Large construction sites consisting of huge trees need to be cleared (in unavoidable circumstances) to progress with the construction work. This is where the feller buncher comes into use. 

A feller buncher is a type of harvester that is used to gather and cut a tree before felling it. It can also gather the cut down trees and make it easier for loaders and dump trucks. 

The buncher consists of felling heads that are attachments built to be mounted either to the chassis on a base carrier or a boom. There are three categories of bunchers, of which include: felling head, processing heads, and bunching heads. 

While bunching heads are designed to gather multiple stems and do not include processing abilities, processing heads are capable of felling as well as processing trees. Felling heads on the other hand, are capable of cutting and felling single stems but do not have processing capabilities. 

Mechanical configuration   

Bunchers are of two types:  buncher with wheels and tracks propel bunchers. To mark a major difference, tracked machine is slower than a wheeled machine, however with the added advantage of high stability on steep slopes. Tracked feller buncher is capable of operating on loose and wet soils, whereas wheel/rubber tired machine fails on such grounds. Feller bunchers also have self-leveling cabs that extend the slope on which they operate. 

Operational considerations 

Feller bunchers are easy to maintain and low operational cost machines. Some of the factors an operator must be aware of before handling the machine are: 

• Treatment options 

 Feller bunchers are highly productive felling machines. They can operate well in clearcuts as well as thinnings. This machine has the ability to control the felling of the trees and reduce residual stand damage in comparison with the manual felling. The ability of the machine to maneuver within the stand without damaging the residual is a crucial consideration. Since the buncher does not have any processing capabilities, the whole tree is extracted to the landing. If it is desired to leave the slash in the woods, then a separate topping and limbing operation should be carried out prior to extraction. This machine is a good option in removal of biomass is desired and the stems that are to be removed fall within the suitable bunching head range. Here the kind of treatment, clearcutting or thinning, will affect the size of feller buncher that is to be utilised. If the spacing is too tight for the machine and the trees being felled are huge for the machine, then either the equipment or treatment needs to be reconsidered.

• Physical limitations 

1. Soil conditions : Tracked machines are less prone to compaction, rutting and have lower ground pressure in comparison with the wheeled machine. Drive to tree feller bunchers should traverse more of the stand to reach each tree to be cut which indicates that more of the stand will witness some impacts from the operation.

2. Slope : Tracked machines have self-leveling cabs and are capable of working on slopes up to 50%. But if the tracked machines do not have self-leveling cabs, then they can work on slopes only up to 40%. Wheeled feller bunchers are restricted from working on higher slopes. In addition to the type of machine, the ground and tree conditions will affect the slope at which the machine can operate. Broken ground, rough, or many ground obstructions, larger trees reduces the feasible operating slope.

3. Tree size : Feller weight and the cutting head capacity limit the size of trees that can be chopped off. Cutting trees at the limit of the buncher limits the ability to bunch trees and would need one tree to be felled at a time. This would decrease productivity while  increasing the cost of operation. Also, the cutting trees larger than the capacity of the machine can be proved dangerous to the operator. 

•  System interactions 

Feller bunchers surpass felling of trees and placing them in a convenient location for the further extraction process. However, due to their lack of processing ability, the process must be done utilising some other machine or manually. The capability of the buncher to build and place bunches makes it a most preferred companion to clam bunk skidders, grapple skidders, and shovel operations. 

• Safety concerns

Feller bunchers are built with Falling Object Protective Structures (FOPS) and Rollover Protective Structures (ROPS) to protect the operator. Whether on steep slopes or flat ground, a large tree is heavy and might tip a feller buncher. Climbing or descending the slope with a load of trees increases the chances of a rollover. Rough, broken ground adds to the danger of tipping. Hence care should be taken while moving with the loads, especially in slopes. Another safety concern with the bunchers is, running hot saw heads with broken cutter teeth. These heads spin at high speeds, and broken teeth may be thrown very far at a faster rate. Hence those working around feller buncher must be cautious. 

Feller buncher looks like an excavator, with the tip of bucketnya replaced by a cutting tool and hence it’s operation is similar to an excavator.