Forest Operations > Conduct Feller Buncher Operations > Feller Buncher Operations Hazard Zones & Work Patterns

Feller Buncher Operations Hazard Zones & Work Patterns

Hazard zones

Before planning any feller buncher operation there needs to be consideration of the hazard zone around the machine.

The rule not to enter the work area within two tree-lengths of a working feller buncher, is designed to isolate hazards associated with the feller buncher operations.

In addition, the hazard zone should take into account the risk associated with debris.

The hazard zone for a disc saw type of felling head during operation recommended by the manufacturer is 91 metres or 300 feet in the cutting direction of the saw blade to prevent being hit by flying debris from the saw.

Clearfell work patterns

The ground conditions, layout of the block (landing and boundary locations), wind direction, and tree lean will influence the felling pattern.

Felling and bunching trees typically start out from the break; felling into standing trees.

Once the you have progressed two tree lengths into the stand of trees, you may then fall the trees onto the clear ground. Bearing in mind you will have to lay the trees in between the already felled trees.

The best preparation of felled trees is to lay the bunched trees in ribbon style with the butts of the trees facing the direction they are to be snigged.  

This has the effect of keeping all the felled trees inside the coupe boundary and reducing debris on access tracks in the forest, which is extremely important in the fire season months. 

Often it is best to first fell the zone within two tree-lengths of the landing site and adjoining road.

This ensures a ready supply of wood close to the landing as the operation commences.

It also reduces any hazards associated with felling too close to the landing site and occupied road throughout the rest of the operation.

Fig 1 shows a blue gum clear fell operation.

The trees are felled and bunched in ribbon style for the skidder to snig to the landing site for processing by the heavy production mobile chipper.

This method allows you to work safely, however the skidder operator snigging trees to the landing site may have to drive past but will notify you of their intentions by 2 way radio.

Fig 1: A typical blue gum clear fell operation, with a track feller buncher harvesting the trees

Fig 2 shows the ribbon style felling and bunching whole trees for the skidder operator.

Fig 2 Felled & bunched blue gum trees.

Fig 3 Feller buncher machine on the left & a Skidder snigging trees to landing site on right.

In figure (3), the feller buncher operator fells and bunches trees as safely as possible.

Then presents the bunched trees neatly, with the tops of the trees pointing in the opposite direction they need to be snigged.

This will ensure that the skidding operation is performed with maximum efficiency.

As the feller buncher operator you have the responsibility of presenting the trees clean, neat and with optimum size bunches to ensure the over all production, quality and efficiency of the whole forest operation.

Bunched trees should not be too small as this could cause inefficiency in the volume of trees being snigged to the landing site.

They also cannot be too big as this will cause the skidder operator to leave 1or 2 trees behind, creating unnecessary additional work.