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Forest cleaning, being an operation that requires investment, but the return on investment is due for the next generations, utilizes tools and methods that mostly haven’t been humanized. Harmful vibration is still present in today’s forestry operations, and new tools provide possible reduction of exposure to vibrations. Petrol chainsaw and battery chainsaw (late cleaning) and billhook, machete, and battery shears (early cleaning) were used and observed in this study. Vibration levels were measured and assessed using validated Brüel & Kjær 4447 vibrometer which complies with the ISO 8041:2017 standard. The measurement was performed according to the recommendations of ISO 5349-1:2001 and ISO 5349-2:2001 standards. Vibration exposure was assesed using work sampling method on the obtained video recordings in order to calculate relative shares of different work elements. Results show that hand tools (machete and billhook) are causing the highest vibration levels, while battery shears cause the lowest. Battery chainsaw causes higher vibration levels while cutting, but lower daily vibration exposure than petrol chainsaw. A detailed revision in the classification of tools is needed, considering their ability to produce and transmit harmful vibrations to the operator. Using the current classification, the daily exposure to vibration of workers in early forest cleaning is high above legislative values.

Motor-manual felling and wood processing is a high-risk work process where the chainsaw, in connection to other variables in the working environment, is a key and constant source of risk and danger for forest chainsaw operators. Pursuant to the foregoing, the purpose of this research is to investigate and compare detected musculoskeletal disorder (MSD) symptoms among the chainsaw workers in Croatia according to their employer (state company – Hrvatske šume Ltd. or private forestry contractor) and self-evaluated Workability Index. A combined three-stage research method was used: (a) defining a sample; (b) preparation and administration of questionnaire; and (c) data analysis and elaboration. The Standardized Nordic Questionnaire (SNQ) was used as a medium to detect musculoskeletal disorder symptoms in chainsaw operators and the Workability Index (WAI) questionnaire was used as a medium for workability self-evaluation. The field part of face-to-face data collection was conducted in the first quarter of 2022 with a total of 158 sampled workers interviewed directly at the forest worksite. Descriptive and inferential statistical methods were used to verify and analyze the data. The anatomical area with the highest 12-month period prevalence of MSD symptoms for all chainsaw operators is the low back (70.89%), followed by the shoulders (41.14%), neck (39.87%) and wrist/hands (36.71%). Research results, according to the employer, showed that workers employed by Hrvatske šume Ltd. have a higher prevalence of MSD symptoms in almost all anatomical locations compared to chainsaw operators employed by private forest contractors. Mean WAI Score among all respondents was 34.96 points (max. 49) falling into the rank »moderate«, while the current workability compared with the lifetime best was 7.33 (range 0–10). The results of MSD symptoms confirm the self-estimated higher values related to health problems caused by forestry work and lower WAI Score by workers employed in the state forestry sector compared to workers employed in private forestry sector. The prevalence of MSD symptoms, observed through WAI Score, showed a significantly lower percentage of affirmative responses for all anatomical regions except for shoulders in workers who need to maintain their workability. The obtained results show positive correlation with descriptive indicators, where younger workers with less chainsaw work experience have a lower prevalence of MSD symptoms and better WAI Score. In the discussion and conclusion part of the research in question, the need for development of possible solutions is emphasized. The proposed solutions can be included into educational programs or on-site training related to the MSD risks for professional chainsaw workers to change their behaviour that will reduce occupational risks.

The aim of this research is to measure the energy consumption and compare the cutting performance of three types of battery-powered chainsaws (Stihl MSA 200, Stihl MSA 220, and Stihl MSA 300). Tested chainsaws were powered by two different battery packs (Stihl AP 300 S and Stihl AP 500 S) with different energy capacity and output current when cutting two wooden beams, European beech (Fagus sylvatica L.) and black locust (Robinia pseudoacacia L.) with different densities and moisture content. Energy consumption was measured using a multimeter built-in battery charger housing, and consumed energy was noted in watt- hours. Each individual cut was recorded with an action camera at 60 frames per second, and the duration of the cuts recorded in centiseconds was observed on the obtained recordings. Results show significant differences in energy consumption and cutting duration between individual chainsaw/battery combinations. Energy consumption ranged from 2.45 to 4.50 Wh per cut for beech (Stihl MSA300E_AP500S and Stihl MSA220_AP300S, respectively) and from 3.10 to 5.00 Wh per cut for black locust (Stihl MSA300M_AP500S and Stihl MSA220_AP500S, respectively). Duration of the cut ranged from 3.48 to 9.24 s per cut for beech (Stihl MSA300M/H_AP500S and Stihl MSA220_AP300S, respectively) and from 3.74 to 9.35 s per cut for the black locust (Stihl MSA300M_AP500S and Stihl MSA220_AP300S, respectively). In general, it can be concluded that more powerful chainsaw/battery combinations (Stihl MSA300_AP500S) consumed less energy per cut and had better cutting performance (shorter cut). In that regard, more powerful chainsaws had greater cutting efficiency, i.e., more cuts on one charge (battery) but shorter cutting time on one charge. The effect of tree species (fresh-sawed beech/air-dried black locust) on energy consumption and cutting performance is absent on the most powerful chainsaw/battery combinations. Today, lithium-ion batteries still have 70 times less energy density than petrol. However, if there is a significant increase in the energy density of the batteries in the coming times, battery chainsaws will most certainly displace petrol chainsaws from use in the future.

In Croatia the assessment of forest companies` performance is mainly based on the evaluation of achievements in meeting the general objectives of management and harvesting operations, that is, it is traditionally based on the ability to harvest and extract wood at the lowest possible cost. The existing evaluation of companies` production results solely through the achieved financial goals emphasizes the economical component of the business, which is in line with the conventional approach to growth and development under the motto "grow now, clean later". On the other hand, the environmental and social component of business operations in the forestry sector, which advocates “green growth” as one of the strategies for achieving defined goals of sustainable development, is neglected. In accordance with the above, this paper presents the role and implementation possibility of selected environmental and safety indicators in evaluation of forest harvesting operations. The results provide an overview of environmental indicators such as energy intensity indicator (EEI), energy return on investment (EROI), greenhouse gases (GHG) emissions, particulate matter (PM) emission, non-renewable (NR) energy consumption and key safety indicators in forest harvesting operations as a social component of business. The central part of the paper provides tabular comparison of selected environmental and safety indicators based on their implementation in the forestry sector. Discussion and conclusion part emphasize the need for calculation and reporting of selected indicators on a weekly basis. Also, it advocates development of a document in the form of an action plan for the operationalization and implementation of environmental and safety indicators in everyday forest harvesting operations.

Problem izloženosti štetnim vibracijama u šumarstvu javlja se s primjenom prvih motornih pila u sječi i izradi. Iako je rad s motornim pilama bio višestruko brži, produktivniji te fizički manje zahtjevan od ručnog obaranja, motorne pile emitirale su velike količine vibracija i s vremenom je došlo do negativnog utjecaja na zdravlje šumskih radnika. Bolest bijelih prstiju (Raynaudov sindrom) postala je stvaran problem s velikim potencijalom za smanjenje radne sposobnosti radnika. Uz primjenu motornih pila, u šumarstvu se za neke radove i dalje upotrebljavaju ručni alati. Glavna tema ovog rada je usporedba dnevne izloženosti vibracijama u uzgojnim radovima čišćenja pri radu s motornom pilom i kosirom. EU Direktiva 2002/44/EC nedvosmisleno propisuje granične vrijednosti za dnevnu izloženost vibracijama, A(8) koje služe kao mjera protiv pretjeranog izlaganja vibracijama. U ovome radu procijenjene su A(8) vrijednosti za rad s motornom pilom i rad s kosirom u čišćenju. Vremenski udjeli pojedinih radnih zahvata u radu čišćenja dobiveni su korištenjem metoda studije rada i vremena na videosnimkama efektivnog rada. Rezultat vremenske analize rada je da radnik pri radu s motornom pilom 46, 7 % vremena provede u radu rezanja, dok se ostatak vremena odnosi na različite načine nošenja upaljene motorne pile. U radu s kosirom radnik prosječno napravi 27 sjekova u minuti. Razine vibracija su snimljene vibrometrom Brüel & Kjaer 4447 i izračunate prema uputama ISO 5349 norme. Dobivene su A(8) vrijednosti od 4, 9 m/s2 na desnoj ruci i 3, 4 m/s2 na lijevoj ruci pri radu s motornom pilom te 13, 7 m/s2 na desnoj ruci pri radu s kosirom. Rezultati upućuju na ozbiljnu zabludu pri organiziranju rada i korištenju ljudskih resursa. Uvriježeno mišljenje da je rad s kosirom, na koji se radnici s narušenim zdravljem većinom alociraju, “lakši” od rada s motornom pilom, može dovesti do ozbiljnih zdravstvenih posljedica za zdravlje radnika. Rezultati ovoga istraživanja indiciraju na smjer kojim se šumarska struka treba voditi pri organiziranju uzgojnih radova čišćenja koji će biti u skladu s važećim propisima zaštite zdravlja radnika.

The main tool used in a forest cleaning is a billhook, a hand tool consisting of a hold and a hooked blade sharpened on both sides. Forest cleaning is physically very tiring and takes place under difficult working conditions (high temperature and humidity, dense vegetation, insects). Moreover, working with billhook is exclusively manual work and its effects on health are mostly unknown. A novelty in Croatia, regarding motor - manual forest cleaning, are battery shears, a more ergonomic and humane approach to forest cleaning. For the purpose of the ergonomic comparison of the two types of forest cleaning methods, a top technology was used – Xsens MVN. Xsens technology consists of sophisticated hardware and software for human movement analysis. It is a full-body human measurement system based on inertial sensors, biomechanical models, and sensor fusion algorithms. The aim of this paper is to present a new and modern method of movement analysis in ongoing research of two mentioned forest cleaning methods, to show challenges of field measurements, and to assume possible application in forestry regarding ergonomic measurements.

U radu se analizira nova metoda za procjenu stanja površinskog sloja šumskih cesta mjerenjem vibracija. Istraživanje je provedeno na dijelu šumske ceste tijekom vožnje vozila opremljenog mjernim uređajem kojim se mjere vibracije u sve tri osi, položaj i brzina vozila te vrijeme. Ispitivanja su provedena u oba smjera vožnje na dijelu ceste s različitim frekvencijama mjerenja, tlakovima u gumama i brzinama vožnje. Na temelju rezultata mjerenja stanja površinskog sloja šumske ceste preporučuje se frekvencija snimanja od 10 Hz, brzina vozila od 20 km/h te tlak u gumama od 2 bara., A new method for assessing condition of forest road surface layers by vibration measurements is analysed in the paper. The research was conducted on a forest road segment while driving a vehicle equipped with a measuring device for determining vibrations in all three axes, vehicle position, vehicle speed, and time. Tests were performed in both driving directions of the forest road segment using different measuring frequencies, tyre inflation pressures, and driving speeds. The recording frequency of 10 Hz, vehicle speed of 20 km/h, and tyre inflation pressure of 2 bars, can be recommended based on the forest road surface measurement results.

Due to fast developing technologies and production process the occupational safety and health in forestry significantly changed through time. From the aspect of energy workload, old ergonomic paradigm “less is better” for traditional forest technologies is now replaced by a new paradigm “more can be better” because reduced physical activity in modern technologies can have harmful impacts on workers’ health. Accordingly, in this paper an evaluation and comparison of cardiovascular workload for three forest machinery operators (chainsaw, harvester and forwarder) has been made from an ergonomic point of view by using the heart rate method. In the conducted research Garmin Fenix 3HR device has been used to measure the heart rate frequency of selected machinery operators. Field measurements and data collection were conducted during the summer of 2017 while applying different harvesting technologies in the same forest stand. During the measurement, apart from heart rate frequency, the shares of effective and additional (rest, stoppage, physiological need etc.) worktime were also monitored. The energy workload of workers when operating the mentioned forest machinery was taken as a relevant comparison factor. The results obtained for average heart rate at effective, but also at additional time, show significant difference between motor-manual and machine work in wood harvesting process. Also, the average recorded heart rate during the additional time is noticeably higher in machine work (harvester and forwarder) than in motor- manual operation. For the improvement of ergonomic conditions in forest machinery operating, discussion and conclusion part of the paper provide examples of good practice and guidelines for further research needs.

The main tool used in forest tending work is a hedging bill, a hand tool consisting of a hold and a blade sharpened on both sides. Working with the hedging bill is physically very tiring and takes place under difficult working conditions (high temperature, dense vegetation, insects). For purpose of humanizing the forest tending work, a tool that has not been yet used in Croatian forestry - the battery cutter, in this case, Stihl ASA 85 - has been tested. In this paper, a comparison of hedging bill and battery cutter was made from an ergonomic aspect. An average and maximum heart rate of a worker when working with the two mentioned tools was taken as a relevant comparison factor. Measuring the heart rate during effective work time the physical workload of the worker was determined. Garmin Fenix 3HR has been used to measure heart rate in the conducted research. The results obtained show less physical workload of workers when working with battery cutter.

Efficiency of timber harvesting systems is traditionally expressed in time and/or monetary values per unit of a product. Unit cost of production is still regarded as a main factor for selecting harvesting systems in the planning phase and for the evaluation of their efficiency. Rapid development of the renewable energy sector and bioenergy sector as its key part raised a question of bioenergy competitiveness when compared to energy produced from fossil fuels as well as from other renewables. At this point, when timber harvesting systems had to be analysed as energy production systems, unit of a timber product could no longer be the sole denominator for calculating the efficiency and novel research methods had to be applied. In this research, energy efficiency of mechanized timber harvesting by a harvester (Timberjack 1470D) – forwarder (Timberjack 1710D) system in an 80-year old broadleaf harvesting site was determined, and expressed as EROI (Energy Return On Investment). Field experiment consisted of time studies and measuring fuel consumption while other input data was gathered from own previous research in similar conditions or literature sources. System boundaries were set at the landing, i.e. roundwood delivered to the roadside is regarded as a system’s final product. Energy investment was calculated on PMH (Productive Machine Hour) level enabling the use of input parameters of cost calculations as well as expressing the results in the span of main factors (DBH and extraction distance) used in the productivity models. Energy investment of a harvester amounted to 1022.4 MJ/PMH (84% fuel ; 9% production of a machine ; 6% oil ; 1% tyres) and that of a forwarder to 529.9 MJ/PMH (75% fuel ; 16% production of a machine ; 5% oil ; 4% tyres). When expressed on a product level, energy investment of a harvesting system reached 130 MJ/m3 (for average DBH = 23 cm and average extraction distance of 360 m). Energy return for beech and hornbeam wood in fresh state (45% moisture content) is 9282 MJ/m3, thus the application of the investigated harvesting system under the conditions of the specified felling site results with EROI of 71.5. Furthermore, EROI is expected to range from 38 (for DBH 12.5 cm) to 102 (for DBH 42.5 cm) with the average extraction distance of 360 m ; and from 76 (for 100 m extraction distance) to 65 (for 800 m extraction distance) with the average DBH of 23 cm. Reduction of the moisture content to half of the initial value (by natural drying of energy wood) would increase the energy gain by 8%. But, in order to cover the EROI of the final energy product, system boundaries should be shifted to the end user. Energy investment calculation should cover the transportation and preferably explore different transformation processes (production of firewood in the household ; mechanized production of oven-ready chopped firewood and production of wood pellets).

Life cycle assessment (LCA) is one of the most used tools for environmental management, but its application in forestry is still slow. Forestry and wood technology together produce vast amount of different wood products, but the production of timber as raw material is still not included often enough in the LCA process. Production steps have a significant influence on the environmental impact of wood products depending on machinery used, building and maintaining forest roads, management type (clear-cut, even-aged management or selective cut) etc. This paper will show past and present of LCA studies in forestry and its sections: 1) harvesting operations, 2) biomass and 3) forest infrastructure network construction and maintenance.

Timber haulage is the last phase of timber harvesting. Due to its characteristics, cycle operation, a lot of unloaded driving, high purchase price of truck, transport of small amounts of goods, high fuel consumption, timber haulage is the most expensive phase of timber harvesting. Also timber haulage has a lot of negative impact on the environment due to its high greenhouse gas emission, especially CO2 emission. The aim of the paper is to analyze fuel consumption of forest truck and trailer during timber haulage in comparison to longidutinal slopes of roads, types of roads and total vehicle mass. Fuel consumption is measured by CANBUS module and data was transferred via Fleet manager system from truck to registred server. Fuel consumption is analyzed by overlapping the positions of truck from GPS signal with maps of public and forest road, in the aim to connect data with types and slopes of the road. Mass of the vehicle is measured with integrated scales on the air cushions on the truck and trailer. Research were performed on public and forest roads placed in mountanious and hilly regions. CO2 emissions are calculated based on fuel consumption data on different slopes and types of road.

Glavni cilj istraživanja je na temelju izabranih geometrijskih, masenih i drugih veličina utvrditi trenutačno stanje, svojstva i zakonitosti, ali i mogući tijek razvoja harvestera. Svrha ovog diplomskog rada je napraviti morfološku analizu različitih tipova harvestera, te usporediti modele harvestera proizvedenih do 2003. godine i nakon 2003. godine i na osnovu rezultata ukazati na posebnosti njihovih značajki, te dati smjernice za budući razvoj harvestera. Na osnovi provedenog istraživanja ističu se slijedeći rezultati: U provedenim analizama izdvajaju se gusjenični harvesteri te ih treba promatrati kao zasebnu skupinu vozila. Zbog negativnog utjecaja mase harvestera na šumsko tlo preporuča se traženje rješenja stabilnosti u drugim morfološkim značajkama. Snagu pogonskog motora potrebno je prilagoditi zahtjevima hidrauličnih komponenti harvestera. Pri konstrukciji harvestera duljina treba biti svedena na minimum. Tehnologija rada harvestera treba biti prilagođena trenutačnim dohvatima hidrauličnih dizalica.

Uz pomoć sustava daljinskog praćenja rada vozila obavljeno je snimanje radnog dana skidera. Kako je pogonski motor glavni izvor vibracija, snimljeni brojevi okretaja su se daljinski prenosili, te su se na temelju njih odredili karakteristični režimi rada pri kojima su izmjerene vibracije na upravljaču i sjedalu skidera. Kombinacijom vrijednosti i trajanja karakterističnih brzina vrtnje motora s izmjerenim vibracijama izračunati će se energijski ekvivalent A(8) potreban za analizu izloženosti radnika vibracijama.