JZⅩ—25型悬挂植树机(定型)试验报告

我场原使用的牵引式植树机作业时与联接器挂接机构庞大,地头转弯半径大,不利于作业和林地间运输,机具本身钢材消耗大、成本高。根据我场造林作业的具体特点,为了节省钢材,一九七五年春季,我们开始试制悬挂植树机,在没有资料、没有样机、缺乏设备的情况下,广大职工发扬大庆人“有条件要上,没有条件创造条件也要上”的革命精神,克服了许多困难,经多次反复的改制、试验、再改制,在省林业局及省林科所和有关单位的指导邦助下,于一九七六年生产了十台悬挂植树机。通过对该机使用,证明该机作业效果好,基本满足造林作业需要。     

谈拖拉机运输作业中的油耗及油门的使用

农业运输是轮式拖拉机的主要作业项目。全年当中,其从事农业运输的出勤天数,往往超过其他农田作业天数的总和。在地形起伏多变的土石山区,其路面复杂、坡路多、坡度大、弯度急,在这种情况下从事运输作业的机组,不仅要克服较大的滚动阻力,而且发动机输出的有效功率也要适应负荷的变化。如果油门使用不当将会增加油耗,使机组的经济性下降．下面笔者就如何降低油耗,正确使用油门等问题谈谈自己的看法。     

YB—30型振动式拔根机的研制及试验

该机的研制成功,为皆伐后的速生丰产林和防护林的拔根整地作业提供了一种新型机具.该机经技术鉴定和生产试用,获专家和生产单位好评,并准备小批量生产.本文介绍了该机的主要技术参数、结构方案的确定及工作原理等.     

林业科技信息

△BX型松树球果脱粒机,1987年1日6在哈尔滨通过鉴定。该机由黑龙江省木材采运研究所研制,是用于红松、云南油松、华山松等大粒种子球果脱粒作业的手摇便携式机具。该机不仅适用于山上采集球果的分散流动脱粒作业,改变传统木棒敲打的原始脱粒方式,而且可适用于室内的脱粒作业,干鲜球果均可使用。该机具有重量轻、结构简单、造价低、携带方便等特点。其脱粒效率为人工棒打的2.5倍,脱净度达97.8%,松籽完好率达99.7%。该项成果属国内首创,达到了国内先进水平。(马玉琴)     

油茶中耕抚育管理机的研制

介绍了油茶中耕抚育管理机总体设计方案的确定,给出了该机技术参数及结构设计。试验表明,该机能够满足南方山地油茶林垦复作业的要求,垦复深度可调,越障能力强,垦复效率高,在改善劳动条件、减轻劳动强度等方面效果明显。     

XJ—200型悬挂式搅浆机的研制

重点介绍了ＸＪ－２００型悬挂式搅浆机的结构及工作原理，对该机的劳动生产率、作业成本、作业质量进行了分析，并探讨了该机械在砂石公路养护方面的应用前景。     

CDI2型营林集材拖拉机研制与试验

该机发动机功率为１２马力，自带绞集装置，可直接在人工林或次生林中进行集材作业，趟载量可达１ｍ３。通过长时期的试验作业，使用该机同目前使用较广的牛集运相比，每台每年可节省成本创直接经济效益１．２６万元。此项研究为国内山地营林间伐抚育集材作业提供了一种新型适用机械设备。     

2BZ—800型容器苗制作机研制成功

<正> 由山西省关帝山森林经营局真武山林场候源亮研制的容器苗制作机和手工容器苗制作器,已于1991年6月17日通过省级鉴定。鉴定认为:该机设计新颖、能结合当前生产实际,有效地解决了在容器中移栽裸根苗作业难度大和生产效率低等技术难题。该机将容器制作、营养土装填和裸根苗移栽容器中的三道工序由机械作业一次完成,符合容器育苗技术要求。作业省工,成本低,是育苗生产中迫切需要的一种新型容器育苗机械。该机结构简单,操作维修方便,手动、电动两用,造价低,生产效率高,适用于平原、山区流动容器育苗作业,还可应用于农业和花卉等容器育苗,具有广阔的应用前景。     

Lamu型播种机

介绍了Lamu型播种机样机的工作情况。该机由一个旋耕装置,一个双壁犁, 两个排种装置和九个化肥漏斗组成,该机主要用于排过水的沼泽地的直播作业,并在芬兰的西南地区的排过水一年的低洼的管茅草沼泽地进行了试验,该机由瓦尔     

CD12型营林集材拖拉机研制与试验

该机发动机功率为１２马力，自带绞集装置，可直接在人工林或次生林中进行集材作业，趟载量可达１ｍ＾３。通过长时期的试验作业，使用该机同目前使用较广的牛集运相比，每台每年可节省成本创直接经济效益１．２６ｄ万元。此项研究为国内山地营林间伐抚育集材作业提供了一种新型适用机械设备。     

Determining the effect of tree size,bark-wood bond strength and tree form on the productivity of an excavator-based harvester in Acacia mearnsii in the KwaZulu-Natal forestry region of South Africa

The aim of this study was to determine the effect of tree size, bark-wood bond strength and tree form on the productivity of cut-to-length harvesting of Acacia mearnsii, using an excavator-based harvester with a SP Maskiner harvester head in the KwaZulu-Natal forestry region of South Africa. Tree diameter and height measurements were used to determine individual tree volumes, after which the trees were classified into different bark-wood bond strength and tree-form classes. Time studies were carried out to determine harvester productivity. The results showed that tree size plays a crucial role in the productivity of the harvester, but bark-wood bond strength and tree form also influence productivity. The harvester productivity varied from 5.5 m³ per productive machine hour (PMH) in 0.05 m³ trees to 16.9 m³ PMH^?1 in 0.25 m³ trees The bark-wood bond strength did not influence harvester productivity when handling small trees of less than 0.1 m³. In small trees, the productivity of the harvester was also not affected by different form classes, but as tree size increased, there was greater productivity variation between the different form classes.     

Performance of small harvester head in a thinning operation

Medium to large size harvester heads mounted on large machines are popular in Japan. These machines encounter some problems during thinning operations,e.g. damage to residual stand and the compaction of soil. The performance of these large harvesters was compared with that of smaller ones operating simultaneously in the same line thinning operation of the same stand. The results of a time study showed that mean cycle times for the smaller and larger harvesters were not significantly different. This means that the work efficiency of the smaller harvester can be at the same level as the larger harvester on sites similar to those of this study. The mean values “Feed” element of the cycle time, however, were significantly different. Although this time difference appears to provide an advantage to the larger harvester, simulation results show that the advantage is not great enough to significantly shorten the total cycle times. That is to say, the work efficiency remains essentially the same even if the feeding performance of the small size harvester becomes as high as that of larger ones. The small harvester performs adequately in thinning operations, and is not inferior to the larger ones. This result indicates that there is economic potential for small base machines that can be mounted with small harvester heads, resulting in less damage to residual trees and site soils during thinning operation. A part of this paper was orally presented at the 109th Annual Meeting of the Japanese Forestry Society (1998). The time study research presented in this paper was supported by the National Federation of Logging Contractors Cooperative Associations.     

伐木联合机间伐作业性能和时间研究

本文介绍了伐木联合机间伐针叶林的时间研究过程和方法。通过欧洲赤松和落叶松的间伐试验、测量了单株作业时间和各动作时段比例。得到(?)SA250EVA型伐木联合机的生产能力为每小时57～68株或6.8～8.5m~3分析不树种、林木胸径及作业方式对伐木联合权作业性能的影响,作业评估表明,伐木联合机生产率高、工作条件舒适安全。对林木和林地捐伤小,适合在针叶林间伐中使用。     

Impact of number of stems per stool on mechanical harvesting of a Eucalyptus globulus coppiced plantation in south-west Western Australia

Coppice regeneration of eucalypt plantations is increasingly being used in Australia to reduce re-establishment costs. However, little is known about the impact of early coppice reduction regimes on harvester performance during clearfelling. The trial compared the productivity, time consumption, cost and fuel use of a single-grip harvester (Hyundai 210LC-9 base and SP 591LX harvesting head) clearfelling a 10.5-year-old, second-rotation coppiced Eucalyptus globulus stand in south-west Western Australia for chip logs. Coppice stems had been reduced to one stem or two stems per stool or left untreated. Time and piece counts were used to determine harvester productivity. Harvester cycle and elemental times and the number of logs and harvester head passes per stem were obtained from video recordings. Harvester fuel use was determined by refilling the fuel tank to the same point each day. Stem size was the major factor influencing harvester productivity (20.8 m3 per productive machine hour without delays [PMH₀], 11.8 m³ PMH₀^?1 and 8.6 m³ PMH₀^?1 in the single-stem (mean stem volume [MSV] 0.21 m³), two-stem (MSV 0.09 m³) and untreated trial areas (MSV 0.06 m³), respectively. Estimated harvester cost (AU$ m^–3) was considerably greater for the two-stem and untreated trial areas, which reflected the lower harvester productivity in these areas. Processing time represented over 60% of the total cycle time for all trial areas. Coppice characteristics resulted in significantly different moving/positioning times between trial areas. However, this difference had no impact on cycle times. Number of logs per stem was a significant variable in cycle and processing time regressions for all trial areas and felling time for the single-stem trial area. Number of harvester head passes was a significant variable in cycle and processing time regressions for the single-stem trial area and processing times for the two-stem trial area, although its effect was less than that of the number of logs per stem. Fuel consumption (L PMH₀^?1) was relatively constant between the trial areas, hence harvester energy intensity (L m^?3) reflected the harvester productivity in each trial area.     

Predicting forwarder rut formation on fine-grained mineral soils

Predictive factors for forwarder rut formation were studied on fine-grained mineral soils. The study was carried out in southern Finland in mid-May, when the soil water contents were high after snowmelt. A total of 7 study tracks of 20?m were cut with a harvester. After removing the logging residues, a loaded forwarder made 3–4 passes on each track. The forwarder rut depth was related to the total overdriven mass driven over the measurement line, volumetric water content, cone penetration resistance and the harvester rut depth. A total of five mixed-effects models are presented to predict the rut depth. The first model includes the overdriven cumulative mass, volumetric water content of the soil and the cone penetration resistance. As a penetrometer is more of a research tool, the second model includes only the overdriven cumulative mass and water content, factors that can be used in practical planning operations. The remaining three models all include the rut depth after the harvester pass and the overdriven cumulative mass and also include volumetric water content and cone penetration resistance. The model including the rut depth after a harvester pass and the overdriven cumulative mass is a good predictor of the rut depth and supports earlier findings on the connection between harvester and forwarder rut formations.     

Possibilities for Harvester-based Forest Inventory in Thinnings

This study investigated the possible estimation of forest characteristics using the information collected by the harvester in first thinnings. For the analysis a complete forest inventory was carried out in a stand, which was subsequently thinned. The global mean values of tree diameter, tree height, basal area and stem density were estimated, and further, a spatial analysis was carried out to investigate whether the data collected by the harvester could be used to generate a continuous spatial model of the forest. The results indicated that the global mean diameter and height may be estimated, whereas area-related properties, such as basal area and stem density, are more difficult to estimate. The spatial distribution of the diameter and height remained similar after the thinning, whereas the basal area and stem density had become more homogeneous after the thinning. From the trees removed in the thinning a continuous spatial model of tree diameter was developed. It reproduced the spatial structure of the original trees to some extent ( R 2 = 0.27, RMSE = 14.3 mm).     

Accurate single-tree positions from a harvester: a test of two global satellite-based positioning systems

Accurate positioning of single trees registered automatically during harvesting operations opens up new possibilities for reducing the field sampling effort in forest inventories utilising remotely sensed data. In the present study, we propose to use a harvester to collect single-tree data during regular harvest operations and use these data to substitute or supplement traditional measurements on sample plots. Today’s harvesters are capable of recording single-tree information such as species and diameter at breast height, and a cut-to-length harvester was equipped with an integrated accurate positioning system based on real-time kinematic global satellite positioning, as well as a low-cost global navigation satellite system (GNSS) receiver mounted directly on the harvester head. Positions from 73 trees were evaluated and compared to coordinates obtained using a total station. At the single-tree level, the mean error for the integrated positioning system was 0.94?m. The low-cost GNSS receiver mounted on the harvester head yielded a mean error of 7.00?m. The sub-meter accuracy obtained with the integrated system suggests that data acquired with a harvester using this positioning system may have a great potential as a method for single-tree field data acquisition.     

Integrated harvesting for conventional log and energy wood assortments: a case study in a pine plantation in Western Australia

Biomass or energy wood harvesting can be integrated with conventional log harvesting (saw log or pulpwood production) to allow more cost-effective energy wood supply. The efficiency of an integrated energy wood harvesting system was evaluated and compared with conventional log harvesting in a 32-year-old Pinus radiata plantation (radiata pine) located in south-west Western Australia. The harvesting system consisted of a harvester and a forwarder. The study included two treatments: a conventional log-harvesting operation where merchantable sawlogs and pulp logs were produced at the stump by the harvester and extracted by the forwarder; and an integrated energy wood operation where the harvester produced sawlogs, pulp logs and energy wood at the stump that were extracted by the forwarder. In the integrated energy wood harvesting plot, 37 m3 ha?1 of energy wood was extracted in addition to the sawlog and pulp log volumes. Extracting the additional energy wood reduced the productivity of the forwarder and increased the cost of extraction (AU$2.7?m?3) compared with the control plot (AU$2.2?m?3). Harvesting system cost was not significantly impacted, with a cost of AU$3.18?m?3 in the control plot and AU$3.23?m?3 in the integrated energy wood harvesting plot. Diameter at breast height (DBH) was a significant factor influencing the working time of the harvester, whereas load volume, extraction distance and extraction type (sawlog, pulp logs, and pulp log/energy wood) significantly impacted forwarding time. Increasing DBH resulted in longer working cycles for the harvester. Heavier loads and longer forwarding distances increased forwarding cycle time, while extracting sawlogs was least expensive and energy wood extraction was the most expensive. The marginal cost of the energy wood was approximately AU$10.2?m?3 (AU$7.0 extraction and AU$3.2 harvesting), which is about double the cost of the sawlogs. Additional material recovered in the integrated energy wood plot resulted in less residual residues on the plot (103.2 green metric tonnes per hectare [GMt ha?1]) than the control plot (144.2 GMt ha?1).     

Evaluation of the Hitman PH330 acoustic assessment system for harvesters

Reductions in Pinus radiata D. Don. (radiata pine) clearfell age have increased the juvenile wood proportion in sawlogs, increasing the need to segregate low modulus of elasticity (MOE) material early in the supply chain to avoid the costly processing of low-value, non-structural boards. In Australian radiata pine plantations, variability in MOE is greater between trees than between stands, requiring tests of individual trees to identify those with low MOE. Time of flight of a sound wave in a tree or log is known to be well-correlated to its MOE. The trial examined the ability of a newly developed acoustic assessment tool, the Hitman PH330 (PH330) supplied by Fibre-gen Limited, fitted to a harvester head, to identify and segregate low MOE sawlogs during a cut-to-length harvesting operation in a radiata pine plantation. The impact of using the tool on the harvester’s productivity was also examined. There was a reduction in the mean productivity of the harvester when using the PH330 compared with normal operations not using the PH330 but it was not significant. Mechanical MOE testing showed that boards cut from sawlogs which the PH330 identified as structural, had significantly greater mean MOE than boards from non-structural sawlogs, demonstrating the PH330 was able to separate high and low MOE sawlogs.     

Continuous felling of small diameter trees in boom-corridors with a prototype felling head

Abstract

Simulations of the continuous felling of trees in boom-corridors have suggested that it may be possible to increase harvester productivity by a factor of 2.4 when thinning young dense stands. A prototype boom-tip mounted felling head for harvesting in this fashion was therefore built and tested in the field. Using the new head, stands with a density of 10,000 trees ha^?1 and a mean diameter at breast height (dbh) of 7 cm were felled at a speed of 0.4 m s^?1, with an efficiency of 3.5 s tree^?1. The felling speed was limited by the speed of movement of the harvester crane's boom. However, additional tests suggested that the new head could be operated at felling speeds of up to 1.3 m s^?1 when cutting trees with dbh values of up to 8 cm. The simulation that prompted this study focused on multiple felling with the crane in continuous motion at speeds of 1 m s^?1; the results obtained in this work suggest that the new felling head is capable of sustaining these speeds and so further technical development of the design (e.g. to incorporate accumulating functionality) is warranted.