What is tractor skidding?

The operation of collecting wood scattered in woodland to cutting area by tractor. This is a widely used mechanized skidding method.

develop

Tractors were first used for skidding in California from 65438 to 0890. At that time, it was an agricultural tractor, driven by steam and with iron wheels. In the 20th century, with the appearance of internal combustion engine, tractors were gradually improved to be driven by internal combustion engine, and developed into crawler type and pneumatic tire type. Later, winches and arches were added to tractors, and their cables were used to collect and haul wood. Soviet Union 1932 to 1933 adopted tractor skidding, and 1948 adopted special tractor skidding equipped with winch and loading plate. In the early 1950s, China first began to use tractor skidding in the northeast forest region. The tractors used at that time were KT- 12 skidding tractors and C-80 agricultural tractors imported from the Soviet Union. Starting from 1964, J-50 crawler tractor and J-80 wheeled folding tractor are manufactured by ourselves. Tractors are flexible, not limited by direction and distance, and can drive near the wood to be collected, and use the steel cable on its winch to twist the wood to the tractor without stacking. However, when skidding, it is necessary to drive along the skidding path many times, which is easy to destroy the woodland and damage the young trees. Suitable for skidding in forest areas with slope below 25, clear cutting or selective cutting. The sliding distance usually does not exceed 1000 meters.

Tractor skidding way

It can be divided into four types: full towing, semi-trailer, semi-trailer and full load.

Full trailer skidding

The wood is tied to the tractor's traction hook with a special rope or hook, and the wood is completely dragged on the ground when the tractor runs. Suitable for log skidding with flat terrain and diameter class generally not exceeding 50 cm. In the process of skidding, the front end of wood is easily blocked by obstacles such as root cutting and exposed rocks, which has great running resistance. The front end of the wood can be lifted by an inclined support plate or covered with a funnel-shaped iron cap.

Semi-loaded and semi-suspended skidding

When skidding, the front end of wood is hoisted or lifted off the ground with special ropes or grapples, and the back end is dragged on the ground. The front end of semi-loaded wood is installed on the loading plate of tractor (figure 1).

Figure 1 The front end of semi-suspended wood is suspended under the arch or hanger at the tail of tractor (Figure 2). This way has little running resistance and is easy to pass through obstacles, so it is the main way for tractors to collect sliver at present. In semi-suspended skidding, the front end of the wood is hung on the arch behind the tractor. When semi-trailer skidding, the small head of the original strip faces forward, and when semi-trailer skidding, the big head faces forward. Since the 1960s, some countries have developed skidding tractors with grappling hooks, which replace tying wooden ropes with grappling hooks, thus eliminating the tying process (Figure 3) and improving production efficiency. This skidding tractor is usually used in conjunction with skidding return stacker.

Figure 2

Figure 3 Full-load taxi

The wood is completely loaded on the tractor or its traction bracket. With hydraulic lifting arm, it is towed by tractor or carried by car. This method is mostly used for skidding short logs, such as pulp wood, in northern Europe and North America. It is also used in some forest areas in the south of China, such as pulling a small trailer with a walking tractor.

Selection of skidding track

Tractor skidding roads are divided into main roads and branch roads. Main roads should be located in areas with concentrated wood, solid soil and less construction workload, and the skidding distance should be shortened as much as possible. In areas with a slope of less than 8, the main road can be set along the mountain, and the branch road can be set on the inclined mountain. When the slope is about 10, the main road is set on the inclined mountain, and the branch roads are set along the mountain. Panshan Road can be set in steep slope. In the valley area, the main road can be set along the bottom of the valley, and the two slopes can be set with branches. When the ditch bottom is wide and the two slopes are long, two main roads can be set along each slope bottom. The skidding track should try to avoid mother and young trees and areas that are prone to soil erosion. The main road is 3 ~ 4.5m wide and the minimum curve radius is 35 ~ 40m. Branches extend from two sides or one side of the main road to all parts of the cutting area, with a width of 3-3.5 meters and a minimum curve radius of 25-30 meters. The spacing is generally 50 ~ 70 meters when skidding on both sides and 30 ~ 45 meters when skidding on one side.

Tractor skidding has become the most widely used mechanized skidding method in the world because of its flexibility and other advantages. With the continuous improvement of skidding tractor structure, the application scope of tractor skidding is also expanding.

See skidding tractor.

Externally heated evaporator

See the production process of tannin extract.

Externally heated vehicle-type dry distillation furnace

See wood dry distillation.

Wang Changfu (19 1 1 ~)

Modern forestry economist and forestry educator in China. Dalian, Liaoning Province. Born on February 2 19 1 1. 1937 graduated from the Department of Agriculture, Hokkaido University, Japan, majoring in forestry. 1937 to 1947, first worked in Aomori Forestry Bureau, Japan, and then worked in Northeast Forestry Technology Administration. 1948 to 1983, successively served as Acting Director of Forestry Department of Shenyang Agricultural College, Director of Experimental Forest Farm of Harbin Agricultural College, Director of Forestry Machinery Department, Dean of Forestry Industry College, Professor of Northeast Forestry College, Deputy Director of Forestry Industry Department, Director of Mining and Transportation Department and Director of Forestry Economic Department, and Director of Forestry Economic Research Institute of Chinese Academy of Forestry. He has served as director of chinese society of forestry, Heilongjiang Forestry Society, Heilongjiang Science and Technology Association, Heilongjiang Philosophy and Social Sciences Federation, vice chairman of Heilongjiang Economic Association, vice chairman of China Forestry Economics Association, and executive director of China Land Economic Research Association and Beijing Agricultural Economics Association.

Wang Changfu's works include Modern Forestry Economic History in Northeast China, Textual Research on the History of Russian Plundering Northeast Forestry, Lectures on Forestry Economics, Basic Knowledge of Highway Construction in Forest Areas and Northeast Forestry (the last three are co-written with others); More than 60 forestry papers have been published, among which the most influential ones are "Study on Farmland Shelterbelt Planning in the West of Northeast China", "Discussion on the Theory of Forest Sustainable Utilization" and "The Second Barren Mountain in Northwest China and North China should not be repeated in the Southwest Alpine Forest Region". Participated in the formulation and drafting of scientific and technological development plans organized by relevant state departments and forestry economy and timber harvesting and transportation in professional teaching plans of colleges and universities for many times.

Wang Kai (19 17 ~) is a famous wood processing scientist in China. People from Xiangtan County, Hunan Province. Born in191710 June 14. 1940 graduated from Northwest Agricultural College with a bachelor's degree in agronomy. 1945 Master of Wood Technology, College of Forestry, University of Michigan, USA. From 65438 to 0947, he returned to China and successively served as the technical director and laboratory director of the wood laboratory of Shanghai Central Industrial Laboratory. 1949 after its establishment, People's Republic of China (PRC) successively served as the director and chief engineer of Beijing Guanghua Timber Factory, the chief engineer of Beijing Timber Industry Corporation, the director of Beijing Timber Industry Research Institute, the director of Wood Industry Research Institute of Chinese Academy of Forestry, the vice president and senior engineer of Chinese Academy of Forestry, the member of Forestry Group of State Science and Technology Commission, the member of Agriculture and Forestry Selection Group of Invention Selection Committee, and the fourth and fifth vice chairman of China Forestry Society. Member of the first and second academic evaluation groups of the State Council Academic Degrees Committee, deputy director, consultant and director of the Basic Sub-committee of China Timber Standardization Technical Committee, consultant of the Fourth Professional Advisory Group of Beijing Municipal People's Government, chairman of the first, second and third sessions of Wood Industry Society of China Forestry Society, adjunct professor of Nanjing Forestry University, honorary professor of Northwest Forestry College, deputy editor-in-chief of Forestry Science and editor-in-chief of Wood Industry.

Wang Kai is one of the founders of China's timber industry. As early as in Shanghai, the production process of plywood was improved, and the product quality reached the export requirements, and new products such as glued wooden rollers, compressed wooden shuttle sticks and glued gun butts were developed. From 1949, I participated in the development plan of wood industry science and technology formulated by China. Has been responsible for the preparation of Beijing Guanghua Wood Factory and Beijing Wood Industry Research Institute. He presided over the development and production of plywood, paper decorative plastic veneer and calcium-plastic decorative board for aviation, ships and carriages, which won the National Science Conference Award, participated in the formulation of national technical policies in 12 important fields, and won the first prize of national scientific and technological progress.