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Automatic data collection is becoming increasingly common in cut-to-length forest operations. However, only few studies have analyzed automatically collected follow-up data from forwarders....

Wood supply is one of the most significant cost items for most forest industries, and costs of forest operations and sale prices of wood is vital information for forest owners. Cost trends ...

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.

Automatic collection of forwarding follow-up data has recently become possible. The objective of this study was to obtain representative values of fuel consumption for large forwarders in final felling operations. Since fuel consumption is dependent on time consumption, speed, and total driven distance, these variables were also included in the study. The study explored data collected and presented by John Deere forwarders’ conventional on-board computers (TimberLink). Nine operators forwarded 15,329 loads, in total, at sites with representative terrain conditions for large parts of mid-Sweden. A limitation with the used dataset was that load-sizes (e.g. volume or mass) were not available. The median driven distance was 670 m/load, and median total fuel consumption was 8.5 l/load or 12.4 l/km. Typically, Driving only and Crane work only accounted for most of the fuel consumption (50 and 40%, respectively). Median forwarding time was 43.1 minutes/load at average speeds of 2.2–3.3 km/h. Fuel consump...

The forwarder loads processed wood and transports it to a landing. Productivity of forwarding could be improved by increasing driving speed, but difficult forest terrain limits this. According to current literature, crane work is the most time-consuming work element of forwarding, so improving crane work productivity is essential for improving forwarding productivity. One way to do this is through automation of recurrent boom movement patterns, or alternatively automation can be used to ease crane work. When using conventional boom control (CBC), the operator manually controls each of the independent boom joint movements and combines them to achieve a desired boom tip movement, but boom tip control (BTC) allows the operator to control boom tip movements directly. The objective of the present study was to examine whether BTC facilitates crane work and affects the slopes of learning curves for beginner-level forwarder operators. The study was carried out using a standardised test routine to evaluate effects of two fixed factors, (levels: CBC, BTC) and (four levels), on five dependent variables. Four of the five dependent variables measured ease of boom control and the fifth measured crane work productivity. The results showed that there were no significant differences in the slopes of learning curves between the but the BTC did increase crane work productivity and made boom control easier.systempoint of timesystems

Recent 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), , , , and 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 and , but minor proportions for the work elements and Based on the means, the crane was used during 74.8% of PM time, the driving speed was nonzero during 31.9% of the PM time, and occurred during 6.7% of the PM time. Time consumption per load was more strongly associated with distance than with extraction distance, indicating that the relevance of extraction distance as a main indicator of forwarding productivity should be re-considered.LoadingUnloadingDriving emptyDriving loadedOther time Driving emptyDriving loadedLoading Unloading. LoadingLoadingSimultaneous crane work and drivingLoadingLoading drive