The Operational Reliability Analysis of Machinery: A Case Study of Forest Forwarders and Their Technological Equipment

Kováč, Ján; Ťavoda, Pavel; Harvánek, Pavol; Krilek, Jozef; Aleš, Zdeněk

doi:10.3390/f12040404

Cited by 4 publications

(1 citation statement)

References 13 publications

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“…Over 13,920,000 m 3 of merchantable timber are harvested in thinned stands, including the majority of medium-sized assortments important for the timber sector (Statistical Yearbook of Forestry 2020). Mechanized logging with harvesters and forwarders, has its particular justification in thinning stands, primarily due to its ecological, economic and ergonomic advantages (Sowa et al 2007, Dvořák et al 2011, Zinkevičiuset al 2012, Kulak et al 2017, Kováč et al 2021, Mederski et al 2018, Szewczyk et al 2020, Kormanek & Dvořák 2022.…”

Section: Introductionmentioning

confidence: 99%

Economic efficiency of fully mechanized timber harvesting in coniferous stands of the 2nd age class

Szewczyk,

Krilek,

Kulak

et al. 2023

AFR

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The aim of the study was to determine the unit costs of mechanized timber harvesting in pine stands where early thinning was being performed, and to determine the relationship between the cost level and the volume of harvested trees, the harvester model and field conditions. Analysis focused on timber harvesting with the use of small- and mid-sized harvesters. The tested harvesters were specialized forestry machines (Vimek, Sampo, Profi-Pro, Ponsse) and a construction machine (Fao-Far). Terrain accessibility variants were distinguished in relation to furrows between which trees had been planted in the past: flat terrain with the depth of unevenness up to 20 cm, up to 40 cm, and over 40 cm. The operating costs of the analyzed harvesters varied significantly, an hour of operation of the machine that was the cheapest to use (Fao-Far) cost nearly 2.5 times less (37.3 €) than the Profi-Pro harvester, which was the most expensive in operation (89.1 €). In stands without furrows, the lowest unit costs were noted for the Sampo harvester: 8.4 €·m-3. The other small harvesters, Vimek and Fao-Far, were slightly more expensive to use: 10.3 €·m-3 and 9.1 €·m-3, respectively. In areas where furrows were up to 20 cm deep, the cheapest solution was timber harvesting with the Fao-Far harvester (9.9 €·m-3). In areas where furrows were up to 40 cm deep, timber harvesting was the cheapest with the Sampo harvester (10.7 €·m-3), while harvesters Vimek and Fao-Far were characterized by a similar cost intensity, amounting to just over 12 €·m-3. In stands with furrows deeper than 40 cm, it was cheapest to use the Ponsse harvester (10.4 €·m-3). The cost of operation of the Profi-Pro harvester was higher by approx. 25% (14.0 €·m-3). With the current level of the financing of mechanized timber harvesting in Poland (about 11 €·m-3), small harvesters Vimek, Sampo and Fao-Far are cost-effective when single tree volume exceeds 0.05-0.06 m3. Medium harvesters, Profi-Pro and Ponsse, are cost-effective when unit volumes of harvested trees reach 0.08 and 0.11 m3 respectively. The cost-effectiveness of the tested harvesters increased when working shifts were extended.

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Section: Introductionmentioning

confidence: 99%

Economic efficiency of fully mechanized timber harvesting in coniferous stands of the 2nd age class

Szewczyk,

Krilek,

Kulak

et al. 2023

AFR

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Performance Evaluation of Faffa Food Share Company through Computerized Maintenance Management System (CMMS)

Alemayehu,

Avvari,

Alemu

et al. 2023

Journal of Engineering

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Since 1962 EC, the Faffa Food Share Company has been producing and supplying flour in Ethiopia both for relief and commercial markets. However, it is incompetent in the market due to a poor maintenance management system. So, the aim of this research is to overcome the poor maintenance management problems by using the CMMS application. The data collected from the company by survey studies, unstructured interviews, and stopwatches and from company records revealed that frequent failure machines, as well as a poor maintenance management system, cause production downtimes, resulting in a 29.19% decrease in production from the planned production. The collected data are analyzed by, tools such as time and motion study, SPSS software and CMMS effectively. The finding from the outcome of the bivariate correlation of CMMS elements and manufacturing performance dimension has an alpha α value of greater than 0.5, which indicates that the relationships between CMMS and manufacturing performance are positive. The findings from company records and stopwatch equipment and manpower (technicians) should be managed to activate machine servicing. Finally, the proposed smart maintenance management system tool, CMMS improves the availability of machines, reduces the frequency of equipment failure, reduces the breakdown time, decreases the cost of maintenance, and then improves the manufacturing performance by 5 percent.

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Influence of Loading Distance, Loading Angle and Log Orientation on Time Consumption of Forwarder Loading Cycles: A Pilot Case Study

Hartsch¹,

Schönauer²,

Breinig³

et al. 2022

Forests

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Fully mechanized timber harvesting systems are well established in forest operations worldwide. In cut-to-length (CTL) systems, forwarders are used for extracting logs from the stand. The productivity of a forwarder is related to site- and stand-specific characteristics, technical parameters, organizational aspects, and the individual skills of the operator. The operator’s performance during “loading” considerably affects forwarder productivity, since this element occupies nearly 50% of forwarding cycle time in CTL operations. When positioning the forwarder for loading, different loading angles and loading distances arise. Additionally, different log orientation angles in relation to the machine operating trail can be observed. Therefore, an in-depth analysis of loading conditions was conducted. The goal of this pilot case study was to explore the potential impact of different loading angles and distances, and log orientation angles, on time consumption per loading cycle in order to derive indications for more efficient work practices. Therefore, controlled loading sequences were tested on a physical Rottne-F10-based forwarder simulator with an experienced forest machine operator. Three loading angles (45°, 90° and 135° azimuthal to the machine axis) with five loading distances (3, 4, 5, 6 and 7 m), and three log orientation angles (45°, 90°, 135°), resulted in a total of 45 settings, which were tested in 10 repetitions each. The time required for a loading cycle was captured in a time study, applying the snap-back method. Results showed that all three tested variables had a significant influence on time consumption per loading cycle. Loading at an angle of 135°, and from a close (3 m) or far distance (7 m) led to especially increased cycle times. Loading from 4 to 6 m distance could be detected as an optimal loading range. Additionally, log orientation angles of 45° and 90° led to increased loading efficiency. Even if the validity of the results may be limited due to different conditions and influencing factors in field forwarding operations, these data can contribute to a better understanding of the loading element and, in particular, to productivity determining factors of forwarder work.

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The Operational Reliability Analysis of Machinery: A Case Study of Forest Forwarders and Their Technological Equipment

Cited by 4 publications

References 13 publications

Economic efficiency of fully mechanized timber harvesting in coniferous stands of the 2nd age class

Economic efficiency of fully mechanized timber harvesting in coniferous stands of the 2nd age class

Performance Evaluation of Faffa Food Share Company through Computerized Maintenance Management System (CMMS)

Influence of Loading Distance, Loading Angle and Log Orientation on Time Consumption of Forwarder Loading Cycles: A Pilot Case Study

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