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Anything worth
considering is worth reconsidering. Take the two most common
methods of excavating for site preparation of residential
tracts, industrial parks, and large commercial/shopping-mall
areas. They are, of course, the hydraulic excavator used with
articulated trucks or the bulldozer (pusher) and self-propelled
scrapers. Each system is worthy of reconsideration in terms
of which is most cost-effective.
And much consideration
has been given in recent years as to what system is better.
Some site-preparation contractors have settled exclusively
on articulated trucks while others use only scrapers. That
has much to do with where the contractor is in the country
and the prevalent ground conditions he works in. Most projects
that require excavating rock in the form of large cobbles
and larger, or competent rock that needs blasting, are best
served by the use of an excavator with articulated trucks.
Arguably this excavating/hauling system is preferred for excavating
in heavy, wet, and slippery soils that have a tendency to
restrict the efficiency of operating scrapers.
As for light to
heavy soils with relatively low moisture and no appreciable
rock in the soil, the scraper is very effective, providing
that the haul distance from point of excavation to the point
of dumping is less than 2,000 ft.
All of this mentioned
about the two excavation systems are the sentiments of Jack
Muschlitz, vice president of Muschlitz Excavating Inc. in
Bath, PA. His opinion is that both systems are effective for
his company’s applications, depending on the given project.
Muschlitz is one
of three family partners who founded the company in 1990.
The other two partners are his father Ronald and brother Dave.
Ronald manages the residential-site projects, and David acts
as a job foreman. Jack supervises all of the commercial and
industrial-site projects.
Jack is a firm
believer in both excavating systems and advances the argument
that, for the area the company serves, there are excavating
ground conditions that lend themselves to both articulated
trucks and scrapers. He explains, "We have some projects
where the cuts are not too deep and the ground to be excavated
is practically rock-free. The cycle distances also are very
short. Here, scrapers do very well. We also have sites where
the haul distances are 2,000 ft. or more or the ground is
too rocky or too wet for operating scrapers, so we use excavators
and articulated trucks."
Here is a lineup
of equipment the company currently uses for excavating and
hauling on site-work projects. There are five Volvo A30C (30-ton-capacity)
articulated trucks and six 20-yd.3-capacity Caterpillar
627E scrapers. Caterpillar D-8 bulldozers are used to push
the scrapers. At present, Jack has three different makes of
100,000-lb. excavators demonstrated on a project for deciding
which one to purchase. One of the excavators is a new Volvo
model 460. Two reasons he is evaluating the Volvo excavator
is because of the very attractive pricing and because the
company owns one each of Samsung model 350 and 130 excavators,
and Jack finds both to be quite satisfactory in performance.
Noteworthy is that the Samsung product line was bought by
Volvo, and now the excavators are sold under the Volvo label.
Volvo has made many design improvements to excavators.
The Volvo excavator
is loading the five Volvo trucks at the Lehigh Valley International
Airport. This project calls for making a deep cut between
the end of a runway and an apron. The purpose of the cut is
to bring to grade and increase the size of the apron. The
excavated ground is used for backfilling a low area at the
end of the runway for the purpose of lengthening it. Once
completed and paved by others, the runway will accommodate
the landing and taking off of larger jet aircraft.
The use of articulated
trucks currently proves more cost-effective than scrapers,
according to Jack, because the cycle distances are 6,000-8,000
ft. Another reason is that there is too much loose rock in
the soil for using scrapers. The production is averaging 5,000
yd.3 per 10-hour shift.
The total quantity
of ground to be excavated is 125,000 yd.3 Once
the project is completed, the trucks will be moved to another
project. The next project is a commercial site that calls
for the excavation of 500,000 yd.3 of ground and
limestone rock. Once the overburden has been stripped using
the scrapers, the rock will be drilled and blasted, followed
with a hydraulic excavator digging and loading the Volvo trucks.
"This is one
of those projects where both trucks and scrapers need to be
used for excavating it at the least cost," Jack notes.
"We have our share of rock projects. In fact, I would
say about half the projects have rock to be excavated."
Rent Them, Buy
Them
Since at least
half of the projects include rock excavation, the company
owns two of the Volvo trucks, which were purchased last year.
The other three are on rent, but that could change depending
on future work for the company. Jack says he generally will
not rent equipment more than six months at a time because
it becomes no longer economical. Rather than continue further,
he takes the option of purchasing.
He would rather
buy new trucks than used ones. By comparison, he prefers to
buy used scrapers. The reasoning is that he finds he can justify
the purchase of new trucks but not scrapers. The advantage
to purchasing used scrapers is that they depreciate less because
of the lower purchase price, and thus this lower depreciation
figure is spread over the scraper’s total production,
keeping the cost per yard excavated lower.
Jack states there
are three factors he considers when buying new equipment,
such as the Volvo trucks: production performance, reliability,
and–least important–purchase price. "I realize
a lot of contractors make the price of equipment the most
important factor when buying new equipment. I do not consider
only the price for the simple reason that it is [more about]
how well that machine performs and its reliability. If it
produces higher and is more reliable than a lower-priced machine,
I will more than likely opt for the higher-producing machine.
It is the profitability of the equipment and not its first
cost that I am interested in," Jack emphasizes.
It’s working
for this company: using both excavation methods, that is.
The company started only 10 years ago and has grown into a
profitable $10 million company that employs 65 people. Business
activities have been robust year-round, with the exception
of occasional interruptions caused by winter weather.
Author Rodney
Garrett of Bernville, PA, specializes in construction subjects.
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