felling of trees
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Felling is the process of cutting down trees during logging. There are two main methods: using a feller buncher machine or hand felling with chainsaws or axes. A feller buncher can rapidly cut and gather multiple trees at once using a cutting attachment. For hand felling, workers use chainsaws or axes to fell trees and then limb and buck them. A harvester is also used which can fell, delimb, and buck trees in one operation as part of cut-to-length logging. Proper planning is needed to fell trees safely based on terrain, tree lean, and felling patterns.
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felling of trees
- 1. FELLING OF TREES Submitted to: Submitted by: Divya mam Md mahmood 12011BB006 Fsp II sem Jnafau & spa
- 2. FELLING IS THE PROCESS OF DOWNING INDIVIDUAL TREES, AN ELEMENT OF THE TASK OF LOGGING. Methods:- 1 Feller buncher :- A feller buncher is a motorized vehicle with an attachment which rapidly cuts and gathers several trees in the process of felling them. In cut-to-length logging a harvester performs the tasks of a feller buncher additionally doing the delimbing and bucking of the trees as well. 2 Hand felling :- In hand felling, an axe, saw, or chainsaw is used to drop a tree, followed up by limbing, bucking, and in traditional applications . In the modern commercial logging industry, felling is typically followed by limbing and skidding
- 3. FELLER BUNCHER A feller buncher is a type of harvester used in logging. It is a motorized vehicle with an attachment that can rapidly cut and gather several trees before felling them. Older style Feller buncher tree cutting machine . Front view of a feller buncher.
- 4. A feller buncher consists of a standard heavy equipment base with a tree- grabbing device furnished with a chain-saw, circular saw or a shear - a pinching device designed to cut small trees off at the base. The machine then places the cut tree on a stack suitable for a skidder or forwarder, or other means of transport (yarding) for further processing (e.g., delimbing, bucking, loading, or chipping). Closeup hard wood grabbing device, with chainsaw for felling trees There are also wheeled feller bunchers with no articulated arm. Instead this type of vehicle drives close and grabs the tree. In cut-to-length logging a harvester performs the tasks of a feller buncher additionally doing the delimbing and bucking of the trees as well.
- 5. HARVESTER A harvester is a type of heavy forestry vehicle employed in cut-to-length logging operations for felling, delimbing and bucking trees. A forest harvester is typically employed together with a forwarder that hauls the logs to a roadside landing. 6-wheeled Valmet harvester Small 4-wheeled Rottne harvester
- 6. Harvester head. Harvester head, chainsaw visible. Harvester consists of :- 1 Chain saw . 2 Two or more curved delimbing knives . 3 Two feed rollers to grasp the tree. 4 Diameter sensors to calculate the volume of timber harvested in conjunction with a measuring wheel which measures the length of the stem as it is fed through the head.
- 7. HAND FELLING:- In hand felling, an axe, saw, or chainsaw is used to drop a tree, followed up by limbing, bucking, and in traditional applications . In the modern commercial logging industry, felling is typically followed by limbing and skidding.
- 8. CHAINSAW FELLING AND BUCKING: PLANNING AND OPERATIONAL FACTORS/VARIABLES Felling Pattern Perpendicular Herringbone Contour
- 9. CHAINSAW FELLING AND BUCKING: PLANNING AND OPERATIONAL FACTORS/VARIABLES Terrain
- 10. CHAINSAW FELLING AND BUCKING: PLANNING AND OPERATIONAL FACTORS/VARIABLES Tree Lean and Weight Distribution
- 11. CHAINSAW FELLING AND BUCKING: PLANNING AND OPERATIONAL FACTORS/VARIABLES Stage Felling and Skidding
- 12. CHAINSAW FELLING: THE PROCESS Choose the lay of the tree Clear brush and identify an escape route from the tree (OR-OSHA: 20-25’ @ 45 angle) Undercut or Face cut Backcut Wedging & Holding Wood (hinge)
- 13. TREE PROCESSING: CHAINSAW CONSIDERATIONS Measure the whole tree before starting the bucking
- 14. TREE PROCESSING: CHAINSAW CONSIDERATIONS Tree lay creates compression and tension wood “Top, bottom and side binds”
Editor's Notes
- #7: Uses:-Harvesters are employed effectively in level to moderately steep terrain for clearcutting areas of forest. For very steep hills or for removing individual trees, humans working with chain saws are still preferred in some countries. In northern Europe small and manoeuvrable harvesters are used for thinning operations, manual felling is typically only used in extreme conditions, where tree size exceeds the capacity of the harvester head or by small woodlot owners.The principle aimed for in mechanised logging is "no feet on the forest floor", and the harvester and forwarder allow this to be achieved. Keeping humans inside the driving cab of the machine provides a safer and more comfortable working environment for industrial scale logging.Harvesters are built on a robust all terrain vehicle, either wheeled or tracked. The vehicle may be articulated to provide tight turning capability around obstacles. A diesel engine provides power for both the vehicle and the harvesting mechanism through hydraulic drive. An extensible, articulated boom, similar to that on an excavator, reaches out from the vehicle to carry the harvester head. Some harvesters are adaptations of excavators with a new harvester head, while others are purpose-built vehicles."Combi" machines are available which combine the felling capability of a harvester with the load-carrying capability of a forwarder, allowing a single operator and machine to fell, process and transport trees. These novel type of vehicles are only competitive in operations with short distances to the landing.Harvester:-A typical harvester head consists of (from bottom to top, with head in vertical position)a chain saw to cut the tree at its base, and also cut it to length. The saw is hydraulically powered, rather than using the 2-stroke engine of a portable version. It has a more robust chain, and a higher power output than any saw that can be carried by a human.two or more curved delimbing knives which reach around the trunk to remove branches.two feed rollers to grasp the tree. The wheels pivot apart to allow the tree to be embraced by the harvester head, and pivot together to hug the tree tightly. The wheels are driven in rotation to force the cut tree stem through the delimbing knives.diameter sensors to calculate the volume of timber harvested in conjunction witha measuring wheel which measures the length of the stem as it is fed through the head.All of this can be controlled by one operator sitting in the cab of the vehicle. A control computer can simplify mechanical movements and can keep records of the length and diameter of trees cut. Length is computed by either counting the rotations of the gripping wheels or, more commonly, using the measuring wheel. Diameter is computed from the pivot angle of the gripping wheels or delimbing knives when hugging the tree. Length measurement also can be used for automated cutting of the tree into predefined lengths. Computer software can predict the volume of each stem based on analysing stems harvested previously. This information when used in conjunction with price lists for each specific log specification enables the optimisation of log recovery from the stem.Harvesters are routinely available for cutting trees up to 900 mm in diameter, built on vehicles weighing up to 20 t, with a boom reaching up to 10 m radius. Larger, heavier vehicles do more damage to the forest floor, but a longer reach helps by allowing more trees to be harvested with fewer vehicle movements.The approximate equivalent type of vehicle in full-tree logging systems are feller-bunchers.