New models developed on the cutting duration, fuel consumption for CTL single grip harvester sawing units

Research, industry, SMEs and forest actors engage in improving technology, engineering and processes across the value chain for a more efficient and profitable forest sector.

Ponsse CTL harvester at work during field trials carried out by Luke, in association with Ponsse, in Eastern Finland.

TECH4EFFECT successfully conducted field trials at two sites in Eastern Finland on the cutting duration and performance parameters of single grip cut-to-length (CTL) harvester sawing units. The field tests were conducted in March 2019 by project partners, the Natural Resources Institute Finland (Luke) and Ponsse, in co-operation with two contractors and their operators.

New models developed for future research

To measure and harness potential efficiency gains in harvesting, the working elements of felling cutting and cross cutting of stems were examined with the machine monitoring data of a harvester. The results of the study provided information on the duration and performance of the cutting phase of the CTL harvester with the overarching aim to eventually reduce fuel consumption in timber harvesting.

The fieldwork trials resulted in new models for effective time consumption in the work phase of cutting as a function of stem size for felling and cross-cutting, and included other performance parameters, such as the respective fuel consumption of this working phase.

Improvements in harvester processing speed, emissions, quality 

Senior Scientist within the group of Forest Technology and Logistics at Luke, Robert Prinz, said that cutting efficiency was essential in forest operations, especially during the felling cutting and cross-cutting processes of big diameter trees with several cuts.

“In wood harvesting, trees are cut by CTL harvesters into smaller assortments. This is an important phase that is part of the tree processing time. During this phase, it is also essential to ensure the delivery of high-quality products, especially in avoiding cutting damage, he said.

“So, we looked at the actual way in which the logs were cut, in terms of the time taken to complete the cutting task, and at the same time calculated how efficient the machine was, in measuring fuel usage. Achieving better fuel efficiency is important to have less emissions and to save fuel costs during operations,” Prinz said.

He also highlighted the importance of being able to work with world-class machine manufacturers and specialist forest engineering companies to engage in research to develop better, more efficient machines and equipment for future forestry operations.

Commenting on the study’s academic relevance, Prinz concluded that new models could also contribute to the planning process of future studies.

European Journal of Forest Research

The results were recently published in the European Journal of Forest Research with the article titled “Cutting duration and performance parameters of a harvester’s sawing unit under real working conditions”. The open access publication is available HERE.

Prinz R, Väätäinen Y and Routa J.

Cutting duration and performance parameters of a CTL harvester’s sawing unit under real working conditions

European Journal of Forest Research

This project has received funding from the Bio Based Industries Joint Undertaking under the European Union’s Horizon 2020 research and innovation programme under grant agreement No 720757.


Dr Robert Prinz is a Senior Scientist within the group of Forest Technology & Logistics at the Natural Resources Institute Finland (Luke). His research speciality is in fully mechanised operations with a focus on improving the performance and energy efficiency of biomass supply.

He has been working as a researcher and project manager in several large EU-funded projects mainly dealing with international forest technology and know-how transfer, holistic supply chain design as well as dissemination and business adaptation.

Within the TECH4EFFECT project (; funded through the BBI JU/Horizon 2020) he is mainly involved in WP3 (Increasing productivity and cost-efficiency in timber harvesting and extraction), but also WP2 (To demonstrate the importance of rational business processes in procuring or marketing services for silviculture, harvesting and wood purchasing), in WP4 (Avoiding, reducing and documenting site impact) and in WP7 (Impact assessment).


Dr. Kari Väätäinen is a Senior Scientist at the Natural Resources Institute Finland (Luke) in Joensuu, Finland. Kari has been studying supply chain logistics of roundwood by utilising Big data. His research ambitions are in biomass and roundwood logistics, in the utilisation of open source data, Big data and digitalisation solutions in sustainable forest operations. He sees a great potential in utilising open source data (Big data) in forestry: “There are already several products and tools available, however, many promising solutions are under development in forestry practice.”


Dr. Johanna Routa is adjunct professor, Ph.D., Research Manager and Senior Scientist at the Natural Resources Institute Finland (Luke). Her research area includes biomass supply, quality management of energy wood, intensive forest management for biomass production, CO2 analyses and costs of different management practices.

She has participated in number of international and national research projects as researcher and project manager. Her current project portfolio includes the WP2 lead (Silviculture) of the TECH4EFFECT project, co-ordination of the Haiku project (energy biomass quality), co-ordination of forthcoming BRANCHES Project (Boosting Rural Bioeconomy Networks following multi-actor approaches), as well as other smaller projects.

She is the national team leader in the IEA Bioenergy Task 43 work and a Member of the Climate and Energy Group of the Regional Council of North Karelia.