京都府における民有林の林業労働災害に関する分析 (I) : 森林作業の現状と作業内容・事故の型から見た労働災害

Abstract

平成元年1月から4年3月までに報告された340件の京都府民有林の労働災害事例について災害の分析を行った。本報告では京都府の森林作業の現状を概観し, 森林作業の内容と事故の型を中心に他の要因との関係を検討した。京都府の人工林の8齢級以上の森林面積は約20%で, 人手のかかる森林が多く, また林道密度は3. 2m/haの低いレベルにある (自動車道のみ)。50才以上の林業労働者は80%を越え, 高齢者に依存する傾向を強めている。森林作業で使用する林業機械器具は小型運材車 (20PS未満), 動力枝打機およびバックホーが増加している。グラップルソーは数の上ではまだ少ないが, 急速な増加傾向を示し, 高能率機械化への方向をうかがわせる状況にある。京都府の林業労働災害の発生件数の順位は全国で25-26位にあるが, 労災保険の収支状況は全国でも特に悪い状態にある。労働災害の要因分析結果について, (1) 作業内容 : 下刈, 枝打, 伐倒, 地拵における災害発生が多い。労働災害の発生件数では50才以上の労働者に特に多いが, 労働災害の発生率では50才未満の労働者が少し高い傾向にある。作業人員については小人数作業では下刈, 枝打に労働災害が多い。1人作業で被災した件数が13件あり, 労働者数の減少にともない, 1人作業が増加するものと予想される。災害発生時刻では下刈, 枝打, かかり木処理が10-11時, 15-16時の時間帯に災害が集中している。起因物・加害物に関して, 伐採木による災害発生が多いが, 林地が災害発生の起因物・加害物になることも比較的多い。(2) 事故の型 : 切れが高い災害発生を示し, 切れ, 転倒, 飛来, 激突, 転落の5種の事故の型で全災害の87. 0%に達する。切れの災害の92. 4%が身体末端部の災害である。転倒は胸に災害が多く, 飛来は伐採関係に, 激突は伐採と集材関係に多く見られ, 転落は枝打ちに災害が多い。切れは携帯式機械器具の基本的安全作業指針に従った取り扱い方法や身支度の安全装備が重要である。さらに転倒, 飛来, 激突に関して林地作業環境の整備および林地に入らずに機械化作業のできる作業システムの開発が期待される。転落については, 京都北山地域の磨き丸太生産は高品質材生産のため, 自動枝打機が多数導入されているにもかかわらず, 人力による樹上作業が行われているようである。高品質材生産に適応した高度の作業処理のできる機械装置の開発が期待される。

Our purpose is to analyze the 340 forestry labour accidents of private forests in Kyoto prefecture from January in 1989 to March in 1992. We mentioned the existing state of forest operations and, in focus on two factors-kind of operation and type of accident-, researched the relations between each of these factors and other factors. Man-made forest area under 7th age-class are about 80%, therefore needs a great deal of workers for tending, but forest road density is 3.2m/ha in low level (including only motor road). And what is worse, forest workers over 50 years old occupied more than 80% of all forestry workers, then forest operations still more depend on aged workers. Kyoto prefecture ranks 25th to 26th among the number of forest labour accident in Japan, but receipts and expenditures of industrial injury insurance is worse. In forest machinery, small type forwarders (less than 20PS), pruning machines and back hoes are increasing. Grapple-saws are few in number, but rapidly tend upward, and we can expect to progress the high efficient machinery in forest operation systems. As for analysis on the forestry labour accidents, (1) kind of forestry operation: labour accidents in weeding, pruning, felling and site preparing, are the most among forestry operations. In number of labour accidents, the most accident cases are workers over 50 years old, but the ratio of labour accidents regarding workers over 50 years old are slightly lower than workers under 50 years old. In small members of operating crew, workers in weeding and pruning met often with accidents. There were 13 cases of labour accidents in one member crew. As number of forest workers decreases, one member crew increases, then we need to consider how to cope with one member crew: such as taking a tranceiver with each worker. Most of the time to meet with accidents in weeding, pruning and proceeding hanging tree was during 10 : 00 ~ 12 : 00 and 15 : 00 ~ 17 : 00 hour. (2) type of accident: cut accident is the highest occurence, and adding to other type of accident - overturn, fly, crash, and fall -, these five types amounted to 87.0% of all accidents. 92.4% of cut accident occures to the tip of the body, and turnover accident often to the chest and central parts of the body. Fallen trees often play roles of accident original cause material and injury material. We have to pay attention that forest land itself pretty often play roles of accident original cause material and injury material, too. Fly accident often occures to the harvesting and yarding, and fall accident often to pruning. To prevent cut accident, it is important that we strictly handle portable cutting tools in accordance with safety operation code, and that equip ourselves with safety outfit. Moreover, to prevent turnover accident, fly accident and crash accident, we expect to equip the difficult forest site condition to wellregulated site condition, and expect to develop the mechanized operation systems to perform forest operations on the forest working roads. To prevent fall accident, at Kitayama district in Kyoto, it is said that workers climb trees to prune with a sickle, a hand-saw or a hatchet to produce the high quality polished logs though workers can use many auto climbing pruning machines. We expect the development of auto climbing machine to prune as delicate and accurate as skillful workers prune.