Cable tensile forces in winch-assist harvesting have been investigated in order to assess the safety concerns of the technology. However, the literature is lacking, particularly in regards to the impact of winch design. In this study, a Summit Winch Assist tethering a feller-director on ground slopes up to 77% was monitored for four days. The cable tensile forces were simultaneously recorded at the harvesting and anchor machine at a frequency of 100 Hz. Cameras and GNSS devices enabled a time study of the operations and the recording of machine positions. Winch functionality and design were disclosed by the manufacturer and used for the interpretation of the results. The cable tensile forces reached 296 kN at the harvesting machine and 260 kN at the anchor machine. The slow negotiation of obstacles while moving downhill recorded the highest peaks, mainly due to threshold settings of the winch in the brake system activation. Lower but significant peaks were also recorded during stationary work tasks. The peaks, however, were limited to a few events and never exceeded the endurance limit of the cable. Overall, the study confirmed recent findings in cable tensile force analysis of active winch-assist operations and provided evidence of the underlaying mechanisms that contribute to cable tensile forces.

中文翻译：

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系绳收割作业中与绞车设计相关的缆索张力：来自太平洋西北部的案例研究

为了评估该技术的安全问题，已经研究了绞车辅助收割中的电缆张力。然而，缺乏文献，特别是关于绞盘设计的影响。在这项研究中，Summit Winch Assist 在高达 77% 的地面斜坡上拴住了一名伐木者，并对其进行了为期四天的监测。在收割和锚固机上以 100 Hz 的频率同时记录电缆张力。摄像机和 GNSS 设备能够对操作进行时间研究并记录机器位置。绞盘的功能和设计由制造商披露并用于解释结果。收割机的缆索张力达到 296 kN，锚固机的缆索张力达到 260 kN。下坡时缓慢通过障碍物记录了最高峰，主要是由于制动系统激活中绞车的阈值设置。在固定工作任务期间也记录了较低但显着的峰值。然而，峰值仅限于少数事件，并且从未超过电缆的耐久极限。总体而言，该研究证实了最近在主动绞盘辅助操作的缆索张力分析中的发现，并提供了导致缆索张力的底层机制的证据。