Increasing Efficiency in Green Waste Reduction
Selecting the Right Chipper or Grinder for your Operation
Most logging operations face — probably routinely
— the same issue: a need to get rid of “slash” and tree
tops left behind after usable timber is harvested from a site. Some operations
have the means to take care of this material themselves. Others hire contractors
to do final cleanup or even complete land-clearing. Either way, someone
needs the right equipment for the job, which typically translates into
a large brush chipper, or a tub or horizontal grinder.
Chipper or grinder?
Two primary criteria are often crucial for clearing operations
when making equipment selection decisions: mobility and productivity (and
the first usually has a hand in the latter). But, the usual size of areas
being cleared is a key consideration as well.
For example, if the land being cleared is most often
limited to one to five acres, a large portable brush chipper is an option.
And, assuming that the slash left behind would mostly involve smaller-diameter
material (compared to usable timber) in this size range, these machines
would be sufficient.
But, if the majority of jobs involve five acres or more,
jumping up to a horizontal or tub grinder may be the best bet. One could
assume that logging operations are most often harvesting land that falls
into this category. In fact, most statistics show that logging involves
40 acres or more, even if it’s a selective harvest.
With respect to mobility, larger chippers are usually
towed, which can be a challenge when trekking through narrow trails of
a forest. In those cases, grinders equipped with tracks, which do not
require a tow vehicle for movement around a jobsite, can be a distinct
mobility advantage. Then come productivity considerations. Larger horizontal
and tub grinders can range from 300 HP to 1000 HP and up. Obviously, they
grind greater volumes of material, and they are faster than smaller machines.
In addition, the size capacity of the units requires less handling of
the branches, with horizontal models featuring 14 to 20 ft. feed tables.
One final consideration: some land-clearing operations
sell the end material as a commodity product, such as mulch for landscaping.
Mulch yards (buyers) sometimes require a uniform chip size. Larger grinders
give you the ability to size the product while chippers usually do not.
Grinders for larger jobs
For many years, both types (tub grinders and horizontal grinders)
have been successful in the market. Both excel in conditions and applications
that match up with their capabilities. In short, tub grinders generally
perform better with heavy, large-diameter material such as stumps and
root balls. Certainly, a logging operation may leave behind unusable stumps.
If stumps are the majority of cleanup, tubs are a good option. But, if
processing longer raw material is the consistent application, a horizontal
model may be the best choice.
There are other considerations though. Smaller loading
equipment can be used for horizontal grinders, because they typically
have a lower feeding height than a tub grinder. This could be a major
factor, depending on the auxiliary equipment an operation has on-site.
These grinder “categories” sometimes come
with options that are specific to each. In a situation where a single
job site may have several debris piles —such as a land-clearing
job, the self-propelled track-mounted option can be highly efficient.
So rather than having to tow the machine short distances, it can be moved
by the operator, possibly into areas where it could not be towed.
Among the primary advantages of having a grapple loader
on your tub grinder is better visibility of the tub; the loader cab provides
excellent view of the tub cavity, so operators can load material more
efficiently. It also helps the operator identify and clear contaminants
mixed in with material. Self-contained loaders may also eliminate the
need for extra pieces of equipment, because transporting or renting a
loading unit may not be required.
Non-loader machines are common on work sites that include
a fleet of multi-purpose loading equipment. Some non-loader tub grinders
require multiple auxiliary loaders to meet the production capabilities
of the machine.
With so many options to consider, selecting the right
equipment for land-clearing can be a challenge. But choice is a very good
thing. Brush chippers, for example, have traditionally been used in tree-care
applications. Now, larger models have made their way into the land-clearing
market. Just a few years ago, tub grinders dominated the market for 400
HP and above. Since then, horizontal options are on the rise, and now
tracked models are proving their worth among more and more processors.