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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
1

An Analysis of Log Truck Turn Times at Harvest Sites and Mill Facilities

Dowling, Tripp N. 02 June 2010 (has links)
The raw forest products transportation sector is inherently unique when compared to other transportation industries. The loggers and contractors who transport raw forest products are at a competitive disadvantage. Older equipment is also commonly used by the raw forest products transportation industry in harsh working environments. The average log truck age is 9.7 years while all trucks average only 3.9 years. Nineteen percent of log trucks are 15 years old or older while only 5.9% of all trucks are older than 8 years. Log trucks are regulated by both the Federal Motor Carrier Safety Administration and the state that the truck operates in, thus making interstate transportation more difficult. In addition to these challenges, there is a lack of information concerning efficiency and productivity improvement opportunities related to transporting forest products. This study evaluated truck turn times at both the harvesting site and mill facilities in order to identify important trucking productivity factors and efficiency improvement opportunities. Regression equations were created to estimate truck turn times at harvesting sites and mill facilities. Gross level studies found that 1268 truck turns at the tract scale averaged 1.40 hours while 576 truck turns at the mill scale averaged 0.56 hours. Elemental time studies at four harvesting locations found that log trucks were idle 32% of the time. Trucks spent 29% of time being loaded and 26% of the time waiting. Elemental time studies at mill facilities found that trucks were idle 27% of the time. Trucks spent the greatest amount of time unloading while unbinding was the second greatest contributor to turn times. Reductions in loading and waiting times can have significant effects on the overall turn time. Harvesting contractors could benefit from maintaining balanced harvesting crews. Estimates indicate that harvesting contractors could earn an additional profit of $106,500 over a period of five years by purchasing an additional skidder for those crews whose production is limited due to a lack of skidding capacity. It is estimated that if adding an additional trailer to harvesting crews would allow an additional 2 loads to be transported to the mill each day, harvesting crews could earn an additional $22,100 per year of profit. Road construction can also affect harvesting contractors profits. By minimizing road construction through the use of easements and improved pre-harvest planning, harvesting contractors could reduce road construction costs by as much as $14,000 per tract. With tools available to estimate truck turn around times, harvesting contractors, fleet managers, and truck drivers will be able to make more informed decisions regarding fleet management. This will enable those owning and operating trucks to operate in more efficient and profitable manners. The models created during this study will allow managers to estimate tract and mill turn times so as to better allocate trucking resources. / Master of Science
2

Entreprenörskap i skogsdrivningsbranschen : en kvalitativ studie om utveckling i små företag /

Hultåker, Oscar. January 2006 (has links)
Thesis (doctoral)--Sveriges lantbruksuniversitet, 2006. / Thesis documentation and errata sheets inserted. Includes bibliographical references (p. 185-199). Also available electronically via World Wide Web in PDF format.
3

A Computer Simulation Model for Predicting the Impacts of Log Truck Turn-Time on Timber Harvesting System Productivity

Barrett, Scott M. 09 February 2001 (has links)
A computer simulation model was developed to represent a logging contractor's harvesting and trucking system of wood delivery from the contractor's in-woods landing to the receiving mill. The Log Trucking System Simulation model (LTSS) focuses on the impacts to logging contractors as changes in truck turn times cause an imbalance between harvesting and trucking systems. The model was designed to serve as a practical tool that can illustrate the magnitude of cost and productivity changes as the delivery capacity of the contractor's trucking system changes. The model was used to perform incremental analyses using an example contractor's costs and production rates to illustrate the nature of impacts associated with changes in the contractor's trucking system. These analyses indicated that the primary impact of increased turn times occurs when increased delivery time decreases the number of loads per day the contractor's trucking system can deliver. When increased delivery times cause the trucking system to limit harvesting production, total costs per delivered ton increase. In cases where trucking significantly limits system production, total costs per delivered ton would decrease if additional trucks were added. The model allows the user to simulate a harvest with up to eight products trucked to different receiving mills. The LTSS model can be utilized without extensive data input requirements and serves as a user friendly tool for predicting cost and productivity changes in a logging contractor's harvesting and trucking system based on changes in truck delivery times. / Master of Science

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