Graduate Thesis Or Dissertation

Logging with a hydraulic excavator : a case study

Public Deposited

Downloadable Content

Download PDF


Attribute NameValues
  • This paper presents a production study of a modified hydraulic excavator used for yarding and loading logs. The machine utilized in this study is a Caterpillar 245. Approximately 3067 cunits (4053 pieces) of old growth Douglas fir were logged from a 29 acre setting in the Coast Range of southwestern Oregon. The purpose of the study is to develop and present important information concerning the application of a logging technique that is generating increasing interest from the forest industry in the Pacific Northwest. This purpose is accomplished by, 1) identifying the conditions affecting production, 2) providing a description of operating techniques, and 3) providing a preliminary investigation of soil impacts. Time study and regression techniques are used to develop equations for predicting yarding production. Significant independent variables include piece size, ground slope, and yarding distance. The relationships between production and piece size and yarding distance are nonlinear. On relatively flat ground the machine travels in a serpentine pattern, methodically swinging logs closer to the road on each pass. On steeper ground slopes (>30%), the terrain may preclude adherence to this otherwise efficient pattern; here the operator uses several techniques to increase the effective reach of the machine. A preliminary investigation of soil impacts indicated that off road soil compaction was not a significant problem; a 2 percent decrease in seedling height growth on 5 percent of the area. The high road density (7 percent of area) appeared to be the main impact on site quality. Mitigation measures could include tillage of the road surface and sidecast pull-back. The actual yarding production rate on the setting was 54.47 cunits/scheduled yarding hour. The yarding cost was $2.02/cunit. Total cost including road construction within the setting and loading was $9.61/cunit. The regression equation overpredicted actual cunit/hour production by 5 percent.
Resource Type
Date Available
Date Issued
Degree Level
Degree Name
Degree Field
Degree Grantor
Commencement Year
Academic Affiliation
Non-Academic Affiliation
Rights Statement
Digitization Specifications
  • Master files scanned at 600 ppi (256 Grayscale) using Capture Perfect 3.0 on a Canon DR-9080C in TIF format. PDF derivative scanned at 300 ppi (256 B+W), using Capture Perfect 3.0, on a Canon DR-9080C. CVista PdfCompressor 3.1 was used for pdf compression and textual OCR.



This work has no parents.

In Collection: