Fuel Consumption In Forwarders

Nordfjell, Tomas; Athanassiadis, Dimitris; Talbot, Bruce

doi:10.1080/14942119.2003.10702474

Cited by 27 publications

(48 citation statements)

References 3 publications

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“…The relative time element proportions in the current study (loading time 42%, travel empty and travel loaded times 29%, unloading and moving during unloading time 19%, moving during loading time 10%) were similar to those modelled by Manner et al (2013) at an extraction distance of 400 m. Given the lower mean cycle time in the current study, this implies that forwarder travel speeds were greater than those in the previous studies. Travel empty and loaded speeds on the track in the current study were almost double those reported in previous studies while travel unloaded speed in the stand was comparable (Nordfjell et al 2003;Tiernan et al 2004;Gingras, Favreau 2005;Nurminen et al 2006). Travel loaded speed in the stand was comparable to that reported by Gingras and Favreau (2005) for travel loaded on a slope of greater gradient than 30%.…”

Section: Discussionsupporting

confidence: 78%

Time consumption and productivity of a forwarder operating on a slope in a cut-to-length harvest system in a Pinus radiata D. Don pine plantation

Strandgard¹,

Mitchell²,

Acuña³

2017

J. For. Sci.

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Strandgard M., Mitchell R., Acuna M. (2017): Time consumption and productivity of a forwarder operating on a slope in a cut-to-length harvest system in a Pinus radiata D. Don pine plantation. J. For. Sci., 63: 324-330.Time consumption and productivity of a Valmet 890.3 8 wheel forwarder were evaluated on an Australian radiata pine clearfell site with a slope of 21 to 45% (12 to 24°). Cycle time was significantly related to extraction distance. Productivity was significantly related to extraction distance and load volume. Slope did not have a significant effect on cycle time or productivity. Productivity was considerably greater than that for many published studies, which was likely to have been the result of many factors at the study site affecting load sizes and cycle times, including the large load capacity of the studied forwarder, larger mean log volumes, larger log volumes per loading stop, fewer log assortments, potentially larger forwarder grapple volume capacity, log lengths suited to efficient loading and higher travel speeds.

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Section: Discussionsupporting

confidence: 78%

Time consumption and productivity of a forwarder operating on a slope in a cut-to-length harvest system in a Pinus radiata D. Don pine plantation

Strandgard¹,

Mitchell²,

Acuña³

2017

J. For. Sci.

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“…In the study the forwarder operated at an average speed of 1 m s -1 , which is very close to the one expected in real work situations (Nordfjell et al 2003). The study gave no indications that deviations would increase substantially with increased speed.…”

Section: Discussionsupporting

confidence: 48%

Path tracking in forest terrain by an autonomous forwarder

Ringdahl

Lindroos

Hellström

et al. 2011

Scandinavian Journal of Forest Research

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Autonomous navigation in forest terrain, where operation paths are rarely straight or flat and obstacles are common, is challenging. This paper evaluates a system designed to autonomously follow previously demonstrated paths in a forest environment without loading/unloading timber, a pre-step in the development of fully autonomous forwarders. The system consisted of a forwarder equipped with a high-precision global positioning system to measure the vehicle's heading and position. A gyro was used to compensate for the influence of the vehicle's roll and pitch. On an ordinary clear-cut forest area with numerous stumps, the vehicle was able to follow two different tracks, three times each at a speed of 1 m s -1 , with a mean path tracking error of 6 and 7 cm, respectively. The error never exceeded 35 cm, and in 90% of the observations it was less than 14 and 15 cm, respectively. This accuracy is well within the necessary tolerance for forestry operations. In fact, a human operator would probably have a hard time following the track more accurately. Hence, the developed systems function satisfactorily when using previously demonstrated paths. However, further research on planning new paths in unknown unstructured terrain and on loading/unloading is required before timber transports can be fully automated.

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“…Thus, it is doubtful whether curvilinear relationships between dependent and independent variables shown in Fig. 3 are accurate, and both linear and curvilinear relationships have been presented in previous studies (see, e.g., Kuitto et al 1994;Kellogg and Bettinger 1994;Väkevä et al 2001;Nordfjell et al 2003;Brunberg 2004;Tiernan et al 2004;Nurminen et al 2006;Manner et al 2013). Erroneous curvilinearity would lead to errors in estimations, depending on the extraction distance (cf.…”

Section: Discussionmentioning

confidence: 99%

Load level forwarding work element analysis based on automatic follow-up data

Manner¹,

Palmroth²,

Nordfjell³

et al. 2016

Silva Fenn.

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Highlights• Recent developments in on-board technology enables automatic collection of follow-up data on forwarder work.• Time consumption per load was more strongly associated with Loading drive distance than with extraction distance, indicating that the relevance of extraction distance as a main indicator of forwarding productivity should be re-considered.• Data, within variables, were positively skewed with a few exceptions with normal distributions. AbstractRecent developments in on-board technology have enabled automatic collection of follow-up data on forwarder work. The objective of this study was to exploit this possibility to obtain highly representative information on time consumption of specific work elements (including overlapping crane work and driving), with one load as unit of observation, for large forwarders in final felling operations. The data used were collected by the John Deere TimberLink system as nine operators forwarded 8868 loads, in total, at sites in mid-Sweden. Load-sizes were not available. For the average and median extraction distances (219 and 174 m, respectively), Loading, Unloading, Driving empty, Driving loaded and Other time effective work (PM) accounted for ca. 45, 19, 8.5, 7.5 and 14% of total forwarding time consumption, respectively. The average and median total time consumptions were 45.8 and 42.1 minutes/load, respectively. The developed models explained large proportions of the variation of time consumption for the work elements Driving empty and Driving loaded, but minor proportions for the work elements Loading and Unloading. Based on the means, the crane was used during 74.8% of Loading PM time, the driving speed was nonzero during 31.9% of the Loading PM time, and Simultaneous crane work and driving occurred during 6.7% of the Loading PM time. Time consumption per load was more strongly associated with Loading drive distance than with extraction distance, indicating that the relevance of extraction distance as a main indicator of forwarding productivity should be re-considered.

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Fuel Consumption In Forwarders

Cited by 27 publications

References 3 publications

Time consumption and productivity of a forwarder operating on a slope in a cut-to-length harvest system in a Pinus radiata D. Don pine plantation

Time consumption and productivity of a forwarder operating on a slope in a cut-to-length harvest system in a Pinus radiata D. Don pine plantation

Path tracking in forest terrain by an autonomous forwarder

Load level forwarding work element analysis based on automatic follow-up data

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