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?.

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.

This study was conducted on a property with a thinning machine team. The purpose was to investigate in which machine, the harvester or the forwarder, that caused most damage to the trees in six different stands. Different factors, related to the damage frequency in the stands, were checked out. For example: basal area per hectare, thinning strength, tree diameter and the rate of production. The harvester drivers were also interviewed about how, when and why stem damages occur and how to minimize them. The study stated that 4.3 percent of the trees were damaged. Out of these 88 percent was caused by the harvester and the rest, 12 percent, by the forwarder..

Mechanical harvesting may result in timber damages leading to reduced saw log quality. The initiator of this study was VIDA ? a privately owned concern operating in the value-adding process industry of forest raw materials. The aim of this study was to examine the type and amount of damages on Alvestakubb caused by the Harvester head during the cutting process. The aim was also to compare the damages caused by different types of feed rollers and to evaluate the effects of temperature on damage occurrence.

Husqvarna is a world leading producer of chainsaws with a well-established brand name. Husqvarna now has an interest in investigating the possibiltiy to expand their production of chains and guide bars to include cutting equipment for timber-harvesters.This project is a technical study which aims to answer questions about cutting equipment for timber-harvesters that have been decided in cooperation with Husqvarna. The questions have mainly been focused on forces, cutting speeds, service and maintenance -as well as general questions regarding the size of the Swedish market.Two methods have been applied to answer the questions. Interviews with retailers of harvesters, producers of Harvester heads and harvester drivers.The main findings in this project show that there is a relatively small selection of harvester chains on the Swedish market. In contrast to the selection of harvester chains the selection of guide bars is quite large.

The background to this study is that the forest company, Holmen, has found large discrepancies between harvested volume and the measured volume at the industry. Factors like bark features, breakage, double tops, bends and stem damages was noted, and all stems were measured manually. Hypothesis testing with the method "random in pairs" were used to examine whether the harvester measured values significantly differed from the manually measured. The result of a properly calibrated harvester shows in average underestimation of the volume with Skogforsk Pine as a bark function. This means that the harvester isn´t the reason why the volume measured in the industry is lower, the fault is elsewhere. The study also indicates a need for a unique bark function for logepole pine..

Today's Swedish large-scale forestry uses almost exclusively computer-aided bucking. It allows the harvester computer, using an optimisation price list (steering price list), to maximize the value of each tree. The optimisation price list can be adjusted so that the industry gets the raw material it demands from the forest. There are various simulation programs that can be used when constructing a optimisation price list. The simulation program merchandise a database of stem shapes using a given price list and mimics a harvester's work. To get the demanded raw material for the industry it is important to use a well-adjusted optimisation price list.

In 2006, Stora Enso Skog implemented an education program in water management for harvester operators, timber purchasers, cut block planners and supervisors. The focus of the program was creating stream crossings with minimal harm to the stream and the surrounding riparian area. This main purpose of this study was to determine the difference in work procedures before and after participating in the program. The methodology consisted of field studies and interviews with harvester operators and their supervisors. The field study looked at how the streams had been crossed concerning the number of crossings, visible damage to the stream and/or the riparian area made by the machines. Biological parameters such as the width and dept of the stream and amount of large woody debris in the stream were also measured. The field result from 30 harvesting sites showed no significant difference between sites that had been harvested before or after the education program. But the harvester operators and their supervisors experienced an increased concern for watersheds after the educational program.

This bachelor?s degree thesis was conducted in mechanical engineering at Halmstad University during spring semester 2010 in close collaboration with the company Gremo AB, located in Ätran, Sweden. Gremo AB produces, developes and sales forest machines in both Sweden and on the international market.Gremo AB belongs to one of the market leaders in forest industry, especially with their forwarder. In order to become a market leader even with their harvester, the company decided to change the harvester to have a swivel and a leveling driver cabin.The aim with this bachelor?s degree thesis was to develop a design concept for the harvester driver cabin, which Gremo AB can apply on the new harvester.

This bachelor?s degree thesis was conducted in mechanical engineering at Halmstad University during spring semester 2010 in close collaboration with the company Gremo AB, located in Ätran, Sweden. Gremo AB produces, developes and sales forest machines in both Sweden and on the international market.Gremo AB belongs to one of the market leaders in forest industry, especially with their forwarder. In order to become a market leader even with their harvester, the company decided to change the harvester to have a swivel and a leveling driver cabin.The aim with this bachelor?s degree thesis was to develop a design concept for the harvester driver cabin, which Gremo AB can apply on the new harvester.

This study was performed in collaboration with Moelven Skog AB, Örebro district. The purpose of the study was to review existing literature in order to describe the current status of harvester based measurement technology as the way to provide information for calculating payment to the forest owners. In addition to this, a short survey was conducted to find out how a switch to harvester based measurement would affect the administrative workload on timber purchasers working for the district. The literature study shows that the harvester measurement technology is ready to use if it is combined with well-established routines for control of the harvesters, methods for automatic quality indexing of the timber and ways of creating pricelists specially adapted for harvester measurement. Pricing each stem seems to be the most promising method. Stem pricing has several benefits.

This bachelor?s degree thesis was conducted in mechanical engineering at Halmstad University during spring semester 2010 in close collaboration with the company Gremo AB, located in Ätran, Sweden. Gremo AB produces, developes and sales forest machines in both Sweden and on the international market.Gremo AB belongs to one of the market leaders in forest industry, especially with their forwarder. In order to become a market leader even with their harvester, the company decided to change the harvester to have a swivel and a leveling driver cabin.The aim with this bachelor?s degree thesis was to develop a design concept for the harvester driver cabin, which Gremo AB can apply on the new harvester.

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.

This report is a thesis work for a B.Sc. in Forestry at the School for Forest Engineers, SLU. The aim of the work was to compare two different pricelists with the actual output from a harvester. The results have also been compared with a volume estimate of standing trees done by the Swedish Forest Agency and the ?true? value registered by the Wood Measurement Association. The study confirms that the output calculated by the computer on the harvester is more reliable than the volume of standing trees estimated by Swedish Forest Agency. .

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.