DOCSLIB.ORG

Forest Research Laboratory Oregon State University Corvallis, Oregon

Total Page：16

File Type：pdf, Size：1020Kb

Download full-text PDF Read full-text
Forest Research Laboratory Oregon State University Corvallis, Oregon Forest Research Laboratory College of Forestry I Oregon State University Corvallis, Oregon March, 1992 I I 'i I MECHANIZED HARVESTING: I A COMPENDIUM OF RESEARCH I I I compiled by I Loren Kellogg 1 Pete Bettinger Steve Robe I Alan Steffert I 1 I 1 1 I Forest Research Laboratory I College of Forestry Oregon State University 1 March, 1992 U I CONTENTS Page LIST OF TABLES INTRODUCTION..............................................1 FOCUS OF THE COMPENDIUM.....................................2 OVERVIEW OF LITERATURE......................................2 Ground-based Harvesting .......................................3 Machine studies.......................................3 System studies........................................3 Cable-based Harvesting.......................................6 Conclusion..............................................7 LITERATURE CITED............................................9 Sources of Information about Harvest Productivity........................9 HOW TO USE THIS COMPENDIUM.................................11 Organization of the Compendium................................11 Studies of individual machines.............................11 System studies........................................13 Format for presentation of information........................13 Other Uses of the Compendium.................................14 HIERARCHY I: MECHANIZED HARVESTING IN CLEARCUTS...............15 Pathways Chart for Locating Abstracts.............................15 Citation Abstracts.........................................35 HIERARCHY II: MECHANIZED HARVESTING IN PARTIAL CUTS............285 Pathways Chart for Locating Abstracts............................285 Citation Abstracts........................................305 APPENDIX A: DEFINITIONS AND ILLUSTRATIONS OF TYPICAL MACHINERY.................................390 APPENDIX B: TABLE OF EQUIVALENTS............................399 11 I I LIST OF TABLES Page I 1. Studies of ground-based machines used in clearcuts .4 1 2. Studies of ground-based machines used in partial cuts........................5 3. Studies of cable-based machines used in clearcuts..........................8 I I I I I 1 I I I Li I I I IiiiI I INTRODUCTION Interest in techniques of mechanized harvesting in the Pacific Northwest region of I the United States has increased, because the cost of labor is high and piece sizes are decreasing as second growth harvesting increases. Stands in the 30- to 80-year range of age classes with average diameters of less than 20 inches at breast height are an I increasingly important part of the timber supply. This changing stand structure raises the need for research aimed at determining cost-effective and environmentally sound Imethods for handling small timber. Greater understanding of the productivity possible with mechanized harvesting equipment under conditions found in the Pacific Northwest will encourage appropriate I developments in mechanized harvesting operations. Computer-based analysis of harvesting systems is one method of gaining this understanding. Computer simulation can be a powerful tool for decision making if properly applied, and simulation can I expand analysis of field studies to delineate areas where additional information is needed. The effectiveness of computer simulation, however, is dependent on the quality of I the input data. Mechanized harvesting in the Pacific Northwest is relatively new, and many of the conventional aspects of harvesting have not been well documented with studies of production. Krause (1988) evaluated several mechanized harvesting I simulation models and found a lack of production data for ground-based harvesting equipment in the Northwest. He attributed this lapse to the short history of mechanized harvesting in the region. No centralized data base, moreover, has yet been compiled for I this subject. Only time and additional field studies can make up for the general lack of I information, but the issue of a centralized data base can be addressed with a compendium of studies about the productivity of mechanized harvesting. This centralized and organized data base will indicate areas that require additional information and help harvesting professionals make decisions and run simulations. The purpose of this I compendium, therefore, is to supply an organized collection of productivity information about mechanized harvesting, and to identify gaps in the literature that delineate areas Iwhereadditional research is needed. I LI I I I I FOCUS OF THE COMPENDIUM This compendium primarily focuses on mechanized harvesting operations thatare appropriate to the Pacific Northwest region of the United States. Mechanized harvesting operations, for the purposes of this compendium, are: Operations with at least one single or multi-function machine for manufacturing (felling, delimbing, bucking or chipping), or operations where treesor logs are placed in bunches prior to primary transport, or operations where primary transportation is able to handle multiple stems. This compendium also focuses on productivity, operations analysis, equipment performance, and cost factors. Studies of mechanized harvesting performed in other regions of the United States or in other countries are included in the compendium if the terrain and stand conditions are characteristic of conditions found in the Pacific Northwest. Typical examples of sites with small timber located on terrain suitable for mechanized harvesting can be found on both the East and West sides of the Cascade Range. A conmion type of small timber found East of the Cascades would bean 85- year-old stand of lodgepole pine with 1,200 to 1,500 trees per acre and an average diameter of 8 to 9 inches at breast height. Stand conditions for thinning operationson the West side are typified by a 40-year-old stand of Douglas-fir and hemlock with 300 to 400 trees per acre and an average diameter of 11 to 13 inches at breast height. Stand conditions on the West side, where appropriate for clearcut operations, are characterized by a stand of 65-year-old Douglas-fir and hemlock with 100 to 200 trees peracre and an average diameter of 16 to 26 inches at breast height. A compendium of productivity information about cable yarding is already available (Aubuchon, 1982); therefore, conventional productivity information relatingto cable yarding will, for the most part, be excluded from this compendium. Productivity information on grapple-yarding operations and on cable-yarding operations in conjunction with another mechanized process, however, is included in this compendium. OVERVIEW OF LITERATURE In the Pacific Northwest, harvesting activities rapidly are shifting from old- growth stands to young-growth stands. In Oregon, the average diameter oftrees harvested will decline from about 21 inches in the decade 1991-2000 to 17 inches in the decade 2041-2050 (Sessions, 1991). The decline in average diameter of harvestedtrees, however, is projected to vary by landowner. Average diameter of trees harvested from National Forest land will decline very little from 1991 to 2020, whileaverage diameter from harvests on BLM land will decline from 25 inches in the decade 1991-2000to 17 inches in the decade 202 1-2030. Average diameter from harvestson State land are projected to decline slowly from 20 inches to between 17 and 18 inches from 1991to 2090, while average diameter from harvests on private land will slowly decline from17 to 16 inches during the same period. Harvesting costs per unit-volume on these small- diameter forests will be higher than with old-growth forests. I Ground-based Harvesting Small tiees growing on tenn with slopes of less than 30 percent are harvested in I the Pacific Northwest in the same manner as they are harvested in the rest of North America. Typical harvesting systems for these areas consist of feller-bunchers used in conjunction with grapple skidders. Processing at the landing varies with markets in the I area, and it may include mechanized delimbing and whole-tree chipping (Johnson, 1981). IMachine studies ClearcuttingTable 1 shows that ground-based clearcutting of small- and medium-sized timber on gentle terrain has been extensively studied. Hierarchy I of this I compendium (Mechanized Harvesting in Clearcuts) includes 146 machine studies that fall within these categories. These studies include 69 in the felling category, 51 in the processing category, 17 in the primary transport category, 8 in the loading category, and I 1 in the bunching category. Table 1, however, shows that as tree size becomes larger and slopes become I steeper, the number of ground-based machine studies rapidly decreases. Only 16 machine studies that cover operations on medium and steep slopes with possible combinations of timber size are included in the compendium. Eight of these 16 studies I are concerned with felling operations on medium and steep slopes in small and medium timber. The remaining studies fall within the categories of bunching, primary transport, processing, and loading. I The decrease in the number of studies with larger tree size and steeper slopes was expected, because few ground-based machines have been developed that are capable of harvesting larger timber on steeper slopes. The abundance of information about ground- I based harvesting of small and medium timber on gentle slopes and the relative lack of information concerning ground-based harvesting of larger timber on steeper slopes, however, suggests that further research efforts should focus on these areas. I Partial cuttingTable 2
Load more

Recommended publications
  • Large Specalog for 521B/522B Track Feller Bunchers & Track Harvesters
    521B/522B Track Feller Bunchers & Track Harvesters – ZTS (Zero Tail Swing) Power Train Operating Weights (without heads, standard counterweight) 521B/522B Track Feller Buncher Engine Model Cat® C9 ACERT™ 521B 27 501 kg 60,629 lb Gross Power 226 kW 303 hp 522B 32 528 kg 71,711 lb Track Harvester Configuration 521B 26 966 kg 59,450 lb 522B 31 993 kg 70,532 lb Cat 521B/522B Features Power Train The Cat C9 ACERT Tier 3 high torque engine provides excellent power, fuel economy, serviceability and durability. The Cat C9 ACERT is a dependable performer, while meeting all U.S. EPA emission standards. Hydraulics Closed Center hydraulic system with electronic programmable controls that produce excellent multi-function system uses; dedicated pilot, travel, implement and saw pumps. Operator Comfort The Cat purpose built forestry cab offers industry leading operator protection and comfort. Cab is designed and tested to meet 120% of machine operating weight, meets ROPS, FOPS, OPS, OR-OSHA and WCB regulations and standards. New ISO mounting system reduces noise and vibration, increasing operator comfort. Leveling System The Cat three (3) hydraulic cylinder tilting system is extremely durable and reliable, and is the only one in the industry to provide two way simultaneous function throughout the full range of tilting motion. Undercarriage The 521B/522B have a new D7 size undercarriage custom designed for reliable operation in tough harvesting conditions, from wet bottomlands to steep rocky slopes. Contents Power Train ..........................................................4
    [Show full text]
  • Missoula Technology and Development Center's 1995 Nursery and Reforestation Programs
    Tree Planter's Notes, Vol. 46, No. 2 (1995) Missoula Technology and Development Center's 1995 Nursery and Reforestation Programs Ben Lowman Program leader, USDA Forest Service, Missoula Technology and Development Center Missoula, Montana The USDA Forest Service's Missoula Technology and Your nursery project proposals are welcome. They should Development Center (MTDC) evaluates existing technology and be submitted to Ben Lowman in writing or over the DG develops new technology to ensure that nursery and reforestation (B.Lowman:RO1A). Write a summary that clearly states the managers have appropriate equipment, materials, and techniques problem and proposes your desired action. The information for accomplishing their tasks. Work underway in 1995 is is used to determine priorities, to link you with others with described and recent publications, journal articles, and drawings similar problems or with solutions to your problem, or to are listed. Tree Planters' Notes 46(2):36-45; 1995. establish a project to solve the problem with appropriate equipment or techniques. The Missoula Technology and Development Center Pollen equipment (project leader-Debbie O'Rourke). (MTDC) has provided improved equipment, techniques, and Thirty years ago the Forest Service launched an expanded materials for Forest Service nurseries and reforestation tree improvement program. A network of seed orchards programs for more than 20 years. The Center has worked to with genetically superior trees was created in an effort to improve efficiency and safety in these areas, and throughout produce top-quality seed. These trees are now in the cone- the Forest Service. The Center evaluates existing technology bearing stage. Protecting the genetic quality of their seed is and equipment and develops new technology and equipment.
    [Show full text]
  • Investigation of Feller-Buncher Performance Using Weibull Distribution
    Article Investigation of Feller-Buncher Performance Using Weibull Distribution Ebru Bilici Forestry Department, Dereli Vocational School, Giresun University, Giresun 28950, Turkey; [email protected] Abstract: With the advancement of technology in forestry, the utilization of advanced machines in forest operations has been increasing in the last decades. Due to their high operating costs, it is crucial to select the right machinery, which is mostly done by using productivity analysis. In this study, a productivity estimation model was developed in order to determine the timber volume cut per unit time for a feller-buncher. The Weibull distribution method was used to develop the productivity model. In the study, the model of the theoretical (estimated) volume distributions obtained with the Weibull probability density function was generated. It was found that the c value was 1.96 and the b value was 0.58 (i.e., b is the scale parameter, and c is the shape parameter). The model indicated that the frequency of the volume data had moved away from 0 as the shape parameter of the Weibull distribution increased. Thus, it was revealed that the shape parameter gives preliminary information about the distribution of the volume frequency. The consistency of the measured timber volume with the estimated timber volume strongly indicated that this approach can be effectively used by decision makers as a key tool to predict the productivity of a feller-buncher used in harvesting operations. Keywords: forest operations; productivity; Weibull distribution; feller-buncher Citation: Bilici, E. Investigation of Feller-Buncher Performance Using 1. Introduction Weibull Distribution. Forests 2021, 12, Innovative management strategies will be necessary in managing forest resources, 284.
    [Show full text]
  • Felling Introduction
    Felling WDSC 422 1 Felling While performing felling operations, we have to consider to: minimize damage to log products maximize product value leave stumps as low as possible maximize the fiber utilization protect boundary trees, neighboring property, follow regulations such as BMPS, OSHA WDSC 422 2 Felling Methods Manual felling chainsaws Mechanized felling felling machines such as feller-bunchers and harvesters WDSC 422 3 Manual Felling Chainsaws are the main tools. are responsible for one of the most radical changes in logging technology in the 20th century. prompt rapid productivity gains. WDSC 422 4 Chainsaws Introduced to North America during World War II. Early models: heavy - 50 pounds or more two persons to operate them Today’s models: lightweight - less than 20 pounds and many less than 10 pounds powerful and fuel-efficient with less vibration and safety features WDSC 422 5 Procedures (Chainsaw Felling) Walk to tree Acquiring Felling Delimbing and topping 6 Mechanized Felling Mechanized equipment designed to fell trees became popular in the 1960’s. High quality, reliable hydraulic systems made the modern feller-bunchers and harvesters possible. Felling machines can be classified or described in terms of: the way the machine being operated, the felling head used WDSC 422 7 Felling Machines Felling devices or heads can be mounted on several types of machine carriers or prime movers. These are typically grouped into two types: Drive-to-tree machines Swing-to-tree machines WDSC 422 8 Drive-to-tree Machines Either rubber-tired or tracked machines which drive to each tree before cutting it. Less expensive to purchase and operate, and most widely used.
    [Show full text]
  • 4-H Virtual Forest User's Guide Timberrr!
    4-H Virtual Forest User’s Guide Timberrr! Concept Timber harvesting is a necessary and useful process for getting trees from the woods to the factories that make products we use in everyday life. This module will illustrate the timber harvesting process. This module supports the following Science Standards of Learning: Resources 4.8 d) forests, soil, and land 6.9 a) management of renewable resources (water, air, soil, plant life, animal life) Module Description Frame 1. The module opens with a title slide that contains the title “Timberrr!”, credits, and a voice shouting “Timberrrrrrrr!” Users will click on the trees located along the top of the screen to navigate through the module. Steps can be viewed in any sequence, but will be described here in order from left to right. Intro. This frame provides an introduction that addresses the importance of timber harvesting and the forest products industry to Virginia’s economy. The text reads as follows: “Timber harvesting is a necessary and important process for getting trees from the woods to the factories that make many of the products we use every day.” The second paragraph leads in to a quiz question, followed by four possible answers: “Virginia’s forests provide jobs for many people. For example, foresters might study, measure, and map trees and forests. Loggers harvest trees and take them to wood using industries or factories. Factory workers help turn these trees into products. Secretaries, bookkeepers, and managers help keep track of details so that the factories operate smoothly. “How many jobs do you think the forest industry and supporting businesses supply for Virginia’s citizens? Click on your answer below.” A) 1,350 B) 75,000 C) 126,319 D) 248,000 The correct answer is (D) 248,000.
    [Show full text]
  • Downloading At
    United States Department of MECHANIZED SYSTEMS FOR Agriculture ARVESTING ASTERN ARDWOODS Forest H E H Service Northern Research Station Chris B. LeDoux General Technical Report NRS-69 Abstract In the central Appalachian region, hardwoods traditionally have been harvested by chainsaw felling with trees and logs extracted from the forest to landings by rubber-tired skidders, bulldozers, and crawler tractors. In recent years, mechanized systems that include feller bunchers and cut-to-length (CTL) processors coupled with forwarders and clambunk and grapple skidders have been used increasingly to harvest Eastern hardwoods. Feller bunchers fell trees and pile stems or logs in bunches. CTL processors fell trees and delimb them, buck the stems into logs, and pile them in presorted bunches. Wood piles and bunches are transported to landings by a clambunk or grapple skidder or a forwarder. These system combinations for processing and transporting essentially eliminate the need for woods workers on the ground, a major advantage from a production and safety standpoint, and greatly reduce adverse effects on the site compared to chainsaw felling and conventional skidding. Feller buncher and CTL systems are reviewed, results of environmental impact studies are presented, and cost equations for a range of operating conditions in Eastern hardwoods are provided. The Author CHRIS B. LEDOUX is a research industrial engineer with the U.S. Forest Service’s Northern Research Station at Morgantown, West Virginia. Manuscript received for publication December 2009 Cover Photo 1. Cut-to-length processor (photo courtesy of Andrew 2 Whitman, Manomet Center for Conservation 1 Sciences); 2. Crawler dozer (photo courtesy of Caterpillar); 3.
    [Show full text]
  • Occupational Safety Health & Environmental Care Learner Guide
    Forest Ops: Feller Buncher © Commonwealth of Australia 2011 Page 1 of 122 © Commonwealth of Australia 2011 The views expressed in this learners guide do not necessarily represent the view of the Minister for Education or the Australian Government. The Australian Government does not give any warranty nor accept any liability in relation to the contents of this work". This work is copyright. You may download, display, print and reproduce this material in whole or in part or in modified form (retaining this notice) for your personal, non-commercial use or use within your organisation. If you use, display, or reproduce this material or a modified form of it in whole or in part within your organisation you must include the following words in a prominent location within the material in font not less than size 12: “Apart from any use as permitted under the Copyright Act 1968, all other rights are reserved. Requests and inquiries concerning reproduction and rights should be addressed to the Commonwealth Copyright Administration, Attorney Generals Department, Robert Garran Offices, National Circuit, Barton ACT 2600 or posted at http://www.ag.gov.au/cc. Funded under the Workplace English Language and Literacy (WELL) Program by the Australian Government Department of Education Employment and Workplace Relations Training material developed by Logging Investigation & Training Association (LITA). Mount Gambier, South Australia email [email protected]. LITA would like to acknowledge the following organisations from which material has been referenced and sourced: Hitachi Australia Tabeel Trading K&G Wright LV Dohnt & Co HVP Plantations Forestry SA Green Triangle Forest Products Worksafe Vic Department of Agriculture Fisheries & Forestry (DAFF) Government SA Primary Industries & Resources SA We would also like to acknowledge and thank the Forest Industry personnel who participated in trialling this resource.
    [Show full text]
  • Bulldozer Movement Kills Operator Standing on Track
    OR 2005-28-1 Bulldozer movement kills operator standing on track SUMMARY On August 20, 2005, a 33-year-old Hispanic equipment operator was killed when he slipped between the tracks and the body of the bulldozer he was operating. The operator gave a coworker a ride to retrieve an ATV located at the top of a hill where the operator was intending to work. The operator stopped the bulldozer on a fairly level area of the slope to let off his rider. He then noticed the coworker had left a jacket in the cab, so he lowered the tractor’s blade to the ground, put the machine into idle, and stood on the track to reach out and give the The Caterpillar D8H bulldozer in this jacket to the coworker. While in this position, the incident unexpectedly rolled backward tractor suddenly moved backward, and the operator lost from a parked position. his balance and fell feet first between the track and the deck. The bulldozer continued to roll 8-10 ft backward, and the operator was pulled beneath the tractor and crushed. Coworkers freed the conscious victim, but he was confirmed dead when emergency medical responders arrived at the scene. The medical examiner reported a blood alcohol content of 0.08, the level of legal intoxication in Oregon for operating a motor vehicle. CAUSE OF DEATH: Multiple traumatic injuries RECOMMENDATIONS • Before exiting a bulldozer, the operator must secure hazardous energy by following all manufacturer recommended steps in parking, including setting the parking brake. • Operators should not use alcohol or other impairing drugs prior to or while operating equipment.
    [Show full text]
  • Johnson Forest Management of Red Creek, New York
    he small town of Red Creek, New York, lies just south of Lake Ontario in the Finger Lakes region of the state. TThe town might be named for the color of the water that flows in Red Creek – a mineral red hue, the result of iron ore in the waterbed. According to local lore, however, the name might also come from an old tannery that polluted the local water supply with red dye. Today, Red Creek is a town of about 500 people, many of whose families have lived there since the tannery days. Among those multi-generational residents are the Johnson family of Johnson Forest Management: Tom Johnson, Trevor Johnson, and Dustin Johnson. LAKE “We grow the nicest hard maple in the world in the Finger Lakes,” said Tom Johnson, who has logged around Red Creek for the past 40 years. “My grandfather and dad practiced forest management before anybody even thought about it. They always set people up on a 10-year rotation; they’d go in and harvest the stuff that was ready and then, 10 years later, go back and cut it again.” As a young man, Johnson watched his dad ONTARIO manage the forest to grow healthy trees, returning to woodlots four or five times over the years. Johnson prides himself in good forest management, as well. “Hard maple keeps growing, and we try to look toward the future for landowners and ourselves,” said Johnson. Tom Johnson got his start logging in 1979, fifty years after his LOGGING grandfather, Ed Johnson, started the family logging business with a crosscut saw, a T-20 International Crawler Tractor, a log truck, and a 1937 Ford.
    [Show full text]
  • Jan Ag Review.Indd
    LXXXV - No. 1 January 2010 On the horizon NCDA&CS offers price-risk management workshops Small Farms Week The North Carolina Depart- futures, energy derivatives, from 10 a.m. to 3 p.m. at each Thursday, Feb. 11 – Halifax ment of Agriculture and Con- and options trading on futures, location, with an on-your-own Community College, Weldon, runs March 21-27 sumer Services will host seven equities and indices. There will lunch break. Registration is not (252) 536-6343; free price-risk management also be information on trading required. Tuesday, Feb. 16 – Pasquotank Each year a small farm in workshops across the state to help strategies to manage exposure to Following are the schedule Cooperative Extension Center, North Carolina is honored farmers better understand the fl uctuations in energy costs. and locations: Elizabeth City, (252) 338-3954; with the Gilmer L. and Clara futures market and other trading “The information covered Tuesday, March 2 – Stanly Y. Dudley Small Farmer of the options to sell their commodities. in these workshops can help Tuesday, Jan. 19 – Robeson Community College, Crutchfi eld Year Award in recognition of The series, “Managing Price farmers improve their bottom County Agriculture Building, Campus, Locust, (704) 991- Small Farms Week. The award Volatility by Using Futures and line, which is critical in today’s Lumberton, (910) 671-3276; 0378; will be presented March 24 at Options,” features workshops challenging economic climate,” Tuesday, Jan. 26 – Wayne Thursday, March 4 – N.C. A & T State University in conducted by NCDA&CS staff said Agri-culture Commissioner Community College, Goldsboro, Carolina Farm Credit, Statesville, Greensboro.
    [Show full text]
  • Harvesting Timber Using the Shovel-Mat Logging Method
    Focus Series on Bottomland Swamp Forests December 2018 #BF-4 Harvesting Timber Using the Shovel-Mat Logging Method The Issue Harvesting timber in bottomlands, swamps and other low-lying areas usually requires specialized logging equipment and methods. The most frequently-used method is known as ‘shovel logging’, also called ‘mat logging’. This method of logging integrates the use of multiple machines mounted upon crawler tracks in tandem with machines that are mounted on extra-wide or dual-rubber tires. This logging method is suited for wet-natured sites where clearcut harvesting will be implemented. The Method First, a track-mounted harvesting machine cuts a pathway through the standing timber. Next, a similar track- mounted, tree-handling/log-loader machine will pick up the trees that have been cut and place them atop of the ground in a finger-joined pattern to create a skid trail atop of the ground surface. Then, rubber-tired skidder tractors drive back and forth atop of this skid trail to shuttle the newly harvested timber from the forest, up to the log deck for merchandizing and staging. Once an area of the tract has been harvested, the trees and logs that were used to build the skid trail are pulled up. Left: A track-mounted tree harvesting machine (called a tracked feller-buncher). Right: A track-mounted log-loader (called a shovel logger, or shovel machine), on the end of a shovel skid trail. NOTE: Over the years, some loggers and foresters have used the term “shovel road” or “mat road” when talking about shovel-logging.
    [Show full text]
  • Fifty Years on Tracks
    - - :. FIFTY YEARS ON TRACKS Digitized by the Internet Archive in 2012 with funding from University of Illinois Urbana-Champaign http://archive.org/details/fiftyyearsontracOOcate FIFTY YEARS ON TRACKS Copyright 1954 by Caterpillar Tractor Co. CAT lH *•>'» * > *\\ BY WAY OF INTRODUCTION . ^1 2 IN 1925, the C. L. Best Tractor Co. and The Holt Manufac- turing Company merged to form Caterpillar Tractor Co.; leading track-type tractor builders of that time, the two firms had chosen an old and familiar Holt trademark for use in their new corporate name. This anniversary book tells the story of Caterpillar— and its important predecessors— from a begin- ning rooted in Nineteenth Century soil. From the vantage point of a reporter, it presents a cross-section view of the Company today— its people, plants, business friends, products, markets. It sketches the colorful industry of which Caterpillar is a prominent part. "Fifty Years on Tracks" is a tribute to the men who build roads and dams and levees and airports . who till and terrace farmland and harvest its abun- dance . stretch pipelines across plains and up over mountains . cut down hills and erect buildings and bridges in their place . fell and snake logs from the woods . clear roads and streets and save lives when winter comes. To the people who build today's pyramids in months instead of decades— with machines and free men instead of slaves by the thousands. To the workmen who keep hammering down the cost of moving a yard of earth . who have more than doubled farm output per man-hour in the last 50 years .
    [Show full text]