Kari Väätäinen

Characteristics and Significance of a Harvester Operators’ Working Technique in Thinnings

Abstract Productivity levels between harvester operators have been noted to vary significantly, by up to 40% in similar stands. It is believed that differences originate from the operators cutting techniques, motoric skills, planning of work, experience, felling order of removable trees, decision processes at the working location, machine properties and the surrounding environment. The objective of this study is to examine and compare six harvester operators and to detect those features of working technique that improve and rationalise the work. Consequently, improving the basic working technique can raise average productivity. The harvester operators’ work was examined by using the normal stopwatch study method and the operators’ working technique was registered for each handled tree. Working technique observations were adjoined to stopwatch the study time units as a large matrix after data collection. Results indicate that unnecessary stem movements in the felling phase should be avoided. The stem should be processed close to the stump so that the positioning-to- cut distance to next removable tree is short. This reduced positioning-to-cut time for the next felling. In processing, a productive operator can operate without big delays and the variations in processing times for same stem sizes are small. Furthermore, the productive operator avoids reversing when he is doing normal harvesting work.

Improving the Logistics of Biofuel Reception at the Power Plant of Kuopio City

Abstract In Finland, many bio power and heating plants have been recently built and existing power plants have been improved to allow increased energy production. To meet the increasing demand of solid fuel at bio power plants, a large transportation fleet is needed and both the logistics of solid fuel transportation and power plant fuel reception must be improved. This study investigated fuel truck arrival and unloading processes at a power plant which produces heat for the city of Kuopio and electricity for the national grid. The aim of this study was to minimize fuel truck queuing times, and balance the use of two delivery bays by improving the logistics of fuel handling at the receiving station and by distributing truck arrivals at the power plant more uniformly throughout the day. Discrete-event simulation was implemented as a method for analyzing the system. To balance the utilization of both delivery bays at the power plant and shorten the queuing times, the most feasible solution was for more effective control of truck interaction with the delivery bays: having the shortest queue and faster fuel flow from delivery bay to combustion by arranging fuel transport with a new conveyor to the boiler. Adaptable scheduling of truck arrivals was found to be feasible during the morning to smooth out the peaks of the truck arrivals in cold periods when fuel consumption at the power plant is at its highest.

Feasibility of Excavator-Based Harvester in Thinnings of Peatland Forests

Abstract In the next twenty years in Finland, annual cuttings on peatland forests are foreseen to increase by up to 30 % of the total cuttings. Cost effective harvesting methods on low yield peatland forests coupled with low ground bearing capacity are required. One solution to improve the feasibility of harvesting could be excavators tailored for forestry use and equipped with a harvesting head. In the study, cost competitiveness and productivity of the excavator-based harvester were investigated. The cost analysis focused on operating hours of harvester use, shift arrangements and purchase prices for the base machine and harvesting equipment when the base machine was used partly as a harvester and an excavator. Results were compared to conventional wheeled harvesters. If the base machine is used more than 3 working months as a harvester in addition to normal (6–8 months) excavator work, the harvesting method would be cost competitive compared to purpose-built harvesters (if 1 V and 2 shift arrangements were used). The 25 % increase of the base machine’s and harvester equipments’ purchasing costs did not eliminate the cost competitiveness of harvesting, when harvesting was carried out in 1 V shifts for at least 4 months. It would be feasible and profitable to invest in harvesting equipment for the excavator and therefore diminish the winter lay-days of the base machine by utilizing it in logging operations. Conditions on peatland sites mean that during the winter time the use of the excavator-based harvester is ideal, when the utilisation of all logging machines is at its highest.

Variation in age, annual usage and resale price of cut-to-length machinery in different regions of Europe

ABSTRACT The high price of cut-to-length machines requires careful planning of investment in new or second-hand machines. The investment is influenced by machine usage, and is also affected by maintenance, insurance and repair costs, harvesting conditions, number of machine relocations, and availability of working opportunities and employment. In this study, age, size, annual usage and price of the cut-to-length harvesters and forwarders for sale in Europe was investigated, using sales data from the online marketplace. The average age of harvesters was 7.3 years and the average age of forwarders was 7.5 years. The newest machines were on offer in the Northern countries (6.5 and 6.1 years for harvesters and forwarders, respectively). The oldest harvesters were on offer in Western Europe (8.1 years) and Eastern Europe (8.2 years) and the oldest forwarders in Eastern Europe (9.9 years). The average annual use of both harvesters and forwarders were notably high in the Baltic and Northern countries compared to the Western and Eastern Europe. On average, the annual use was 1759 and 1913 h year−1 for the harvesters and forwarders, respectively. The average resale price of harvesters was more dependent on age than total use. For forwarders, both age and total usage had a similar explanatory value. For newer CTL machines, aged between 1 and 5 years, the bigger size class of the machine corresponded to higher price. Older machines did not exhibit such correspondence, whereas the annual usage showed high correspondence on the resale value of the machine.

Modeling Biomass Logistics

This chapter will presents the current status and the main challenges of biomass logistics. Logistical aspects of the biomass supply chain will be delineated. It further provides a thorough description of different methodologies to design biomass value chains combined with relevant logistical assessment criteria. This includes also descriptions for how to integrate the various logistical components in modeling logistical tools that are currently available to implement the described methodologies. The chapter finishes with a set of case studies based on local data and made with these logistical tools.

Alternative operation models for using a feed-in terminal as a part of the forest chip supply system for a CHP plant

The fuel supply of forest chips has to adapt to the annual fluctuations of power and heat generation. This creates inefficiency and unbalances the capacity utilization of the fuel supply fleet in the direct fuel supplies from roadside storages to power and heat generation. Terminals can offer an alternative approach for the fleet management of fuel supplies in terms of smoothing the unbalanced fleet use towards more even year‐round operations. The aim of the study was to compare the supply costs of a conventional direct forest chip supply to an alternative fuel supply with the use of a feed‐in terminal using the discrete‐event simulation method. The influences of the terminal location, terminal investment cost, outbound terminal transport method, terminal truck utilization and quality changes of terminal‐stored forest chips for the fuel supply cost were studied in the case environment. By introducing a feed‐in terminal and a shuttle truck for the transports of terminal‐stored forest chips, the total supply cost was 1.4% higher than the direct fuel supply scenario. In terminal scenarios, the supply costs increased 1–2% if the cost of the terminal investment increased 30%, the distance to the terminal increased from 5 to 30 km or the total annual use of a terminal truck decreased 1500 h. Moreover, a 1 per cent point per month increase in the dry matter loss of terminal‐stored chips increased the total supply cost 1%. The study revealed that with the relatively low additional cost, the feed‐in terminal can be introduced to the conventional forest chip supply. Cost compensation can be gained through the higher annual use of a fuel supply fleet and more secured fuel supply to power plants by decreasing the need for supplement fuel, which can be more expensive at a time of the highest fuel demand.

Hakkuukoneen syöttörullien vaikutus rungon prosessoinnin nopeuteen, polttoaineenkulutukseen sekä tukkipuuvaurioihin

Seloste artikkelista: Operational efficiency and damage to sawlogs by feed rollers of the harvester head / Yrjo Nuutinen ... [et al.] - Julkaisussa: Silva Fennica 44 (2010) : 1, s. 121-139.