Current issue: 58(5)
Articles containing the keyword 'katkonta'
Category : Article
Effectiveness of 18 different saw blades of wooden bow saw from four producers (Oy Suomen Sandvik Sahat, Epilä Oy, Ab Orsa Sågbladsfabrik Oy, Kone ja Terä Oy) was tested in 1937. The experiments were divided into test series according to type of maintenance of the blade and tree species (Scots pine, Norway spruce and birch) to be sawn. Each saw blade was sharpened into four different sharpening angles (54°, 60°, 64°, 70°). Four blades had markedly longer sawing times compared to the others. These blades had a special serration. In addition, two blades with sparse serration had slightly poorer results than the blades in general. When the tree species were compared, birch (Betula sp.) was slowest to saw followed by Scots pine (Pinus sylvestris L.) and Norway spruce (Picea abies (L.) Karst.).
The PDF includes a summary in German.
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Aro,
E-mail:
pa@mm.unknown
A time study was conducted in saw log harvesting site in state forests of Evo in Southern Finland in 1934. Felling was performed in teams of two loggers. Two teams were observed. The work was divided into several stages of work: felling, branching, cross-cutting, barking and making of top log. On the site grew Scots pine (Pinus sylvestris L.) and Norway spruce (Picea abies (L.) Karst.).
The daily working hours not including breaks was in average 5 hours and 33 minutes. The most time-consuming stage of the work was barking of the stem (55% of working time for Scots pine and 47% for Norway spruce), followed by felling (22.5% for pine and 19.4% for spruce), branching (11.7% and 21.6%) and cross-cutting (11.3% and 11.8%). Temperature affects barking strongly. Scots pine is slower to bark than Norway spruce. Similarly, butt and middle logs are slower to bark than top logs. It took in average 79.02 min to process one solid m3 of timber with bark and 91.45 min without bark.
The PDF includes a summary in German.
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Seppänen,
E-mail:
vs@mm.unknown
