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Preparing sites for new construction receives
as much negative publicity as anything in our industry, often
because the complainers have a narrow and inaccurate view of what
is happening. There are countries where the destruction of natural
resources has been uncontrolled and little thought has been given
to the infrastructure or health of future generations, but we
have been fortunate in the United States in that few of our land-clearance
projects have precipitated disasters for the communities in which
they are located. Most states, for example, have developed strict
and sensible regulations about what you can and cannot do with
living trees. Before you start any clearance you should check
those local rules, bearing in mind that this is not a battle but
cooperation between professionals for the benefit of everybody
in the community.
Say "land clearance" and many people think
of beautiful trees cut down, but that is only part of the picture.
There have been movies that depict land-clearance workers as villains
because they cut down Boy Scout cabins by Lake Gitcheepooree or
ruin the secret trail to the hunting grounds behind the Leaning
Cypress Country Club. Most land-clearance projects are nothing
like that. They are well-planned, well-regulated, and completed
without melodrama.
Sample Regulations
Trees are the principal beneficiaries of
protection by public authorities—trees and all the other aspects
of nature that rely on them. That includes us. "Trees transpire
considerable amounts of water each day and assist in purifying
the air," says Rick Joyce, director of the Lee County Division
of Environmental Services in Fort Myers, FL. "They precipitate
dust and other particulate airborne pollutants from the air and,
through their root systems, play an important part in countywide
soil conservation, erosion control, and flood control. Trees supply
shade for the community and cool the air and land. They reduce
noise levels and glare. The protection of trees in our county,
then, is not only desirable but essential to the health, safety,
and welfare of all our citizens, present and future." Protecting
trees is not just a role for registered environmentalists. (Mind
you, we all occupy and rely on our environment, so who isn't an
environmentalist?) "Some trees are more beneficial than others
as necessary contributions to our county's environment and it
is not necessary to protect each and every tree in order to attain
the publicly beneficial result of a tree-protection program,"
Joyce explains.
"We have worked hard to evolve our working
relationship with land-clearing and site contractors," Joyce adds.
"We attempt to be responsive and realistic about fill amounts,
site excavation, grading, and the retention of trees. These efforts
are improved by having five certified arborists on the ES [Environmental
Sciences] staff. We have also evolved our vegetation-removal process
to be pretty straightforward, with clear parameters for approval.
All of this has resulted in fewer time delays, less arm wrestling,
and fewer violations—a good thing for all involved."
Are any trees exempt from the regulations?
In many counties nationwide, you can remove trees if they are
on public rights of way and their removal is done by or on behalf
of a state, county, federal, municipal, or other governmental
agency in pursuance of its lawful functions and activities in
the construction or improvement of public rights of way. You can
remove a protected tree if it is dead, or if it has been damaged
or destroyed by natural causes beyond saving, or if the tree is
a hazard as result of an act of God and endangers life and property.
After severe thunderstorms, floods, tornadoes, and hurricanes
there is plenty of land clearance, more than anybody wanted. Water,
electrical, sewer, and communication companies can remove protected
trees if they are in or adjacent to a public easement or right
of way, as long as the removal is limited to areas necessary for
maintenance of existing lines and facilities or for construction
of new lines and facilities required to provide essential service
to the community. There are other exceptions to the "no cutting
down the trees" rule, so you can see that the regulations involved
have a large measure of common sense in them. From our research
it appears that we should not cut down protected trees unless
the removal is beneficial to a community's growth and healthy
survival. That would usually mean that you can cut trees, say,
on a lot zoned for single-family residential use—a lot, in many
communities, that is less than 5 acres.
Cooperation at the
Site
At some sites the clearance of wooded areas
is done by two separate groups. The first comes in with its chain
saws and cuts down the trees, and then takes the trunks away for
use by the timber industry. The second group (often grading and
excavation contractors) then comes to clear the branches, take
out the stumps, and grade the site to its specified standard for
building. This second group uses chippers, stump grinders, and
tub grinders to turn vegetation into useful byproducts and to
reach the level of clearance that the builders see. At Toyota's
site for its new production plant (a 2,000-acre site in South
San Antonio, TX) one company undertook all the work.
Houston-based W.T. Byler Construction LP
specializes in grading, excavation, soil stabilization, paving,
and railroad construction. "We usually subcontract the land-clearance
work," notes Jimmy Price, project manager for the contractor.
"This job for Toyota was so big, however, that we decided to take
it on for ourselves." W.T. Byler has enough employees—almost 500
of them—but needed to rent the necessary timber-processing equipment
because it was something not used every day. There were some basic
challenges. "Toyota is really strict about all of the environmental
aspects of any job," Price adds. "Our contract required that we
implement several erosion control measures into the land clearing
and mulching processes. We built a complex structure around the
site to filter out all wood chips, rocks, and silt to keep them
from entering a nearby river and creek." Add to that the stipulation
that the land clearance had to be completed in a two-month window,
in the months of January and February. They are seldom favorite
work months in any state.
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Choosing the right grinder
was important because speed and efficiency were essential. The contractor
received many proposals from manufacturers, several of whom advised
the work couldn't be completed in the scheduled time. "A Vermeer
factory representative visited the site and brought along an HG525,
a 525-horsepower horizontal grinder," Price recalls. "We saw it
in action. I couldn't tell that a competitive 1,000-horsepower grinder
was doing any better than the Vermeer, so we gave the Vermeer grinders
a try, and we're glad we did." The company rented two, one with
tracks and one with wheels; the tracks would serve well if it were
wet or raining. The Vermeer HG525 horizontal grinders have a high-capacity
infeed system, a patent-pending SmartFeed system, and the first
standard thrown-object deflector for horizontal grinders. At the
Toyota site, the crew of 28 used both grinders constantly, 10 hours
a day. The estimated production was about 80,000 yards of trees
in the two months specified for the job.
At a very different site, some 15 miles north
of Tucson, AZ, 80% of the 1,035 acres for Saguaro Ranch will remain
undisturbed, natural open space. Parcels for the single-family
luxury residences will be 4 to 5 acres. The ranch is an upscale
residential development situated at the base of Tortolita Mountain
Park. "The greatest challenge related to infrastructure development
on the project is ensuring that the sacred desert setting is treated
sensitively," notes Dan Keeley, vice president of KE&G Development
LLC, the contractor handling all infrastructure development. The
company has been based in Arizona for more than 30 years and employs
275 people. "The owner of the project, Saguaro Ranch Development
Corporation, is committed to developing the property with a new
standard of minimal environmental impact."
One way in which the KE&G crew is managing
the project's environmentally stringent requirements is by using
an unusually large and powerful machine in the clearance and preparation
work. It's another Vermeer, a 600-horsepower, 220,000-pound surface
mining machine usually called a terrain leveler. After salvaging
native plants and collecting boulders, the contractor's crew uses
the Vermeer T1255 Terrain Leveler to establish the roadway subgrade.
"This machine cuts the rock in place instead of fracturing it
on a seam," Keeley observes. "It's less invasive than some other
methods and offers minimal disruption of the terrain outside the
working space." The terrain leveler can be used for trenching
at the site when the milling attachment is replaced by a trenching
boom.
Using the Waste
One of the reasons that
land clearance was viewed so negatively was that all the waste generated
by sawing and cutting, pulling, and tearing used to be just that:
waste. For some years now, land-clearance contractors have realized
that the materials they generate have value to others. It may be
the mulch made by grinders and chippers that is used residentially.
It may be the tree trunks that are taken for processing to lumber
mills. In days gone by the "rubbish" used to be taken to the landfill.
Then the landfills didn't want it because they had so little space
available for uncut branches and tree stumps. To take the materials
from cleared land to the landfill became expensive.
Instead of throwing materials away—and paying
to do so—many contractors looked for ways to profit from them.
In some states, they make arrangements with other contractors
for mutual profit. An example would be the land-clearance contractor
who grinds up the debris and gives it to a hauler who transports
it (by the truck load) to electric plants and paper mills. The
contractors do their work for nothing! The land-clearance company
doesn't pay the other for hauling away the debris and the hauler
has free cargo for his business. It works well for everybody.
Among other practical and beneficial uses for the debris of land
clearance is its ending up as the base for mat systems that prevent
soil erosion. It's a kind of mulch but, in some ways, more important.
Wind and rain in storms precipitate soil erosion and so does some
road and house construction. The wood from grinders can stabilize
the ground, prevent unwanted chemicals from going into rivers
and streams, and protect the topsoil for future growths. The second
layer of soil is frequently incapable of supporting plants.
Dozers in Land Clearance
You
expect to find saws, chippers, and grinders in land-clearance
work, but there are still contractors who remove trees with a
dozer. Dozers have been successful for small tree and shrub clearance
at many sites where houses, small shopping centers, or apartments
will be built. Those are often the sites that just look messy
before site preparation, with no large trees or other obstacles.
Dozers are excellent machines for removing rocks and boulders,
too. A grading and excavation contractor can sometimes do the
land clearance with his existing equipment. If this is the method
you choose for your site—maybe because you have a powerful
dozer and only a few trees to remove—there are precautions
to take.
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We gleaned the following
words of advice from several contractors. All of them warn you to
be cautious, to look up to see what is happening above you, to look
around to see that nobody is within harm's reach, and to determine
before you proceed with the dozer the direction in which the tree
will probably fall. For small trees (with diameters less than 4
inches) and brushwood, experienced workers recommend that you put
the blade a few inches below grade and travel forward slowly. The
first pass will probably knock over small trees and brush. Your
second pass will clear them away to a pile for collection and removal.
If the trees have diameters between 4 and 10 inches, you would raise
the dozer blade for increased leverage. As the tree begins to fall,
back away smartly to clear the roots that are coming up, then go
forward again with the blade lower to dig the roots free with the
dozer's pushing and lifting action. If you want to use a dozer for
large trees (more than 10 inches across), it's a slow job. Check
the tree first to see if there are dead branches that could fall
on the dozer (and you). When satisfied that you won't shake limbs
down, move the dozer forward with the blade high and centered on
the trunk as much as possible. Some contractors recommend that you
attack large trees with large root systems from more than one direction.
Make a cut on the side of the tree opposite to the direction of
its likely fall. Go down to cut away some of the larger roots there.
Then do the same on either side of the tree, so that you have three
sides of a rectangle. If you build a ramp above that first cut you
can get good leverage for pushing the tree down. When the roots
start to come up, get back.
It would be wise to protect the dozer. If
possible, protect the engine from branches (even small ones) with
side covers. If you are using more than one dozer, it will be
better if they are not working closely together. Protect your
workers, too. Many of the trees you uproot will not be dead and
they will want to unbend and fly back when they dislodge themselves
from any tangles. Most of the damage caused to dozers in land
clearance seems to come from limbs puncturing the radiator or
breaking a hydraulic line. Final advice from those who have done
this before: It is easier to bring down a whole tree with a dozer
than to cut it down to a stump and then try to doze away the stump.
One of the most interesting related tools we've seen is the tree
saw from attachment maker Rockland; it goes on the front of a
dozer.
Equipment for Land
Clearance
Much of the equipment
you need for land clearance is already in your yard, but you will
need to get the specialized items. A caution about everyday tools
like chain saws: they can be, literally, lethal and should never
be treated as if everybody is an expert. For the shredding, grinding,
and chipping, there are several companies that specialize in this
kind of equipment. Names that spring to mind are Morbark, Vermeer,
Bandit Industries, Packer Industries, Diamond Z, Peterson Pacific,
Rockland, Valby, and Universal Refiner. The machines are built to
be durable and safe. One of the best changes in the last several
years has been the standardization of enclosed operation or a thrown-object
restraint system.
The Predator Shredder from Morbark is now
available in a configuration on a fifth-wheel frame. With a two-
or three-axle design, the machine is more portable and offers
contractors quick setup time. The Predator usually processes the
more difficult materials, such as construction-and-demolition
debris, railroad ties, and others that are not suitable for high-speed
grinding. Horsepower ranges from 325 to 455. Two of Morbark's
hand-fed brush chippers (the 2070XL Twister and the 2050 Clipper)
now offer two knife drums as standard. What this means for productivity
is that there are two cuts per revolution instead of one. Other
features of the compact Clipper that may appeal to land-clearance
contractors are the torsional axle (for stability), wheels independent
of each other for smoother towing, and that heavy-duty tubular
steel-welded frame.
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When usable timber has
been removed from a land-clearance site, the remaining materials
are often referred to as "slash." To handle this waste, you need
a large brush chipper, a tub, or a horizontal grinder. Which is
best? If the land involved is 15 acres, a large towable brush chipper
may be your best choice. Vermeer has several models in this range,
with capacities for handling diameters of 18 to 20 inches. If the
acreage involved is more than 5 acres, you may be more productive
with a tub or horizontal grinder, Vermeer advises. Larger chipping
machines are often towed, but Vermeer offers some models with tracks
for negotiating the site more easily. Another advantage of a grinder
versus a chipper, even from the same manufacturer, is that the larger
grinders give you the ability to size the end product. Chippers
usually can't do that.
Check the Web sites of the manufacturing
companies mentioned above. You will find good, detailed information,
and there is advice available on the selection of the most appropriate
equipment and techniques for your particular applications.
Grinders wear out; that is the nature of
their function. If the hammers are allowed to go without the correct
maintenance for any length of time, the hammermill could go out
of balance, causing unnecessary wear on the bearings and several
other (costly and dangerous) accidents related to excessive vibration.
One reason why maintenance used to be ignored by too many contractors
was that it took so long. Replacing teeth and hammers could take
a whole day. Today, companies like Vermeer have designed machines
where the operator can change an individual hammer in minutes,
without removing the other hammers. When you shop today, make
sure the hammers are reversible, too, to double their service.
Safety is our final aspect of land clearance,
but it is also the most important. Everything happening in a land-clearance
operation is breaking, cutting, pushing, pulling, and reducing.
Every action is dangerous to the person doing it, but probably
more hazardous to any careless bystander. There shouldn't be any
bystanders! Before the saws cut and the dozers push and the grinders
grind, every worker should know what is going on where, and how
to stay a safe distance from any flying objects. Horizontal grinders
have become so popular because they tend to minimize the danger
of flying objects, but experienced contractors say the occasional
flying menace is something everybody should be alert to. Ask your
chosen manufacturer about the safety features of the equipment.
Tell your crews about all the dangers at the site.
Paul Hull writes on construction and environmental
topics for several magazines.
GEC
- November/December 2004
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