PREFACE 



During the summer of 1967, David B. Brown and Michael R. Carter, both 

 graduate students in industrial engineering at Montana State University, were 

 temporarily employed by the Station to investigate the economics of skidding 

 systems commonly used in western Montana, Idaho, and northwestern Wyoming. 



Brown had completed a thesis entitled "An economic comparison of skid- 

 ding methods employed in the Northern Rocky Mountain area" in partial fulfill- 

 ment of the requirements for a master's degree from the University. In it, he 

 compared relative profits of four types of skidding methods --crawlers, wheeled 

 vehicles, cranes, and high-lead towers. During their summer assignment, he 

 and Carter gathered data on a fifth type, coordinated these data with those used 

 in Brown's thesis, and constructed a mathematical model to provide comparative 

 cost information on these five types of skidding methods. They chose to substi- 

 tute "costs" for "profits" as the measure of comparison to avoid confounding 

 their task because (1) some company policies preclude general dissemination of 

 profit and loss information, and (2) fluctuating market conditions affect profits. 



Lack of time cut short the data collection necessary to fully satisfy the 

 objectives of the study. Most of the values in the tables are based on informa- 

 tion obtained within a 75-mile radius of Bozeman, Montana. The values pre- 

 sented in the cost tables should be viewed as tentative- -as estimates based 

 only on information that was available at the time of the study. Furthermore, 

 the author recognizes that these estimates can be upgraded in terms of accu- 

 racy when additional data are gathered in future studies. However, the tables 

 are presented at this time purely for their possible interest to contractors, who 

 shouldn't assume the values will accurately apply to their particular operations. 



