Parker GOLD CUP® And Premier Pumps Drive ... - launchrun.com

CUSTOMer
Cottrell Contracting
Corporation
APPLICATION
Dredge Lexington
SOLUTION
Parker GOLD CUP
P30S pump (cutter head)
and Premier P16/P12
tandem pumps (winches,
spuds, anchor, carrier)
VALUe
Precision cutter control
for new deepwater
market opportunities;
6 years continuous
GOLD CUP operation.
Hydraulic Pump Division SUCCeSS STOrY: Cottrell Contracting
Parker GOLD CUP ®
And Premier Pumps Drive Dredge
362 Days-A-Year Under Massive Torque Demand
ABOUT COTTRELL CONTRACTING
CORPORATION
Cottrell Contracting Corporation has been engaged
in the hydraulic cutter suction dredging business since
1928. Over the years, its areas of operation have
grown from the Virginia/Maryland regions in the 1930s
and ‘40s to the entire eastern seaboard today.
Cottrell Contracting serves a wide variety of customers
from government agencies to private industry groups,
undertaking new work as well as maintenance dredging
projects. In addition, the company specializes in habitat
creation and environmental restoration projects.
ABOUT DREDGE LEXINGTON
Over its 80-year history, Cottrell Contracting has
performed both shallow and deepwater projects. The
company has the capacity to pump sand from any
inland borrow site to be placed on the beach up to
eight miles. Dredge Lexington is built to ABS standards
that allow it to operate in an ocean environment,
with the capability to mine sand from either inland or
offshore sites.
Lexington with spuds extended and piping system behind
Dredge Lexington Stats
Dredge Type:
Length:
Breadth:
Weight:
Pipe Size:
Pump HP:
Total Installed HP:
Spud Carriers:
Cutter Section
200 feet
38 feet
800 gross tons
18-inch I.D.
2,000
4,250
2
THE CHALLENGE
“The hydraulic method of dredging and material
transport has been around forever,” points out
Jimmy Cottrell, Vice President, Cottrell Contracting
(Chesapeake, Va.). “Our success is that we have
been able to stay on the cutting edge of the
technology to upgrade old systems to ones that
are more precise and efficient."
“Our dredge Lexington has now been in service
for seven years doing maintenance and navigation
dredging along the Atlantic Intercoastal Waterway for

Figure 1A: Lexington’s cutter head HPU (Parker Premier pumps in background)
Figure 1B: Lexington’s suction cutter
most eastern seaboard deep water ports and
harbors. With the ability to dredge down to a
depth of 65-feet, Lexington utilizes a suction
cutter (Figures 1A & 1B) and piping system
(Figure 2) to excavate sand, mud, and hard
packed clay.
“All of this is accomplished hydraulically, where
the cutter head cuts the material that is then
evacuated through a 2,000-horsepower
centrifugal pump and pipeline system that can
extend 20,000 feet without the need of additional
pumps. Depending on the specific gravity of the
material being dredged and pumped, we have
additional pumps that can be put in the pipeline
as needed.
THE SOLUTION
“The ‘heart’ of the hydraulic system,” Jimmy
continues, “consists of Parker GOLD CUP ® and
Premier tandem pumps. A P30S GOLD CUP
pump drives the cutter head hydraulic motor in
an advance design suction cutter system from
the Netherlands with strong rotating teeth. This
allows us to work a multitude of hours before
the teeth need changing depending on the
material being cut.
"Parker P16/P12 tandem pumps drive the rest
of the winches and spud system (Figures 3A
& 3B). They are located in the hydraulic power
Figure 2: The piping evacuation system is
towed behind Lexington

A P30S GOLD CUP pump drives the
cutter head
unit (Figure 4). This allows us to control and
manipulate the winches, which swing the dredge
back and forth from side-to-side and raise and
lower the dredging ladder with the suction cutter
weighing a combined 83 tons. Additionally, the
Parker P16/P12 tandem pumps drive two
30-inch diameter 83-foot long spuds that are
raised and lowered by hydraulic cylinders to
accurately position the dredge within the cut.
P16/P12 tandem pumps also drive the anchor
and carrier.
Figure 3A: Swing ladder and starboard anchor winch
Premier P16/P12 tandem pumps drive the
winches, spud system, anchor and carrier
“The ability to accurately position the dredge
within the cut is important in that we only
get paid by the material that is within the pay
template. The torque demand is massive. In
effect, dredging is the equivalent of the demand
in the mining industry that requires the greatest
safety factors because the entire system is
under strenuous load 24/7. Dredge Lexington
operates 24/7, 362 days-per-year. There are
only three days off for the Christmas holiday.”

THE RESULT
“The suction cutter Parker GOLD CUP P30S
pump worked continuously for six years before
a replacement was needed,” notes Jimmy.
“That is a very long time for a hydraulic pump.
Recently, we had the two Parker Premier swing
winch pumps inspected, and they showed very
little wear.
“Summed up, the hydraulic system we’re using
has been very good to us. It is very precise in
swinging the machine and moving within the cut
we’re trying to dredge. Again, we only get paid
within the desired dredge template. Dredging by
nature is a very inexact science. So, long story
short, we are able to concentrate on moving the
material we get paid for more economically. Part
of our cost success with our customers is that
we only handle the material one time—we cut
it and it goes through the pipeline to the
deposal site. There is no double handling like
there is with bucket dredging that puts the
material on a hopper dredge or scow and then
carries it to another site and off loads it. That’s
very inefficient.
“Prior to designing, building and launching
dredge Lexington, our work with our three other
dredges was limited to shallow draft projects.
They are electric-based and work through
pinions, gears and clutches. Hence, the control
is not as great. With Lexington, we have been
able to do very precise work in a whole new
deepwater market that has given us many
more chances at success—the ability to costeffectively
dredge deepwater harbors, aircraft
carrier piers and nuclear submarine bases."
© 2012 Parker Hannifin Corporation 2/2012
Parker Hannifin Corporation
Hydraulic Pump Division
14249 Industrial Pkwy.
Marysville, OH 43040
phone 937 644 3915
fax 937 644 0827
www.parker.com
www.phpump.com
Figure 3B: P & S swing and port anchor winch
Figure 4: Cutter head HPU (left), swing anchor,
and spud system HPU (right); tank unit shown
in background.