Current issue: 58(4)

Under compilation: 58(5)

Scopus CiteScore 2023: 3.5
Scopus ranking of open access forestry journals: 17th
PlanS compliant
Select issue
Silva Fennica 1926-1997
1990-1997
1980-1989
1970-1979
1960-1969
Acta Forestalia Fennica
1953-1968
1933-1952
1913-1932

Articles containing the keyword 'forest tractor'

Category : Article

article id 5186, category Article
Kaarlo Rieppo, Seppo Väyrynen. (1983). Kuormatraktoreiden huolto-ominaisuusvertailu haastattelemalla. Silva Fennica vol. 17 no. 2 article id 5186. https://doi.org/10.14214/sf.a15102
English title: Interview survey on the servicing properties of forest tractors.
Original keywords: metsäkoneet; metsätraktorit; ergonomia; huolto; kunnossapito; huoltotyö; kuormatraktori; työolosuhteet
English keywords: maintenance; working conditions; forest machines; forest tractors; ergonomy; serviceability
Abstract | View details | Full text in PDF | Author Info

The aim of this concise interview survey was to collect information about the servicing properties of forest tractors. Ten interviewees gave grades (in a scale from 4 to 10) concerning two servicing properties of various types of forest tractor. The rating covered the general safety during servicing (structural serviceability) and work postures during the work. Four types of forest tractor widely-used in Finland were chosen. The forwarders were of different size and structure.

According to the rating, the lightest forwarder was clearly superior to the other types. This machine was also the smallest in size and the most modern. Differences between the other three forwarders were not quite so clear. The variation between the machines as regards both so-called easy and troublesome tasks was considerable. Lubrication of the articulated shafts and supporting bearings was, however, very troublesome regardless the machine type. The heaviest tractor was considered the most difficult to service.

The PDF includes a summary in English.

  • Rieppo, E-mail: kr@mm.unknown (email)
  • Väyrynen, E-mail: sv@mm.unknown
article id 4936, category Article
Erkki Wuolijoki. (1976). Metsäkoneiden heilunnan ergonomiset haitat. Silva Fennica vol. 10 no. 2 article id 4936. https://doi.org/10.14214/sf.a14781
English title: Ergonomic effects of jolting of forest machines.
Original keywords: metsäkoneet; ergonomia; työkyky; terveydelliset vaikutukset; tärinä
English keywords: forest tractors; ergonomy; working capacity; occupational health; vibration
Abstract | View details | Full text in PDF | Author Info

The paper deals mainly with the effects of jolting of forest tractors and processors on the health and working capacity of the driver. The literature surveyed presents especially the following points of interest: Jolting of the machine may hamper the focusing of the eyes and mastery of the controls. Long-term exposure to jolting may result in reduced sympathetic nervous activity at rest, and may impair an already existing back problem. Workers exposed to vibration, get more frequently gastric changes and changes in reproductive functions than usual. Jolting, as also the other negative physical factors of working environment, must be minimized as early as possible during the design of the machines.

The PDF includes a summary in English.

  • Wuolijoki, E-mail: ew@mm.unknown (email)
article id 4843, category Article
Unto Silvennoinen, Rihko Haarlaa. (1971). Metsätraktoreiden liikkuvuus lumessa. Silva Fennica vol. 5 no. 2 article id 4843. https://doi.org/10.14214/sf.a14645
English title: The mobility of logging tractors on snow.
Original keywords: puunkorjuu; metsäkuljetus; maastoluokitus; maasto; lumipeite; metsätraktorit; talvikorjuu
English keywords: snow; forest haulage; forwarder; timber harvesting; terrain; forest tractor; skidder; terrain classification
Abstract | View details | Full text in PDF | Author Info

The mobility of logging tractors was tested in the winter 1969 on difficult snow conditions to gather information for planning of logging operations and for logging machinery design. The tractors tested were Clark Ranger 666, Timberjack C, Valmet Terra, Ford Brunett 5000, Fiskars 510, BM-Volvo SM 660, BM Volvo SM 661, Ford Country 6, MF-Robur I and BM-Boxer T-350.

According to the results, there is a preference of tracked vehicles in difficult snow conditions compared to wheeled tractors. Ford Country with long and bearing full-tracks proved to have the best mobility. On downhill grades it was found significant differences between three-quarter-track-tractors and skidders, although the performance on level ground and uphill grades was relatively similar. The tracked vehicles can easier move on the packed snow layer and reach a higher speed.

The driving speed does not increase significantly until the density of snow has entirely changed through getting wet. Wet top layer of snow affects positively on driving, because it increases packing of the snow. Increasing density of the snow improves especially the mobility of broad-tired wheeled tractors. To be able to predict the driving speed of a tractor in winter working conditions one must know the depth of the snow layer and the density of the snow and the grade of the slope. In addition, the passages on the same route and the packing of the snow must be regarded.

The PDF includes a summary in English.

  • Silvennoinen, E-mail: us@mm.unknown (email)
  • Haarlaa, E-mail: rh@mm.unknown

Category : Article

article id 7615, category Article
Erkki Wuolijoki. (1981). Effects of simulated tractor vibration on the psychophysiological and mechanical functions of the driver : comparison of some excitatory frequencies. Acta Forestalia Fennica no. 168 article id 7615. https://doi.org/10.14214/aff.7615
Keywords: forest work; forest tractor; ergonomy; occupational health; vibration; tractor driver
Abstract | View details | Full text in PDF | Author Info

The aim of the study was to search for differences in ergonomic effects between lateral 1, 2, 3 and 4 Hz whole-body vibrations of the forest tractor driver. Healthy male volunteers, both professional drivers and students, were exposed to 692 different vibrations in four different experiments, total number of subjects being 34.

Increase of vibration displacement affected clearly the subjects’ manipulating ability. The subjective magnitude rating of vibration correlated with energy content of vibration, but no correlation was found between subjective rating and heart rate, blood pressure or urinary catecholamine excretion, although the last variables mentioned indicate the energy consumption of the body. The professional drivers rated the vibration with smaller ratings than amateur drivers.

Frequency alteration of tractor vibration can be a possibility for reduction of vibrational effects as a tool for industrial hygiene.

The PDF includes a summary in Finnish.

  • Wuolijoki, E-mail: ew@mm.unknown (email)
article id 7562, category Article
Rihko Haarlaa. (1973). The effect of terrain on the output in forest transportation of timber. Acta Forestalia Fennica no. 128 article id 7562. https://doi.org/10.14214/aff.7562
Keywords: forest haulage; timber transportation; terrain; forest tractor; transportation costs
Abstract | View details | Full text in PDF | Author Info

The first part of the study includes a summary of conclusions from five earlier reports dealing with terrain transportation costs, effect of terrain, load, snow and additional machine components on the mobility of forest tractors, and the distance a vehicle has to move in forest transportation of timber. In the second part of the study the effect of these separate factors on the transport output have been analysed on the basis of simulating a transportation of 3,000 loads by computer.

It was concluded that no specific terrain factor had a dominating effect on any component of the forwarding output. However, many terrain-factor combinations with a nonsignificant effect on the mobility and also on the forwarding output were identified. The most significant factors affecting the output were the size of load and the distance driven during the cycle.

The PDF includes a summary in Finnish.

  • Haarlaa, E-mail: rh@mm.unknown (email)

Register
Click this link to register to Silva Fennica.
Log in
If you are a registered user, log in to save your selected articles for later access.
Contents alert
Sign up to receive alerts of new content
Your selected articles