INFLUENCE OF WHEELED TYPES OF A Skidder ON PRODUCTIVITY AND COST OF THE FOREST HARVESTING

AbstractThe objective of this study was to evaluate the influence of different wheel types of a skidder on productivity and cost of Pinus taeda L. wood extraction. The study was conducted in a forestry company located in the municipality of Mandirituba, Paraná state, Brazil. The technical and cost analyses included a time and motion study of the wood extraction activity. The productivity, operative efficiency, energy consumption and the production and operational costs were determined for the machines with different wheel types: SDP - skidder with rubber tires; SD2 – skidder with tracks on the two front tires; and SD4 – skidder with tracks on the four tires. Results showed that the activity that demanded most time in the operational cycle was the maneuvering of the machines to pick up more than one tree, resulting in lost of productivity and need of improvement in the operational planning. The skidder equipped only with rubber tires showed higher productivity and lower production cost in the longest extraction distances, caused by the higher operating speed of the machine.Keywords: Timber extraction; wheel types; operating efficiency. ResumoInfluência dos rodados de um skidder na produtividade e no custo da extração florestal. Este trabalho objetivou avaliar a influência de diferentes tipos de rodados de um skidder na produtividade e no custo da extração de madeira de Pinus taeda L. O estudo foi conduzido em uma empresa florestal localizada no município de Mandirituba, estado do Paraná, Brasil. As análises técnica e de custo englobaram um estudo de tempos e movimentos da operação de extração florestal. Foi determinado a produtividade, eficiência operacional, rendimento energético e custos operacionais e de produção das máquinas equipadas com diferentes tipos de rodados: SDP – skidder com rodados de pneus; SD2 – skidder com pneus dianteiros recobertos com semiesteiras e SD4 – skidder com os quatro pneus recobertos com semiesteiras. Os resultados mostraram que a atividade que demandou o maior tempo do ciclo operacional foram as manobras realizadas pelas máquinas para apanhar mais de uma árvore, ocasionando perda de produtividade e necessidade de melhoria no planejamento operacional. O skidder equipado somente com rodados de pneus apresentou maior produtividade e menor custo de produção nas maiores distâncias de extração, ocasionado pela maior velocidade operacional da máquina.Palavras-chave: Extração florestal; tipos de rodados; eficiência operacional.AbstractThe objective of this study was to evaluate the influence of different wheel types of a skidder on productivity and cost of Pinus taeda L. wood extraction. The study was conducted in a forestry company located in the municipality of Mandirituba, Paraná state, Brazil. The technical and cost analyses included a time and motion study of the wood extraction activity. The productivity, operative efficiency, energy consumption and the production and operational costs were determined for the machines with different wheel types: SDP - skidder with rubber tires; SD2 – skidder with tracks on the two front tires; and SD4 – skidder with tracks on the four tires. Results showed that the activity that demanded most time in the operational cycle was the maneuvering of the machines to pick up more than one tree, resulting in lost of productivity and need of improvement in the operational planning. The skidder equipped only with rubber tires showed higher productivity and lower production cost in the longest extraction distances, caused by the higher operating speed of the machine.Keywords: Timber extraction; wheel types; operating efficiency

QUALITY FUNCTION DEPLOYMENT (QFD) APPLIED TO THE VARIABLES THAT INFLUENCE QUALITY COSTS IN MECHANIZED FOREST HARVEST OPERATIONS

Globalization and client demands result in the need for investments for the survival of the companies. Forest harvest represents the highest costs and losses of wood production. Quality function deployment (QFD) is recommended to achieve quality by detecting customer needs. Thus, this study aimed to determine the variables that influence quality costs in the mechanized harvest to reach the quality control of forest activity. The research was developed in a company located in the State of Santa Catarina, Brazil. The variables that influence quality costs in four categories (evaluation, prevention, internal and external flaws) were identified. The QFD method was used to translate the needs of internal and external customers (critical success factors) of mechanized harvesting activities into measurable technical characteristics (variables that influence quality costs), determining the weight for each relationship and, consequently, the balance of the categories, besides the correlations of the variables evaluated as strong, medium, weak, and non-existent. Among the 29 variables identified, 18 consisted of evaluation and prevention, representing the relative weights of 37.17% and 26.49%, respectively, and 11 represented internal and external flaws, with values of 26.57% and 9.73%, respectively. The correlation matrix found 334 correlation of the 406 cells: 195 (58%) strong, 86 (26%) medium, and 53 (16%) weak. In conclusion, the company must improve process quality by investing in evaluation and prevention aimed at reducing non-conformities and expansion of revenues

Compaction of a cambisol caused by forest harvesting machines with spatialized geostatistics.

Este trabalho objetivou avaliar o impacto e a extensão em que Resistência à Penetração (RP) de um Cambissolo Húmico é afetada pelo tráfego de máquinas de colheita da madeira em povoamentos de Pinus taeda, utilizando métodos geoestatísticos. O estudo foi conduzido em áreas de uma empresa florestal localizada em Santa Catarina. Os tratamentos avaliados advieram da simulação de diferentes intensidades de tráfego. Foram realizadas leituras de RP nas trilhas de passagem dos rodados das máquinas e transversalmente em intervalos de 0,25 até 1,00 m e entre rodados, perfazendo uma malha de 5 x 20 m, sendo 55 pontos por tratamento e 330 no total, com dados obtidos em intervalos de 0,01 m até 0,80 m de profundidade. Os dados foram avaliados por estatística descritiva e ajustaram-se modelos de semivariogramas para análise da dependência espacial e posterior realização de krigagem ordinária. Houve grande amplitude e variação da RP e predominância de ajuste de semivariogramas do tipo gaussiano, com forte grau de dependência espacial, de 0,774 a 0,929, e alcance variando de 0,83 a 2,12 m. Os métodos geoestatísticos permitiram determinar a extensão dos efeitos do tráfego, podendo servir de subsídio para melhoria no manejo do solo e planejamento das operações florestais.The objective of this study was to evaluate the impact and the extent which Penetration Resistance (PR) of a Humic Cambisol (HC) is affected by traffic of timber harvesting machines in stands of Pinus taeda, using geostatistics methods. The study was conducted in areas of the forestry company located in the Santa Catarina State, Brazil. The treatments were derived from simulation of different machines traffics intensities. The soil penetration resistance (PR) measures were taken in wheel tracks trails and in horizontal intervals of 0.25 up to 1.00 m, and in between the tracks, making a grid of 5 x 20 m, with 55 points per treatment and 330 in total, being the data collected at intervals of 0.01 up to 0.80 m of depth. Data were analyzed with descriptive statistics and were adjusted semivariogram models for the spatial dependence analysis. The results showed a great range and variation of compaction dates. Gaussian models predominated in adjusted variogram models, with strong spatial dependence degree, from 0.774 to 0.929, and range ranged from 0.83 to 2.12 m. The geostatistics methods allowed to determine the extent of the traffic effects, and may provide support for improvement soil management and planning of forest operations

PREDICTABILITY IN THE PRODUCTIVE PROCESS OF THINNING AND CLEARCUTTING MECHANIZED OPERATIONS IN Pinus taeda L.

Some organizations in the Brazilian forestry sector, especially in the activities carried out in forest stands, do not follow the development pace of other industries and the adoption rate of management and quality methodologies and tools. This study aimed to evaluate the predictability of timber harvesting process based on critical points identified in the selective thinning and clear cut operations. Interviews and Pareto chart were used, for the identification and evaluation of the critical points, respectively, and for the evaluation of the process, it was used the Statistical Process Control (SPC) by attributes and variables in the main failures. In the interviews conducted with workers, seven critical points were identified. The evaluation with Pareto chart showed that 80% of the failures identified during harvest are attributed to the damage to the remaining trees, sorting (measures of length and diameter of the product) and stump height. Among the possible causes of the critical points are problems with employees’ training, regular maintenance of machinery and operations planning. In the evaluation with the CEP, the control charts indicated that the sorting and stump height, although within the limits specified by the company, was considered unstable and unpredictabl

EFFECT OF INDIVIDUAL TREE VOLUME ON OPERATIONAL PERFORMANCE OF HARVESTER PROCESSOR

The need to obtain multi-products from the forest makes the wood processing an important step in the timber harvest, being necessary, then, to understand the influence of the stand characteristics on the operational performance of the machines. The aim of this study was to evaluate the effect of the individual tree volume on the operational performance of the harvester forest processor in Pinus taeda L. stands, in order to assist in planning operations and reducing production costs. The analyzes were carried out by means of a time and motion study, determining the time consumed in the phases of the operational cycle, mechanical availability, operational efficiency, productivity, and production costs in three stands with different individual mean volumes (IMV): I (1.21 m3 tree-1); II (1.34 m3 tree-1) and III (1.61 m3 tree-1). In a completely randomized design, the averages of the variables were compared, as well as models for estimating productivity and production costs were fitted according to individual tree volume. The results showed that the processing element consumed a significant part of the total operational cycle time, with 46, 53 and 64% in treatments I, II and III, respectively, with an average operational efficiency of 56% in all treatments. Productivity increase and reduction of production costs were observed in the order of 43 and 30%, respectively, with the increase in IMV from 1.21 to 1.61 m3 tree-1. Such behavior can be represented by the third degree polynomial, which demonstrated the operational limit of 1.5 m3 tree-1 for the harvester forest processor

COMPACTAÇÃO CAUSADA PELO TRÁFEGO DE FELLER BUNCHER E SKIDDER EM UM NEOSSOLO REGOLÍTICO SOB DISTINTAS UMIDADES

http://dx.doi.org/10.5902/1980509817482This research evaluated the influence of water content on soil compaction of an Entisol under traffic of forest harvesting machines and developed models to estimate soil compaction. The study was conducted in areas of a forest company, located in the state of Santa Catarina, Brazil. The sampling was performed under various conditions of soil moisture, contemplating three classes: Ug1 (Ug < 0,30 kg kg-1); Ug2 (0,30 ≤ Ug < 0,40 kg kg-1); Ug3 (Ug ≥ 0,40 kg kg-1). The soil bulk density was determined (Ds), total (Pt) and air-filled porosity (PA) and penetration resistance (RP), under the conditions without traffic (WT) and after traffic (AT) of a Feller-buncher (CAT 522) and a Skidder (CAT 545) employed in wood harvesting of Pinus taeda stands. Multiple regression equations were adjusted to estimate the soil penetration resistance, through arithmetic and logarithmic models with pure and mixed variables. The results indicate that in moisture condition above than 0,40 kg kg-1 (Ug3), the traffic promoted increase in Bd and PR of 10 and 24%, respectively, and decrease in αt and αair, in order of 12 and 43%. In low moisture content (Ug < 0,30 kg kg-1), the increase of Bd and PR was 3 and 13%, respectively, and the decrease of αair of 8% and without effect in αt. The stepwise logarithmic model with mixed variables (SLMM) showed the best results for the estimation of soil penetration resistance, but caution must be raised in their employment due to the possible influence of other factors in the estimation and determination of PR.http://dx.doi.org/10.5902/1980509817482Esta pesquisa objetivou avaliar a influência da umidade na compactação de um Neossolo Regolítico submetido ao tráfego de máquinas de colheita florestal e desenvolver modelos para estimativa da compactação. O trabalho foi conduzido em áreas de uma empresa florestal localizada no Estado de Santa Catarina. A amostragem foi realizada em diversas condições de umidade do solo, contemplando três classes: Ug1 (Ug < 0,30 kg kg-1); Ug2 (0,30 ≤ Ug < 0,40 kg kg-1) e Ug3 (Ug ≥ 0,40 kg kg-1). Determinou-se a densidade do solo (Ds), a porosidade total (Pt) e de aeração (PA) e a resistência à penetração (RP), nas condições sem tráfego (ST) e após tráfego (AT) de um Feller buncher (CAT 522) e um Skidder (CAT 545) utilizados na colheita da madeira de povoamentos de Pinus taeda. Foram ajustadas equações de regressão múltipla para estimar a RP, por meio de modelos aritméticos e logarítmicos com variáveis puras e mistas. Os resultados indicaram que em condição de umidade superior a 0,40 kg kg-1 (Ug3), o tráfego promoveu aumento da Ds e RP da ordem de 10 e 24% e redução da Pt e da PA, da ordem de 12 e 43%, respectivamente. Em baixa umidade (Ug < 0,30 kg kg-1), o aumento da Ds e RP foi da ordem de 3 e 13%, respectivamente, e redução da PA da ordem de 8% e sem efeito na Pt. O modelo por stepwise logarítmico com variáveis mistas (MSLM) (Ln RP = –1,11 + 0,64Ds-2 + 0,14Ug-1) apresenta os melhores resultados para estimativa da resistência do solo à penetração, mas deve haver cautela no seu emprego, devido à possibilidade de influência de outros fatores na estimativa e determinação da RP

COMPACTION CAUSED BY FELLER-BUNCHER AND SKIDDER TRAFFIC IN AN ENTISOL UNDER DISTINCT MOISTURES

This research evaluated the influence of water content on soil compaction of an Entisol under traffic of forest harvesting machines and developed models to estimate soil compaction. The study was conducted in areas of a forest company, located in the state of Santa Catarina, Brazil. The sampling was performed under various conditions of soil moisture, contemplating three classes: Ug1 (Ug &lt; 0,30 kg kg-1); Ug2 (0,30 64 Ug &lt; 0,40 kg kg-1); Ug3 (Ug 65 0,40 kg kg-1). The soil bulk density was determined (Ds), total (Pt) and air-filled porosity (PA) and penetration resistance (RP), under the conditions without traffic (WT) and after traffic (AT) of a Feller-buncher (CAT 522) and a Skidder (CAT 545) employed in wood harvesting of Pinus taeda stands. Multiple regression equations were adjusted to estimate the soil penetration resistance, through arithmetic and logarithmic models with pure and mixed variables. The results indicate that in moisture condition above than 0,40 kg kg-1 (Ug3), the traffic promoted increase in Bd and PR of 10 and 24%, respectively, and decrease in \u3b1t and \u3b1air, in order of 12 and 43%. In low moisture content (Ug &lt; 0,30 kg kg-1), the increase of Bd and PR was 3 and 13%, respectively, and the decrease of \u3b1air of 8% and without effect in \u3b1t. The stepwise logarithmic model with mixed variables (SLMM) showed the best results for the estimation of soil penetration resistance, but caution must be raised in their employment due to the possible influence of other factors in the estimation and determination of PR.Esta pesquisa objetivou avaliar a influencia da umidade na compactacao de um Neossolo Regolitico submetido ao trafego de maquinas de colheita florestal e desenvolver modelos para estimativa da compactacao. O trabalho foi conduzido em areas de uma empresa florestal localizada no Estado de Santa Catarina. A amostragem foi realizada em diversas condicoes de umidade do solo, contemplando tres classes: Ug1 (Ug &lt; 0,30 kg kg-1); Ug2 (0,30 64Ug &lt; 0,40 kg kg-1) e Ug3 (Ug 650,40 kg kg-1). Determinou-se a densidade do solo (Ds), a porosidade total (Pt) e de aeracao (PA) e a resistencia a penetracao (RP), nas condicoes sem trafego (ST) e apos trafego (AT) de um Feller buncher (CAT 522) e um Skidder (CAT 545) utilizados na colheita da madeira de povoamentos de Pinus taeda . Foram ajustadas equacoes de regressao multipla para estimar a RP, por meio de modelos aritmeticos e logaritmicos com variaveis puras e mistas. Os resultados indicaram que em condicao de umidade superior a 0,40 kg kg-1 (Ug3), o trafego promoveu aumento da Ds e RP da ordem de 10 e 24% e reducao da Pt e da PA, da ordem de 12 e 43%, respectivamente. Em baixa umidade (Ug &lt; 0,30 kg kg-1), o aumento da Ds e RP foi da ordem de 3 e 13%, respectivamente, e reducao da PA da ordem de 8% e sem efeito na Pt. O modelo por stepwise logaritmico com variaveis mistas (MSLM) (Ln RP =-1,11 + 0,64Ds-2 + 0,14Ug-1) apresenta os melhores resultados para estimativa da resistencia do solo a penetracao, mas deve haver cautela no seu emprego, devido a possibilidade de influencia de outros fatores na estimativa e determinacao da RP

Efeito da idade, sortimento e tempo de estocagem na densidade verde da madeira de Pinus taeda L.

Green density knowledge is essential in the commercialization and industry supply, enabling conversion between wood volume and mass units. Thus, study objective was evaluated influence of the wood age, its dimensions and storage time in the Pinus taeda L. green density variation. To this, were studied logs with thin tip diameters between 8-18 cm (S1) and 18-24 cm (S2), aged 9 years. In addition to these, two others assortments were also analyzed for 21 year-old logs, 24-35 cm (S3) and over 35 cm (S4). Wood green density was determined by log diameter measurements and weighing at the harvesting time and on six other occasions, at 7, 14, 21, 28, 60 and 90 storage days in the field. Age, assortment and storage time effect were verified by general linear model (p&lt;0.05). Subsequently, equations to green density estimating were adjusted in function of the wood basic density and log average diameter. Results showed that all factors considered had significant effect in wood green density. Older wood presented higher values for this variable and, within each age, wood green density increased as the log diameters decreased. Storage time had influence only S1 and S2 assortments green density at both ages. Adjusted equations showed satisfactory results to green wood density prediction. Thus, we concluded that factors studied must be considered in sampling process to wood green density determination, being possible use variables easily obteined, such as log average diameters to estimate this variable with satisfactory precision.O conhecimento da densidade verde é fundamental no processo de comercialização e abastecimento industrial, possibilitando a conversão entre unidades de volume e massa da madeira. Dessa forma, o objetivo deste estudo foi avaliar a influência da idade da madeira, sortimentos e tempo de estocagem sobre a variação da densidade verde de toras de Pinus taeda L. Para isso, foram estudadas toras com diâmetros na ponta fina entre 8-18 cm (S1) e 18-24 cm (S2), com idade de 9 anos. Além desses dois sortimentos (S1 e S2), outros dois também foram analisados para toras com 21 anos de idade, 24-35 cm (S3) e acima de 35 cm (S4). A densidade verde da madeira foi determinada por meio da cubagem rigorosa e pesagem das toras no momento da colheita das árvores e em outras seis ocasiões, aos 7, 14, 21, 28, 60 e 90 dias de estocagem a campo. O efeito dos fatores idade, sortimento e tempo de estocagem foram verificados pelo modelo linear geral (p&lt;0,05). Posteriormente, equações para estimativa da densidade verde foram ajustadas em função da densidade básica e diâmetro médio das toras. Os resultados demonstraram que todos os fatores considerados tiveram efeito significativo sobre a densidade verde da madeira. A madeira mais velha apresentou maiores valores para essa variável e, dentro de cada idade, a densidade verde da madeira aumentou à medida que o diâmetro das toras diminuiu. O tempo de estocagem exerceu influência apenas sobre a densidade verde dos S1 e S2 em ambas idades. As equações ajustadas mostraram resultados satisfatórios para a predição da densidade verde da madeira. Assim, conclui-se que os fatores estudados devem ser considerados em amostragens para a determinação da densidade verde da madeira e que é possível utilizar variáveis de fácil obtenção, como o diâmetro médio das toras, para a estimativa dessa variável com precisão satisfatória

INFLUÊNCIA DO VOLUME DAS ÁRVORES NO DESEMPENHO DO PROCESSADOR FLORESTAL HARVESTER EM POVOAMENTO DE EUCALIPTO

Objetivou-se avaliar a influência do volume das árvores no desempenho operacional do processador florestal harvester em um sistema de árvores inteiras. O estudo foi realizado em povoamento de Eucalyptus grandis Hill ex. Mainden com 84 meses, submetido ao corte raso e localizado em Telêmaco Borba, Paraná, Brasil. Os dados foram obtidos por meio de estudo de tempos e movimentos para determinar os tempos do ciclo operacional, as disponibilidades mecânica e técnica, a eficiência operacional, a produtividade e os custos de produção. O efeito do volume das árvores na produtividade e nos custos de produção foi avaliado por meio de análise de regressão. Com os resultados obtidos, foi possível verificar que o elemento processamento consumiu 74% do tempo total efetivo do ciclo operacional. As disponibilidades mecânica e técnica foram de 80,8 e 79,5%, respectivamente, com uma eficiência operacional de 60,5%. A produtividade média foi de 49,1 m³ he-1, com custo médio de produção de R$ 5,45 m-3. Para a estimativa da produtividade e dos custos de produção, ambos em função do volume das árvores, o polinômio de terceiro grau foi o modelo ajustado, gerando equações com coeficiente de determinação de 0,24 e 0,23, respectivamente. Com isso, mostrou-se que o desempenho operacional da máquina é influenciado diretamente pelo volume das árvores, sendo a produtividade crescente e os custos decrescentes, à medida que há aumento do volume da árvore até aproximadamente 0,6 m³, após este valor, o aumento do volume proporciona efeito inverso no desempenho operacional do harvester

EVALUATION OF ASSORTMENTS CONSIDERING DIFFERENT STUMP AND PRE-BUCKING DISC HEIGHTS IN MECHANIZED HARVESTING OPERATIONS OF A Pinus taeda L. FOREST

This study aimed to evaluate assortments by adopting distinct stump heights and pre-bucking disc heights in the mechanized harvesting operations of a Pinus taeda L. forest, which is owned by a company located in Campo Belo do Sul (SC). To that end, the simulation of six scenarios was carried out after the forest’s clear-cutting. The scenario 1 includes the company's specifications. Scenario 2 includes the real situation, that is, the measurements made in sample units installed on the field and scenario 3 includes stump heights of 10 cm and pre-bucking disc heights of 5 cm. In the other scenarios, stump and pre-bucking disc heights with values higher than the ones specified by the company were included. Then, using a taper function, we calculated the assortments in tons per hectare (t ha-1) and monetary value per hectare (R$ha-1), considering the price of wood with bark (R$ t-1) for each assortment. Results show that Scenario 1 presented a larger amount of wood, however, Scenario 3 represented higher revenue due to the higher wood quantity of the value-added assortments. On the other hand, Scenario 6 presented the lowest amount of wood comparing to the others, and Scenario 2 presented the lowest economic return. All things considered, the company performs its activities below what is planned, but with production higher than the other evaluated scenarios. Regarding the economic return, the other scenarios are more feasible than Scenario 2, which shows that the company needs to seek process improvements with the implementation of another scenario that could bring better results