亚布力林业局适宜集材方式的探讨

本文根据几种集材方式的特点,结合亚布力林区的实际情况,对目前亚布力林业局适宜的集材方式进行了探讨。通过比较论证,认为畜力原木集材是目前亚布力林区适宜的集材方式。今后集材方式的改革应是机畜结合,以畜力原木集材为主,机械原条集材为辅。     

介绍新式集材法——冻槽集材

冰槽集材法适合于北方林区冬季集材。这一新的集材方法是大兴安岭林区海牙斯德林场老工人王永泰创造的。这一创举,经过实地实验证明,是一经济适用、效率很高的集材方法。它的主要优点是:在北方寒冷的林区,借助自然力量集材,可节省大量的畜力、机械和许多工具,方法简     

FYJ-1型轮式抚育伐集材拖拉机应用经济效益分析

通过对FYJ-1型轮式抚育伐集材拖拉机与畜力集材两种生产作业方式进行比较,对两个冬运期集材作业的实测数据进行整理与核算表明,集材拖拉机比畜力集材生产方式的经济效益提高2.99倍,生产效率提高2～3倍。 FYT-1型轮式抚育伐集材拖拉机不仅适合在零星分散的森林抚育间伐场地作业,更适合在集中连片和远距离（800m以上）、坡度适中的场地作业。     

浅谈畜力集材

集材作业是伐区木材生产的重要工序，集材成本约占伐区木材生产总成本的２／３左右．集材方式的选择对集材任务完成的好坏、提高效率、降低生产成本至关重要．目前，由于“天保工程”的实施，可采森林资源逐渐减少，承包经营的发展，使畜力原木集材方式转变为重要的集材方式．山河电林业局于１９８５年后全部采取伐区造材、畜力原木集材作业方式。现结合多年的生产实践，对畜力原木集材的特点、措施、发展方向探讨如下：ｌ畜力集材的特点 畜力集村适用于伐区坡度大、森林资源分散、公顷出材量小、集材距离长的林相。畜力集材具有机动灵活；…     

原条集材方式经济适宜条件的探讨

目前林区适于原条集材方式的伐区越来越少,为正确确定集材方式,充分发挥机械作用,本文从伐区生产和准备作业方面对原条方式和畜力短材方式的生产成本进行了分析、比较,对拖拉机原条集材方式的经济适宜条件进行了探讨。     

畜力集材措施的探讨

畜力集材可降低生产成本。有利于森林资源培育,提出了畜力集材措施     

浅淡畜力集材

集材作业是伐区木材生产的重要工序,集材成本约占伐区木材生产总成本的2/3左右.集材方式的选择对集材任务完成的好坏、提高效率、降低生产成本至关重要.目前,由于"天保工程”的实施,可采森林资源逐渐减少,承包经营的发展,使畜力原木集材方式转变为重要的集材方式.山河屯林业局于1985年后全部采取伐区造材、畜力原木集材作业方式.现结合多年的生产实践,对畜力原木集材的特点、措施、发展方向探讨如下:     

低强度择伐伐区集材方式的探讨

这篇文章探讨了低强度择伐伐区集材方式，分析了各种集材方式的优缺点，讨论了新的集材工艺和集材方式。新的集材工艺和集材方式是：由轻型绞盘机或小型拖拉机或畜力将原木或原条运到集材道两侧，完成小集中作业；再由拖拉机或索道或畜力将这些原木或原条运到伐区楞场，完成集材作业。     

利用轮式小拖拉机进行集材的研究

将轮式小拖拉机进行改造,装配绞盘机和搭载板后进行集材,在集材距离200~300 m时,日集材量为:冬季20~30 m3,夏季15~20 m3,比畜力集材提高了4~6倍;集材成本为15~20元.m-3,是畜力集材的50%。利用轮式小拖拉机进行集材,对地表及幼苗幼树的破坏程度大幅度降低,是目前可供选择的一种较好的集材方式。     

伐区集材机械的经济更新期及合理选型

伐区集材机械的经济更新期及合理选型是企业生产全过程中的重要手段,它具有提高生产效率、降低生产成本的重要作用。下面将通过集材—50,集材—80两种拖拉机的寿命周期费用分析,找出最佳的经济更新期和优选的机型。选择机械最佳的经济更新期,是伐区机械管理中的一个重要环节。传统的机械管理,不注意更新的最佳时机,往往采用无限次修理的方法来延长机械的更新期。这样,由于有形和无形磨损的加剧,虽经大修,仍无法恢复原有的技术状态,在生产中表现为故障增多,开动     

The Method of Calculating Average Skidding Distance

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伐区作业类型划分与集材作业系统相适应性的研究

本应用模糊聚类分析方法,选取作业区坡度、单位面积出材量、集材距离以及地表承载能力等作为因子,对吉林林区伐区作业类型进行了区划。又应用层次分析法,对与每类伐区相适应的集材作用系统进行系统分析。     

Time consumption, productivity, and cost analysis of skidding in the Hyrcanian forest in Iran

The performance of the skidder Timber jack 450 C was presented in timber skidding of non-coniferous trees in hilly and mountainous conditions.An empirical time study was conducted to evaluate the current skidding system in Hyrcanian forest in northern Iran for improving production rate of skidding and finding out the production cost for planning.Based on the identified elements of skidding work phase and 130 recorded cycles,we calculated the models for effective time consumption,total productivity,and unit cost.The validity of the model was tested at 95% confidence interval.The average load volume per cycle was 2.82 m 3,average one way skidding distance was 450 m,and the average slope was 18%.The average travel speed of unloaded skidder was 5.8 km·h-1,and the average speed of loaded skidder was 0.1 km·h-1 higher than the speed of the unloaded ones.The travel speed was predominantly affected by longitudinal slopes and types of strip roads.The average speed of pulling the cable was 1.16 km·h-1,and that of load winching was 0.74 km·h-1.The average outputs in skidding was 10.6 m 3 ·h-1 and the unit cost was 12.1 US$ per hour.The time consumption and productivity of skidding depends on distances and slope,number of logs per cycle,volume,log length,etc.However,the influence of variables is not the same.     

ASSESSMENT OF ANIMAL SKIDDING AND GROUND MACHINE SKIDDING UNDER MOUNTAIN CONDITIONS

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Time Prediction Models and Cost Evaluation of Cut-To-Length (CTL) Harvesting Method in a Mountainous Forest

Time equations are derived for felling with chainsaw, skidding with cable wheeled skidder, loading with grapple hydraulic loader and trucking of logs within a cut-to-length harvesting method. The continuous time study method was applied to collect data for felling, skidding, loading and a transportation model. Multiple regression analysis via SPSS software was applied to develop the time models. Felling time was found to be highly dependent on diameter at breast height. Skidding distance, winching distance, slope of the trail and piece volume were significant variables for the skidding time prediction model. The loading time model was developed considering piece volume. Transportation distance and load volume were used as independent variables in modeling the transportation time. The net production of felling was estimated at 12 trees/h (56.65 m³/h). The net production rates for skidding, loading and traveling averaged 18.51, 41.90 and 3.32 m³/h respectively. The total cost of harvesting from stand to mill was estimated 19.70 €/m³. The skidding phase was the most expensive component of the cut-to-length method. The bucking and delimbing components were less costly than the other logging phases. The results of this study can be used for harvesting planning and productivity optimization.     

A Comparison of Productivity in Five Small-Scale Harvesting Systems

The use of small-scale harvesting equipment continues to grow in forestry in many regions of the world. This equipment includes various devices and methods used to harvesting that generally are smaller, less expensive and less productive than advanced forestry machines. The objective of this study is to compare the efficiency of five alternative extraction methods implemented in a harvesting unit located in a mixed beech and oak forest ecosystem in northwestern Turkey. A continuous time study was conducted during primary transport operations that included skidding with animal power, skidding with farm tractor, hauling with farm tractor, hauling with forest tractor, and extraction by skyline. Timber was skidded uphill on a skid trail, and an average skidding distance of 100 m for all haulage methods was considered. Average slope of the harvesting unit ranged from 20 to 40 %. Average productivities for respective haulage methods were 3.80, 6.25, 2.80, 5.25 and 10.09 m³/h. Significant differences were found between productivity of haulage methods using one-way analysis of variance. The extraction by skyline, skidding with farm tractor, and hauling with forest tractor were determined to be the most statistically different methods, the productivity of these methods was found significantly higher than the other methods. Skid trails are useful for shortening distances during forest operations and skidding with farm tractor is a productive method in small-scale forestry of Turkey.     

A productivity model for first thinning of Pinus patula using a tractor and double-drum winch in South Africa

The productivity of skidding tractors in intermediate harvesting operations has not been determined in Mpumalanga, South Africa. The objective of this study was to develop a productivity model using a farm tractor in first thinning operations in Pinus patula compartments. A work study design was used to assess the performance of a skidding agricultural tractor. From 350 samples, important data variables collected were elemental times for each work cycle, extraction distance, slope and load volume. Stepwise and subsets regression analyses were conducted prior to multiple linear regression analysis. Analysis of variance was used to compare mean productivity estimates of the different models developed. Results showed that the best model was estimated by an interaction of distance × slope (ds), distance × load volume (dv) and slope × load volume (sv) as follows: ln(?₂) = 1.33–0.00154ds + 0.00174dv + 0.161sv. The mean estimate for this model was 5.036 m³ m h^?1. The developed models predicted similar results to estimation results of the observed model, although there were statistically significant (P < 0.001) differences among mean estimates (3.6–5.5 m³ m h^?1). All of the three models yielded R²_adj. = 38%; SE = 0.458% at P < 0.001. It can be speculated that the remaining variation not explained by the models may be associated with long extraction distances, delays and the effect of slope as a main variable in the model. While the developed models mirrored reasonably well with the observed estimates of skidding productivity, these models should not be stretched to conditions dissimilar to those of their generation. Future research focus should be made on (1) effects of weather conditions and vehicular characteristics on skidding productivity and (2) the effect of winching lines on skidding productivity.     

不同采伐、集材方式对林地土壤理化性质影响的研究

选择５种不同集材方式的皆伐作业与采伐强度为３０％的择伐作业,进行土壤理化性质指标变化程度的比较。在考虑各种作业的集材量和集材道面积的情况下,经主成分分析得出不同采伐、集材方式对林地土壤理化性质的干扰程度。认为,以皆伐作业手扶拖拉机集材为最大,其次为皆伐作业土滑道集材,其余依次为皆伐作业半悬索道集材,皆伐作业手拉板车集材,皆伐作业全悬索道集材,最低为择伐作业人力集材。     

南方集体林区集材生产优化选择分析研究

应用马秋思理论和数理统计方法综合分析木材生产中较为普遍采用的 3种典型集运材方式的成本K与集材距离L的关系 ,并给出集材生产优化选择计算实例。     

小型环境友好集材装备的研究进展

在集材过程中,集材作业不当会造成林地的土壤压实,会对幼苗、保留木造成损伤,影响森林生态环境。本文介绍国内外集材拖拉机和集材拖车的研究进展,对国内外的集材装备存在的问题进行总结和陈述,根据以上分析得出今后集材装备设计的理念和发展方向。