Efficiency of Topping Trees in Cable Yarding Operations
The extraction of biomass and nutrients out of the forest is implicit to every harvest operation. In cable yarding, whole-tree harvesting (WTH) has become more prevalent in the last few decades and processing takes place at the roadside. There is a concern that WTH impairs site productivity due to n...
| Main Authors: | , |
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| Format: | Article |
| Language: | English |
| Published: |
University of Zagreb, Faculty of Forestry
2015-01-01
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| Series: | Croatian Journal of Forest Engineering |
| Online Access: | https://hrcak.srce.hr/file/223297 |
| _version_ | 1819044956079128576 |
|---|---|
| author | Karl Stampfer Christoph Huber |
| author_facet | Karl Stampfer Christoph Huber |
| author_sort | Karl Stampfer |
| collection | DOAJ |
| description | The extraction of biomass and nutrients out of the forest is implicit to every harvest operation. In cable yarding, whole-tree harvesting (WTH) has become more prevalent in the last few decades and processing takes place at the roadside. There is a concern that WTH impairs site productivity due to nutrient removal. One option to increase the amount of biomass remaining in the stand is to top the trees before extraction. In order to estimate the influence of topping on system productivity, time studies on a medium-sized tower yarder were carried out in three spruce dominated stands. Heart rate monitoring of the chainsaw operator was performed to examine the physiological workload. The analysis showed that topping only impacts system productivity if it takes place during the inhaul of the load as it leads to interruptions of the extraction progress. These interruptions took on average 13 seconds per turn. In addition, if topping was performed on already lifted trees, a reduction of line-speed during the lateral yarding of the loads was observed. This led to a reduction in productivity between 5 and 11%, assuming that all trees would have been topped during the lateral yarding process. Analyses of the physical workload of the chainsaw operator showed that the workload of topping trees is significantly lower than that of the felling process. Relative heart rate of the subject was lower at the cable corridors where topping was ordered. This confounding result may be a consequence of many additional factors like slope gradient or cycle time. Under both scenarios, the worker never surpassed the limit of a sustainable cardio-vascular workload for an 8 hour working day. Hence, recovery time for the chainsaw operator can be considered as adequate when topping is performed in a three-man crew. |
| first_indexed | 2024-12-21T10:20:54Z |
| format | Article |
| id | doaj.art-e9047bd3b7864078bcdbc9b480efc720 |
| institution | Directory Open Access Journal |
| issn | 1845-5719 1848-9672 |
| language | English |
| last_indexed | 2024-12-21T10:20:54Z |
| publishDate | 2015-01-01 |
| publisher | University of Zagreb, Faculty of Forestry |
| record_format | Article |
| series | Croatian Journal of Forest Engineering |
| spelling | doaj.art-e9047bd3b7864078bcdbc9b480efc7202022-12-21T19:07:27ZengUniversity of Zagreb, Faculty of ForestryCroatian Journal of Forest Engineering1845-57191848-96722015-01-01362185194151779Efficiency of Topping Trees in Cable Yarding OperationsKarl Stampfer0Christoph Huber1University of Natural Resources and Life Sciences Department of Forest and Soil Sciences Peter-Jordan-Strasse 82/3 1190 Vienna AUSTRIAUniversity of Natural Resources and Life Sciences Department of Forest and Soil Sciences Peter-Jordan-Strasse 82/3 1190 Vienna AUSTRIAThe extraction of biomass and nutrients out of the forest is implicit to every harvest operation. In cable yarding, whole-tree harvesting (WTH) has become more prevalent in the last few decades and processing takes place at the roadside. There is a concern that WTH impairs site productivity due to nutrient removal. One option to increase the amount of biomass remaining in the stand is to top the trees before extraction. In order to estimate the influence of topping on system productivity, time studies on a medium-sized tower yarder were carried out in three spruce dominated stands. Heart rate monitoring of the chainsaw operator was performed to examine the physiological workload. The analysis showed that topping only impacts system productivity if it takes place during the inhaul of the load as it leads to interruptions of the extraction progress. These interruptions took on average 13 seconds per turn. In addition, if topping was performed on already lifted trees, a reduction of line-speed during the lateral yarding of the loads was observed. This led to a reduction in productivity between 5 and 11%, assuming that all trees would have been topped during the lateral yarding process. Analyses of the physical workload of the chainsaw operator showed that the workload of topping trees is significantly lower than that of the felling process. Relative heart rate of the subject was lower at the cable corridors where topping was ordered. This confounding result may be a consequence of many additional factors like slope gradient or cycle time. Under both scenarios, the worker never surpassed the limit of a sustainable cardio-vascular workload for an 8 hour working day. Hence, recovery time for the chainsaw operator can be considered as adequate when topping is performed in a three-man crew.https://hrcak.srce.hr/file/223297 |
| spellingShingle | Karl Stampfer Christoph Huber Efficiency of Topping Trees in Cable Yarding Operations Croatian Journal of Forest Engineering |
| title | Efficiency of Topping Trees in Cable Yarding Operations |
| title_full | Efficiency of Topping Trees in Cable Yarding Operations |
| title_fullStr | Efficiency of Topping Trees in Cable Yarding Operations |
| title_full_unstemmed | Efficiency of Topping Trees in Cable Yarding Operations |
| title_short | Efficiency of Topping Trees in Cable Yarding Operations |
| title_sort | efficiency of topping trees in cable yarding operations |
| url | https://hrcak.srce.hr/file/223297 |
| work_keys_str_mv | AT karlstampfer efficiencyoftoppingtreesincableyardingoperations AT christophhuber efficiencyoftoppingtreesincableyardingoperations |