Shrub shears are used for clearing areas of
Choosing a shrub shearer: for what works it is necessary and how to use it effectively
Neatly trimmed “live” hedges, no dry branches, nicely shaped bushes. every gardener dreams that his favorite garden will be well-groomed!
A wide range of garden tools and equipment Greenworks can easily maintain a neat and attractive appearance of your garden, the main thing remains. the right tools for different types of work. Care of small trees and shrubs, giving a beautiful appearance to “live” fences, shaping the designer crown of your favorite plants. in all of these works an indispensable assistant is a functional and practical shrub shearer.
What types of hedge trimmers exist, for what kind of work they are designed, what are the advantages of battery-powered hedge trimmers and what are the advantages of electric hedge trimmers. a detailed review of hedge trimmers is presented in this article.
Shrub shears
Main purpose clearing saws. clearing areas overgrown with bushes and small woods. Usually these operations are performed during reconstruction of low-value forest plantations, making cuttings and roads, land development for forest nurseries, etc.
There are two types of shrub shears for cutting bushes and small wood (separate trunks): with a cutting head and a clearing tool passive action and with a working tool active operations.
Producers use active hedgetrimmers mower type. The cutting (mowing) unit reciprocates and cuts small bushes. Forced cutting blades movement is carried out from the tractor PTO or other means of drive.
For clearing of the shallow shrubbery on the soil not clogged with stones the CAR-1,2 and CAR-2,1 shrub shears with active working body are used saw of mower type. The branch cutters are mounted on the tractor. On the working body of the shrub shear K AP-1,2, made in the form of a disc with a diameter of 1.2 m, are fixed with bolts and segments cutting (right and left) and cleaving blades. Shrub shear cuts bushes of any thickness and trees up to 0.25 m in diameter. Brush cutter KAR-2,1 differs from the brush cutter KAR-1,2 as its operating device consists of three discs installed on the frame and on the sides, covered by the cover. Both brushcutters have hydraulic control and working parts drive from tractor PTO.
Brush cutters are subdivided into two types: with with rope-block и hydraulic control. Fig. 2.3 shows the D-514A shrub shear (DP-4) with the working body of the passive action, with hydraulic control. It is an attachment mounted on the T-100MGP tractor. How the hedge trimmer works is as follows. Entering young growth or bushes, the tractor driver lowers the branch cutter with the help of hydraulics on supporting skis. As the tractor moves, the branch cutter blades cut shrubbery, and the dozer blade picks it up in rollers on the tractor’s sides.
- 1. guard, 2. hydraulic cylinder, 3. visor, 4 sloping shield, 5. blade,
- 6. knife-hammer. 7. side knives, 8. vertical board, 9. socket, 10. removable ball head, 11. thrust leg. 12. universal pushing frame, 13. frame support
For sharpening of blades in the process of work bushes are equipped with sharpening attachment, consisting of sharpening head with an emery wheel, flexible shaft and drive mechanism operating from front end of diesel engine crankshaft or reduction gear of tractor hydraulic pump drive.
Let’s consider the scheme of action of forces of a shrub shearer with side blades set at an angle of 0 to the mowing line of progressive motion according to the method A. И. Baranova.
In the diagram (Fig. 2.4) it is visible that the blade pressure on the trunk, t.е. Рtah, with which the blade cuts into the wood, depends on the value of traction, or to be more exact, pushing force of the tractor Рtr. Knife of the hedge trimmer pushed by the tractor’s pulling force Ptr. tilted to the mowing line of the hedge trimmer movement at an angle of 0 and pressed into the trunk normal to the blade, making a sliding cut along the blade. On the blade of the blade there are reactive forces: normal to the blade Ni and N2 and tangential forces Fi and F2. The equipotential forces of these forces are R] and R? If sum of resultant forces is more than tractor pushing force R1R2 Rtr, then during work process speed of the machine must be decreased in order to increase traction. Thus, for example, the angle of the blade tangent to the mowing line of KB-4A hedge trimmer movement is 0.525 rad (30°), (2 0 = 1.05 rad). Blade length bl. determine from expression
Ptah. force, with which the blade cuts into the wood; Ptr. pushing force of the factor;
Ni and N2. normal to the blade reactive forces; Fi and Fo tangential to the blade reactive forces; Ri and R2. equilibrium force; 2 ) skids (skis) of the brush cutter are calculated on the basis of the ratio
qK- specific pressure, equal to 4 ? 10 4 N/m 2.
Traction resistance (Н) of the cut tree and shrub vegetation trunks during shrubbery works is determined by the formula
where Gk. is force of gravity of hedge trimmer, attributable to supporting skids, N;
f. coefficient of sliding friction of the skids on the ground, taken as an average of 0.5;
A’re5. total, wood cutting coefficient, which depends on the species, on average is taken equal to 7.84 10 4 / 19.6 10 4 N/m;
dc. average diameter of the trunks of bushes and small wood cut, m;
ps. average number of trunks in contact with blades at a given moment, pcs.;
then. is a coefficient of simultaneous cutting of trunks, usually assumed to be 0,1. 0,9.
Productivity (m 2 /shift) of a brush cutter is calculated by the formula
CR-V. working time use factor;
п. number of turns at the ends of working strokes;
w “o. number of passes at one place.
In addition to the above bush cutters at forestry clearing use rooter mounted harrow K-1, bush rake K-3 and bush rakes mounted on a universal frame MK-P, machines MTP-43, etc. Machine MTP-43 (based on the loading crane KPT-1) is designed to cut bushes and trees up to 0.25 m in diameter and up to 16 m high. the horizontal disk milling machine.
MACHINES FOR RECLAMATION OF BACK LANDS
Land reclamation includes a complex of measures aimed at radical improvement of hydrological and soil-climatic conditions of the territory in order to obtain high and stable crop yields.
Both special (reclamation) and general construction, road and agricultural machines are used for reclamation works. The machines for removal of bushes, small wood, stumps, stones, construction of canals and drainage systems, leveling, primary soil treatment, irrigation, etc. are referred to as special-purpose machines. Taking into account big variety of machines applied in land reclamation, only special machines are considered in chapter 19. Material about machines for primary soil treatment, plows, harrows, tillers, rollers, etc. are outlined in Chapters 1 and 2, and about irrigation machines. in chapter 20.
MACHINES FOR THE DEVELOPMENT OF BRUSH LANDS
Small shrubs are driven into the soil with bush and marsh ploughs and cutters. Ploughs are equipped with flat knives with supporting skid. When cutting the turf, the stratum is compressed with a ski, in the slots of which a flat knife is placed, and ensures that the woody inclusions are firmly embedded in the soil. The ploughs are used for plowing shrubbery on thorny and mineral soils, if humus layer of the latter reaches 26. 30 cm. Shrubs up to 1 m high are plowed to a depth of not less than 25 cm, 1. 2м.to a depth of 30. 35 cm and more than 2 m high.to a depth of 45. 50 cm. After plowing the layers are cut with heavy disc harrows in two or three passes and rolled with rollers. Shrubs plowed into the soil decompose within three to four years, and the deadline for entering developed land is delayed.
Shrubbery is shredded and mixed with soil by milling machines MTP-42A and FKN-1,7. Shrubs up to 12 cm in diameter and up to 6 m high are removed by milling. At the same time it removes tree bumps, small stumps and crushes the topsoil.
This method replaces all operations of the main tillage and pre-sowing tillage and allows for sowing immediately after packing. This method is most effective for reclamation of drained alluvial lands overgrown with bushes up to 60. 100 %.
Big shrubs are cut by brush cutters or bulldozers and raked into heaps up to 400 m 3 with tractor rakes or pullers-gatherers. The machines are most effective in winter conditions on frozen ground with snow cover up to 50 cm thick. heaps are burned in the spring, after the snow melts. In summer the remaining stumps are removed with a rooting harrow and the roots of the shrubs are removed at the same time.
Pits and irregularities are levelled with bulldozers. Primary plowing of such areas is done with bush and marsh plows to a depth of 25 cm on mineral soils and to a depth of 30. 35 cm on top of the topsoil. The layer is cut in two or three passes using heavy disc harrows. The lands cultivated with such technology are sown with seeds of grain crops, annual and perennial grasses in the first year.
The most productive and cost-effective method of removing shrubbery and bushes, allowing maximum mechanization of all operations in a single technological cycle and excluding loss of humus layer. For this purpose they use combined machines with the puller and rotary separators that provide pulling of the bushes, clearing of the roots from the soil and loading the timber into the transport vehicles.
Deep milling machine MTP-42A is designed for rapid development of brush lands with shredding and embedding of bushes into the soil. It mills the top layer of topsoil together with shrubs, stumps and buried wood.
The machine is equipped with a milling tool 8 (Fig. 19.1, a), mounted on a frame 2, two front 7 and one rear 6 rollers, gear mechanism and hydraulic cylinders 5.
rice. 19.1. Machines for brush removal:
а. scheme of working process of the machine MTP-42A, b. shrub shear DP-24, in. shrub shear MTP-43X, 1, 6. rollers, 2, 14. frames, 3, 4.gearboxes, 5, 13. hydraulic cylinders, 7, 16. knives, 8, 21. cutters, 9. plate, 10. wedge-hammer, 11. body, 12. guard, 15. blade, 17. accumulator-stacker, 18. grips, 19. platform, 20. arm, 22. electric motor
Working body consists of a body and a milling drum. Cups for fixing blades are welded into the cylindrical drum shell. self-sharpening disc knives 7 with cutting edge with diameter 95 mm are arranged on the drum in eight rows of twelve knives in a row. blades are bolted. When blunt knives loosen fastening and turn knives on an angle of 120°. Cutter drum rotates on ball bearings. A baffle plate 9 is installed in front of the milling drum, which limits the milling depth, presses down and holds the woody vegetation during milling. The clearance between the edge of the plate and the blades should be 3 cm. 5 mm diameter. The milling depth is set by means of exchangeable plates.
In transport position the machine is supported by two 1000 mm diameter front and one 1500 mm diameter rear roller. The front roller is mounted on a separate frame with a supporting pivot and trailing device. Rear roller is lifted and cutter is lowered with hydraulic cylinders 5. The milling drum rotates at 183 min.1 from tractor PTO through gearboxes З and 4.
Blade and radiator guard are mounted on the tractor. The mouldboard tilts the crop, the tractor tracks, the front rollers and the baffle plate flatten it and the cutting drum crushes and mixes it with the soil. The shredded mass is thrown under the rear roller and compacted by it.
Grind bushes up to 12 cm in diameter, stumps up to 10 cm in height and up to 20 cm in diameter with the machine. Machine working width 1,7 m, working speed 0,1. 0.76 km/h, milling depth in mineral soil 25 cm, milling depth in bogs 40 cm, throughput 0.12 ha/h. This machine is aggregated with T-130B and T-UMBS tractors.
There are two types of branch cutters: with passive and active cutting units. First type shrub shears are equipped with horizontal knives, which blade is set at an angle of 28. 32° to the driving direction. They are good for cutting bushes with stiff trunks and diameter of the root neck at least 2. 3 cm, but shift part of the fertile soil layer. Machines of the second type are equipped with knives making not only straight motion but also rotary or reciprocating motion. Such knives do not damage the turf when cutting bushes.
Hegde trimmer DP-24 (fig. 19.1, b) is designed for clearing areas overgrown with bushes and small woods with trunk diameter up to 120 mm. Shrub shears are mounted on the T-130BG tractor. Main parts of the shrub shear: pusher frame 14, body 11, guard 12, grinder and hydraulic system. Horseshoe-shaped pushing frame 14 composed of two box-section half-frames. The frame is connected to the body by a spherical joint. Frame with body is lifted and lowered by hydraulic cylinders 13.
Blades 15 with blades 16 forming a dihedral wedge with an angle of 64° are mounted on the sides of the body 11. A flat wedge-hammer 10 is welded to the front part of the body. The body frame is lined with sheet steel from above. A socket is welded to the body crossbeam, where the ball part of the pushing frame removable head enters.
The cab is protected from falling trees and limbs by a fence 12 and the radiator. Shield. The working body slides along the ground surface and splits the stumps with the wedge 10 and spreads the fallen trees. blades 16 cut bushes and double-sided blades /5 lay them in swaths. Quality of cutting depends on the height of knives installation above the field surface and the sharpness of their blades.
By adjusting the height of the copying skis, the distance between the blades and the soil surface changes within 0. 2 cm. On the sections clogged with stones the blades are lifted. Sharpen blunt blades with a grinder, for which the mouldboard is placed on the support. The machine is connected to the tractor engine only for the time of blade sharpening.
Grasshopper working width 3.6 m, working speed 2.5. 4,5 km/h, productivity 0,8 ha/h.
Brush cutter МТП-43Х (Fig. 19.1, c) with an active cutting tool is used for cutting and windrowing shrubs and small trees with trunks up to 250 mm in diameter and up to 16 m in height. Working equipment of the brush cutter, which includes a cutter 21, a storage- stacker 17 and arrow 20, is hinged to the lean diesel-electric crane KPT-1M, from which the crane equipment is removed.
Disk mill 21 fitted with teeth is fixed on the vertical shaft of the gearbox. A fixed deflector plate above the cutter bar ensures that the weight of the cut wood is absorbed when it is moved into the laying area. Mill with 1500 mm diameter is driven in rotation by 30 kW electric motor 22, which is included in the crane’s power supply. Cutter rotation speed 590 min-1. Cutter, gearbox and electric motor are located on the outrigger frame fixed to the arm 20. The boom is raised and lowered with a winch and ropes.
The collecting-bracket 17 consists of a vertical truss and U-shaped grippers 18, fixed one above the other at a distance of 1,5 m. Grips are used for accumulation of cut woody vegetation.
The hedge trimmer works positively. switch on the drive of the platform rotation 19 and the tiller rotation 21 in each position. The platform rotates with the arm from left to right (clockwise) through an angle of 180°, making the working stroke. When the platform rotates the cutter bar cuts the bushes and trees which after cutting are supported by the protective disk and leaning on the grips 18. At the end of the working stroke of the boom unload the trees, lower the cutter down to the contact surface of the field and turn the reverse stroke of the platform. Cutter, moving in the opposite direction, cuts bumps and stumps. Then the machine is moved to a new position at a distance of 1,5 m and the cycle repeats. Shrub rake with disc milling unit is used for cutting bushes on the even ground.
From one position the machine cuts the bushes from a 16 m wide swath. Machine productivity up to 0,1 ha/h.
Shrub rake K-3 rakes shrubbery, small wood and stumps with a diameter up to 15 cm in the heap with the following incineration.
Brackets are welded to the frame crossbeam, with eleven tines inserted into the slots, secured with pins. The length of tines is 1250 mm, thickness 60 mm and distance between them 470 mm. Rake is mounted on tractor of traction class 6. On the place of the top link of the tractor’s linkage a hydraulic cylinder is installed, by which the angle of the tines is changed. On the front of the tractor mounted on the puller D-513A. At brush burning by the puller the wood is pushed into the heap. Rake is loosened from wood on the move, their teeth are lifted by main hydraulic cylinders and hydraulic rotation cylinder.
Rake working speed 2,3. 2.4 km/h, their productivity is 0.58 ha/h, working width is 5 m.
MACHINES FOR PREPARATORY WORKS
Earthworks are preceded by preparatory works, which include clearing of the future construction site of forest, bushes, and stones; removal of vegetative layer, loosening of soils; water drainage and dewatering. When performing preparatory work, brush cutters, rooters and rippers are used, as well as water drainage (pumps) and dewatering equipment (needlefilters, airlifts and hydro-elevators).
Brush cutters are designed for cutting the above-ground part of bushes and small-wooded growth when clearing areas for construction and are designed as attachments to caterpillar tractors with drawbar category of 100 kN.
A distinction is made between hedge trimmers with a passive (knife-type, Fig. 5.3, а) and active (rotary, Fig. 5.3, b, c) working bodies. Brush cutters can be mounted, mechanically (rope) and hydraulically controlled.
Fig. 5.3. Brush cutter tool diagrams
Blade (passive) tool shrub shear. a double-sided wedge with flat, horizontal blades 1, set at an angle of 56. 60° to the direction of travel. Blades have smooth or saw-shaped cutting edges. As the branch cutter moves, its blades cut the above-ground vegetation, the working body wedges between the trunks and the fallen vegetation slides down from sloping surfaces 3 and slides to both sides. Front part 2 The blade is additionally reinforced with a cleaver for splitting stumps and tossing fallen trees. Small diameter shrubs and trees (150. 200 mm) shrub shears cut in one pass, but trees 300 mm in diameter can be cut in one pass. 400 mm splits and cuts on opposite sides in 2-3 passes.
Rotary (disk) cutting device it is a circular saw (cutter) 4 (see EB&G), the blade is a circular saw (milling cutter). Fig. 5.3, б) With cutting teeth, which is mounted on the end of the handle 5 or on the front of the tractor’s encompassing frame. The mill is driven by tractor universal joint shaft or a hydraulic motor. The cutter bar on the arm can be set for cutting in the desired plane and rotated by means of two hydraulic cylinders. The horizontal cutter at the front is covered with a horizontal plate at the top, and a vertical steel plate is placed in front of the frame at an angle to the axis of the machine to roll back the cut shrubs to the side.
Working body with rotating blades 6 (see Fig. Figure. 5.3, в) works in the same way as a circular saw. Rotary cutter heads are able to cut tree trunks with a diameter of up to 300 mm.
Chain saws, circular saws and bulldozers are also used to remove trees from cleared areas.
Brush cutters with a passive power tool are the most common, because they are designed simply and are very reliable in operation. Shrubbery productivity (area cleared of trees and bushes, m 2 / h)
where В. working width, m; vcp. average working speed of the hedge trimmer taking into account time loss for stops during turns and for speed reduction during slipping, m/s (vcp = (0.7. 0.8)v, here v is the rated value of the working speed of the brushcutter); п. number of passes on one track.
Robbers are designed for pulling up large stumps, boulders, uprooting part of small forests, raking and shaking. They are attachments to caterpillar tractor or powerful wheeled tractor. Depending on the purpose of the tool, differentiate between pullers-pickers and pullers-loaders; depending on where they are mounted on the basic tractor, pullers of front and rear location.
Rake pickers Mouldboards are equipped with nine tines, so they are better suited for shrub raking and moving stumps and rocks into heaps or windrows.
Forward-mounted pickups based on class 30 crawler tractors are currently the most common. 350 kN with power of 50. 390 kW.
The main components of the puller-loader (Fig. 5.4) are a dozer blade 2 with tines, pushing frame 1 and control system.
The blade is a lattice structure with slots for attaching the tines. The mouldboards are rigidly mounted, as well as pivotally mounted. The moldboard shown in the figure is articulated, which allows hydraulic cylinders to 3 Rotate the blade with the tines after driving it under the stump, greatly increasing the uprooting efficiency. Hydraulic cylinders that raise and lower the pushing frame are powered by the tractor hydraulics.
Stump loaders The moldboards are equipped with a blade swivel device and can load stumps and stones on vehicles.
Figure. 5.4. Stump-collector
Modern pullers remove stumps by ripping roots by pushing force of the tractor with simultaneous application of vertical force created by hydraulic cylinders of the blade lift and turn. When uprooting, raking, and transporting uprooted (or cut by brush cutters) wood, these machines move swaths and piles, a significant amount of soil. Since a lot of soil is left on the stumps and large undergrowth holes are created, it is necessary to level the area afterwards.
Raking capacity is determined in the same way as for the brushcutter. When pulling up stumps, throughput per hour is up to 45. 55 pcs., Stone picking. up to 15. 20 м 3. For raking cut trees, uprooted stumps and shrubs. up to 2,500. 4000 м 2.
Ploughs are attachments for tractors or single-bucket shovels, designed for loosening hard, stony and frozen soils in layers. The use of rippers allows using earthmoving machines of small capacity for development of strong soils, significantly increasing productivity of more powerful machines and significantly reducing the cost of work.
rippers are also used for ripping covers in road repairs and open-cut water, sewage and gas pipeline construction.
Static ripper (fig. 5.5) for loosening soil layer by layer is an attachment mounted in the rear of the tractor 2. Dozer equipment is attached on the front of the tractor 1 (see. § 5.3). The first working body consists of a beam 6, weather vane 8 (from one to three) and the teeth mounted on them, consisting of struts 9 with interchangeable tips 10. Ripping equipment is suspended from the frame 3 and traction 4. Frame, drawbar and beam form a parallelogram system that ensures a constant cutting angle at varying ripping depths. Working tool is controlled by hydraulic cylinder 5 From the tractor’s hydraulic system. To be able to work with a tractor-pusher, a removable buffer device is mounted on the middle vane 7.
The tines are driven into the ground to a predetermined depth by enforced pressure created by a hydraulic cylinder during the forward motion of the machine. When the machine keeps on moving, the ground is loosened.
Fig. 5.5. Static ripper with bulldozer equipment
Ripping can be performed according to two technological schemes: without turning at the edge of the site with return of the machine to initial position in reverse (shuttle pattern) and with the ripper turning at the end of each pass (longitudinal-turn pattern). The tractor with chandelier is the most rational at small scope of work in cramped conditions, the longitudinal-swivel pattern is the most rational at long distances. Maximum ripping depth is determined by drawbar class of base machine and is within the range 0.45. 1,2 м.
For tractors with hydromechanical transmissions the speeds of working and rearmost drives are vp = 1,7. 3,2 km/h, yх = 7,5. 14.5 km/h; for tractors with mechanical gears vp = 2.35. 3,2 km/h, v3x = 7,5. 8,5 km/h.
Operating capacity of static ripper (m 3 /h)
where b. average width of loosening strip for one pass at multitooth working body or between two adjacent passes at single-tooth working body, m; h. average ripping depth in given soil conditions, m L. ripping track length, m; kv. coefficient of machine use in terms of time; Hz. cycle time, s.
When excavating by longitudinal-turning passes with turning at the ends of area
where /p, t. time required to turn and control the machine during the work cycle, s; v. v3x. speeds of working and return travels, km/h.
percussive rippers. is an attachment mounted on a tractor or a single-bucket excavator. The most widespread type of the percussive working device is a free-falling hammer of wedge-shaped, cone-shaped and pyramidal shape with the weight of 0.5. 4,0 т.
The wedge hammer is suspended to the hoisting rope of the load friction hoist winch of the jib self-propelled crane or single-bucket mechanical excavator with a crane arm, pulling up to the jib head with a winch, and thrown down from a height of 6 cm. 8 м. The free-falling wedge hammer strikes the ground non-directionally, reducing the quality of work and making the process more energy-intensive.
efficient are percussion rippers, where the cutting unit runs in a rigid guide (Fig. 5.6). The working body. the wedge. is attached to the hammer 4, which is mounted in a guide rail 2 and suspended on a pulley 1. The guide at the top is connected by a pin to the excavator boom, and at the bottom by the tracker rail 3 with shock absorber.
The chain block is driven by a hydraulic cylinder, whose dimensions allow the hammer to drop freely. To lift the hammer the hydraulic control valve lever is turned to “Lift” position. After pulling out the hydraulic cylinder rod with blocks of the mobile block and lifting the hammer up to the permissible height the lever of the hydraulic valve is switched to the position “Reset”, when the hammer freely falls and strikes the ground with the working tip.
There are other designs of impact rippers as well, for example, with the use of hydraulic and pneumatic hammers that are suspended instead of a bucket on the backhoe arm of an excavator. Use of mounted pneumatic hammers as replaceable work equipment
Fig. 5.6. Impact ripper
in single-bucket hydraulic excavators does not require a change in the design of the base machine. Workers in two for 10. 15 min can install a pneumatic hammer instead of a bucket.
Pneumatic hammers have a simple design and consist of three main assemblies (Fig. 5.7): tool mounting block, hammer mechanism with air distributing device, unit with automatic starting of the pneumatic hammer in operation. The design of all pneumatic hammers is basically the same, the only difference is their overall dimensions and weight (350. 500 kg).
Fig. 5.7. Pneumatic hammers
Pneumatic hammer striker part consists of a barrel 3, in which, under the action of compressed air (operating pressure of 0,6 MPa), the striker 4 Performs reciprocating motion. Air supply to the shaft is controlled with a three-step spool
As a working tool / on pneumatic hammers in the box 2 a wedge or a spade is set.
To start the air hammer it is necessary to push it against the material to be broken, as a result the start valve opens and the air hammer goes into operation. Air hammers are supplied with compressed air by mobile compressor stations with a capacity of 10 m/min or stationary air networks. Technical capacity of pneumatic hammers per 1 hour of work is 16. 22 m 3 of the destructible rock. Compared with foreign machines, domestic hinged pneumatic hammers at a lower metal intensity in 2-2,5 times have 1,5-2 times higher impact energy (1300. 2400 J).
Hydraulic hammers have become very popular nowadays due to widespread use of hydraulic excavators for ripping of frozen ground and destruction of hard pavement.
The breaker is powered directly from the excavator’s hydraulic system, making better use of the machine’s operating power and reducing operating costs. Compared with pneumatic hammers, hydraulic hammers provide greater impact energy (up to 9000 J). Besides, an excavator with a hydraulic hammer is more mobile.
All hydraulic hammers in Russia are made according to a single principal scheme and are unified with each other by a switchgear (Fig. 5.8). The hydraulic hammer with its power tool is attached to the excavator boom and its hydraulic cylinders.
The boom cylinder is used to raise the breaker, and crank cylinders are used to rotate it and set the desired inclination. A hydraulic breaker can be replaced with a bucket handle by one operator in 1.5. 2 ч.
There are also vibratory dredgers of various designs in the form of a vibrating wedge, a vibrating bucket for excavators, etc. However, most rammers are very energy intensive in frozen ground and therefore their use is justified only when relatively weak soils are developed.
Be aware when operating impact machines that they impose extremely high dynamic loads that are harmful to the base machine as well as nearby structures and utility lines.
Dewatering and dewatering is performed by pumping water out of excavations or by artificial lowering of groundwater level with the help of needle-filtering devices, airlift or hydro-elevator.
Dewatering pumps Vibrating pumps are subdivided into diaphragm pumps, centrifugal pumps and piston pumps.
Diaphragm pump (Fig. 5.9, а) Consists of the housing 1 with suction nozzle 8, cover 4 с diverter spout 3, rubber diaphragm 6, attached to the hood 5, suction 7 and discharge 2 of the valves. The bonnet moves up and down in a reciprocating motion from the actuator. When it is lifted the diaphragm flexes upwards, the discharge valve closes, a vacuum is created in the housing, the suction valve opens and the liquid is sucked into the pump housing. When the bonnet moves backwards the valve 7 closes and the valve 2 opens and water flows into the return pipe. The pump drive can be manual, from combustion engine or electric motor. The suction height of the diaphragm pumps is up to 6 m and the suction capacity is 30. 45 m 3 /h.
Fig. 5.9. Diagrams of dewatering pumps
The working body of the centrifugal pump (Fig. 5.9, б) is the impeller 4, mounted in the valve body 3, diaphragm pumps with suction 2 and pressure line 5 of mowing line. When the wheel rotates, a vacuum is created in the suction mowing line of the pump, so that the water is sucked into the pipeline and is fed first into the pressure pipe, and then into the pressure hose 6. To prevent coarse mechanical particles from entering the pump, a suction strainer is installed at the suction hose end 7.
Centrifugal pumps are divided into single and multistage according to the number of impellers, and according to created head into low pressure (up to 0,2 MPa), medium pressure (0,2. 0,6 MPa) and high-pressure (over 0,6 MPa). Main features of centrifugal pumps: suction height up to 7 m, delivery 24. 250 m³/h.
Piston pumps, used for pumping heavily contaminated water, provide a large suction height and do not require priming before operation.
Needle filter unit (Fig. 5.10) consists of several needle filters 7 submerged in the ground to a depth of 6. 8 m, water collector 2, Vortex self-priming pump 3 and electric motor 4. For sinking of needle-filters into the ground the method of underflooding with a stream of water supplied at pressure through the filter. Needlefilters are placed at a distance of 0,75. 2 m from each other and connect with rubber reinforced hoses to the water collector. When the pump is running, the water is sucked out of the ground and flows into the water collector
Fig. 5.10. Needle filter unit
flows into the receiving devices or is discharged into the sewage system. Suction height of the needle filter unit is not more than 6 m and the capacity is up to 100 m3 /h.
During excavation of flooded pits with water level over 3 m, airlifts and hydro-elevators are used.
Earlifts. air water elevators (Fig. 5.11, а); in spite of their comparatively low efficiency (up to 36%) they have a number of advantages: simple design, reliable and trouble-free operation. Compressed air or gas at up to 0,3 MPa is forced through a gas pipe 1 into the liquid pipe 2, where an emulsion is formed. a mixture of air or gas with water. Water is carried upward by air or gas bubbles. Working pressure of air or gasр (MPa) is numerically equal to р = 0,01 (H- I), where Н- minimum immersion depth of mixing chamber, m; h. Height of pulp lifting, m.
Fig. 5.11. Schematics of erlift (a) and hydro-elevator (b)
Hydro-elevator (Fig. 5.11, б) sucks the pulp due to vacuum created by high velocity water jet flowing through the mixing chamber orifices. Hydro-elevator held by a rope 6, is lowered with a crane onto the loosened soil to be excavated, and the suction shoe is cut into it with a toothed crown 3. Water is supplied through the pipeline under pressure of at least 0,4 MPa. Water passing in the slurry pipeline 5 creates vacuum inside the ejector 4, providing pulp suction and ascent along slurry pipeline. At a water pressure of 0.4. 0,8 MPa suction height reaches 1. 1.5 m, discharge. 6. 7 м. Supply of hydro-elevators and erlifters at development of sandy loam soil is 5. 20 m3 /h at a pulp saturation of 5. 20%.
Features and types of shrub shears
Work at the dacha and on the country site in many cases complicated by the large number of small shrubs. Knife and secateurs are already labor-intensive to use against them, and saws (conventional, gasoline, electric) are extremely inconvenient. Specialized equipment comes to the rescue, but you need to know how to use it correctly.
Features of hand-held hedgetrimmers
Hand-held shrub shears are ideal for cutting low shrubs and young fruit trees. The tool is indispensable for forming hedges and carrying out decorative pruning of some conifers. If you have very few trees, there is absolutely no need for electric or battery-powered pruning shears.
Surely many will like the idea of working with their hands in the fresh air and bring beauty and order to their area.
Shrub shears. Shrub shears are designed for clearing construction sites from shrubs and small wood. They are used in road and rail construction when laying road tracks, as well as for clearing clearings in forested areas, reclaiming new lands and reclamation work in agriculture. In winter, brush cutters can be used for snow removal from roads and construction sites, as well as for snow clearance.
Device. The brush cutter is the front attachment of the crawler tractor. The hedge trimmer’s equipment consists of a universal frame, an implement, and a tractor guard (Fig. 7.2). Shrubs and trees are cut by knives bolted to the lower edges of the tool frame. There is a nose plate welded to the front part of the frame for splitting stumps and pulling apart fallen trees.
Universal frame is used when attaching both the branch cutter blade and other equipment (puller, rake, bulldozer, snowplough, etc.) to the tractor.). In order to soften the blade against the pushing frame and to limit its rotation on the ball head, on the right and left sides of the blade frame there are two shock absorbers made of rubber sheet. To protect tractor cabin from falling trees and limbs, bush cutter is equipped with a guard welded from pipes and covered over the cabin with a steel plate.
4 dozer blade; 5 operating equipment lift cylinder.
For sharpening the knives during operation the brush cutters are equipped with a sharpening device consisting of a sharpening head with an emery wheel, a flexible shaft and a drive mechanism operating from the front end of the diesel crankshaft or the tractor hydraulic pump drive reducer.
It is expedient to chop the bushes and small wood cut by shrub shears and use the received chips, first of all, for fuel. For shredding bushes and small wood domestic and foreign-made chippers are used.
Grapples. Pullers are designed for pulling out stumps, clearing building sites of roots and boulders, removing trunks and brush cut by shrub shears, raking deadwood and branches. They can also be used for felling trees and ripping up compact soils. A clearing machine is equipment mounted on a crawler tractor. By the way they are mounted on the tractor, the pullers are divided into two types: front-mounted and rear-mounted. The operating mechanism of the majority of today’s uprooters is hydraulically driven.
Design. The working body of the pullers mounted on the tractor at the front is the blade with curved teeth. It is mounted on a push frame of a covering type, which hinges rear ends to the tractor longitudinal members. Installation of the blade on the pushing frame can be of two types: rigid and with the ability to rotate relative to the frame in the vertical plane. In the latter case stumps and stones can be mowed not only by pulling tractor and lifting plough frame but also by turning plough blade. Design of the puller with front mounted working tool is shown on Fig. 7.3.
mouldboard with teeth; 2. universal pushing frame;
3 Hydraulic cylinder for lifting implement.
The rear mounted ripper is mounted on the tractor’s rear axle and consists of a vertical leg, a trapezoidal pusher frame and two massive double-arm arms (tangs). The arms are rigidly connected to each other and rest on the axis of the pushing frame, in respect of which they can be rotated by means of rope or hydraulic drive, thus achieving uprooting. Tractor operation in this case is performed in reverse.
Rippers. The ripper (Fig.7.4) is designed to loosen strong and frozen soils and is a mounted or trailed equipment to crawler tractors or basic tractors of different power and traction.
The rippers are classified according to the main parameter of maximum traction force T of the basic tractor:
Max. depth, mm 300 350 400 500 700 900
If the tractive force is 30-100 kN, rippers are light, 100-150 kN. medium, 250 kN. heavy and 500 kN. extra heavy.
Apart from being classified by tractive force, rippers are also subdivided by the base machine engine capacity (kW): light rippers less than 120, medium ones 120-250, heavy ones 300-500 and super-heavy ones 550-1000.
Ploughs effectively excavate frozen and many hard soils. The cost of ripping these soils with their transportation over a distance less than 4 km with powerful scrapers with reinforced buckets is 3-4 times cheaper than ripping by explosion and loading with excavator and hauling in dump trucks, 2-3 times cheaper than using loaders, and 8-3 times cheaper than ripping with wedge-tube. Labor productivity increases from 78-80 m3/person compared with ripping by explosion and backhoe loading. shifts up to 220300 m3 /h. shifts.
ripper diagrams. There are three basic schemes of ripper’s attachments which differ by mechanisms of lowering the tine tip when lowering and lifting (unloading): 1) radial (three-link), 2) parallelogram (four-link), 3) parallelogram adjustable. The peculiarity of each of these schemes is that the trajectory of the cutting part of the working body is different.
According to the radial scheme (Fig. 7.5, a) the tip of the tooth tip moves as the frame is lifted and lowered along the arc. Ripping (cutting) angle varies from 60 to 80, thus, high ripping force is required. At the greatest ripping depth the frame is horizontal. Ripping angle should be able to change during ripping within 30-60, that with the radial scheme requires repositioning of the tooth, for which the outreach of the tooth relative to the cross beam changes, and therefore, changes the depth. Diagram of ripper working equipment with parallelogram scheme is shown on pic. 7.5, г. In this ripper the cross beam, in which the tooth is installed, is attached to a four-point suspension, which is a parallelogram.
ripper operation process. First of all the teeth are lowered into the ground simultaneously with the travel of the machine. After driving the tines to a depth that enables the tractor to travel at the optimum speed, the machine continues to advance at the optimum depth and then the tines are lowered until they come out of the ground. After driving a defined length section the ripper is turned and the process repeats in the opposite direction. When the work area is short, the tractor does not have to make a U-turn. Each penetration length is selected depending on the working conditions and the combination of the ripper and the other implements used. When working in open pits at considerable depth, the rock is ripped up in layers.
Ripping performance. Ripper works in combination with a bulldozer, scraper or excavator. When working in combination with a bulldozer or a scraper the ripping depth should be 20% greater than the thickness of the layer captured by the bulldozer blade or the scraper blade. Loosening degree, i.e. е. Ripping unit output is affected by the size of lumps of loosened rock and soil.
ripper productivity depends on the tractor’s pulling force Tc and ripping speed v (optimal vp = 1,6-2,5 km/h). Tractor’s traction power depends on its size and is usually equal to 1-1.1 tractor’s weight with bulldozer or ripper equipment at an optimum ripping speed of 1.5 km/h. At equal T and v the producer
the thickness depends on the number of teeth working at the same time, the distance between them and the ripping depth h.
According to experimental data, the shape of loosening area in hard and soft soils at work with one tooth is different. For 300 kW tractor with 500-520 kN of bulldozer’s gravity the average ripping depth h = 50-60 cm in very hard and h
90-100 cm in soft soil. As the power or gravity decreases or increases, the depth changes approximately in proportion to the root of the cubic of their change.
Technical productivity Pt, m3 / h, depends on the effective width of the ripper B, m, effective thickness of the loosened layer h, m, ripper speed vp m / h, the coefficient of overlap knep, the coefficient of the nature of passes (parallel or cross) kn, the number of passes p repeated:
The value of knep depends on the physical and mechanical properties of the soil; usually k = 0.75. For parallel passes k = 1, for cross passes kn = 2.
Operating capacity P, depends on the time of machine use (K = 0.75), taking into account the time of machine preparation for work, its inspection and maintenance. Working average speed in this case is reduced by 20% to account for random delays. At that
If ripping speed is less than specified, it is necessary to increase tractor size or reduce ripping depth. It is possible to increase the pulling power, if it needs to be more than 80%, by using a push-pull or a rigid tandem hitch of tractors with a ripper mounted on the rear tractor. To increase pulling power up to 50-80% it is better to use a caterpillar pusher, if less than 50%. wheeled.
General information. A bulldozer is a machine consisting of a tracked or wheeled tractor equipped with a blade. the blade can be installed either perpendicular to the tractor’s longitudinal axis or at an angle of p’ (p’ is the angle at which the blade turns in plane, t. е. angle between longitudinal axis of tractor and cutting blade of dozer blade), which allows to move soil to the side. In the latter case, the machine is called a dozer with a swivel blade. In addition, the blade can sometimes swivel in a transverse vertical plane and tilt to change the cutting angle.
⚒ Using Manual Hedge Shears. QG Day 159 ⚒
If the blade is mounted perpendicular to the tractor longitudinal axis, a bulldozer with a pivoting blade works like a bulldozer with a non-pivoting blade. Depending on the type of work, rippers, branch cutters, ditchers, grubbers and other interchangeable working equipment are mounted on the bulldozer frame with either rotary or nonrotary blade.
A distinction is made between bulldozers with the implement mounted on the front and rear of the machine.
Bulldozers are divided into hydraulic and rope-driven versions, depending on type of access mechanism drive.
Bulldozers can do the following jobs:
1) develop excavations and semi-excavations on slopes and also excavations with earth moving into embankment at zero marks in mountainous terrain;
2) level the terrain in mountainous terrain for road construction;
3) level soil and building materials;
5) to plan construction and airfield sites;
6) to clear sites and routes from snow, bushes, woods, etc. д.;
9) some bulldozer designs are able to work in water up to 1 m deep.
In terms of engine power of the basic tractors, super-heavy bulldozers with power over 220 kW (300 l. с.), heavy 110220 kW (150-300 l. с.), medium 60-108 kW (81-147 hp. с.), light 15,5-60 kW (21-80 hp. с.) and small-sized up to 15.0 kW (20 hp. с.).
The main parameter, describing the bulldozer work, is the nominal tractive force T. It is defined by the tractor (prime mover) and implements total gravity Go6 when the bulldozer is moving on the solid ground and tractor slipping is not more than 7%, and not more than 30%, at speed of the crawler vehicles 2,5-3 and the wheel ones. 3-4 km/h.
By nominal tractive force value, dozers are divided into extra light (up to 25 kN), light (26-75 kN), medium (80-145 kN), heavy (150-300 kN), extra heavy (over 300 kN).
Operation Process. The dozer digs, moves and spreads material in the process. To separate the soil from the material, the blade blade penetrates the ground and the bulldozer simultaneously moves forward. The excavated material is deposited in front of the blade and creates a drag prism.
Cutting is performed until the drag prism reaches the top edge of the moldboard. The blade is then raised and the bulldozer drives up and down, pulling the drag prism to the point of unloading.
The dozer blade is raised and lowered by hydraulic or wire rope mechanisms. On dozers with cable control the blade penetrates the ground by its own gravity of the blade and frame. The dozer blade can be raised, lowered by gravity and has a floating position.
On dozers with hydraulic dozers, the blade is forced into the ground by the force of the hydraulic system. These forces can reach 40% and more of the tractor’s total gravity.
Changing the blade position in horizontal and vertical planes of dozers with a pivoting blade is performed by rearrangement of the scaffolding arms and turning the blade manually, and on some machines by means of hydraulic cylinders. Cutting angle in large bulldozers is sometimes changed with a hydraulic cylinder.
swinging blade; 1. hydraulic cylinder; 2. strut;
blade; 4. push bar; 5. push bar attachment to the undercarriage; 6. ball joint; 7. double arm strut;
universal frame; 9. frame mounting pin to undercarriage.
Designs. The dozer’s operating equipment with a non-pivoting blade consists of the blade, the pushing frame and the control mechanism (Fig. 7.6).
The blade is a welded, rigid, box-section structure. Along the lower edge of the front plate curved in the arc of the circle, blades are attached. The moldboard is reinforced with ribs on the rear side and has eyelets for connection to the push frame beams. Flanges on sides of moldboard are welded.
The pushing frame connects the dozer blade with the base machine and transmits the working force to it. Spatial stiffness of operating equipment is attached by braces, installed in horizontal and vertical planes.
Blade and push frame on light dozers are usually made as one-piece welded construction.
The length of the bulldozer’s swivel blades (Fig. 6b) is usually greater than the width of the front end of the machine. 7.The length of dozers shovels (Fig. 6, b) is usually longer than the length of non-turned shovels. This is because the moldboard in a swivel position needs to overlap the cross-sectional dimensions of the basic machine. Its working conditions require a different face shape and do not allow for jaws.
Determining the bulldozer’s digging resistance
Let’s consider questions of traction calculation with regard to the most widespread way of work. frontal pushing of soil during trenchless method of work.
The volume of the drag prism depends on the geometric dimensions of the blade and the properties of the soil:
kp coefficient, which depends on the nature of the soil (cohesiveness, loosening coefficient) and the ratio of.
This coefficient is the result of processing experimental data on the performance of bulldozers. ^
Buy cordless brushcutter: which model is better
The battery-powered brushcutters work on the basis of a self-contained battery that needs to be recharged from time to time. The tool is used when shrubs are far from the power grid or hedges are small in size.
Cordless brushcutters may not be able to cope with thick branches, they cannot handle large amounts of work. The device needs to be constantly recharged, approximately every 40 minutes. Very intensive loading of the blades may require recharging after only 20 minutes of work.
Bosch batteries charge quickly and last a long time
This shrub shear is therefore especially well suited for cutting 2 cm thick branches. For cutting tall trees, it is better to use telescopic hedgetrimmers with folding booms. Even three-meter-high shoots can be trimmed with this type of shrub shears.
The best of these models are Bosch and Gardena cordless hedge trimmers from Germany, as well as their Japanese counterparts Hitachi and Ryobi.
Bosch cordless brushcutters are cordless devices for cutting hedges and bushes. Most models have a removable lithium-ion battery pack that takes just under an hour to charge. The tools have an anti-blocking system for uninterrupted operation. They are light and compact designs that run for quite a long time. And they have practically no effect on human fatigue. The cutting system, with special serrations in the front part of the blade, allows fast removal of branches up to 25mm thick.
Useful tip! Do not use the product for cutting branches with a thickness greater than specified in the product’s technical data.
Ryobi cordless brushcutters are some of the best
Ecology Reference Book
Brush cutter DP-24 of passive action, designed for clearing areas overgrown with bushes and small wood with trunk diameter up to 12 cm. Mounted in front of T-130G-1 tractor.130BG. The working device is the blade, at the bottom of which there are two horizontal blades with an angle of 64° at the top of the triangle formed by the blades, there is a wedge for splitting stumps and pulling apart of fallen trees. The branch cutter is equipped with an armored shield, a guard and a device for sharpening knives with a tractor drive. Working width 3.6 m. Output 0.6 g/h.[. ]
The KB-4,0A passive branch cutter is mounted in front of the T-1 ZOB tractor. Design of the branch cutter is similar to DP-24 branch cutter and D-514A branch cutter. Working body. Two-sided blade with undercutting blades.attached to the pushing frame. Angle of blade installation. 60° (fig.З).[. ]
Busheshopper MTP-43 with active working tool. For one pass the machine cuts the bushes in strips up to 16 m diameter by 1,5 m disc with cutting teeth (fig.4), cuts down bushes and small woods with trunks up to 25 cm thick and up to 16 m high. The machine is self-propelled and fully rotating on caterpillar move. Mounted on the crane KPT-1M. Boom and crane equipment replaced by shrub shearing equipment. Track surface pressure 2.3 Pa. For propulsion and operating the tools on the machine was set a station DPS-50E of 30 kW. At one pass the machine cuts a strip of bushes up to 16 m. Machine performance 0,7. 1.0 ha/h at 0.78 km/h travel speed.[. ]
MTP-43 brush cutter with active operating device. Cutter with diameter of 1,5 m, which is a disc with cutting teeth (fig.4), cuts shrubs and small woods with trunks up to 25 cm thick and up to 16 m high. The machine is self-propelled, full-turn, tracked. Assembled on the base of crane KPT-1M. Boom and crane equipment are replaced by the equipment for bushes cutting. Track pressure on the ground surface 2,3 Pa. For movement and actuation of working elements on the machine is set DPS-50E power station with capacity of 30 kW. In one pass the machine cuts the bushes up to 16 m in a strip. Machine productivity 0,7. 1.0 ha/h at a travel speed of 0.78 km/h.[. ]
Busheshopper MTP-43 with an active working body. The machine is equipped with a 1.5 m diameter mill, which is a disk with cutting teeth (fig.4), cuts bushes and small woods with trunks up to 25 cm thick and up to 16 m high. The machine is self-propelled, full-turn, tracked. Mounted on the base of the crane KPT-1M. Boom and crane equipment replaced with brush-cutting equipment. Track pressure on the ground surface 2,3 Pa. For movement and actuation of working elements on the machine is set station DPS-50E power of 30 kW. The machine will cut a strip of brush up to 16 m in one pass. Machine capacity 0.7. 1.0 ha/h at a travel speed of 0.78 km/h.[. ]
Shrubber MTP-43 with an active operating tool. A blade with a diameter of 1,5 m, which is a disc with cutting teeth (Fig.4), cuts bushes and small woods with trunks up to 25 cm thick and up to 16 m high. The machine is self-propelled, full-turning on caterpillar. Mounted on the base of the crane KPT-1M. Boom and crane equipment are replaced by the equipment for bushes cutting. Track pressure on the ground surface 2,3 Pa. To move and actuate the working elements the machine is equipped with 30kW DPS-50E power station. At one pass the machine cuts the bushes up to 16 m. Machine capacity 0.7. 1.0 ha/h at a travel speed of 0.78 km/h.[. ]
MTP-43 shrub shearer with active tool. For driving the machine by 1,5 m diameter cutter head, which is a disc with cutting teeth (Fig.4), cuts bushes and small woods with trunks up to 25 cm thick and up to 16 m high. Self-propelled, full-turn, tracked machine. Assembled on the base of crane KPT-1M. Boom and crane equipment replaced by brush cutting equipment. Crawler pressure on the ground surface is 2,3 Pa. For driving and activation of working elements on the machine there is the station DES-50E with the power of 30 kW. In one pass the machine cuts the bushes in a strip of up to 16 m. Machine productivity 0.7. 1.0 ha/h at a travel speed of 0.78 km/h.[. ]
The basic figures of the shrub shears are given in tab. 1.[. ]
The technical characteristics and working conditions of brush cutters, uprooters, bulldozers, ditch diggers, excavators and tractors used for the construction of the drainage network are reviewed.[. ]
Manual on forest land drainage [b] recommends using the following brands of brush cutters: D-514A; DP-24; KB-4,0A and MTP-43X. Brush cutters can be passive or active. Brush cutters with passive working bodies perform cutting by pressing knives into the wood at forward motion of the tractor. Such brush cutters are coupled with tracked tractors of traction class b. 10.[. ]
Plow PLP-135 gives a furrow width of 135 cm, turning layers on both sides. It is hinged in front of the C-80 tractor to the bulldozer, uprooter or brush cutter frame.[. ]
Silvicultural maintenance consists in complete or partial suppression, even destruction of undesirable wood and shrub vegetation with the help of shrub shears “Secor-3”, KOM-2,3 or KOCK-2 type clarifier roller. Axes are still widely used in clearing and clearing.[. ]
Apparently, research thought should work towards the integrated use of mechanizable methods of care in corridors (with the use of shrub-cutters, etc.). п.). We also have to take into account the type of growing conditions. According to our calculations, clearcuts were promising for only 12% of the entire forested area for the Zavidovsky Reserve and Hunting Farm. All this greatly limits the possibility of their productive use in the interests of hunting in conjunction with forestry.[. ]
In Leningrad region along with bulldozers trawl chains are used to clear away arboricid-treated overgrown vegetation, in Pskov, Novgorod and other regions. brush cutters. To clear away brushwood which is weakly affected by arboricides widely use pullers-gatherers.[. ]
On meadows and pastures, where over 25% of the area is occupied by bushes and small woods, it is necessary to remove all woody vegetation in order to improve agrotechnical conditions. For this purpose, they use brush cutters DP-24 on tractor T-130 and D-514 on tractor T-UMGP, pullers K-2A on tractor T-UMGP, KM-1 on tractor LHT-55, pullers-gatherers D-513A, MP-2A, MP-7A on tractor T-UMGP or T-130, and bulldozers D-493A on tractor T-UMGP.[. ]
The predominance of pure low-value young growth on considerable areas causes the necessity to create coniferous crops. Introduction of economically valuable species into low-value deciduous young growth by artificial regeneration is an important way of reconstruction, especially with modern means of mechanization: bulldozers, brush cutters, ditch diggers, powerful two-plow plows. With their help one can quickly make corridors among deciduous bushes for further placing in them crops of more valuable tree species. For the same purpose it is possible to make plough furrows and ditches, on some parts of which (banks, etc.) the crops can be placed.) to place crops.[. ]
In the mid 60’s Leningrad reclamation workers developed a more progressive complex technology of reclamation of overgrown lands, providing stream work during the year and improving their quality (O. K-Harzev et al., 1969). According to this technology, the cutting of bushes and shrubs in wintertime at air temperature not higher than 5 ° C and snow cover is not thicker than 50-60 cm with D-514A shrub shears with a working body of passive action, or bulldozers D-271, D-492A, D-493, D-694. Individual large trees were recommended to fell and cut with Druzhba gasoline-powered saw. Raking in piles of woody mass after brush cutting was performed by tractor rakes MUK-4. GKT-2.5, GKT-3 or other designs. The wood in the piles was burned after drying, using waste and non-recoverable fuel and lubricants. Afterwards, large stumps were uprooted using pullers-pickers, while the main mass of small and medium-sized stumps was removed using a rooting harrow. Remains of stumps and roots were raked in piles and burned.[. ]
In dry, fresh and wet oak forests silvicultural tending is a very important measure, because after agro-technical tending, 6-9 years old oaks are strongly suppressed by soft-leaved species. The complexity of silvicultural treatments is that when soft-leaved species are removed with a clarifier roller KOC-2, clarifier cutter KOM-2,3, valuable companions of oak are also destroyed. Therefore, the use of shrubs should ensure the preservation of a one-meter strip of soft-leaved species, which preserves valuable companions oak and undergrowth. In this case, the width of the slats should be increased up to b. 7 м. Selective hand picking of softleaved species with the retention of valuable oak companions should not be neglected either.[. ]
The low productivity of natural grasslands is also determined by the fact that their vast areas are overgrown with bushes and trees. Shrubs overgrowth displaces grass from meadows, impedes mechanization of tending and harvesting operations. Besides, the presence of thickets in meadows and pastures contributes to the spread of various insects: horseflies, ticks, etc., which are more often eaten by oaks. But the damage caused by woody and shrubby vegetation is not limited to this. After the shrubbery is removed from the remaining roots and stumps with the shrub cutter, the shrub will regrow. If the blockage areas are developed for arable land it is necessary to uproot bushes and trees, which requires a lot of labor and funds. Besides, during felling the top, the most fertile, soil layer is destroyed. In this respect chemical methods of struggle against vegetation clogging up natural forage lands gain great importance.[. ]
Clearing the right-of-way involves the removal of obstacles that interfere with the breakdown of the roadbed and the execution of works. Felling of trees and bushes on right-of-way must be done to the minimum extent necessary, as determined by the design, within the right-of-way. Special machines and mechanical tools are used for felling and bucking of trees. Skidding to intermediate stores is performed by skidders or construction tractors, tractor winches and logging trucks. Stumps up to 0.5 m in diameter shall be removed by pullers, winches, bulldozers, rippers, and those over 0.5 m in diameter. by explosive method. It is allowed to leave stumps of height not more than 0,1 m in the base of embankments of height not less than 1.5 m when making pavements with improved, lightened, transitional types of coatings. Remove brushwood (if not numerous) with bulldozer or brush cutter. In summertime with small amount of trees felling is performed by bulldozer without chopping down. Clearing waste must be completely removed before the beginning of excavation work. It is not allowed to leave debris on the edge of right-of-way. Upon agreement with the forestry and environmental authorities it is allowed to liquidate non-business waste after clearance (burying or burning) in specially allocated places with observance of fire prevention measures. Remaining pits after stumping or felling trees are backfilled with soil and compacted.[. ]