ORGANIZATION AND TECHNOLOGY OF
WOOD HARVESTING IN FINLAND
Department of Forest Resource Management
University of Helsinki, Finland
FOREST MANAGEMENT AND UTILIZATION
Finland located in Northern Europe has 20.1 million ha of forests. About 64% of the forests belong to private persons, 28% to the state and 8% to companies. Scots pine dominates 45%, Norway spruce 37% and broadleaved trees, mainly birch, 18% of growing stock. The mean annual increment is about 3.4 m3/ha. The annual allowable drain is 67.1 million m3. In spite of partly unused forest resources Finland is importing wood from several countries some 4-5 million m3 per year.
From forest management and wood harvesting point of view it is important to note, that the national economy of Finland very much depends on forests and on earnings from the export (40%) of forest industry products. During the past decades much effort has been expended to increase the production of wood and to build up a modern forest industry. As a result of these various activities the growing stock of the forests is larger than ever; the age of stands is about correct; the best tree species are occupying the sites; most of the reforestation is done artificially to a cultivated soil by using seedlings with breeded origins. Suitable peatlands have been drained and abandoned farmlands reforested. For stand treatment fixed thinning regimes have been developed, which give a good basis for planning of wood harvesting during the rotation. More than 80 000 km of forest roads have been constructed all over the country, but 2000-3000 km per year are still being made to make efficient forestry operations possible.
When speaking about forestry in Finland it is good to remember that the growing season ranges between 120-180 days per year, the precipitation 550-700 mm per year, the soils are mostly rocky moraines, the target rotation period in southern Finland 70-90 years and 100-120 years in Lappland. The country is rather flat (0-300 m) with the highest peak 1300 m a.s.l. So the terrain is from a forestry work point of view quite easy. Only the big share of low-bearing sites (swamps) cause during the summer and deep snow layers (max.>120 cm) in winter some problems to the mobility of forestry vehicles.
There are organizations for the management of both private and government forests. The private forests comprise 284 000 forest holdings larger than five hectares. They form about 400 forest management associations. There are 19 forestry boards under Forestry Centres Tapio and Skogskultur, the latter serving the Swedish-speaking population. The Finnish Forest and Park Service and the Ministry of Agriculture and Forestry are the highest administrative bodies for forestry matters. At the moment some 1500 graduate foresters, some 3500 diploma holders and about 4000 certificate holders are taking care of the national forestry property of Finland.
In Finland the annual area of logging is estimated as follows:
The annual cut by species is estimated as follows:
The flow of wood to various users is estimated as follows for 1993:
There has been some 47 pulpmills, 30 papermills and 16 board mills or machines in Finland. The number of sawmills is today less than earlier, since bigger units are better able to compete in the world market.
Planning of wood harvesting in the environment being described above is very demanding. The majority of forest lots are small in size, the mean size is about 33 ha and thus the annual harvest is very small.
The long-distance transport of wood adds some complexity to wood procurement. There are three methods in common use, the transport by truck, by floating and by rail.
The forest management plans made for the private forest holdings are being used as a basis. On the other hand, the forest industry has its wood procurement organizations, which take care of the rawmaterial supply of each industrial unit according to the set quality requirements. The management of various small operations also sets high demand for the information system required for controlling and monitoring functions. It is an exception, if a mobile forest machine does not have a telephone.
MECHANIZATION IN WOOD HARVESTING
There is an obvious difference in the work environment related to whether there is a thinning or a clear-cutting operation. This gives us the opportunity to discuss the wood harvesting technology separately in each case. However, in Finland the same machinery is usually being used in both cases. The planner of wood harvesting must consider the affecting factors accordingly.
Forestry and forest industry are closely linked together. Both of them have their own management organizations. About 75% of all wood harvesting in Finland is taken care by the organizations of the wood buyers, i.e. by the forest industry. A part of the forest owners are delivering their wood, about a quarter of all, as delivery sales to the road side landings. We also could distinguish between the farmers' and the companies' wood harvesting technology. In general, the farmers are using more labour-intensive and simple technology compared to contractor-based work methods preferred by the industry organizations. Both of these organizations are also doing thinnings. However, the forest industry would like to leave more of them to the forest owners in the future.
The development of wood harvesting operations is estimated as follows:
In wood cutting the handtools were replaced by chainsaws, shortly after by processors and now more and more by harvesters. Debarking by handtools in Finland's forests finished completely in the 1960s. Portable debarkers were in use at road-side landings up to the end of the 1970s. All wood is now being debarked at the mill. It was not until the 1960s that horses were replaced by farm tractors in the off-road transport of wood. During the late 1960s and the early 1970s some tests were made to introduce North America's cable skidders (Timberjack, Tree farmer) in Finland. However, the forwarders took gradually over almost of these tasks. The reasons behind these developments are discussed in detail by HAKKILA (1989 and 1995).
WOOD HARVESTING TECHNOLOGY
The main reasons behind the development of wood harvesting technology to its present form may be found from the infrastructure in Finnish forestry. The log-length system (short-wood logging method) is used in 99% of the cases. This is due to the large share of thinned timber from the wood being cut, the small average stem size, the type of terrain conditions, the small quantity of timber sold from a private forest lot at one time and thus frequent moves of machines from one operation to another along public roads, the shortage of landing areas for processing of tree-lengths, the need to sort and measure the timber at the road-side landings, and the use of floating as a long-distance transport method.
The persons employed today in wood harvesting operations are well-trained and skilled, so they know how to prepare timber assortments according to the requirements set by the users of wood. The role of private full-time contractors is more and more important. They must be able to perform a good job on a yearly renewed contract basis, which fulfils the technical, environmental and economic goals being set to the work.
The present technology itself may be divided into two main options: the motor-manual and mechanized cutting methods. Less than half of the timber is cut by a chainsaw operator, who follows a strip-road system in his work. In this method a network of striproads is planned for the cutting area with 30 m intervals. In a clear-cutting area this spacing may be only 20 m or even less depending on the volume being harvested. The logs and pulpwood will be, after directional felling and minor bunching, separately or in small piles, ready for loading into the forwarder, which moves along the opened striproads. The forwarder unloads the sawlogs, the pulpwood and eventual other wood assortments to their own piles at a landing located alongside a permanent forest road. The mean forwarding distance in whole Finland is today some 350 m.
The mechanized wood cutting differs from the earlier mentioned one only in that the actual cutting operation is carried out by a single-grip harvester, a multi-function wood harvesting machine which in a continuous operation fells a tree, delimbs it, measures it, cuts the stem into timber assortments and during the bucking piles the logs according to the assortment desired. The harvester is equipped with a crane having a reach of 10-12 m. Thus it may mainly be moving along a striproad cover an area of about 20 m wide. If a striproad spacing of 20 m is considered to be too short, a narrow uncut strip between the thinned strips is afterwards cut inside the stand in a way that the logs may be loaded onto the forwarder driving along the striproads. Both the harvester and the forwarder are able to drive on a mat of branches and tops, which in addition to making the operation safe on soft ground, it is also an advantage from environment protection point of view.
In addition to the main solutions described above there is a variety of other technologies in use. When the forest owner sells his timber as delivery sale, he himself takes the responsibility to cut and forward the wood to the roadside. He may now use his chainsaw for the cutting of wood, or even have a small processor or harvester mounted on his farm tractor. For the off-road transport of wood, farm tractors equipped with a crane and trailer are used. These additional devices usually have a lighter construction, their productivity in the work is lower, but also the purchase price is less than the special logging machines.
It also should be mentioned here, that a special technology has been developed for harvesting small-sized trees. A proven alternative for raising productivity and improving biomass recovery in early thinnings is based on whole-tree logging. One of our modification towards the log-length (short-wood) method is the tree-section method. This method can be used in conditions, where the industry is able to take pulpwood in undelimbed form. Here the tree-sections are first simultaneously delimbed and debarked in the drum of the industry before feeding the produced clean chips to the pulping process.
PRODUCTIVITY OF WOOD HARVESTING WORK
In any production the ratio of output produced with one unit of input indicates the productivity of the work. The share of different input components is often changing with time, e.g. labour input is being replaced by capital input when mechanizing the operation. By rationalization measures the activities are converted to use less costly inputs. The competitiveness of motor-manual and mechanized harvesting methods in Finland is illustrated in the following graph:
In forwarding of wood a similar development may be illustrated, although there the popularity of the method is used as a measure. The most important factors behind the choice of a work method in Finnish working conditions has been the productivity and unit costs involved.
When looking at certain wood harvesting operations, one naturally must consider the affecting environmental conditions. In forest work this is important, as seen in the example below, how the stem volume is affecting the productivity in motor-manual cutting of wood.
Stem volume, Product Scots pine Norway spruce
0.05 Pulpwood 11.0 8.2
0.10 Pulpwood 15.0 11.5
0.20 Sawlogs + pulpwood 19.3 15.1
0.30 Sawlogs + pulpwood 22.1 17.4
0.50 Sawlogs + pulpwood 26.2 20.6
Thus, if looking at the work environment in thinnings, the following observations may be made:
_ tree size to be harvested is clearly smaller than in the final cuts;
_ amount of harvest per hectare is always small;
_ remaining trees are hampering the work in many ways;
_ there is a risk to damage the remaining trees;
_ from the operators point of view there is a poor visibility, which lowers the productivity of the work;
_ also the working machinery must be designed to be narrow and able to move in the stand itself or to follow the narrow strip roads.
There are therefore essential differences in the work environment of the first and later thinnings, too.
Due to the climatic and external factors the forest work cannot be evenly carried out all year round. The seasonal variation is illustrated in Fig. 9. As a result of this, seasonal fluctuation and over-capacity of the machines exist, the number of yearly operating hours of forestry machines remains therefore modest.
The productivity of wood harvesting work has been studied in some countries and the results of productivity are as follows:
Period Bulgaria British Baden- Finland
Annual increase in the productivity of logging work, %
1953-60 .. .. 6.0 4.3
1960-64 4.8 7.8 5.7 6.7
1966-70 0.6 3.8 8.5 9.4
1970-74 3.0 -0.9 3.9 12.2
1974-80 2.6 1.7 7.1 7.6
During the late 1980s the productivity of forest work in Finland was about:
Cutting 11 m3/man-day
Off-road transport 55 m3/man-day
Cutting and off-road transport 9 m3/man-day
All work in forestry 6 m3/man-day
As a result from the mechanization and rationalization of the wood harvesting the need for labourers in forestry work in Finland has continuously decreased. Forest owners' delivery cuttings excluded, today about 15 000 persons are working annually in the forest sector. On the other hand, the requirements set to the quality of training of these persons must be set much higher than earlier. In developing curricula and in designing training programmes for forest machine operators and mechanics, Finland has excellent results to demonstrate.
FOREST MACHINE INDUSTRY
The post-war time in the 1950s may be considered as a starting period for the establishment of the Finnish forest machine industry. First, the farm tractor was considered as a basic unit and it was then adapted for forestry work by mounting accessory equipment onto it. Sledges, trailers, half tracks, winches and mechanical boom loaders were designed locally. Still today products with ideas originating from that time are being manufactured in a modern way and exported to many countries. The best known abroad are the Farmi-winches, the products of Orion Yhtymä Oy Normet.
Farm tractor proved also to be a suitable prime mover for portable debarking machines. Since the 1960s the VK-debarkers manufactured by Valon Kone Oy have been adopted all over the world. In a similar way mobile chippers of different size have been developed for both forestry and industrial use. There are several machine manufacturing companies producing wood chippers.
Since the mid-1960s specially designed Finnish forwarders exist on the market. Valmet was the first to combine the knowledge gained from the design of skidders to the manufacturing of forwarders. As a hydraulic crane is an essential component of a forwarder, even an industry for manufacturing them was established. The name Fiskars is well-known worldwide and produced today by Loglift Oy Ab, which also owns Hiab-Foco Ab in Sweden. Kesla Oy, L. Marttiini Ky Konepaja and Rovaniemen Konepaja Oy are also significant manufacturers of log loaders.
Development of multi-function forest machines actually started in the 1960s. Sakari Pinomäki is known as a pioneer for the first processor PIKA 50 and in 1973 it became the first European manufacturer of a harvester PIKA 75. The period of processors did not last long, as indicated earlier. From the processor the production moved gradually to a double-grip harvester after the introduction of a felling head onto it. Still today a double-grip harvester is a superior machine in large clear-cutting operations with big trees. However, a single-grip harvester requires a lighter carrier, it is more compact in design and it also better suits in thinning operations. A large single-grip harvester head may also be mounted on an excavator, which makes the unit very usable even for clear-cuttings. Supplying the harvesters with sensors and microprocessors for accurate log measurement, bucking selection and scaling automation became a standard procedure in the turn of the 1990s.
There are both big and small manufacturers of forwarders and multi-function forest machines. They have increasingly moved from small machine shops to fewer large international companies, who make use of high-technology and engineering skills and, due to the scale of operation, are in a better position to export. The bulk of the production of Nordic logging machines is under the control of three Finnish groups:
_ Timberjack Group with an annual turnover of 2.4 billion FIM is the largest forest machine manufacturer in the world controlling a considerable share of global forest machine markets. It produces machinery for the log-length system in Finland and in Sweden, and machinery for the tree-length systems in Canada.
_ Another consortium is the Sisu Group (formerly Valmet) with an annual turnover of 682 million FIM. It has units in Finland, Sweden, Brazil, and the United States.
_ The third logging machine consortium is Ponsse Oy with an annual turnover of 236 million FIM. It consists of the parent company and subsidiary, Kajaani Automatiikka Oy, located in Finland.
In this connection, other manufacturers in this field are: Nokka-Tume/Tume Oy, Oy Logset Ab, Kesla Oy, Kone-Ketonen Oy, L. Marttiini Ky Konepaja, Orion-Group Oy Normet, and S. Pinomäki Ky.
When developing the Finnish wood harvesting machinery, the contractors are very useful for the forest machine designers. The contractors will only buy machines with a high performance, reliability and productivity. Earlier it was important to develop the ergonomics of the machines from the operators' point of view. Nowadays, all the machines fulfil even the highest requirements set by the authorities. The Institute of Agricultural Engineering (MTT-VAKOLA) is the organization which tests and works in close cooperation with the manufacturers and uses international standardized methods when checking the ergonomics of new models. More than elsewhere the machine designers have also paid attention to the development of such an end-product, which enables the use of environmentally sound wood harvesting methods.
This paper was written in 1992, was revised in 1995 and is largely based on the following publications in English, from where the reader is able to find additional information on the subject:
HAKKILA, P. 1989. Logging in Finland. Acta Forestalia Fennica 207.
HAKKILA, P. 1995. Procurement of timber for the Finnish forest industries. The Finnish Forest Research Institute. Research papers 557.
The author thanks Professor Hakkila for critics received in drafting the original paper.