Holmen Skog is currently using a GPS-program called TraktInfo, originally developed within the company. They are now planning to switch to a new GPSprogram or allowing the contractors to buy other programs available from the logging equipment manufacturers. To be able to offer this flexibility, Holmen Skog needs to obtain information about the features offered by the different manufacturers in their specific programs, and also when the manufacturers are planning to start selling programs adapted to the new standard called StanFord2010. According to the study, the manufacturers are hesitant to StanFord2010 and there has also been a lack of clear signals from the customers and clients about what kind of different new features to include in the programs. The feature most frequently used by forest machine operators today is the option to keep record of the Harvester?s path by creating a ?log plot?. This feature was not used to its full potential however, since only one out of eight of the forwarders included in the study had computers that were compatible with the Harvester?s computer.

One of the most important components of a Harvester is the crane. Most Harvester cranes are only possible to pivot (or horizontally rotate) at the crane pillar. Cranab in Vindeln, Sweden, has developed a new type of Harvester crane which has an extra pivot point on the outer boom. This makes it possible to reach around residual trees, easing thinning work in dense stands. The aim of the study was to analyze if the use of a pivoting outer boom (POB) crane gave an increase in thinning production and if there were any differences in time consumption between the work elements for the POB crane and a conventional crane. A Valmet 911.3 equipped with a POB crane was used in the study.

Nowadays the majority of the thinnings made in Swedish forests are done by machines, Harvesters and forwarders. The most common model in thinning with a Harvester is strip-road operated thinning and stand-operated thinning with one intermediate passage between the strip-roads. This study is a time study with some quality follow ups on a strip-road operated thinning model, a stand-operated thinning model with one intermediate passage between the strip-roads and a stand-operated thinning model with two intermediate passages between the strip-roads. The machines in the study were a small Harvester (Forestline MPM C90) and a medium sized forwarder (Timberjack 1110). The study was made in Litsnäset outside the city of Östersund in Sweden and was made during the autumn 2007. In a lodgepole pine stand six study units (0,6 ha) were thinned with the three different models, two study units per model.

The aim of this study was to quantify the productivity and the costs of different harvesting systems (teams), containing Harvesters equipped with accumulating Harvester heads and forwarders, in first commercial thinnings were an integrated harvest of pulpwood and energy wood were performed. In the beginning the plan was to study and measure 20 sites before and after harvest. Due to storms during the summer of 2010, complete data could only be obtained from 8 of these 20 sites. Seven of these sites were privately owned and one was owned by UPM, all of the sites had been pre-commercially thinned. The mean stem density before harvest was 2578 stems per ha and the mean stem volume was 0.074 m3solid over bark.On average 1518 stems/ha was harvested.

The aim of the study was to compare productivity in first thinning of birch stands, when either energy- or pulpwood was harvested. The systems total profitability was also compared by including forwarding and chipping costs. A Gremo 950 HPVR Harvester was used and the same driver was used under the entire study. During the pulpwood harvest a Logmax 4000b Harvester head was used and a feller buncher head made by Silvatec was used during the energy wood harvest. Six study unit pairs were located in a birch dominated stand outside Ängelholm in Skåne.

Stora Enso Skog has a long term contract regarding felling rights and silvicultural activities on forest owned by Bergvik Skog. In the autumn 2006, Bergvik Skog proposed a new thinning program, ?Bergvikgallring?. The new program implied an increased focus on extraction of smaller trees compared to the present thinning program, Stora Enso Skog?s ?Kvalitetsgallring?.

This study was made for the Swedish forest company Sveaskog because the sawmills they delivered timber to had noticed a high frequency of bucking splits in their products. Coworker Jim Edström at Sveaskog also wanted to know if there was a big difference between different felling heads. The purpose with this study has been to find out the amount of bucking splits and if there is any felling head brand that did a bigger damage that the others. The study was made in two steps, where the first part was a literary review to find out results and conclusions in earlier studies. The best measuring method to check bucking splits was the known ?trissmetoden?.

In Sweden, harvesting pre-commercial thinning (PCT) stems for energy purposes is a interesting way of financing the high cost of preparing dense stands for a profitable first conventional thinning. This concept can be labelled bioenergy thinning. The aim of this study was to quantify the productivity of a Vimek 404R light Harvester with an accumulating Naarva-Grip cutting head during the bioenergy thinning of a self-regenerated stand west of Sunnansjö in Dalarna. The stand was birch-dominated, contained 15 371 stems/ha, and measured on average 4,6 cm Dbh and 7 m tall. Even though the driver was well experienced with the machine, the stand in question was the first one that he ever thinned in this manner. Nevertheless, the driver strived to accumulate as many stems as possible during each crane cycle and chose to cut taller stems in half so as to make the handling and forwarding of the harvested stems easier.

Forest ebeaver is, equipped as a bio-energy Harvester, approximately four and a half meter long and weigh just over two tons. The main purpose of this report is to find out whether a small machine like Forest ebeaver can be profitable used in early thinning. To find this out a study has been made using the machine to thin in a young pine stand..

With an increased demand for biomass based energy and with development of better technique harvest biomass, new possibilities open up. With the possibility to combine traditional cleaning of road?s right of way with biomass harvesting, the work of suppressing tree vegetation could become profitable or at least decrease the road maintenance cost. However, knowledge about productivity and profitability in mechanical biomass harvesting in roads? right of ways are still limited.

This study is one of five that has been done based on Lunds Energi?s planned investment in bioenergy. The plan is to build two large burners, at Örtofta, that?s going to be supplied with biofuels. In this study I take a closer look on the profitability when you choose to sell your cereal as bioenergy. I?ve been calculating with selling the straw from the grain crops and winter rape, selling the rye weat as whole crop and fertilize the hemp with sewage sludge.

Detta arbete behandlar mätteknik vid kontroll av dubbskadedjup på sågtimmer. Mätmetoder och mätverktyg har sammanställts och bedömts som lämpliga för olika mätsyften. Data rörande skadedjup från olika dubbtyper har sammanställts ifrån tidigare publicerade studier. Resultat från en egen kartläggning av dubbskadedjup på gran- och talltimmerstockar styrker en allmänt rådande uppfattning: Att de djupaste dubbskadorna uppstår närmast centrum av matarhjulens anliggningsyta mot timret om matarhjulen inte konstruerats med hänsyn till att utjämna matningskraften runt en så stor andel av stockens yta som möjligt. Eftersom heltäckande mätning av dubbskadedjup är tidsödande finns behov av att rationalisera mätproceduren.

This report is a thesis work for a B.Sc. in Forestry exam at the School for Forest Engineers, SLU. The work was an assignment from Sydved and the aim of the work was to investigate the economical output of removing understorey trees before first thinning. Four treatments were studied. - no cleaning before thinning - cleaning of all trees less than DBH 5 cm before thinning - cleaning of all trees less than DBH 7 cm before thinning - cleaning of all trees less then DBH 9 cm before thinning The result shows a decrease of the cost per m3 for the Harvester with about 38% if all trees less than DBH 9 cm was cleaned before thinning compared with the un-cleaned area. At the same time the total net revenue increases with about 22%. .

In this study it was investigated if the adoption of a new routine for quality control could improve the precision of the dimension measurement obtained by Harvesters. Data was collected from three different Harvesters. First, a reference data set was collected before the new procedures had been incorporated, and then when the new methodology was implemented another data set was collected by the Harvester operators, allowing the two data set to be compered. The results indicated that following the implementation of the new procedures, the reliability and the precision of the measurements has increased. All Harvesters included in the study had improved regarding most of the controlled factors such as standard deviation, systematic difference and hit rate within ± 2 cm for length and ± 4 mm for diameter..

The predominant forestry harvesting method is based on the Harvester-forwarder method, theHarvester folds, branches and cuts trees, and sorts the logs into piles, while a forwarder transportsthe logs to a landing area.This master thesis work is about realization of a dynamic forwarder simulation model, and itspurpose is to provide an integrated forwarder simulation model in MATLAB/SimMechanicswhere the forwarder is based on a concept using pendulum arms to connect wheels and chassis.Active suspension control is developed and implemented into the simulation model, and finallycompared in simulation with passive suspension.In a first step, an integrated forwarder simulation model is developed, containing a simplifiedforwarder model, a tire-to-ground interaction model and a test track model. The simplifiedforwarder model is based a rigid multi-body system with a spring-damper suspension of thependulum arms. The tire-to-ground interaction model calculates the reaction forces, friction fromthe ground and applies the propulsion force. The test track model is a simplified version of thereal test track in Skogforsk. The propulsion wheel torque control is used to regulate theforwarder speed.