the machines, mechanisms, auxiliary structures, and devices designed for production operations in logging.
Logging equipment includes motorized tools; transport facilities; machine tools, units, and semiautomatic lines for initial processing of wood (such as trimming branches, bucking and sorting tree-length logs, barking assorted pieces, and splitting blocks); and hoisting and transport machinery and devices. Among the motorized tools are gasoline engine and electromotor saws, used for felling, trimming off large branches, and bucking tree-length logs; gasoline engine and electromotor twig cutters; and tools created to work with saws and twig cutters, such as roller wedges and winches, brush trimmers, bark strippers, engine-driven drills, snowplows, pumps, and power winches. Saws using gasoline engines (see Table (1) are widely used in logging, the annual demand in the USSR being 180,000–200,000 units.
|Table 1. Brief specifications for some power saws produced in the USSR|
|When produced||Engine power, killowatts||Weight, kilograms|
|MP-5 Ural ........||since 1969||4||11.61|
|EP-K6 ..........||since 1958||1.7||9.3|
Transport facilities are subdivided into primary transport, which is used to skid (or carry) cut lumber from the felling site to the loading points near logging roads, and transport used to ship wood over logging roads. Skidding tractors equipped with loading gates, power winches, and trailer attachments (chokers) are used for initial transport. In the USSR the KT-12, the first special crawler-type skidding tractor, was developed in the late 1940’s. In subsequent years more powerful and advanced skidding tractors were developed (see Table 2).
|Table 2. Brief specifications of skidding tractors produced in the USSR|
|When produced||Power (kilowatts)||Weight (tons)|
Wheeled tractors are more maneuverable and faster than crawler-type tractors. The K-703 and T-157 transport skidding modifications were developed on the basis of series-produced general-purpose wheel tractors (prime movers). To eliminate manual coupling and uncoupling for skidding, the tractors are equipped with hydromechanical devices instead of chokers. For example, the TB-1 and LP-11-1 (based on the TDT-55 and TT-4 tractors) are fitted with hydromanipulators, and the T-157 wheeled collector tractors are fitted with hydraulic claws. Cable units driven by LL-12, LL-14, and LL-8 skidding winches are used for transport in mountain forests and marshy forests. Logging vehicles such as the VTM-4 roller-skidding vehicle and the LP-2 roller-bundling vehicle also are used for initial transport.
The equipment for initial processing of wood is subdivided into mobile and permanent types. Mobile equipment usually is installed at logging sites or temporary lumber yards. This includes LO-25 pruning units and SM-2 and SM-55 mobile trimmers. In some cases crosscutting and bark strippers and equipment for producing industrial chips are used. Fixed equipment is used at permanent lumber yards. PSL-2M semiautomatic units and MSG-2 units for large-scale pruning, which handle 20–25 and 100–125 cu m of wood per hour respectively, are used for pruning. The bucking and sorting of tree-length logs is carried out on the PLKh-3AS and LO-15S lengthwise-feed semiautomatic lines with a capacity of 25–30 cu m per hour. The KTs-7 chopper is used to halve blocks, the GK-2 hydraulic chopper splits them into halves or quarters, and the LO-46 hydraulic chopper splits them into halves, quarters, or sixths. The sorting and shipping of lumber are carried out by lengthwise chain transporters with semiautomatic dumping units. The OK-36, OK-63, OK-40B, and LO-23 bark strippers are used for removing bark.
Logging enterprises are outfitted with specialized equipment: frame saws, railroad tie-cutting machines, various woodworking machine tools, crushers, and equipment for the production of fiberboard and particle board.
Timber loaders and stackers are used for stacking and loading wood in the logging process.
Auxiliary structures and units such as scaffold bridges, crane-ways and spur tracks, access routes, and platforms are built for the normal and efficient operation of logging equipment. Portable sheds—preventive maintenance buildings, rebuilding-repair shops, and fueling and heating units—are used for technical maintenance and repair of vehicles in the forest. There are also permanent machine shops equipped with a complement of standard machine tools and other repair equipment.
D. K. VOEVODA and V. I. ALIAB’EV