A feller buncher is a type of harvester used in

logging Logging is the process of cutting, processing, and moving trees to a location for transport. It may include skidder, skidding, on-site processing, and loading of trees or trunk (botany), logs onto logging truck, trucksheavy equipment Heavy equipment, heavy machinery, earthmovers, construction vehicles, or construction equipment, refers to heavy-duty vehicles specially designed to execute construction tasks, most frequently involving earthwork operations or other large con ...

base with a tree-grabbing device furnished with a

chainsaw A chainsaw (or chain saw) is a portable handheld power saw, power saw that cuts with a set of teeth attached to a rotating chain driven along a guide bar. Modern chainsaws are typically gasoline or electric and are used in activities such as t ...

circular saw A circular saw or a buzz saw, is a power-saw using a toothed or Abrasive saw, abrasive disk (mathematics), disc or blade to cut different materials using a rotary motion spinning around an Arbor (tool), arbor. A hole saw and ring saw also use ...

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 A skidder is any type of heavy vehicle used in a logging operation for pulling cut timber, trees out of a forest in a process called "skidding", in which the logs are transported from the cutting site to a landing. There they are loaded onto t ...

forwarder A forwarder is a forestry vehicle that carries big felling, felled Timber, logs cut by a Harvester (forestry), harvester from the stump to a roadside landing for later acquisition. Forwarders can use rubber tires or tracks. Unlike a skidder, a ...

, or

yarder A yarder is piece of logging equipment that uses a system of cables to pull or fly logs from the stump to a collection point. It generally consists of an engine, drums, and spar, but has a range of configurations and variations, such as the swing ...

for transport to further processing such as

delimbing Limbing or delimbing is the process of removing branches from a standing or fallen tree trunk (botany), trunk. In logging, limbing follows felling. Limbing plays a role in fire prevention by removing branches from live trees that can otherwise ...

bucking Bucking is a movement performed by an animal in which it lowers its head and raises its hindquarters into the air while kicking out with the hind legs. It is most commonly seen in herbivores such as equines, cattle, deer, goats, and sheep. Most ...

, loading, or chipping. Some wheeled feller bunchers lack an articulated arm, and must drive close to a tree to grasp it. In

cut-to-length logging Cut-to-length logging (CTL) is a mechanized harvesting system in which trees are delimbed and ''cut to length'' directly at the tree stump, stump. CTL is typically a two-man, two-machine operation with a harvester (forestry), harvester felling, d ...

, a harvester performs the tasks of a feller buncher and additionally does delimbing and bucking.

Components and felling attachment

Feller buncher is either tracked or wheeled and has self-levelling cabin and matches with different felling heads. For steep terrain, tracked feller buncher is being used because it provides high level of traction to the steep slope and also has high level of stability. For flat terrain, wheeled feller buncher is more efficient compared to tracked feller buncher. It is common that levelling cabins are matched with both wheeled and tracked feller buncher for steep terrain as it provides operator comfort and helps keeping the standard of tree felling production. The size and type of trees determine which type of felling heads being used.

Types of felling heads

Disc saw head – It can provide a high speed of cutting when the head is pushed against the tree. Then, the clamp arms will hold the tree when the tree is almost completed cutting. It is able to cut and gather multiple trees in the felling head. The disc saw head with good ground speed provides high production, which allows it to keep more than one

working continuously. Shear blade head - It is placed against the tree and the clamp arms will hold the tree firmly. Then, the blade will activate and start cutting the tree. Same as disc saw head, it can hold multiple trees before they are placed on the ground.

Chain saw A chainsaw (or chain saw) is a portable handheld power saw that cuts with a set of teeth attached to a rotating chain driven along a guide bar. Modern chainsaws are typically gasoline or electric and are used in activities such as tree fell ...

head – The floppy head provides minimal control to place the trees on the ground. It might not suit to collect the cut trees or gather the cut stems in the felling head.

Cost-effectiveness

The purchase cost of a feller buncher is around $180,000 USD and its fuel consumption and lubricant consumption is high among other mechanical

harvest Harvesting is the process of collecting plants, animals, or fish (as well as fungi) as food, especially the process of gathering mature crops, and "the harvest" also refers to the collected crops. Reaping is the cutting of grain or pulses fo ...

ing equipment. The feller buncher also has the highest hourly cost which is around $99.5 when comparing other equipment such as a harvesters and grapple

s. Although the total cost of feller buncher is high in overall, the unit production price is the lowest which explains why feller buncher is considered the most cost-effective harvesting equipment. The average unit cost of the feller buncher is $12.1/m3 while the unit cost of the harvesters is $16.5/m3. The unit cost of the feller buncher is primary affected by the tree size and the tree volume. The unit felling cost is lower when the tree size increased. For example, tree with 5 inches at DBH has the unit cost of $70 while tree with 15 inches at DBH has the unit cost of $12. As the cost of feller buncher is high, only large tree volume can produce more profit to cover the high average cost. In terms of stump height, lower stump height can maximise the use of natural resources and prevent wood waste. Mechanical felling such as using feller buncher can prevent 30% of value loss caused by the high stumps.

Maintenance

Feller buncher requires daily maintenance before operation and some components only require periodic maintenance. It could ensure the safety of operators and all the workers around the operation. If damaged or faulty machine is operated, it could result in further damage to the machine which can be more expensive to repair.

Daily or Every 8 hours

Lubrication

The felling head is considered one of the hardest part of the feller buncher and it is necessary to apply

lubricant A lubricant (sometimes shortened to lube) is a substance that helps to reduce friction between surfaces in mutual contact, which ultimately reduces the heat generated when the surfaces move. It may also have the function of transmitting forces, ...

to every joint for daily maintenance. It is suggested to apply lubricant to saw head clamps, wrist attachment and

driveshaft A drive shaft, driveshaft, driving shaft, tailshaft (Australian English), propeller shaft (prop shaft), or Cardan shaft (after Girolamo Cardano) is a component for transmitting mechanical power, torque, and rotation, usually used to connect ...

bearings during every maintenance. The use of grease should meet the extreme pressure performance standard and contains 3% of

molybdenum disulphide Molybdenum disulfide (or moly) is an inorganic compound composed of molybdenum and sulfur. Its chemical formula is . The compound is classified as a transition metal dichalcogenide. It is a silvery black solid that occurs as the mineral molybde ...

(MoS₂). MoS₂ can prevent the wear that takes place where

metal A metal () is a material that, when polished or fractured, shows a lustrous appearance, and conducts electrical resistivity and conductivity, electricity and thermal conductivity, heat relatively well. These properties are all associated wit ...

to metal contact exists.

Fuel

It is also important to check if there is enough

fuel A fuel is any material that can be made to react with other substances so that it releases energy as thermal energy or to be used for work (physics), work. The concept was originally applied solely to those materials capable of releasing chem ...

for the operation. Feller bunchers use

diesel fuel Diesel fuel, also called diesel oil, heavy oil (historically) or simply diesel, is any liquid fuel specifically designed for use in a diesel engine, a type of internal combustion engine in which fuel ignition takes place without a spark as a re ...

to generate power. In most of the cases, the fuel is preferably to have cetane number greater than 50 (minimum 40). This is suitable for operation at temperatures below -20 °C (-4 °F) or elevations more than 1500m (5000 Ft.).New John Deere L-Series II Skidders & Wheeled Feller Buncher. (2018, September 19). ''M2 Presswire''. The Cloud point of the fuel is preferably at least 5 °C (9 °F) lower than the expected low temperature.Track Harvester & Feller Buncher Guide. (2013). ''Canadian Forest Industries'', 20–. It is also suggested that the

sulphur Sulfur (American spelling and the preferred IUPAC name) or sulphur (English in the Commonwealth of Nations, Commonwealth spelling) is a chemical element; it has Symbol (chemistry), symbol S and atomic number 16. It is abundance of the chemical ...

content of the fuel should not be more than 0.5% as it could reduce 50% of the service interval for the

engine oil Motor oil, engine oil, or engine lubricant is any one of various substances used for the lubrication of internal combustion engines. They typically consist of base oils enhanced with various additives, particularly antiwear additives, deter ...

and filter. Feller-1

Engine coolant

Operators have the responsibility to check the engine coolant level of the feller buncher before starting the engine. The coolant prevents cylinder linear erosion and pitting, and provides protection during extremely low temperature for up to -37 °C (-34 °F). It is recommended to use coolants for heavy-duty engines which are relatively low

silicate A silicate is any member of a family of polyatomic anions consisting of silicon and oxygen, usually with the general formula , where . The family includes orthosilicate (), metasilicate (), and pyrosilicate (, ). The name is also used ...

ethylene glycol Ethylene glycol ( IUPAC name: ethane-1,2-diol) is an organic compound (a vicinal diol) with the formula . It is mainly used for two purposes: as a raw material in the manufacture of polyester fibers and for antifreeze formulations. It is an odo ...

base. There are two forms of coolants: pre-diluted or concentrate. Water is required to dilute the concentrated coolant with an approximate ratio of 50:50. The use of supplemental coolant addictive might be also required in the concentrated coolant in order to provide protection against

corrosion Corrosion is a natural process that converts a refined metal into a more chemically stable oxide. It is the gradual deterioration of materials (usually a metal) by chemical or electrochemical reaction with their environment. Corrosion engine ...

Distilled Distillation, also classical distillation, is the process of separating the component substances of a liquid mixture of two or more chemically discrete substances; the separation process is realized by way of the selective boiling of the mixt ...

, deionised, or demineralised water is suggested for mixing the concentrated coolant because when some water compositions mix with other substances could form a

precipitate In an aqueous solution, precipitation is the "sedimentation of a solid material (a precipitate) from a liquid solution". The solid formed is called the precipitate. In case of an inorganic chemical reaction leading to precipitation, the chemic ...

, causing damage or blockage in the engine.

Risk management approach

During maintenance, there are common working hazards related to two main areas: working environment and

exhaust system An exhaust system is used to guide reaction exhaust gases away from a controlled combustion inside an engine or stove. The entire system conveys burnt gases from the engine and includes one or more exhaust pipes. Depending on the overall syste ...

. When working on the exhaust system, be aware of the hot components around the engine. Workers should wear

personal protective equipment Personal protective equipment (PPE) is protective clothing, helmets, goggles, or other garments or equipment designed to protect the wearer's body from injury or infection. The hazards addressed by protective equipment include physical, elect ...

such as safety spectacles, heat-proof gloves and safety boots. When a feller buncher is elevated for service or maintenance, falls from height might happen. Related injuries could be avoided by ensuring dryness of all the walking surface, wiping any oils or other liquid substances on the floor. Also, ensure the feller buncher is parked on a level and stable ground during maintenance. When getting in and out of the machinery, workers are suggested to use three point of contact with two hands holding the handrails and one foot on a step. It is also important to provide sufficient lighting for all the working sites at all time of service.

Safety

Logging Logging is the process of cutting, processing, and moving trees to a location for transport. It may include skidder, skidding, on-site processing, and loading of trees or trunk (botany), logs onto logging truck, trucksloggers are injured by the falling objects which are large in size and heavy. “Struck by object” is the most common injuries that reported in the logging industry due to the manual use of equipment during the logging procedures. There is evidence that using mechanized

harvesting Harvesting is the process of collecting plants, animals, or fish (as well as fungi) as food, especially the process of gathering mature crops, and "the harvest" also refers to the collected crops. Reaping is the cutting of grain or pulses fo ...

equipment could reduce the rate of “struck by” injuries. One study indicates that total injury claims could be reduced by 14.2%, while the “struck by” injuries could be reduced by 8.2%, when comparing the changes before and after the use of feller buncher. The significant decline in the number of “struck by” injuries after using the feller buncher in the logging companies supported the statement that using mechanized harvesting equipment could lessen overall injuries. The evidence also found that the rate of injuries in the logging companies without using feller bunchers had increased slightly throughout a period of time, increasing from 14.5% to 17.5%, in five years. In terms of trees fatality, areas with lower levels of

mechanization Mechanization (or mechanisation) is the process of changing from working largely or exclusively by hand or with animals to doing that work with machinery. In an early engineering text, a machine is defined as follows: In every fields, mechan ...

in harvesting resulted in higher rate of trees fatality. For instance, in Eastern areas of the United States, research which compared the conventional and mechanized logging operations, indicated the number of injuries, when using the conventional approach, is three times greater than that of using the mechanized equipment such as a feller buncher. However, mechanized related injury could be raised accordingly, especially when performing machine maintenance or repair. These kinds of injuries could be serious and also costly.

Limitations

Feller buncher could be highly productive and cost-effective but there are several limitations. Feller buncher is less beneficial when performing operations on a very rough and relatively steep land. For example, in

Appalachia Appalachia ( ) is a geographic region located in the Appalachian Mountains#Regions, central and southern sections of the Appalachian Mountains in the east of North America. In the north, its boundaries stretch from the western Catskill Mountai ...

hardwood Hardwood is wood from Flowering plant, angiosperm trees. These are usually found in broad-leaved temperate and tropical forests. In temperate and boreal ecosystem, boreal latitudes they are mostly deciduous, but in tropics and subtropics mostl ...

area, trees have heavy crowns and are grown on the steep slopes which requires tracked feller bunchers in the operations. Although tracked feller bunchers allow operations on a steep slope, the cost-effectiveness is not well studied. Also, manual felling can operate on the steeper slopes than the feller bunchers do. On the other hand, feller bunchers are cost-effective only when there is a high volume of trees in the operations. If there is not enough

timber Lumber is wood that has been processed into uniform and useful sizes (dimensional lumber), including beams and planks or boards. Lumber is mainly used for construction framing, as well as finishing (floors, wall panels, window frames). ...

to harvest, the unit cost can be expensive, especially when the majority of the operation site is steep slopes. A 2013, University of Maine study suggests that the use of feller bunchers could cause medium to high level of stand damage from 7% to 25%. However, in comparison with other equipment such as harvesters, the damage that is caused by the feller bunchers is less severe.

References

External links

{{DEFAULTSORT:Feller Buncher Logging Forestry equipment Mechanical engineering Forest management