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 Energy AB. The aim of the work was to compare the operational productivity between two kinds of Forwarders for extraction of harvesting residues, one Forwarder with a special compression device and one ordinary, slightly modified Forwarder. Two sites were studied for each Forwarder. The study shows that the annual production was about 11,000 m3 higher for the traditional Forwarder. The cost for the traditional Forwarder was SEK 0.9 lower per m3.

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.

Holmen Skog AB is an important supplier of conifer pulpwood to the Iggesund Paperboard mill. After logging and transport to the landing by a Forwarder, the wood is loaded on trucks for further transport, often by using separate loaders. During this handling process considerable amounts of stone material is sometimes mixed into the pulpwood and this causes problems for the industry. The aim of this study is to identify which part of the chain from forest to pulpmill, that contributes the most to this contamination. Sizes and total volumes of the contaminating stones were also investigated.

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..

BAE Systems Hägglunds has a long history of producing high performance terrain tracked vehicles (mostly for military applications), and they are now aiming at developing a tracked Forwarder with similar techniques.The Forwarder will be of series hybrid type where a diesel engine via a generator will power the motors (one for each drive wheel). Thanks to individually controlled motors and the gentle rubber tracks, this Forwarder is calculated to have a considerably higher average speed in the terrain and to be more gentle to the soil. The Forwarder with a weight of 11 metric tons and a load capacity of 15 metric tons is specified to have an average working speed of 7-10 km/h, a top speed in terrain of 15 km/h and a top speed on roads of 40 km/h.This master?s thesis aims at developing a conceptual design of the Forwarder?s drive module which includes electric motor, gear unit, brake and drive wheel.To investigate if the requirements can be fulfilled a study of the dimensioning loading scenarios has been carried out. The resulting needs regarding the torque has been considered in order to determine the required gear ratios for different motor options.

The efficiency of the harvesters work is more often reviewed, than the work of the Forwarders. In a local Stora Enso office the differences between the harvesters reported volume of timber, and the actual volume delivered to the industry had been noticed. Therefore, the decision was made to do a review on the Forwarders work. The review was conducted together with a worker from Vmf Qbera, who is working daily with wood measurement, in order to get a valid evaluation of the logs. Eight sites were included in the survey, and on each site 50 logs were marked. Approximately one third of the marked logs were pulpwood, and the remaining logs marked were timber.

The cost of forwarding corresponds to about one tenth of the forestry industries raw material cost. This gives a motive to do good follow-ups to get a good overview of the forwarding distance and, thus, enable improvements. Follow-ups are also justified by the possibility to make more accurate calculations of the harvesting costs, if better estimations of forwarding distance are achieved. Today (2009) Stora Enso has GPS and vehicle-computers in most of their Forwarders. These are used mainly for the Forwarder to follow the tracks of the harvester and for the planning leader to see how the Forwarder has been driving within the stand.

The global climate-change means increasing mean-temperature and higher precipitation in Sweden, which leads to shorter periods of frozen ground in the forest. At the same time the harvesting machines are getting bigger and more powerful. The forest industry aim at an even wood flow, and the ground damage has to be as low as possible. The two biggest causes for ground-damage is the bearing capacity of the forest ground and the ground-pressure of the harvesting machines. The aim of this study was to find out some rules for the machine choice considering ground pressure, when harvesting on ground with low bearing capacity.A field study, using a Valmet 890.3 Forwarder, was carried out where different ground pressures and their effect on the ground were tested on two different types of ground.Additionally, an inventory of damaged harvesting grounds was made.

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.

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.

During the last few years the harwarder has developed from a prototype into a market product. Holmen Skog owns two harwarders and uses two more owned by entrepreneurs. In previous studies it has been shown that the harwarder was a slow and expensive Forwarder. In this study the unloading at road-site was studied. The goal was to describe the differences in time consumption between unloading two-sided or single-sided (only from side of the road) and also the difference between unloading with three and four assortments in the carrier.

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 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.

In published studies it is found that the fuel consumption on a Forwarder is relatively constant, on time basis. A certain variation between different sizes of Forwarders occurs as well as between different working elements. The aim of the study was to establish a Forwarders comparatively fuel consumption when driving on road and in the terrain, loaded and unloaded, with high and low gear and with high and low speed as well as with hydrostatic and hydrodynamic transmission. A hypothesis was that low rpm gives lower fuel consumption on distance basic, at all trials. The test driving was made with a Hemek 750 which is a three geared hydrostatic machine and with a Hemek 700 which is a hydrodynamic machine with six gears.