shifting of the third drum from clockwise to counterclockwise rotation is accomplished by simply depressing the push button on the control lever for Ihe skyline drum. 1 would like to emphasize the configuration of the three drums: the skyline, the main and the third drum. The drum barrels are long and the depth of the flanges is shallow. One outstanding result from this design is the slight difference in line speeds and pulls between full drum and bare drums. In our Model 108 Skylok, about 10 percent is the difference in the speed or line pull of the two extremes. We, therefore, establish a better, overall average figure of two of the most important factors that a yarder of any type depends upon, the line pulls and speeds. Another advantage of the large-diameter barrel is additional life. We have made an improvement on the assembly of the straw drum with the introduction of a smoother, more controllable strawline brake on our Skylok machines. Because all of the interlocking yardcrs made by Washington iron Works power the straw drum in either direction of rotation, we needed a brake system that we could control equally well in either direction. We have thus adapted a caliper brake, known in the automotive industry as a disc brake, for this purpose. In summary, infinitely variable interlocking design results in infinite interlocking of the skyline drum assembly, which provides: Infinitely variable speed ratio; Infinitely variable line tensioning control; Control of maximum line pull on skyline; Instant reversing of skyline drum to pick up, or pay out, line to suit terrain or line deflection; Elimination of running brakes; Elimination of a haulback clutch (The closed hydraulic circuit that operates the infinitely variable interlocking system does not create enough heat to require a cooling system for the oil. We can assume, therefore, that much less horsepower is required for tensioning the skyline than would the braking system of A N Y brake design that needs a cooling system. Thus, more of the available engine horsepower is released to line pulls and speeds.); and Simplified operating controls (The controls include one lever for infinite skyline control; one push button on the same lever for reversing the third drum; a four-speed gearshift lever and reversing lever for the power-shift transmission; a foot and hand throttle for the diescl engine; and four foot-treadles for the air-actuated drum brakes.). 83 125. APPENDIX VII Marking D o u g l a s - f i r f o r Thinning at Kaingaroa F o r e s t Kningnroa F o r e s t , via Kctarua. 22 Zn temper 1965. • I t ha* been decided that where the stooging i s s u f f i c i e n t In Dougteg f i r hauler settings. 12C trees por acre vd.ll "be marked f o r retention. The. pro-p o r t i o n of the s e t t i n g taken xip by trackr- w i l l vary fro.n hauler to b«cA:3ii» and to obtain r.:i ever, stocking of ore", trees, i t w i l l •therefore fee neoc••r.rt.ry to "art: aore t r e t s to*-, res the f r o r . T ?..-.d lees tove.ror. the bark of -!-..» se t t i n g . Ursder ftvori.'gi: conditions of track width and rraek spacing (/..i the "be z^.i~^}. it''.rould bo lieceisary to snsrl: 300 s.p.n. at of the di.itancf! free, /viuler T O b a c k l i n e , 275 s.p.a. at £ way, '15° s.p.a.. a t the 3 - mark, etc. i n order to er<5 up with 120 s.p.a. o v e r a l l a f t e r thinning. The- f o l l o w i n g procedure f cr Barking i s prescribed : (1) Dan-arc*te 15' wide tracks e i t h e r by spotting trees to be f e l l e d f o r tracking or by dropping out th«« tracks. (2) l r . the areas *«fr)wen tracks w>rk as follows (where s t o c k i i i g a l l o w s ) : (a) 'Proas halfway to the backline ( i . e . generally the. face opposite the hauler) nark 150 s.p.a. f o r r e t e n t i o n . This i s equivalent to a spacing of 1?" x 17' (square) or 18-' x 16i' (-txi&ivpulsa-). (b) Sroa quarter to balf«ray, mark 200 s.p.a. 1$' z 15' (square , or 16' x 16' (tr.taneular). .(c) .fe-om the hauler to quarter v*y r e t a i n a l l .trees between -the tracks except gross c a l f o r a s . The r e s u l t w i l l be an average crop a f t e r thinning of about 120 s.p.a. Marking to the prescribed intensities can be made before t r a c k s are demarcated but large gaps may then r e s u l t a f t e r thinning and t h i s should bs avoided. aiarked trees should be of good fern arid as evenly spaced as pc;.iaibl< 127.' APPENDIX VIII Simulation Program L i s t i n g and Output V a r i a b l e L i s t A a uniform random number AA c o e f f i c i e n t "a" i n a quadratic equation ax^ + bx + c = 0. AAA an array used i n r o u t i n e 0LQF AREA area logged on the road B a uniform random number BB c o e f f i c i e n t "b" i n a quadratic equation ax^ + bx + c = 0. BBB an array used i n r o u t i n e QLQF BACK width of a s k y l i n e road at the b a c k l i n e BO Breakout time C Chase time CC c o e f f i c i e n t "c" i n a quadratic equation ax^ + bx + c = 0. DR Drop Rigging time FR width of a s k y l i n e road at the l a n d i n g G Get Clear time H hangup f a c t o r i n the Yard element I hundreds of f e e t e x t e r n a l yarding d i s t a n c e ICH number of chokers flown IC5ET number of chokers set IIC ' number of pieces i n a turn minus number of chokers set Appendix \J1II A cont' d) 128 i" IYDR yarder number; 1 f o r West Coast Tower, 2 f o r Washington 98 JRAD e x t e r n a l yarding d i s t a n c e minus 100 f e e t KROA equals 1 to simulate l o g g i n g at Kaingaroa, • at Longview K number of road being logged KPCS cumulative piece count f o r a road KRAD e x t e r n a l yarding d i s t a n c e L e x t e r n a l yarding d i s t a n c e LAT h a l f - w i d t h of a road LK a l o g i c a l v a r i a b l e ; i f set = .TRUE., s t r a i g h t l i n e cannot be f i t t e d by r o u t i n e QLQF LL e x t e r n a l yarding distance i n hundreds of f e e t , minus 1. MPC cumulative piece count f o r a road IMFR width of s k y l i n e road at l a n d i n g , plus 1 NBACK 161 minus width of s k y l i n e road at b a c k l i n e NTREE 0 i f t a i l t r e e not rigg e d ; 1 i f t a i l t r e e r i g g e d NPC piece count f o r the turn P a uniform random number PB percentage of Breakout time PP percentage of P u l l Slack time PR percentage of Return time PS P u l l Slack time PT t o t a l time, d i v i d e d by 100 PY percentage of Yard time Appendix VI11 (Cont'd) 1 2 9 •" PPA pieces per acre (average) PPT pieces per turn (average) PPP an array c o n t a i n i n g the c o e f f i c i e n t s of the f i t t e d polynomial PRCH percentage of Road Change time PTI percentage of I d l e time PTT percentage of Turn time Q a uniform random number R Return time RA Raise Rigging time RC Road Change During Yarding time RIG Rig time RCH Road Change time S Set Chokers time SA an array c o n t a i n i n g c o e f f i c i e n t s of the orthogonal polynomials generated by r o u t i n e QLQF SB cumulative Breakout time 5C cumulative Chase time SD standard d e v i a t i o n of the times per thousand square f e e t SDR cumulative Drop time SG cumulative Get C l e a r time SIGMA a s t a t i s t i c a v a i l a b l e from r o u t i n e QLQF SLQPE slope f a c t o r SRA cumulative Raise Rigging time SR cumulative Return time Appendix :VII I (Cont'd) 130. SRC cumulative Road Change During Yarding time SRIG cumulative Rig Time SS cumulative Set Chokers time SSQ sum of squares, from r o u t i n e QLQF STT cumulative turn time SU cumulative Untangle Chokers time SWA cumulative Wait f o r Skidder time SP cumulative P u l l Slack time SY cumulative Yard time TI I d l e time TIME cumulative time to l o g a road TIMEPA average time to l o g a thousand square f e e t , f o r ten roads TP time to l o g a thousand square f e e t on each of ten roads TPERA time to l o g a thousand square f e e t , on one road TT turn time U Untangle Chokers time Y yarding d i s t a n c e YA Yard time YY i n c r e a s e i n yarding d i s t a n c e from one turn to the next WA Wait f o r Skidder time WID width of a s k y l i n e road WT 1 i f a l l (x,y) p a i r s given equal weight i n r o u t i n e QLQF Appendix tfm (cont'd) 131. XD arra,y c o n t a i n i n g values of the independent v a r i a b l e , yarding distance f o r r o u t i n e QLQF XL v a r i a b l e used to keep track of 100 foot yard-ing d i s t a n ce i n t e r v a l s XRAD e x t e r n a l yarding d i s t a n c e 2 XX term b -4.a.c i n s o l v i n g q u adratic equation ax^ + bx + c = 0 YT array c o n t a i n i n g values of the dependent v a r i a b l e , time, f o r r o u t i n e QLQF YF an array c o n t a i n i n g f i t t e d values of the dependent v a r i a b l e i n r o u t i n e QLQF YD an array of r e s i d u a l s i n r o u t i n e OLQF YDIST e x t e r n a l yarding d i s t a n c e Z a uniform random number ZB cumulative Breakout time ZP cumulative P u l l Slack time ZR cumulative Return time ZRCH cumulative Road Change time ZY cumulative Yard time ZTI cumulative I d l e time ZTT cumulative turn time The program l i s t i n g and t y p i c a l output are presented i n the pocket at the back of the t h e s i s . APPENDIX IX 1 3 2 . Thinning P r e s c r i p t i o n f o r D o u g l a s - f i r Stand i n New Zealand P r e s c r i p t i o n Oayc-r^-a-xi O f f i c e r i n Charge, "mumiKOS: KAINGAROA FOREST. 28/0/5 BW:ELS KAIKOAROA FOSEST VIA BOTOEUA August 21*, 1966. THINNING PRESCRIPTION FOR CPT> 112? STAND DATA: PRESCRIPTION Douglas F i r Planted 1923, 8x8. High pruned 1950 Preaent stocking about 380 e.p.a. The same as for the h a u l e r - s e t t i n g i n 1127, 1128 repeated hereunder. 1 -1 0 , I A I .,o Thin with e x t r a c t i o n to leave 120 s.p Qa, o v e r a l l , , ^ ' Crop trees to be evenly spaced dominant, or co-JrU,C_ *tv.^-£ Cfe,wv.o A.<.. 2.7~f dominant high pruned where-over p o s s i b l e . Largo unstoclced gaps to be avdded. v$-02. < — y j j g n o t e for marking Douglas F i r hauler s e t t i n g s ^ad^ ' ^ ^ ( r ^ - c i v / a ^ - . . i t should be adhered too. O.A.tfoyd Actin g O f f i c e r i n Charce 133. Map of area at Kaingaroa, New Zealand, f o r which t h i n n i n g was simulated. 134. APPENDIX X-C a l c u l a t i o n of Hourly Machine and Labor Rates Reference Sources Various s u p p l i e r s and owners s u p p l i e d i n f o r m a t i o n on the cost of equipment, i t s working l i f e , f u e l , r e p a i r s , s e r -v i c e , r i g g i n g , and t i r e s . The I n t e r n a t i o n a l Woodworkers of America at Port Angeles, Washington s u p p l i e d wage r a t e s which were taken to be t y p i c a l f o r the D o u g l a s - f i r r e g i o n . Wage adjustments were taken from the United States Department of the I n t e r i o r Bureau of Land Management Logging Costs Manual, Schedule .15, Page .81. New Zealand wage r a t e s and adjustments were s u p p l i e d by the New Zealand Forest S e r v i c e . Machine Rate Determination The procedure should be s e l f - e x p l a n a t o r y . S t r a i g h t -l i n e d e p r e c i a t i o n was used. I n t e r e s t was not charged, be-cause i t was not considered that the " l o s t o p p o r t u n i t y " p h i l o -sophy was v a l i d , but r a t h e r that i n t e r e s t should be charged only where money was a c t u a l l y borrowed to buy the machine. Insurance was not i n c l u d e d , as some owners do not i n s u r e equipment. Taxes were not i n c l u d e d because they vary between 5tates and c o u n t r i e s . F r e i g h t to the work s i t e was not added. The same r e t a i l p r i c e f o r each machine was assumed f o r both the United States and New Zealand, and t h i s i s only an a p p r o x i -mation. Appendix X (cont'd) 135. Operation Rate Determination Again, the procedure i s s e l f - e x p l a n a t o r y . Overheads were not i n c l u d e d as these w i l l depend on the company. MACHINE COSTS 1. West Coast Tower Investment: Yarder Carria g e $92,750 6.500 $99.250 Depreciable value: 90% of investment $89,375 dep r e c i a t e over 6 years at 1750 hours = 10,500 hours Fixed cost R igging: annual r e p l l i n e s : chokers, b e l l s 5 times a year: blocks ( d e a l e r estimate) Rigging F u e l (dealer estimate) S e r v i c e (•£• f u e l ) Repairs and l a b o r @ 63% of depre-c i a t i o n Operating cost T o t a l machine cost $8.50/hour $2300/year $1.31/hour .13/hour 1.44/hour .76/hour .38/hour 5.35/hour  7.93/hour  Sl6.43/hour Appendix X (Cont'd) 136:. 2. Washington Model 98 Skylok Yarder Investment: Yarder $110,000 Depreciable value: 9Q% of investment 99,000 dep r e c i a t e over 6 years @! 1750 hours = 10,500 hours Fixed cost 9.43/hour Rigging: C a r r i a g e and chokers r e p l a f t e r 2 years: $67Q/year = ,38/hour blocks, l i n e s $2Q26/year r i g g i n g Fuel (dealer estimate) S e r v i c e (dealer estimate) Repairs and l a b o r @ 63% of d e p r e c i a t i o n Operating cost T o t a l machine cost 1.16/hour 1.54/hour ,90/hour .39/hour 5.94/hour  8.77/hour  $ 18.20/hour 3. Nelson Batson Highway Model Preload Bunk Investment: Bunk with 30 f t . reach d e p r e c i a t e to nothing over 13,000 hours Fixed cost Fuel 2 gal./day S e r v i c e Repairs and l a b o r $400/1750 hours Operating cost  T o t a l machine cost % 20,200 1.55/hour .10/hour .10/hour .23/hour .43/hour $1.98/hour 137. 4. F r a n k l i n 170 PS skidder with 42 i n c h Esco grapple Investment: Skidder 126,150 Grapple ( i n s t a l l e d ) 6,850 Depreciable value: 80$ of investment 26,400 dep r e c i a t e over 7000 hours (de a l e r estimate) Fixed cost 3.77/hour' Repairs and l a b o r (owner estimate) 3.00/hour T i r e s — 4 sets 23.1 x 26 Logger S p e c i a l 12 p l y $482.75 x 4 1.13/hour Fuel .33/hour Lube .04/hour Hyd r a u l i c o i l .02/hour Operating cost $4.52/hour T o t a l machine cost $8.29/hour 5. McCulloch 610a chainsaw with 20 inch bar Investment: saw $250. depr e c i a t e over 3000 hours; but i n use say of the time on the l a n d i n g ; d e p r e c i a t e over 6000 yarder hours Fixed cost Repairs and l a b o r @ 9Q% of d e p r e c i a t i o n Fuel and o i l Chain o i l Chains $20 f o r 160 hours Operating cost T o t a l machine cost .04/hour $ .04/hour .04/hour .03/hour .02/hour .13/hour  .22/hour $ .26/hour 138, 6. T a l k i e Tooters Investment: 1 r e c e i v e r , 2 w h i s t l e s Depreciable value 9 0 % investment d e p r e c i a t e over 8000 hours D e p r e c i a t i o n  T o t a l machine cost 12400 2100 ,27/hour  .27/hour 7* Communications User estimate T o t a l cost $ .60/hour 8. Axes, climbing gear, tapes, e t c . User estimate T o t a l cost $ ,25/hour 9. T o t a l Cost of Miscellaneous (5,6,7,8) Saw, communications, T a l k i e Tooters, axes, e t c . 1.38/hour 139* 10. Priestman Bison Loader Investment Loader C a r r i e r (used truck) Deprecieble value: 90% of investment d e p r e c i a t e over 10,500 hours Fixed cost Rigging (user estimate) Repairs and l a b o r @63% of d e p r e c i a t i o n F u e l (user estimate) Lube T i r e s (user estimate) Operating cost  T o t a l machine cost $35,000 10.000 $45,000 40,500 $ 3.86/hour ,46/hour 2.42/hour ,50/hour .10/hour .10/hour  3.5B/hour  $ 7.44/hour 11. P r e n t i c e D-100 Hy d r a u l i c Loader Investment: Upper works $23,835 C a r r i e r (used truck) Depreciable value 90$ of investment 10.000 $33,835 30,500 depr e c i a t e over 10,500 hours Fixed cost Repairs and l a b o r @ 80$ of d e p r e c i a t i o n Fuel @ 20 g a l / 6 h i I 110/gal Lube Hydraulic o i l 100 gal/1750 hrs. @ 850/gal $2.90/hour 2.32/hour .28/hour ,04/hour .05/hour 140. 11. (cont'd) T i r e s .10/hour Operating cost 2.79/hour T o t a l machine cost 5.69/hour LABOR COSTS WASHINGTON Wages: yarder engineer $4.55 Unit hooker 4.28 Chokersetter 3.78 Chaser 3.80 Hooker 5.35 Wages f o r yarding crew 21.76 Workman's b e n e f i t s @.5Q/hr 2.50 Sup e r v i s i o n 1% 1.52 Employer's c o n t r i b u t i o n s 15% 3.26 T r a n s p o r t a t i o n 1.25 T r a v e l pay 1.75 Labor cost f o r varding crew 32.04 per hour Wages: Skidder operator 4.75 Workman's b e n e f i t s .50 S u p e r v i s i o n .33 Employer's c o n t r i b u t i o n .71 T r a n s p o r t a t i o n .25 T r a v e l pay .35 Labor cost f o r Skidder $6.89 per hour Labor Costs Washington (Cont'd) Wages: Loader operator 5.13 Workman's b e n e f i t s .50 Employer's c o n t r i b u t i o n .77 Su p e r v i s i o n .36 T r a n s p o r t a t i o n .25 T r a v e l pay .35 Labor cost f o r Loader $7.36 per hour 142, NEW ZEALAND Wages: Hooker $1.12 Yarder engineer 1.04 Chaser 1.02 Unit hooker .97 Chokersetter .97 Wages f o r yarding crew $5.12 Wet time 10% .51 Bonus 1.50 Transport 1.90 Su p e r v i s i o n 10% .51 Employer's c o n t r i b u t i o n s .80 B e n e f i t s - 5% .26 Labor cost f o r yarding crew $10.60 per hour Wages: Skidder or Loader operator 1.10 Wet time .11 Bonus .30 Transport .38 Su p e r v i s i o n .11 Employer's c o n t r i b u t i o n s .16 B e n e f i t s .05 Labor cost f o r Skidder or Loader $2.21 per hour OPERATION COSTS 143. 1. West Coast Tower Washington New Zealand Machine $16.43 $16.43 Miscellaneous 1.38 1.38 Labor 32.04 10.60 -T o t a l vardinq cost $49.58 $28.41 per hour 2. Washington Model 98 Machine $18.20 $18.20 Miscellaneous 1.38 1.38 Labor 32.04 10.60 T o t a l vardinq cost $51.62 $30.18 per hour 3. Grapple Skidder and Pre- l o a d Bunk M a c h i n e s — s k i d d e r $ 8.29 $ 8.29 bunk 1.98 1.98 Labor 6.89 2.21 T o t a l l o a d i n a cost $17.16 $12.48 per hour 4. Priestman Bison Loader Machine $ 7.44 $ 7.44 Labor 7.36 2.21 T o t a l l o a d i n q cost $14.80 $ 9.85 For a loader per 2 s k v l i n e s 7.40 $ 4.92 per hour 5. P r e n t i c e D-100 Hydraulic Loader and pre -load bunk M a c h i n e s — l o a d e r $ 5.69 $ 5.69 bunk 1.9'B 1.98 Labor 7.36 2.21 T o t a l l o a d i n q cost $15.01 $ 9.90 per hour . '-\/\/\ /\ s\ f \ *\ /\ f\. /\ /\ s\ r\ AAAAAAAAAAA AAAAAAAAAAAAAAAAAAAAAA AAAAAAAAAAAAAAAA AAAA AA AAAAA AAA A A AA AAAAAA AA.AA AAA RFS NO. 160032 UNIVERSITY OF B C COMPUTING CENTRE MTS(AN120) 10:14:02 08-31-70 $SIG EHOA P=20 T=10 ••i.AST ^ I G N O N WAS: 1 0 ; 1 3 : 5 1 0 8 - 3 1 - 7 0 USER "EHOA" SIGNED ON AT 10:14:04 ON 08-31-70 $ L I S GENERAL 1 .2 r LD.GCJJVLG.. AT. K A T NG.ARDA : KR0A=1. ADD 1,01, SLOPF FAC TOR.**** 1.5 KROA=G 1.7 SLGPE=1. ? TFIKROA.EO.1 ) SL0PE=1.1 3 IF ( K R O A . G T . l ) GO TO 480 4 • DO 450 IYDR=1,2 5 DIMENSION X D ( 1 0 ) , Y T ( 10>,YF( 10).YD( 10) .«T( 10) .SA( 5) . 6 1 SIGMA<5),AAA<5),BBB{5>,PPP(5) 7 LOGICAL LK 8 LK=.TRU E. -8.5 c LOOP INCREMENTING WIDTH AT LAND ING;BY PASS ROADS TOO WIDE OR 8.6 c TOO NARROW FOR WASHINGTON YARDER. 9 ._ DO _45 1 NFR= 12 1.161. 40 9.5 I F {IYDR.EQ.2.AND.NF R.LT.44) GO TO 451 9.7 IF«IYDR.EQ.2.AND.NFR.GT.122) GO TO 45 1 1 0 FR=NFR-1 10.5 c LOOP INCREMENTING WIDTH AT BAC K L I N E . 11 DO 452 NBACK=1,41,40 1? _ ._ BAC.K=FLOAT (161-NBACK) 12.4 IF(BACK.GT.122..AND.IYDR.EQ.2) GO TO 452 12.6 IF(BACK.LT.45..AND.IYDR.EQ.2) GO TO 452 12. 8 c. LOOP INCREMENTING EXTERNAL YARDING DISTANCE. 13 DO 442 KRAD=201»lOOlt100 P 14 WRITEI6,7) KRAD,FR,BACK 15 7 F FIRM A T ( 1 » f*ROAD LFNGTH* .15/* * «' FRONT * , F6 .0 « * BACK • , F6 .0// ) 16 XRAD=FLOAT(KRAD) 17 K=0 18 N TR E E = 0 19 DIMENSION Y D I S T ( 1 1 0 0 ) , T I M E P A ( 1 1 0 0 ) , T I M E I 1 1 0 0 ) , S D ( 1 1 0 0 ) , 20 1 SSQ(1100) , T P ( 1 1 G Q ) , K P C S 1 1 1 0 0 ) , Z R < 1 1 0 0 ) , Z Y { 1 1 0 0 ), 2-1 - 2 ? P M 1 0 0 ) f 7 R { I 100) ,ZRCH<1100) ,7TT <1100) , 7TT(1 100) 21.5 C SET SUMS TO ZERO. 22 DO 1 L = l t l 0 0 1 t l O O ?3 K P C S ( L ) = 0 . 24 Z R ( L ) = 0 . 25 Z Y ( L ) = 0 . ' 26 7 P I I ) = n. 27 Z B ( L ) = 0 . 28 Z R C H ( L ) = 0 . • ' 29 Z T K L h O . 30 Z T T ( L ) = 0 . 31 S S Q ( L ) = 0 . / 32 1 T P ( ! ) = 0 . 33 3 XL=-100 33.5 C INCREMENT # OF ROADS LOGGED. 3 4 K=K+1 35 y=i. . I N 36 SRA=0. 3 7 r, 94 SPA + ?0% RRFAKAGF = 113 PC. <; PA 38 PPA=113. 39 I F ( K R O A . E Q . l ) PPA=360. 40 * * * * ? 7 7 SPA + 303? BREAKAGE AT KAINGAROA**** 41 R=0. 42 ICH=4 43 SR-0. 44 SRC=0. 45 SDR=0. 46 SRIG=0. J 47 su=o. 48 SG=0. 4.9.. ss=n. 50 SP = 0. 51 SB=0. 52 SY=0. 53 sc=o. 54 SWA=0. 55 M P C = O . 56 TT=0. 57 STT=0. 57. 5 C INCREMENT # OF A 100 FT. SECTION. 58 4 XL=XL+10Q. 59 C WIDTH DF ROAD. 60 10 WTn=ARS(Y/XRAD*<BACK-FRV+FR) 61 IF<WID.LT..01) GO TO 333 62 PPT=4.6 V 62.2 C ****SMALLER PIECE SIZE AT KAINGAROA: MORE PIECES PER TURN**** 62 .5 IF{KROA.EQ.1) PPT=5.7 62.7 C AVERAGE AREA PER TURN. 63 APT=43560.*PPT/PPA 63.5 C C FIND HOW MUCH FURTHER TO NEXT TURN. 65 IFiABS(BACK-FR).LT.1.) GO TO 13 66 AA=ASS(BACK-FR ) / t XR AD*2. ) 67 BB=WID 72 CC=-{APT) 73 12 XX=BB**?-4.*AA*CC 74 YY=(SQRT(XX)-BB)/(2.*AA) 75 GO TO 14 76 13 YY= AB S(APT/WID) 77 14 y=Y+YY 77.5 C FIND LATERAL DISTANCE CLASS. 7ft 1 AT = WJ D/2. + 10. 79 IF(LAT .LT.90) LAT=90 80 IF(LAT.LT.70) LAT=70 81 IF(LAT.LT.50) LAT=50 82 IF(LAT.LT.30) LAT=30 83 C RETURN 83.5 f. T 1 84 15 R=.06+.00065*Y 85 IFUYDR.EQ.2) R=.08+..0015*Y • 86 R=R*SLOPE 87 SR=SR+R 88 C DROP 88 ,5 f T 2 89 DR=.09 90 SOR=SDR+0R 91 C UNTANGLE TIME 91.5 C T 3 92 A=RAND(0.) Q3 U=-.07+5.06*A-25.62*A*A+76.61*A**3-117.56*A**4>87,19*A**5 94 1 -23.94*A**6 95 IF( A.GT.170.7177. ) U=29.*A-26.4 Q6 T F ( TCH.FQ.3 ) U= .0 3+. 7 5* A+-3. 7*A*A-1 2. 1 6*A**3+13. 6?*A**4-4. 91#A**5 o it o « _J + • z> r> oo <— II =) I - I oo IX) 00 Of LU a x o o CM a C7 X C o i — i <J — cc LL II i ~ < X CJ o f - t O C M J ' O ' -o <?• a o a CM II LU LU oo <s o <_ CM CM LU oo o CM fM LU < 00 — O LL LL, C rH C\ r\l .—i I— fl C a H i— LU <r oo O O LL CD I - I > -o CM CM ro -* in -o r-O O Q O O C CM ,-1 II !1 h- t-LU LU 00 00 O O oo oo CM CM 03 ,H IT, r-CM CM 3 LU > CD o oo < LU LU •< 00 LU 00 00 cc LU O I X o • • 00 < I— r- od LU CD CD LU id a: a o x LU < < U- IX. 1-4 in LU oo (— in r~-oo cr d o o O O -4 rH —I LU < 00 a LU X. c O0 < oo a < •«• •if-o — o tn c ro ro o o c I— h- I— o a c CO cD CD' <r ro CM1 a o a LU LU LLi t- I- |4 LU LU LU 00 1/5 00 o o <J I—I I—* r-j LL LL LLJ I < r-II oO CM rO IA \0 H 4 -5S-< CM • in CM CM + * < in • s0 O CM i 1 ro * < # ro ro • oo PH + < r-l < fM ft < r—1 rv t •5S-o + sr-r— CM • • o o II <r o oo i < — , * • NT o o • in ro • • rH • b--J M O + • Y— •& 00 < CM o • LL o II - — 00 r-in rH I < in in • o rH II oo ro in oo q o in co rH <J> o ro CD • o <t t— o CD oo 00 O Q •—1 CM re rH pH CM <M CM c\ I < ro ro • ro r-il oo in ro ro ro o • in I— r-l CD • o < r~ LL O cD ro <i *| ro q c<i l! <• #1 <i 1^ aj • rd +i 00 or < LU —J O 00 + 00 00 II O0 oo LU O c ^* , rH O r- O in CJ rH <r in sQ r- r- oc CM CM nj CM CM <\ CD + CM O ro oo • II II CD CD oO 00 LU 00 00 < CJ LU O •z. < K-00 1—4 O <r cc LU < «-d J C ^ ^ z - J OC < </> C QC | LL II -J < J • a. CM o LL! a > LL CT> O •—i rM ro CM m ro ro ro re # < • oo • ro ro 1 ro + •).<• ro * < * •!.-< rH * rH • ro • m + l < * < < < r-l ro • CM • rH CM 1 rH < + * < • sO CM •M- + • * CO 1 ro • • CO II •' II 00 CO oO a CM + —. LT o * in # • <S as LU <2 • CM i- i < rr _J QC — I LL < rH CO « + < I ro c II 00 a in — * o # <: a rH LU CM • r~ < + ~ LL m vo r- co a ro ro ro ro ro r<-ro •if < ro CM • + CO < in * H < O CM H m' o CD — ^ O ro in cd < •if CM • + CO < •pf ro sC • I ro < CM f> O h O m LU +| in rH • <h rH < < CM o < < I- _J I Q LL oo O CD CL O CM in + •H C o • < II ~ 00 LL 0_ CO in rH CM ro >t >t o II oo a. t— oo —i a * + 00 CL a oo z> oo OX uu. a < CM O0 LU oo oo < o -< LU i-l O z o c < h- r-r -00 O C w CD <S Q rr —1 CM < • or at LU LU a LL in q • i<2 LL < ai • 04 r-03 • LL <X. Q >-a: h _ LL LL •£> r~- 00 CO CT> C -4- <lr st LC 151 IF.LAT .E0.50 ) GO TO 16 5 152 IF(LAT.EQ.70) GO TO 170 153 B0=.04+2.77*A-16.25*A*A+54.59*A**3-86.37*A**4+51.48*A**5 154 IF(A.GT..8I B0=17.*A-12. 155 GO TO 175 156 160 B0=-1. 13+18.6 2*A-96.13*A*A+23 6. 13*A**3-27 2. 72*A**4+119.89*A**5 / 157 IF(A.GT..74) B0=2. 15*A-.87 \ 158 IF(BO .LT.0. ) B0=0. 1 59 GO TH 175 160 165 B0=-.03+3.1*A-18.24*A*A+5 7.43*A**3-82.82*A**4+44.03*A**5 1.61 IFIA.GT..8) B0=21.2*A-16.24 162 IFCBO.Lf.O.> B0=0. 163 GO TO 175 164 170 80=-.06+3.2 6*A-13.17*A*A+32.31*A**3-42.05*A**4 165 1 + 22. 5*A**5 . 166 GO TO 174 167 171 IF(LAT.EQ.70) GO TO 173 168 80=22.*A-16.4 169 IF(A.LT..8) B0=.07+.18*A+24.5 8*A*A-17 5.85*A**3+509.28*A**4 170 1 -655.73*A**5+310.72*A**6 1 7 1 GO TO 174 172 173 B0=18.74*A-12.08 173 IF(A.LT..76) BO=-.02+.55*A+21.61*A*A-149.59*A**3 174 1 +402.06*A**4-472.35*A**5+204.94*A**6 175 174 IF(BO.LT.O.) B0=0. 176 175 SB=SB+BO 1 77 C YARD 177.5 C T 8, FOR 2 YARDERS. 178 H=0. 179 A=RAND(0. ) 180 IF(IYDR.EQ.2) GO TO 182 181 IF<A.GT.5./233.) GO TO 180 1 8? H=.3*233.*A 183 180 YA=( . 10719+.00126*Y)<*{ l . + H) 184 GO TO 185 185 182 IF(A.GT.4./75.} GO TO 183 185 .5 C (1+H) IS A HANGUP FACTOR. 186 H=.4*A*75. 1 87 L83 YA = (.17199+.0O?09*Y)*(1 .+H) 188 185 YA= YA* SL OP E 189 SY=SY+YA 190 C CHASE 190 .5 C T 9, FOR EACH X. 191 A=RAND(0.) 1 92 TF(TCSFT.FQ.4) GO TO 190 193 I F { ICS ET . EQ. 3 > GO TO 19 5 194 IF(ICSET.EQ.2) GO TO 200 195 C=.16+.56*A 1 96 GO TO 205 197 190 C=.15+3.49*A-7.06*A*A+5.43*A**3 ] 9 8 an m ?0 5 199 195 C = .14+5.45*A-26.1 4*A*A+61.28*A**3-66.68 *A**4 + 27.7*A**5 200 IF(A.GT..9) C=10.*A-7.76 201 GO TO 20 5 202 200 C=.24+.21*A 203 IF(A.GT..57) C=1.67*A-.59 ?04 205 srr=s r.+r. 205 C RAISE RIGGING 205 .5 C T 11, FOR 2 YARDERS. . , . ?05B6 c CDF APPRnX TMATFD BY SERIES OF STRAIGHT LINES. J . 206 - A=RAND(0.) 207 I F { I Y D R . E Q . 2 ) GO TO 206 1 208 IF{A . G T . 1 0 0 . / 1 1 5 . 1 GO TO 2051 209 A=A*115./100. 210 RA=.1+.83#A 211 I F ( A . G T . . 1 2 ) RA=.18*A+.18 ) 212 I F I A . G T . . 6 9 ) RA=..58*A-.l 213 I F ( A . G T . . 9 5 ) RA=5.*A-4. 214 an Tn ?OQ 215 205 1 A = R A N D (0 .) 216 RA=1.+6.*A ' 217 OO Tn ? 0 9 218 2061 I F I A . G T . 3 7 . / 4 1 . ) GO TO 20 7 219 A=41.*A/37. 220 RA= T1 fl + T 1 4#A 221 I F I A . G T . . 8 6 ) RA=2.86*A-2.16 222 GO TO 208 ? ? 3 ' 207 A=RAND (0.) 224 RA=.7+3.#A 225 208 RA=RA-.025 2 26 ?nq RA=RA-.O?<S 227 SRA= SR A+RA 228 C WAIT 228.5 f. T 10. FOR 2 Y A R D E R S : CDF A P P R O X . BY S T R A I G H T L I N E S . 229 W A= 0 . 230 A= R A N D ( 0 . J 2^1 T F ( T Y P R . F Q . ? ) GO TO 206 232 I F ( A . G T .34.7229. ) GO TO 210 233 A=229.*A/34. 234 WA=3?5.*A-315. 23 5 I F ( A . L T . . 9 8 ) WA=12.5*A-8.7 236 I F ( A . L T . . 8 2 ) WA=1.83*A 2-37 Gfl TH ? ] ( ! 238 206 I F ( A . G T . 1 0 . / 7 5 . 1 GO TO 210 239 A=RAND{0.) ?4f! WA=.15 241 I F I A . G T . . 4 ) WA=.45 242 I F( A . G T . . 7) WA=.75 243 I F ( A . G T . . 9 ) W A = l . n s 244 210 SWA=SWA+WA 2 45 C ROAD CHANGE D U R I N G Y A R D I N G ?4«,.<S r. T 12. FDR 2 Y A R D F R S . 246 RC=0. 247 I F < B A C K . L T . 1 . ) GO TO 220 . 24-8 A = R A N n ( f i T } 249 I F ( I Y D R . E Q . 2 ) GO TO 215 2 50 I F < A . G T .6./233.) GO TO 220 2 51 RC=3.72 252 I F { I Y D R . E Q . 1 ) GO TO 220 253 215 I F ( A.LT .4.77 5. ) RC=4.19 254 ??0 <;Rr = sRr + Rr 2 55 C R I G 255.5 C T 13, FOR 2 Y A R D E R S . 256 RTR=0. 257 A= RAND ( O . J 258 I F { I Y D R . E Q . 2 ) GO TO 225 25Q 1 F ( A , r, T, 12-/2 33.) GO TO ? 30 260 A= RAND ( 0 . ) 26 1 R I G = 6 . * A TF ( A . i T. s. / f t . ) an TO ?3ci J 263 A=RAND(0.) 264 A=10.*A 265 GO TO 230 266 2 2 5 IF1A.GT..027) GO TO 230 267 A=75.*A/2. 268 RIG=5.*A 269 230 SRIG=SRIG+RIG 270 C PIECE COUNT 221 A=R AND(0.) 2 7 2 IIC=0 273 IF(A.LT.122./232.) IIC=1 2 7 4 I F ( A . L T . 5 5 . / 2 3 2 . ) IIC=2 275 I F( A.LT. 15./232. ) IIC=3 276 IF! A.LT .5.7232. ) 1IC=4 2 7 7 T F ( A - l T - l . / 2 3 2 . ) T I 0 = 5 2 7 7 . 5 IF(KROA.EO.1) I IC = I IC + 1 2 7 7 . 7 C PIECE COUNT=# CHOKERS SET + SIMULATED INTEGER. 278 NPC = ICSET+I IC 279 MPC=MPC+NPC 280 C TURN SUMMARY ?an. 5 c L IS A 1 0 0 FOOT SECTION. 281 L=IFIX(XL)+1 282 KPCS( L ) =KPCS< D + NPC 283 ZR(L)=ZR(L)+R 284 ZY(L )=ZY(L)+YA 2 85 ZP(L)=ZPIL)+PS 2 8 6 7 R f 1 > = 7Rf 1 l + R f l 286.5 C TURN TIME FOUND BY ADDING THE TIMES FOR THE ELEMENTS. 287 , TT=R+DR+U+S+G+PS+BO+YA+C+WA+RC+RIG+RA 288 IF(BACK .LT.FR) W ID=( XRAD-Y)/XRAD*(FR-BACK)+BACK 289 301 STT=STT+TT 289.2 IFfK.GT.1) GO TO 311 2 8 9 .4 WR'TTFfft. 3J.3 . TT.Y.WTn 289.6 303 FORMAT(1 •,* TURN TIME•,F8.2,6X,«Y•,F8.2,6X, »WIDTH 1,F8.0) 289.8 C IS A NEW 100 FOOT SECTION TO BE LOGGED? 290 311 IFtY.LE.XL+85. ) GO TO 10 291 C ROAD CHANGE 2 9 2 333 A=RAND(0.) 2 93 R=RANn(0.) 294 P=RAND(0.) 295 Q= RAND ( 0. ) 296 Z=RAND(0.) 297 I F i Z . L T . . 875) Z=0. 298 RCH=27 .*A+3.*B + 19.*P + 17.*Q+10.*Z+28. 2 9 9 TF(FR.GT.l.) RCH = Rf.H+l 2-*R + 2. 3 0 0 IF(IYDR.EQ.1) GO TO 350 301 IF(IYDR.EQ.2) RCH=5.*A+10.*B+10.*P+3.*Q+6.*Z+22. 3 0 2 A=RAND(0 . ) 3 0 3 I F ( A . L T . . 0 5 ) RCH=RCH+200.*A 3 0 3 . 5 C EXTRA 14 MIN. FOR TAIL TREE; 11 MIN. LESS IF SAME TAILHOLD FOR 2 ROADS. 3 0 4 3 SO TF f MTRFF . F O_ 1 . AMO. rYOR . FO . 1 > R C H = R f H + 1 4 . 3 05 IF(BACK.LT.l . ) RCH=RCH-11. 306 C IDLE 307 A=RAND(0.) 308 IF<IYDR.EQ.1) TI = STT*A*.326 309 IF(IYDR.EQ.2) TI= STT*A*.222 3 1 0 c SFCTION SUMMARY 310. 2 WID = Y/XRAD*(BAC K—FR)+F R 310 .5 c PROGRESS OF THE 'LOGGING' MAY BE SUMMARIZED EVERY 100 FT. 31 1 7Rf.HM ) = 7Rf.Hll ) + RCH 312 ZTI( L ) = Z TI { L ) + TI 313 ZTT(L) = ZTT(L )+STT 314 TIME(L)=STT+RCH+TI 315 AREA=(WID+FR)#Y/2. 316 TPERA=TIME(L)*1000./AREA 316-4 377 FORMAT{« '.'TIME FOR ROAD',F10.2) J 316.6 C SUM, AND SUM OF SQUARES, OF TIME PER THOUSAND SQUARE FEET. 3 17 SSQ(L)=SSQ(L.+TPERA**2 , 3.1.8 TP (1 )=TPFRA + TP(1 ) 319 YDIST(L) = Y 3 20 400 IF(Y.LT.XRAD) GO TO 4 3?1 IFIK.I f . l f l ] GO TO 3 321 .5 C NEW ROAD, IF 10 NOT LOGGED. IF 10, SUM TIMES FOR 10 ROADS. 322 JRAD=KRAD-100 3.23 nn 441 1 =1» JR AD,100 324 I F(L.EO.l) GO TO 424 325 ZR(L)=ZR(L)+ZR<L-100) 7YU ) = ZY<L »+ZY(L-100 ) 327 ZP(L)=ZP(L)+ZP(L-100) 328 ZB(L)=ZB(L)+ZB(L-100) 32-9 - KPGSd )=KPf.S( !1+KPCSM -100) _ 329. 5 C AVERAGE TIME TO LOG A THOUSAND SQUARE FEET, AND STANDARD DEVIATION. 330 424 TIMEPAtL)=TP(L)/IO. 331 SD(Ll=S0RT(iSSQ(L)-TP(L)**2/10.)/8.) 332 IF(L.LT. JRAD) GO TO 441 333 WRITE(6, 425) TIM EPA(L),YD I S I V L ) , S D ( L ) 334 4?<S FORMATJ31H 10 ROADS * AV-TTMF PFR M SQ.FT=,F10.2, 335 1 11H FOR R0AD,F7.0,8H FT.LONG/ 9H STD. DEV= , F8 .2.//) 336 WRITE<6,430) KPCS ( L ), ZR ( L ) , ZY( L ) , ZP ( L ) , ZB I L ) , ZRCHi L ) , 337 1 ZTIIL) .ZTT(L) 338 430 FORMAT ( * «,'#PCS ON 10 ROADS', I 6/' • , ' RETURN' ,F9 . 2 • 339 1 • YARD',F8.2/' ','PULL SLK',F8.2,' BREAKOUT', 340 2 Fft.2/' ' ,'RD.CH» . FR.2 , ' iniF»,F8.?,» TURN T I MF' , 341 3 F12.2) 341.5 C PERCENTAGE TIMES. 342 PR=ZR(L)/ZTT(L)* 100. 343 PY^ZY(L)/ZTT(L)*100. 344 PP=ZP{L)/ZTT(L)*100. 34^ PB=7RU)/7TT())*1O0. 346 PTMZRCH(L)+ZTI (L) + ZTT(L ) )/100. 347 PRCH=ZRCH(L)/PT 348 PTI=ZT I (L )/PT ' 349 PTT=ZTT{L)/PT 3 50 WRITEl6,440) PR,PY,PP,PB,PRCH,PTI , PTT 351, 44D FORMAT (• » T ' P FR C FNT A GF S OF TURN T T MF • / * .. * , * R E TURN ' . F 5 .1 , 352 1 ' YARD' , F 5 . l t * PULL SLK«,F5.1,' BRK 0UT',F5.1/« 353 2 'PERCENTAGES OF TOTAL TIME'/' * ,' RD. C H* ,F5 . 1 , * IDLE', 354 3 F5.1 ,• PROD',F5.1//// ) ' 355 441 CONTINUE 355 .5 C CREATE PAIRS TO FIT CURVE TO. 356 U = I F I X { F| 0 AT (.IR AD-1 ) / 1 00 . ) 357 YT(LL)= TIME PA{JRAD) 358 XD( LL ) = YDIST(JRAD)/100. 359 442 CONTINUE 359.5 C FIT PARABOLA. 360 CALL OLQFl2,9,XD,YT,YF,YD,WT,0,SA,SIGMA,AAA,BBB,SQ,LK , PPP) 36] WR I TE ( ,445 ) •( PPP ( .| ) , .1=1 , 3 ) ,S Q. RACK, FR 36 2 445 FORM AT ( ' •, 'COEFFTS ' , 3F 6. 2, • SS',F6.2/' »,'BACK', .3 63 1 F6.0,' FRONT *,F6.0) 363.5 f. WORK OUT FTTTFD VAIUF.S FVFRY 100 FFFT. 3 64 00 448 1=2*10,1 365 AB=PPP(1)+PPP{2)*FL0AT< I ) + P P P ( 3 )* FLOAT ( I.)*FLOAT(I ) 366 J= 100*1 367 WRITE(6,447) AB, J 368 447 FORMATS 'FITTED TIME/M SQFT=* ,F8.2 ,« AT',I 5, » FT') 368.5 448 CONTINUE  368.6 452 CONTINUE 368.8 451 CONTINUE _3J6JSL_ 4 5 . 0 CONTINUE ^ . , . 370 480 STOP 371 END FND OF FILE $ S I G S ROAD LENGTH 901 FRONT 80. BACK. 120. 10 ROADS: AV.TIME PER M SQ.FT= 5.06 FOR ROAD 890. FT.LONG STO.DEV= 0.17 s , „#.PXS„ .QN.JLO. J? OA.DS- _ 2 2 1 7 : , RETURN 402.60 YARD 620.62 PULL SLK 159.99 BREAKOUT 485.02 RD.CH 358.32 IDLE 526.42 TURN TIME 3587.96 PERCENTAGES OF TURN TIME RETURN 11.2 YARD 17.3 PULL SLK 4.5 BR K OUT 13.5 PERCENTAGES . OF. TOTAL ..T IJ1E_ : • RD.CH . 8 . 0 IDLE 11.8 PROD 80.2 .ROAQ_L.EN.GJH 10D.1 _. FRONT 80. BACK 120. 10 ROADS: AV.TIME PER M SQ.FT= 5.03 FOR ROAD 995. FT.LONG STD.DEV= 0.34 #PCS ON 10 ROADS 2462 RETURN 498.21 YARD 754. 45 ; . PULL SLK 196.70 BREAKOUT 621.32 RD.CH 377.44 IDLE 398.95 TURN TIME 4208.50 • PERCENTAGES .OF. TURN . T IMF „ : . RETURN 11.8 YARD 17.9 PULL SLK 4.7 BRK OUT 14.8 PERCENTAGES OF TOTAL TIME RD.CH 7.6 IDLE 8 .0 PROD 84. 4 COEFFTS 5.90 -0.32 0.02 SS 0.14 BACK 120. FRONT 80. FITTED TIME/M SOFT= 5 .37 AT 200 FT F ITTED TIME/M SQFJ= • 5.17 AT 300 FT FITTED TIME/M SQF_I=_ 5.01 AT 400 FT FITTED TIME/M SOFT = 4 .90 AT 500 FT FITTED TIME/M S0FT= 4. 84 AT 60 0 FT FITTED TIME/M SQFT = 4.83 AT 70 0 FT FITTED TIME/M SQFT= 4 . 86 AT 800 FT FITTED TIME / M SQ FT= 4.94 AT 90 0 FT F I T J E p X I M.E/M_S.Q.FI=_ ROAD LENGTH 201 5 .06 AT J.fiop_ FT '• -FRONT 120. BACK 120. 10 ROADS: AV.TIME PER M SQ. F T= ' 5.19 FOR ROAD 193. FT . LONG SJD.DEV= .. ... 0..4.9_.. _ „•.__ ' #PCS ON 10 ROADS 5 87 J 

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