Poštovane čitateljice i čitatelji!

Iako bi se na ovom mjestu moglo pisati i raspravljati o mnogim, lijepim i onim nešto manje lijepim, ali svakako i višene goaktualnim temama povezanima s hrvatskim šumarstvom, odlučili smo se za jednu, po našem mišljenju, zanimljivu i korisnu temu – predstavljanje međunarodnoga savjetovanja pod naslovom Položaj i perspektiva šumarskoga inženjerstva (Position and Perspectives of the Forestry Engineering). Savjetovanje će se održati u Zalesini i u Ravnoj Gori 12. (četvrtak) i 13. (petak) travnja 2007. godine. Organizatori su ovoga skupa: Zavod za šumarske ehnike i tehnologije Šumarskoga fakulteta Sveučilišta u Zagrebu, Zavod za šumsku tehniku i ekonomiku Biotehničkoga fakulteta Sveučilišta u Ljubljani te Šumarski institut Slovenije. Ideja o potrebi organizacije ovakva međunarodnoga skupa u Hrvatskoj provlačila se, više u neslužbenim nego u službenim razgovorima hrvatskih i slovenskih kolega šumara, od 1999. godine…

This paper presents the results of simultaneous research of fuel consumption and time consumption of a skidder during three types of wood skidding (long roundwood skidding, long roundwood skidding along with stackwood forwarding, stackwood forwarding), aimed at analysing the advantages of fuel consumption as an indicator of productivity. In doing so, the time of wood skidding was divided into the following components or groups of work components: unloaded travel, loaded travel, total travel, gathering travel, cable pulling out, load hooking, load winching, load adjusting, felling site work, load unhooking, load bunching, landing work, and felling site and landing work.
Based on simultaneous measurement of time consumption and fuel consumption of the above components of wood skidding, linear regression analysis was used for observing time consumption dependences of individual components of wood skidding and fuel consumption of the skidder depending on: distances of unloaded travel and loaded travel, gathering travel, cable pulling out, load winching and volume of an average piece in the load.
Regression analyses show greater dependence of fuel and time consumption of individual components of wood skidding on distances than on the volume of an average piece in the load. The volume of an average piece in the load is significant for the following components: load hooking and unhooking, and load modelling.
The comparison of determination coefficients of work components, in which time consumption and fuel consumption were analysed, show in all three types of wood skidding that the correlations between time consumption and fuel consumption in regression equations are the strongest in case of long roundwood skidding, less strong in long roundwood skidding performed together with stackwood forwarding, and they almost disappear in stackwood forwarding.
For the purpose of searching for reliable indicators that would give an answer to the key question of this paper, regression analysis was carried out and determination coefficients were established of the dependence of fuel consumption on times of individual components (groups) of wood skidding. The analyses indicate that there are strong correlations between the above values in case of comparison of all the three types of wood skidding, as well as in case of a higher number of work components. However, analyses showed hat time consumption was a more reliable indicator of skidding efficiency than fuel consumption. Along with insufficient sensibility of devices for measuring fuel consumption, the deficiency of fuel consumption as the indicator of efficiency was especially observed in case of a loaded skidder downward travel, as well as during operations depending on the volume of an average piece in the load.

Keywords: skidder, timber extraction, work time, fuel consumption

The paper addresses different aspects of safety in forestry work during the transformation and transition period of Croatian forestry.
To assess the current status of safety and quality of forestry work in Croatia, the following should be taken into account:

• As regards safety and worker protection indicators, forestry holds an unenviably high place in Croatia in terms of work injuries and occupational diseases, as well as in terms of the number of work invalids,
• With the exception of those employed in the state forestry company, all other workers-contractors (private entrepreneurs, forest owners, local population) engaged in forestry activities are excluded from any system of safety and health protection,
• The prevailing working method in forestry consists of non-standardized working procedures and/or various sub-variants of technological processes,
• There is still no secondary vocational education for forest workers and neither is there any systematic research in the field offorest work,
• There are no professional criteria and rules designed to regulate work quality and safety of forest activities.

According to injury statistics in the state forest company, which manages about 2 million hectares of forests, an average of about 500 workers are injured every year, about 15,000 days are lost due to injuries, and work protection costs for about 10,000 employees amount to approximately 3 million EUR, which accounts for 1.14% of overall losses of the company. This is about 300 EUR per employee, or about 650 EUR per production worker. In the structure of injury causes, two thirds of all injuries are caused by falls during movement, or by unsafe practices and disregard for work safety rules.

A significant, although unknown, extent of injuries suffered by workers employed by private forest contractors arouses special concern. These workers perform over 50% of the annual amount of work related to timber harvesting, extraction and transport in Croatia. The selection of a contractor is basically determined by the lowest price and not by the quality and business expertise. In order to improve the safety and health offorest workers, introduction of licensing offorest work contractors is being proposed.

The system of licensing forest work contractors is currently at a standstill due to sluggish establishment of organizational and personnel prerequisites for licensing. This justifies criticism levelled at theforestry sector of not caring sufficiently for the level of professionalism and care in forestry activities.

Keywords: forestry, safety and health of workers, occupational injuries, licensing

Within comprehensive research of assortment structure of beech cut blocks of even-aged forests, records were also made of time consumptions required for carrying out field measurements of 2,308 beech trees obtained as a result of thinnings and shelterwood cuttings. Sample trees were processed in accordance with the requirements of the Croatian standards related to products of forest harvesting of 1995 (HRN), and the same trees were used for carrying out »bucking simulation« in accordance with the European Standard EN 1316–1:1997, i.e. in accordance with its Croatian variant, with the status of the Croatian Standard (HRN–EN). A sample consisting of 787 trees was made in thinning operations. 788 trees were measured in preparatory cuts, 467 in seeding cuts and 266 in final cuts.

The research goal was to establish possible dynamics of carrying our field measurements (time consumptions required for measuring sample trees by type of cut, average tree diameter and way of processing stackwood), which is a considerable contribution to planning and performing future researches of assortment structure of individual species of trees.

The research showed that the average time required for felling, processing and measuring sample trees increases from thinning to final cuts. Time consumption of processing and measuring sample trees is most strongly influenced by the way of processing stackwood, i.e. processing of fuel wood ranging in length from one to several metres. In carrying out these researches, the cutters’ productivity was lower by approximately 20 to 30 % compared to their regular production process. Such researches can be carried out simultaneously with the regular process of timber production, and by optimisation of the number and content of sample trees suitable for field measurement (technical staff and cutters) its efficiency may be affected depending on the features of the researched felling site.

Field measurements, whose aim is the preparation of assortment tables applicable in practice in accordance with the requirements of a specific standard, can be carried out with lower average time consumptions per sample tree than determined in this research. Consequently, although relatively large groups of sample trees are required for such researches, they can also be carried out with not as high time consumptions and research costs, and hence it can be concluded that actually there are no obstacles for the forestry science and practice to solve satisfactorily the problem of wood assortment structure of the main tree species.

Keywords: assortment structure, field measurements, time consumptions, common beech

The research of damage caused to standing trees in timber extraction by a 17-ton forwarder Timberjack 1710B was carried out at the felling site of pedunculate oak, 99 years of age, with the growing stock of 398 m³/ha and basal area of 27.35 m²/ha and with 183 trees/ha. Gross harvesting density in thinning was 29.8 m³/ha (~ 21 tree/ha). The investigated felling site wasn’t provided with secondary openness through skid trails and hence the forwarder travelled across the felling site to the processed roundwood without any restrictions.

As a result of the research, the damage caused to the stand was presented along with the analysis of structuralfeatures of incurred damages. Actions and activities causing tree damage were observed and assessment was carried out of suitability of timber forwarding from late thinnings with respect to the level and structure of damage

During its operation, the forwarder caused damage to 2.5 trees/ha, which is 1.5% in relation to the number of the remaining trees after felling.

Keywords: timber extraction, forwarder, damage to trees, lowland forests

The paper shows the research results of a tractor with a crane in stacking long stackwood on the landing by applying teamwork. Time and work study was performed by using snap-back chronometry method.

Long stackwood was processed in 4 m lengths. Work of tractor with crane was recorded during 11 days. Average volume of crane grasp was 0.411 m³. Effective time of tractor with crane was 25.12%, and delay times 74.88%. Allowance time of tractor with crane was determined in amount of 87.44% of the effective time.

The data of measured and calculated values were processed by mathematical-statistical methods of multiple linear regression. The result are mathematical models of calculations of effective time based on which, along with allowance time factor, standard time and daily output are calculated. The modelled effective time for wood stacking by tractor with crane is 4.80 min/m³ and standard time 8.97 min/m³. It is possible to achieve daily output of 53.53 m³/day.

Keywords: tractor with a crane, long stackwood, standard time, daily output, cost

This paper deals with basic terms related to forestry contractors. Different expressions used for forest contractors in Croatian and English are presented, the terms entrepreneur and entrepreneurship are defined and the basic characteristics of the actual forestry contractors are shown in the paper. The English expression ‘forestry contractor’ is considered the most suitable since it denotes the person who contracts the performance of forestry services. Professional programmes of recognition of forestry contractors are considered and their significance is pointed out in regulating the state and relationship offorestry services on the market as well as in achieving the status of reliable and responsible contractors. Registration, certification and licensing are presented as three main procedures for professional and business recognition of forestry contractors. Only licensing and licence are considered as the guarantee of professional and high-quality performance of forestry services. Licence can be withdrawn if the contractor permanently fails to meet the set qualification requirements or business criteria. Incentives are given for establishing a model, which would include the confirmation of qualification requirements and operating competence of the contractor as well as encourage contracting services only with authorised and licensed contractors. Professional and timely performance of services is expected to be a sufficient guarantee for forest owners to accept this model.

Keywords: forestry, forestry contractors, entrepreneurship, registration, certification, licensing

Budući da sam od samoga početka (od pokretanja inicijative) bio uključen u postupak osnivanja Hrvatske komore inženjera šumarstva i drvne tehnologije (u daljnjem tekstu Komora), smatram svojom moralnom i profesionalnom dužnošću upozoriti na određene probleme i zastoje koji su se, pri samom kraju oživotvorenja Komore, pojavili. Ne namjeravam nikoga prozivati i apostrofirati, već potaknuti odgovorne osobe (među ostalima i sebe kao člana Odbora strukovnoga razreda inženjera šumarstva) na učinkovite aktivnosti koje su, što zbog objektivnih, ali više zbog subjektivnih razloga mnogo sporije nego što bi trebale i morale biti. Kako bi postojeću situaciju raščistili u potpunosti, nužno je vratiti se u ne tako daleku prošlost…

Šumarska savjetodavna služba specijalizirana je javna ustanova kojoj su osnovne djelatnosti provođenje javnih ovlasti i unapređivanje stanja u šumoposjedničkim šumama. Osnivač je Šumarske savjetodavne službe Republika Hrvatska, a osnovana je Uredbom Vlade Republike Hrvatske, 2. lipnja 2006. godine (Narodne novine, 64/06). Zakonom o šumama (Narodne novine, 140/05) predviđeno je da Šumarska savjetodavna služba obavlja javne ovlasti koje je do sada obavljalo državno poduzeće »Hrvatske šume« d.o.o. Zagreb…