Skyline tensile force monitoring of mobile tower yarders operating in the Italian Alps

Mologni, Omar; Lyons, C. Kevin; Zambon, Giulio; Proto, Andrea Rosario; Zimbalatti, Giuseppe; Cavalli, Raffaele; Grigolato, Stefano

doi:10.1007/s10342-019-01207-0

Cited by 19 publications

(13 citation statements)

References 16 publications

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“…The results of this study are especially important because they indicate that the endurance limit of the skyline was not reached during the trial -even if SWL was often exceeded during lateral skidding and inhaul. That matches the findings of another study conducted a few years earlier in a similar three-cable setup also in the Italian Alps (Spinelli et al 2017), and those of a larger observational study covering multiple installations and configurations also performed in the same region (Mologni et al 2019). Taken together, these studies suggest that loggers in the Italian Alps (and possibly in the SPT = skyline pre-tension; PTBR = peak tension during breakout; TIF = tension increase factor, i.e.…”

Section: Discussionsupporting

confidence: 87%

Skyline tension and dynamic loading for cable yarding comparing conventional single-hitch versus horizontal double-hitch suspension carriages

Spinelli

Magagnotti

Cosola³

et al. 2021

International Journal of Forest Engineering

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Wire rope used in cable logging, where a series of cables facilitate the extraction of timber on steep terrain, experiences high tensions that must be managed to ensure safety. Innovations change practices over time and double-hitch carriages, which allow trees to be extracted horizontally, are a recent example. This makes it feasible to harvest across terrain with limited deflection, increases the recovery of biomass, and potentially reduces high-dynamic load events associated with ground contact. In this study, a standard single-hitch carriage was compared against a new double-hitch carriage under controlled conditions. Tension was measured continuously and specific elements, such as tension when the carriage was at midspan, maximum tension at breakout and inhaul, and magnitude of cyclic tension during inhaul were identified, measured and compared against payload. While payload was similar in the treatments, the additional weight of the double-hitch carriage resulted in higher skyline tensions. In both treatments, payload and skyline tension when the carriage was at midspan were strongly correlated. Cyclic tension was reduced by the double-hitch carriage system. While a number of unique high-dynamic loads were identified that were not part of the normal extraction, they represented only 6% of the cycles and the maximum tension was similar to that experienced during break-out and inhaul. This study increased the understanding of skyline tension during logging operations and the effect of carriage type. It showed that, though tension often exceeds the safe working load of the cable, it does not exceed the endurance limit for a well-designed and operated system.

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Section: Discussionsupporting

confidence: 87%

Skyline tension and dynamic loading for cable yarding comparing conventional single-hitch versus horizontal double-hitch suspension carriages

Spinelli

Magagnotti

Cosola³

et al. 2021

International Journal of Forest Engineering

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“…However, comparisons of software outputs with actual operational field data are extremely limited. One of the main reasons is probably related to the limited availability of field operational data due to the costs and challenging conditions to record skyline tensile forces (Dupire et al 2015, Mologni et al 2019.…”

Section: Discussionmentioning

confidence: 99%

“…Excessive skyline tensile forces, in particular, is a primary safety concern in the risk assessment, being the main reason for broken supports, anchor tree and cables (Tsioras et al 2011). Field trials have shown frequent exceeding of the recommended safety limits in skyline tensile forces during ordinary cable logging operations (Hartsough 1993, Harrill and Visser 2016, Spinelli et al 2017, Mologni et al 2019. In standing skyline configurations, improper installation of the cable structure or poor operational practices are the predominant elements in the noncompliance with the safety regulations, but dynamic loads can lead to tensile force increase up to critical values (Spinelli et al 2017, Mologni et al 2019.…”

Section: Introductionmentioning

confidence: 99%

Skyline Tensile Forces in Cable Logging

Mologni

Marchi

Lyons

et al. 2021

Croat. j. for. eng. (Online)

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Skyline tensile forces have been shown to frequently exceed the recommended safety limits during ordinary cable logging operations. Several models for skyline engineering analyses have been proposed. Although skyline tensile forces assume a dynamic behaviour, practical solutions are based on a static approach without consideration of the dynamic nature of the cable systems.The aim of this study was to compare field data of skyline tensile forces with the static calculations derived by dedicated available software such as SkylineXL. To overcome the limitation of static calculation, this work also aimed to simulate the actual response of the tensile fluctuations measured in the real environment by mean of a finite element model (FEM).Field observations of skyline tensile forces included 103 work cycles, recorded over four different cable lines in standing skyline configuration. Payload estimations, carriages positions, and time study of the logging operations were also collected in the field. The ground profiles and the cable line geometries were analysed using digital elevation models. The field data were then used to simulate the work cycles in SkylineXL. The dynamic response of six fully-suspended loads in a single-span cable line was also simulated by a dedicated FEM built through ANSYS®. The observed data and the software calculations were then compared.SkylineXL resulted particularly reliable in the prediction of the actual tensile forces, with RMSE ranging between 7.5 and 13.5 KN, linked to an average CV(RMSE) of 7.24%. The reliability in predicting the peak tensile forces was lower, reporting CV(RMSE) of 10.12%, but still not likely resulting in a safety or performance problem. If properly set-up and used, thus, SkylineXL could be considered appropriate for operational and practical purposes. This work, however, showed that finite element models could be successfully used for detailed analysis and simulation of the skyline tensile forces, including the dynamic oscillations due to the motion of the carriage and payload along the cable line. Further developments of this technique could also lead to the physical simulation and analysis of the log-to-ground interaction and the investigation of the breakout force during lateral skidding.

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“…Some kinds of sensors are, of course, also usable to pursue one of the most important aims of sustainable forest management, i.e., forest workers' safety. One application is on-field continuous measuring of cable tensile force during winching operation, which can be performed by cable tensile force measurement device like Cable-Bull ® SR22/800 XR sensor (manufactured by the Honigmann Industrielle Elektronik GmbH) [88][89][90]. A summarizing view of the contribution of various sensors and electronic devices to SFM is provided in Table 2.…”

Section: Machine Sensorsmentioning

confidence: 99%

“…In the forest utilization world, the most advanced technology machines are harvesters and, secondly, forwarders. Nevertheless, these require almost complete operator input and so even mechanized harvesting or forwarding extraction method could be considered to have a LOA 0 [90].…”

Section: Machine Vibration Sensorsmentioning

confidence: 99%

Recent Contributions of Some Fields of the Electronics in Development of Forest Operations Technologies

et al. 2019

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In the last years, there has been a growing need to improve forest-wood chain concerning all three pillars of sustainability (economic, environmental, and social). Using electronic systems, in particular GIS, GNSS, and various kinds of sensors related to forest harvesting, is clearly one of the most powerful instruments to reach this aim. The contribution of these tools to forest operation is wide and various. One of the most important application was integrating ICT and GPS/GNSS on-board systems on modern forest machines. This allowed one to ensure multiple benefits to forest operation field. On the one hand, electronic systems, and particularly GIS, could be used to improve forest harvesting with a previous planning of the skid trails network, in order to minimize utilization impacts and risks for operators, ensuring at the same time high work productivity. Moreover, GIS developed files could also be implemented in modern forest machine GPS/GNSS systems, helping forest machines operators to move only along a designed skid trails network or making it possible to avoid restricted access areas. On the other hand, modern forest machines could be equipped with complex and accurate sensors that are able to determine, register, and share information about wood biomass quantity and quality and even undertake economic evaluation of stumpage value. Finally, the input and output of these systems and sensors could be implemented in a decision support system (DSS) ensuring the best silvicultural and operative alternative from a sustainable forest management point of view. A detailed review of the contribution of electronics in the development of forest operations is provided here.

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Skyline tensile force monitoring of mobile tower yarders operating in the Italian Alps

Cited by 19 publications

References 16 publications

Skyline tension and dynamic loading for cable yarding comparing conventional single-hitch versus horizontal double-hitch suspension carriages

Skyline tension and dynamic loading for cable yarding comparing conventional single-hitch versus horizontal double-hitch suspension carriages

Skyline Tensile Forces in Cable Logging

Recent Contributions of Some Fields of the Electronics in Development of Forest Operations Technologies

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