Fernando Seixas

Effect of Slash on Forwarder Soil Compaction

Abstract A study of the effect of slash on forwarder soil compaction was carried out. The level of soil compaction at two soil moisture contents, three slash densities (0, 10, and 20 kg/m2), and two levels of traffic (one and five passes) were measured. Results indicated that, on dry, loamy sand soils, the presence of slash did not decrease soil compaction after one forwarder pass, but did provide some protection from subsequent passes. The density of slash (over 10 kg/m2) did not affect compaction. On the same soils in a wetter condition, however, slash density at 20 kg/m2 was significantly less than on bare plots. At 10 kg/m2, the increase in bulk density after five passes was smaller than on the bare plots, but not significantly so.

Avaliação e efeito da compactação do solo, devido à freqüência de tráfego, na produção de madeira de eucalipto

RESUMO – A compactacao do solo devido ao trafego de maquinas de colheita de madeira, assim como a extensao da area impactada, constitui fator de preocupacao, em virtude da possibilidade de efeitos prejudiciais para o crescimento da floresta. O objetivo deste trabalho foi avaliar os efeitos da frequencia de trafego de um trator mais carreta na compactacao do solo e na produtividade de um plantio de Eucalyptus grandis, no final da primeira rotacao de sete anos. A compactacao do solo, avaliada por meio da densidade e resistencia a penetracao, foi determinada para tratamentos com 1, 3, 5, 10 e 20 passadas do veiculo carregado com 12,5 estereos de madeira, com peso total de oito toneladas, alem de uma testemunha sem a ocorrencia de trafego. Apos as cinco primeiras passadas ocorreram cerca de 80% do adensamento total do solo, resultante das 20 passadas, sendo recomendado restringir o trafego de veiculos dentro do talhao na menor area possivel, diminuindose a extensao de possiveis efeitos da compactacao sobre o povoamento florestal. Contudo, nessa situacao em particular a compactacao do solo nao prejudicou o crescimento das arvores em nenhum dos tratamentos avaliados.

Avaliação ergonômica do posto de trabalho de modelos de "forwarder" e "skidder"

The logging mechanization process in Brazil means, most of the time, the use of adapted or imported machines from countries where the operators have different anthropometric characteristics. The objective of this work was the cab evaluation of four forwarders and two skidders, considering the position of commands and instruments and the operator visual area, based on the anthropometrics characteristics of a sample of Brazilians operators. The following machines were studied: forwarders Timberjack models 1210B and 1710D, Valmet 890.2 and Volvo A25C, and also the skidders Caterpillar 545 and Tigercat 630 B. The command position was determined in three dimensions (x, y and z), considering the operators seat reference point as the origin. A qualitative evaluation with the operators was also carried out, showing their satisfaction with several ergonomic factors related with the forest machines. The operator anthropometric evaluation was performed using a special chair developed by the Fundacentro, resulting in areas of maximum and excellent access of command position. The machine presenting the best command positions, according to the biotype of the operator sample, was the forwarder Valmet 890.2, followed by the skidder Caterpillar 545, being the only tractors showing more than half of commands well positioned, 66.7% and 54.5% respectively. The results of this study demonstrated that, in terms of command position, the ergonomic design of these machines was not very favorable to the set of analyzed Brazilians operators.

Análise técnica e econômica de prestadores de serviços na colheita florestal

The objective of this study was to describe the financial conditions of forestry contractors, concerning life quality aspects, condition of work and equipments, operational costs, and economic credit to invest in new technologies. Five companies had been analyzed, with an annual income between US

Evaluation of Job Rotation Effects on Chain Saw Operators

400,000.00 and US

Avaliação de um sistema de cavaqueamento de ponteiras de eucalipto para aproveitamento energético

1,720,000.00, with an average of US

Soil compaction effects of forwarding and its relationship with 6- and 8-wheel drive machines

950,000.00. The number of employees varied between 33 and 181, and the companies were classified in terms of size as: one small, two average, and two big. The main difficulties to invest in new machines were high financial taxes, more than 12% an year, and a lack of long term contracts to guarantee the payment capability. It was observed that the contractors did not consider the capital remuneration and a correct depreciation of machines, resulting in an average machine life higher than 10 years. The final conclusions were that the costs were above the paid values for the services, when computed the depreciation and capital remuneration, with negative results in the financial analyzes of three companies. Finally, the mechanization process increased the workers life quality, however, the annual income was around US

Evaluation of two round baling systems for harvesting understory biomass

2,112.00 per worker, approximately 39% lower than the average Brazilian population.

Compactação do solo devido ao tráfego de máquinas de colheita de madeira

This paper analyses the effects of job rotation on physical effort in chain saw operations. This study was conducted in a seven-year old Eucalyptus grandis plantation harvested with a short-wood clearcut system. A practical application of ergonomie principles was utilized, considering heart rate as the method to evaluate the heaviness of work. Data were collected in a situation where the chain saw operator and his assistant rotated primary tasks to reduce physiological workload. Piling logs was the most demanding activity for the assistant, while the chain saw operator primarily is exposed to chain saw noise and vibration. Rotating jobs on this situation did not significantly reduce the total physiological workload on saw operators.

Efeito da camada de resíduos florestais na compactação do solo causada pelo transporte primário da madeira

The objective of this study was to evaluate the performance and to estimate costs of a wood chipping system for tree tops, which are considered residuals from wood harvesting, to be used for energy. The study was developed in a forest industry in the Para State, located in the north region of Brazil. The system was comprised by one wood chipper, two forwarders and one front loader. Data collection was based on time study, fuel consumption and chips load weighting. System average productivity was 17.51 tonnes per effective hour. Machine utilization rate was 51.9% due to many delays, mainly for repair and maintenance of the chipper. Chips transportation was considered to be the critical point of the system, due to some lack of trucks available for blowing chips. The system can produce between 94 and 162 times more energy than the energy consumed. System cost per effective hour was R