roads and railroads intended for the removal of wood from felling sites in the form of round grades, tree-length logs, or trees to timber yards and processing sites.
Logging routes are subdivided into rail, motor vehicle, tractor, and horse routes according to the type of rolling stock operating on them. Logging routes usually connect with railroads or waterways, which convey the wood to the user. There are permanent routes (trunk lines and branches) and temporary routes (spurs). A trunk line is the main section of a logging route that connects a forest tract with the lower woodyard for the duration of the operation of the enterprise’s logging base. A branch route is an offshoot of the trunk line and serves part of the logging base for several years. A logging spur is a temporary route with a useful life of no more than one year which joins a branch or trunk line and is intended for the opening of a particular felling site. Large combines or lumber complexes that fully process the wood are joined to logging enterprises by so-called freight-assembling logging routes. In the early 1970’s, 70–75 percent of the lumber procured in the USSR was shipped by motor-vehicle roads, 20–25 percent by railroad, and about 5 percent over other types of roads (chiefly tractor roads). Motor vehicles (ZIL, MAZ, KrAZ) with a special trailer unit—semitrailers and pole carriages—are used to transport wood. The simplest type of motor-vehicle logging route is the dirt road. In the periods in the spring and fall known in Russia as the rasputitsa, as well as after rains, the roads are bad. Logs, slabs of wood, or other materials are sometimes laid down in difficult sections of dirt logging roads. Gravel and rubble roads, which have a sand bed (50–70 cm thick) and a layer of gravel or rubble (20–40 cm thick) on a shaped earthen bed, are more reliable. Tandem trailer trucks that transport over 35 cu m may travel over them. Binding organic or mineral additives (such as asphalt, pitch, or lime) are sometimes incorporated in them to strengthen (stabilize) the soil on the road surface. Logging roads covered with reinforced-concrete blocks are quite reliable. More than 25,000 km of permanent logging routes were in use in the USSR in 1971. Snow, snow-ice, and ice roads are classified as seasonal logging roads. An earthen bed is cleared and leveled for such logging roads in the summer and is thoroughly packed down before the onset of the first autumn frosts. In the winter the snow is packed (snow roads) or covered with water (snow-ice roads). Ice is frozen onto the ground in the construction of ice logging roads.
Logging railroads may be either normal gauge (1,524 mm) or narrow gauge (750 mm). Narrow-gauge logging railroads, numbering about 400 in all, are common in the USSR. Their total length is over 20,000 km. Permanent narrow-gauge logging railroads feature both track superstructure and roadbed. In the construction of temporary railroads, crossties and rails are placed on a simplified roadbed. Flatcars (with a carrying capacity of 8–20 tons) are used to carry assorted types of wood, and coupled cars (with a capacity of 24–25 tons) are used for tree-length logs.
D. K. VOEVODA and V. I. ALIAB’EV