Operator's physical workload in simulated logging and timber bucking by harvester

Dvořák, Jiří; Natov, Pavel; Natovová, L.; Krilek, Jozef; Kováč, Ján

doi:10.17221/21/2016-jfs

Cited by 10 publications

(13 citation statements)

References 22 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…control measurements were done in videos made during harvester operation. The method of unit time consumption measurements, extended to include shift and batch time and load volume measurements, was published by Dvořák et al (2011). similar to standardization of most transport activities, the primary independent factors include the mean-tree volume, forwarding distance and the forwarder load volume (eriksson, lindroos 2014).…”

Section: Methodsmentioning

confidence: 99%

“…one of the models expressing the time consumption necessary for felling and processing a tree by a medium and high-power harvester in relation to the mean-tree volume was published by Dvořák et al (2011). The formula is derived from spruce and pine harvesting in advance and planned principal felling.…”

Section: Performance Of Medium and High-power Harvestersmentioning

confidence: 99%

“…in a technological line consisting of a harvester and a forwarder in our case it is difficult to ensure full performance of both vehicles. in our case it is the distance necessary for forwarding timber from a forest stand to a roadside landing which significantly influences machine performance and in most cases represents the key factor in performance standards for planning timber forwarding productivity regardless of the means of transport (nouzová 1995;Dvořák et al 2011). Among other things, this fact allows us to select suitable roadside landings at an acceptable (optimum) distance from the production block.…”

mentioning

confidence: 95%

“…mean-tree volume, forwarding distance, engine performance and type of logging -are selected for the purpose of determining the basic standard in the czech republic (Dvořák et al 2011). other factors are taken into account by percentage adjustment of the basic standard or through supplementary standards.…”

mentioning

confidence: 99%

“…one of the most significant short-term factors which affect the volume of forwarded timber in time, regardless of the mechanization used, is forwarding distance (nouzová 1995;Dvořák et al 2011;stankić et. al.…”

mentioning

confidence: 99%

See 4 more Smart Citations

Modelling of forwarding distance to maximize the utilization of medium and high-power harvester technology

Dvořák¹,

Natov²,

Lieskovský³

2017

J. For. Sci.

View full text Add to dashboard Cite

Dvořák J., natov P., lieskovský M. (2017): Modelling of forwarding distance to maximize the utilization of medium and high-power harvester technology. J. for. sci., 63: 45-52.every technologist aims to maximize the performance and capacity of vehicles, particularly when deployed in technological lines. to maximize the utilization of harvester technology, particularly of forwarders following the work of harvesters, it is useful to determine the maximum forwarding distance for consequent transport of timber, which was the aim of this study. the analysis presented in this study was conducted in medium and high-power vehicles which are dominantly deployed in the czech republic. the same performance of harvesters and forwarders is achieved by the calculation of the maximum forwarding distance. other variables are constant for the time models (average load volume of forwarders is 12.1 m 3 and the mean-tree volume is constant for every logged stem). our conclusions suggested a maximum forwarding distance ranging from 116 to 1,052 m, depending on the decreasing mean-tree volume which ranged from 0.3 to 1.0 m 3 per tree in the monitored logged stand.Keywords: forwarder; performance standards; work productivity; time consumption; timber transportThe increasing proportion of cut-to-length logging and the associated expensive harvester technology are becoming the focus of targeted research driven by the objective to maximize performance and work efficiency. The number of forwarders in the czech republic at the end of 2013 stood at 779 and cut-to-length logging accounted for 31% of the annual volume of harvested timber, which represents 4.7 million m 3 of timber (Ministry of Agriculture of the czech republic 2014). owing to its high investment costs and the highly diverse production conditions throughout europe, the proportion of cut-to-length logging in individual countries differs, with approximately 25% in russia (Gerasimov et al. 2013), about 50% in Germany (opferkuch et al. 2014) and almost 90% in scandinavian countries, particularly sweden and finland (Gellerstedt, Dahlin 1999;nordfjell et al. 2010). timber haulage by forwarders, along with cable and horse skidding, is considered a naturefriendly technology and receives government subsidies at the average of 0.76 eUr·m -3 (Ministry of Agriculture of the czech republic 2014).Machinery performance is influenced by a number of both changeable and constant factors. terrain conditions, among them slope inclination, obstacles and ground bearing capacity (Persson 2013) are particularly important and as such are specified in supported by the Ministry of Agriculture of the czech republic, Projects no. QJ1530032 and no. QJ1520005.

show abstract

Section: Methodsmentioning

confidence: 99%

Section: Performance Of Medium and High-power Harvestersmentioning

confidence: 99%

mentioning

confidence: 95%

mentioning

confidence: 99%

mentioning

confidence: 99%

See 3 more Smart Citations

Modelling of forwarding distance to maximize the utilization of medium and high-power harvester technology

Dvořák¹,

Natov²,

Lieskovský³

2017

J. For. Sci.

View full text Add to dashboard Cite

show abstract

Stand-specific working methods for harvester operators: a simulation study

Schmiedel

Beaudoin

Rönnqvist

2022

International Journal of Forest Engineering

View full text Add to dashboard Cite

Innovative productivity improvements in forest operations: a comparative study of the Assortment Grapple using a machine simulator

Manner¹,

Berg²,

Englund³

et al. 2020

J. For. Sci.

View full text Add to dashboard Cite

Because of generally small log piles, loading forwarders during thinning is time consuming. The Assortment Grapple, an innovative grapple with an extra pair of claws which facilitates the handling of two assortments during one loading crane cycle, has been designed to decrease forwarders’ loading time consumption. A standardized experiment was performed in a virtual thinning stand using a machine simulator with the objectives to form guidelines for working with the Assortment Grapple and to analyse its development potential. Four experienced operators participated in the study. According to the results, the Assortment Grapple’s accumulating function is beneficial only when there are no remaining trees between piles loaded during the same crane cycle. In such cases, none of participating operators lost time, and 3 of 4 operators saved time notably. The problem with the remaining trees is the extra time required to steer the crane tip around them. Therefore, a harvester should place those log piles that are later to be forwarded together in the same space with no remaining trees between the piles. Furthermore, we recommend that the Assortment Grapple’s usability will be improved by adding an own rocker switch on the forwarder’s controls to command the extra claws.

show abstract

Operator's physical workload in simulated logging and timber bucking by harvester

Cited by 10 publications

References 22 publications

Modelling of forwarding distance to maximize the utilization of medium and high-power harvester technology

Modelling of forwarding distance to maximize the utilization of medium and high-power harvester technology

Stand-specific working methods for harvester operators: a simulation study

Innovative productivity improvements in forest operations: a comparative study of the Assortment Grapple using a machine simulator

Contact Info

Product

Resources

About