Transport work for the supply of pine sawlogs to the sawmill

The aim of the presented research is to characterize the scale of transport work performed on the supply of large-size pine wood to the sawmill, with indication of factors influencing its structure and parameters. Appropriate analyzes were carried out for deliveries to a sawmill in northern Poland, which supplies pine as a sawlogs and long wood assortments. The distance of deliveries on public and forest roads was determined, as well as transport work for each type of road and the total value. The transport work was defined as a multiplication of driven kilometers with the load and the weight of the load in ton kilometers. Data on the distance traveled was obtained on the basis of information from the driver, and the parameters of the transported pine sawlogs on the basis of the delivery note. Based on the collected data over a period of 12 months, the transport work was determined for selected courses.

The total transport work for the 1,509 analyzed deliveries was 3,447,486 tonne-kilometers (tkm). The average transport work for one course amounted to 2,286 tkm and was characterized by a high variability SD = 1 207. The minimum value of the transport work was recorded at the level of 83 tkm, and the maximum as much as 7,803 tkm. The median of the analyzed deliveries was 2,220 tkm, while the first quartile Q1 = 1,358, and the third quartile Q3 = 2,997. The transport work for a single course is at a comparable level in all months, but the analysis using the Kruskal-Wallis test showed statistically significant differences (p = 0.0000). Comparison of the transport work for deliveries carried out in each months by using the Dunn's test shows statistically significant differences only when comparing the results between XI and I; III; IV, VI and X and III from I, IV and X and the last pair differing from IV is from VIII. The deliveries in July and December were not included in the statistical analyzes due to the insufficient sample size due to plant maintenance breaks.