1A-4 Parker

Proceedings, WEDA XXXII Technical Conference & TAMU 43 Dredging Seminar

DREDGE “OREGON”: REPOWERING AND REFIT
Christopher Parker, P.E.1
, Walt Haynes, P.E.2
, Marcel Hermans, P.E.3
ABSTRACT
The average age of the U.S. dredging fleet has increased steadily to 25 years of age, and continues to increase. This
trend suggests a rising need for repowers and retrofits. The apparently simple task of repowering an older dredge
involves complex program and project-related issues.
Determining the scope, performance requirements, schedule, costs and funding sources are complex tasks in
themselves, and are interrelated. Additionally, with both the regulatory and equipment capability environments
changing over time, properly defining project goals and objectives can become a tough challenge.
The Port of Portland is currently in the process of repowering and refitting its 76.2 cm (30-inch) cutter suction
pipeline dredge, the Dredge OREGON.
This paper provides an overview of the general considerations the Port of Portland used in defining a solution to
these complex and interrelated tasks. Determining scope, defining the performance specifications of major
equipment and controls, defining budget, procurement strategy and schedule, and evaluating grant and other funding
available for repower and refit of a cutter suction dredge are all described.
This paper also provides specific insights on how the Port of Portland dealt with these decisions for the Dredge
OREGON repower and refit project, including insights into the Port’s decision to pursue repowering versus
procurement of a newly built dredge.
Keywords: Efficiency, engines, fuel savings, emissions, funding, repower
INTRODUCTION
The average age of the U.S. dredging fleet has increased steadily to 25 years of age and continues to increase
(Anonymous, 2009). This trend suggests a rising need for repowers and retrofits. The apparently simple task of
repowering an older dredge involves complex program and project-related issues. The Port of Portland is currently
in the process of repowering and refitting its 76.2 cm (30-inch) cutter suction pipeline dredge, the Dredge
OREGON. The project is scheduled to be completed in May of 2014.
Determining the scope, performance requirements, schedule, costs and funding sources are complex tasks in
themselves. They are also interrelated, which makes the total process even more complex. Additionally, with both
the regulatory and equipment capability environments changing over time, properly defining project goals and
objectives can turn out to be a tough challenge.
The Dredge Oregon: A Typical U.S. Dredge
In many ways, the Port of Portland’s Dredge OREGON can be called typical of lots of other dredges currently in
service in the U.S. Like many other dredges in the current U.S. fleet, the dredge OREGON has for many years been
successfully using technology that dates from just after World War II. The dredge has a season-averaged production
rate of about 19,000 m3
(25,000 cubic yards) per day of Columbia River sand (D50=350, D85=805).

1
Project Engineer, Port of Portland, P.O Box 3529, Portland, OR 97208, USA, T: 503-415-6401, Fax: 503-548-
5617, Email: Christopher.Parker@portofportland.com
2
Engineering Project Manager, Port of Portland, P.O Box 3529, Portland, OR 97208, USA, T: 503-415-6343, Fax:
503-548-5772, Email: Walt.Haynes@portofportland.com
3
Engineering Project Manager, Port of Portland, P.O Box 3529, Portland, OR 97208, USA, T: 503-415-6305, Fax:
503-548-5992, Email: Marcel.Hermans@portofportland.com
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The dredge’s hull is a repurposed riverboat, built in 1945. The vessel was re-commissioned as a dredge by the
Bauer Dredging Company in 1965. The repurposed hull houses a Cooper Bessemer LSV-16 four-stroke diesel
engine rated at 3,717 kW (4,985 hp) for the direct drive main pump, turning at 360 RPM.
Figure 1. The Dredge OREGON’s Cooper Bessemer LSV-16 four-stroke diesel engine.
Two 1965 vintage Cooper-Bessemer JS-8 engines serve as primary and backup generators. Each four-stroke diesel
engine is rated to produce up to 753 kW (1010 hp).
Based on an average season, the current fuel consumption for the Dredge OREGON plant is about 2.3 million liters
(600,000 gallons) per year.
The dredge pump is a 1965, rubber lined type featuring a 213 cm (84 in) impeller with 43 cm (17 in) vane separation
and a 76 cm (30 in) diameter outlet. The Port owns and maintains the tooling for many of the pump’s components.
The rubber-lined pump has an estimated pumping efficiency of approximately 65%. Modern, high chromium white
iron pumps are reported to carry estimated efficiencies of 85 to 90%, making pump replacement a worthy
proposition.
As far as pump design is concerned, there are competing interests to pump efficiency, as the modern dredge pump
typically has a smaller vane separation that may lead to more frequent debris-induced shutdowns than currently
experienced on the Dredge OREGON.
An additional benefit to obtaining a new pump is being able to procure “off the shelf” impellers and other
components on reasonably short notice (six weeks), versus a long procurement effort using the Port’s tooling (12
weeks minimum).
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Figure 2. The Dredge OREGON’s rubber-lined pump casing.
Figure 3. One of two Cooper-Bessemer JS-8 engines, serving as primary and backup generator.
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The cutter head motor is a wound rotor AC type, rated for 600 kW (800 HP), with an associated resistor bank used
for speed control.
Figure 4. The Dredge OREGON’s cutter head motor and gearbox.
REASONS TO ACT: REPOWER OR REPLACE
Given Dredge OREGON’s great record of performing cost-effectively and reliably, the question could be asked why
one would even consider refitting or replacing the OREGON: “If it isn’t broken, why fix it?”
This project’s motivation came from several drivers that, when combined, make repowering and refitting the dredge
a compelling decision. Many of these same factors apply to other dredges in the U.S. dredging fleet as well, and
will do so increasingly in the future:
 Reliability concerns associated with the difficulty of obtaining replacement parts for old engines.
 Increased fuel costs and the resulting change in balance between efficiency and cost-effectiveness.
 EPA-mandated changes to diesel engines that will likely add significant costs to future projects.
 Owner’s focus on environmental stewardship and green initiatives, including reductions in emissions of
CO2, NOx, SOx and diesel particulate matter.
 Current window of opportunity as to grant funding for voluntary measures: Future legal requirements for
emission reductions will make grant funding less applicable and obtainable.
Reliability Concerns
Replacement components for the out-of-production 1965 vintage Cooper-Bessemer engines have become
challenging to locate on short notice. This has required the operation to carry a large inventory of spare parts that
would not otherwise be needed. In some cases, the parts needed for this backup inventory have taken more than a
year to be located and procured. The lack of readily available spare parts is a risk to the operational readiness of the
dredge. Cost to procure and inventory these components also places a financial burden on the operation. Given the
impacts of a potential long-term dredge shutdown caused by an equipment failure that cannot be quickly resolved, it
simply becomes unacceptable not to have main replacement components available, regardless if the chance of
failure is very low.
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Fuel Efficiency and Cost Effectiveness
Over the last several years, the Dredge OREGON’s operations consumed nearly $2 million in fuel per year.
The approximate financial benefits of fuel efficiency upgrades can be derived simply by multiplying that cost by the
percentage of fuel efficiency improvement that would be accomplished. In the particular case of the Dredge
OREGON, fuel economy is expected to be enhanced with the use of modern electronically-controlled engines, a
modern dredge pump, and use of a Variable Frequency Drive (VFD) for cutter head speed control.
As shown in Figure 5, these items (main pump engine and the generator sets) currently consume about 89% of the
fuel budget of the Dredge OREGON’s operations.
Figure 5. Share of fuel use of different components of the Dredge OREGON operations.
Fuel prices have increased steadily over the past decade. As fuel costs represent an increasingly larger portion of
operational costs, the operational cost savings to be gained from a repower also become more significant (both
relatively and in absolute value).
Quantifying the actual fuel savings to be expected is a difficult task. This is because the fuel efficiency is very
sensitive to the total horsepower being produced versus the engine’s capacity. Typically, as engines are loaded to a
smaller percentage of their rated power, their efficiency decreases. A typical curve showing liters/Btu or liters/Kw-
hr (gallons/hp-hr), also known as “Brake Specific Fuel Consumption” (BSFC) is shown below.
As can be seen in Figure 6, a diesel engine’s fuel consumption, expressed as BSFC, could increase by 50% if its
operating load drops from within the 50-100% range to a value in the order of 25%.
68%
21%
2%
2%
5% 2%
Oregon Pump Engine
Oregon Generator Set
Crew Boat 'Deliverance'
Tender 'Don'
Tender 'Williams'
Tender 'Clackamas'
Source: Estimated based on Dredge OREGON tender fuel log, Oct. 2008 and average 19,000 liters
(5000 gallons) of diesel/day
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Figure 6. Typical brake specific fuel consumption graph showing that optimal fuel efficiency occurs between
50 and 100% load.
Because the Dredge OREGON operates in numerous locations with varying loads, predicting its actual fuel savings
with any reasonable precision is unfeasible. Insights obtained from industry experts, including dredge and tug
operators with recent experience in similar repowering efforts and pump replacements, led to a rough estimate of
40% fuel reduction as a likely realistic target value.
EPA-Mandated Changes
Based on accepted findings and general consensus that diesel particulate emissions are carcinogenic, the
Environmental Protection Agency (EPA) has partnered with industry to establish a tiered implementation to
introduce technology that reduces diesel particulate matter emissions. As with any piece of legislation affecting
multiple stakeholders, the legislation is complex and contains many exceptions and special rules. Those considering
a repower around the time this paper is published are advised that this implementation will result in marine engine
offerings changing from Tiers II through IV in the period from the year 2012 through the year 2017.
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Asking engine manufacturers what engine technology may be available from their companies has also proven to be
problematic. As example, the Port had assumed a Tier II engine would be available in accordance with the EPA
guidance; but a special rule has allowed manufacturers to delay implementation of technology for rail applications,
if they accelerate implementation for marine applications. Many manufacturers are using this special rule for their
larger generator sets. These Tier III engines are newer technology, which is not always a good thing aboard a
dredge, especially since a troubling mismatch can result from installation of such unproven, somewhat high-tech
technology on a floating production plant with high demands to its operational reliability. As a result of these
factors, the Port will be utilizing a Tier III pump engine and Tier II generator sets generating in parallel, but will use
three instead of two, each 50% smaller than the originals. This solution allows the dredge to operate more
efficiently, because the crew will be able to bring additional power on and offline in smaller increments, which in
turn allows them to operate each individual generator closer to its design load point. This operating point tends to be
far more efficient, as seen in the BSFC graph in Figure 6, above.
Emissions Control
With its 1960’s vintage engines, the Dredge OREGON is one of the largest emitters of carbon dioxide and diesel
particulate matter on the Lower Columbia River. The Port of Portland has set a goal of reducing carbon emissions
for all its operations, including Portland International Airport and all of its marine cargo facilities, by 15% of its
1990 levels by 2020. Because of the large amount of fuel used by the Dredge OREGON, a major step towards this
larger overall goal can be met if Dredge OREGON’s fuel use can be reduced by 30-40%, making this project an
attractive target for the Port’s reduction initiatives.
Besides the environmental benefits of CO2 reductions, the use of a Tier III pump engine will also reduce the
emissions of Diesel Particular Matter, SOx and NOx, even if similar amounts of fuel are used. A comparison of the
anticipated annual emissions reduction is presented in Table 1.
Table 1. Annual emissions reductions.
Pollutant New Engines (kg/yr) Existing Engines
(kg/yr)
Emission Reduction
(kg/yr)
Percent Reduction
NOx 173,004 210,016 -37,013 -18%
HC 2,989 7,955 -4,967 -62%
PM10 463 3,023 -2,561 -85%
PM2.5 385 2,705 -2,319 -86%
CO 3,066 17,501 -14,435 -83%
SOx 3,737 6,365 -2,628 -41%
The total emission reductions over the project’s lifetime (assuming 25 year life) are presented in Table 2.
Table 2. Total project emissions reductions.
Pollutant New Engines (kg) Existing Engines
(kg)
Emission Reduction
(kg)
Percent Reduction
NOx 4,392,718 5,331,271 938,553 -18%
HC 76,296 201,938 125,653 -62%
PM10 11,803 76,736 64,933 -85%
PM2.5 9,845 68,662 58,817 -86%
CO 79,189 444,268 365,079 -83%
SOx 95,370 161,557 66,187 -41%
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An estimate of the project’s total carbon dioxide (CO2) reduction is presented in Table 3.
Table 3. Project’s total CO2 emissions reduction.
Total Estimated Carbon Dioxide Reduction

Existing Dredge = 7,354,600 kg CO2/yr * 25 Year Lifetime = 183,859,500 kg CO2
Refit Dredge = 4,413,200 kg CO2/yr * 25 Year Lifetime = 110,322,300 kg CO2
Reduction = 2,941,400 kg CO2/yr * 25 Year Lifetime = 73,538,300 kg CO2
Grant Funding Window
As detailed elsewhere in this paper, grant funding is available to help defray the cost of repowering the dredge. This
funding is available only for a relatively short amount of time. Currently, there are no legal requirements to replace
the existing engines or to reduce fuel use and/or emissions. Similarly, the Dredge OREGON will now be outfitted
with a Tier III pump engine, even though that is not yet legally required as a minimum standard. Therefore, the
project undertaken by the Port of Portland is a fully voluntary and proactive initiative with significant environmental
benefits. Based on these criteria, this project qualified for several grant opportunities that will not likely remain
available once such environmental requirements have become standard practice or legal requirements.
Part of the grant funding for this project comes from a state transportation program (Connect Oregon III) that
strongly emphasizes improvements in energy efficiency and environmental performance. Since that emphasis
matched very well with the specifics of this project, this was a unique opportunity to fund part of the project through
grants. This grant program, with its specific emphasis on environmental improvements, cannot be expected to be
available frequently – if at all – in the future.
It is important to note that, although these grant opportunities described above apply to repowering projects, they
would not apply or be available for dredge replacement. An owner who has a new dredge ordered and built is
simply expected to have it outfitted – with current technology and equipment, of course.
THE CHALLENGES OF THE REPOWERING PROCESS
Working through the process for the repower of the Dredge OREGON, multiple challenges were encountered that
can be assumed to exist at least somewhat similarly for other dredge repowering projects.
The Question of Scope
As the initial engineering study progressed, it became clear that the main pump engine, as well as the two auxiliary
generator sets, should be replaced. Since systems are connected, this major choice impacts other systems of the
dredge as well. Due to the higher speed of modern diesels, the driveline would need to be reengineered, which
necessitated adding a gear reduction, which in turn required a new driveline; and the entire engine control system
would need to be upgraded. Integration issues of a similar nature further expanded the initial scope of the project,
and scope definition and scope control became primary tasks in the early stages of this project.
The integration requirements were studied and as a result, the refit scope was expanded to include the following:
 Replace main pump engine, including modifications to ancillary systems
 Replace main pump driveline, including the addition of a new gearbox
 Replace main pump control system with a digital control system
 Replace auxiliary generator sets (enlarged to 1500 ekW from 800 ekW)
 Replace existing switchgear with automated switchgear, including power distribution feeders to all panels
 Replace main pump, including major structural changes to allow for mounting of a new 213 cm (84”) pump
 Replace all panels in the lever house and engineer’s operating station
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 Replace wound rotor AC cutter head motor and resistor bank based control system with an AC induction
motor and a variable frequency drive
A schematic showing these locations is presented in Figure 7.
Figure 7. Schematic of Dredge OREGON, showing main systems targeted for repower/refit project.
Based on this increase of scope, insights regarding project budget requirements increased accordingly. This issue of
cost increase led the Port to reevaluate the decision to repower the dredge versus possibly replacing the dredge:
“Does it make sense to repower and refit a dredge that is more than 50 years old?”
A study was performed to assess the cash flow for the two options. The analysis indicated that it is more cost-
effective to repower the dredge. Market studies showed that the total cost of replacing a dredge of this size and type
would easily be double the estimated cost to repower. The increased costs of maintaining a 50 year old dredge were
not enough to offset the large initial capital outlay required to buy a new dredge. This study did not specifically
quantify other soft costs, such as outfitting a new dredge, that certainly exist, but are difficult to define.
A question that came up several times during this repower-versus-replace decision process concerned the age of the
hull. A unique aspect in this particular case of the Dredge OREGON – which may not equally apply to other
dredges – is that the Dredge OREGON solely operates on the freshwater Columbia River, and is therefore not
subject to the same level of corrosion as dredges that operate in salt water. The hull is examined every five years
and has been found to be in good shape. The age and condition of the hull is not expected to be a limiting factor in
the remaining life of the OREGON.
Funding Sources and Financing
The increasing costs for the refit and repower were a barrier to approval of the project, in part due to funding
limitations. The project team partnered with in-house environmental staff to see if any of the work could be funded
by federal and/or state grants.
The EPA has recognized that the increased cost of cleaner engines can inhibit the implementation of lower emission
diesel engine technology. The EPA also recognized that the life of a diesel engine can be well over 30 years. To
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accelerate the desired change, the EPA established the National Clean Diesel Campaign, and through the NCDC, the
Diesel Emissions Reduction Act (DERA) was established.
As part of the Energy Policy Act of 2005, DERA authorized funding of up to $200 million annually for FY2007
through FY2011 to help fleet owners reduce diesel emissions. Under this act, EPA has developed four programs:
 The National Clean Diesel Funding Assistance Program awards competitive grants to fund projects that
implement EPA or CARB verified and certified diesel emission reduction technologies.
 The National Clean Diesel Emerging Technologies Program awards competitive grants for projects that
spur innovation in reducing diesel emissions through the use, development and commercialization of
emerging technologies. Up to 10 percent of the national funds may be spent on emerging technologies.
 SmartWay Clean Diesel Finance Program issues competitive grants to establish national low-cost
revolving loans or other innovative financing programs that help fleets reduce diesel emissions.
 State Clean Diesel Grant Program allocates funds to participating states to implement grant and loan
programs for clean diesel projects. Base funding is distributed to states using a specific formula based on
participation, and incentive funding is available for any states that match their base funding. Currently all
50 States and the District of Columbia are participating.
On January 4, 2011, President Obama signed legislation (H.R. 5809) reauthorizing grants to state, local, and tribal
governments for programs to reduce emissions from existing diesel engines. This bill, which was passed by the
Senate on Dec. 16, 2010, and the House on Dec. 21, 2010, authorized up to $100 million each year for the DERA
program for fiscal years 2012 through 2016, and provides new opportunities which are being evaluated.
*Source: www.EPA.gov
Figure 8. Federal Funding through the Diesel Emissions Reduction Program.
The Port has successfully applied for DERA funds to repower the Dredge OREGON under the State Clean Diesel
Grant Program, with funds being administered through the Oregon Department of Environmental Quality (DEQ).
Schedule and Timing
The Port’s usual dredging season is annually from June until October. The timing of this dredging season is
determined by natural factors (such as sediment transport, river flow and river stage) and the need to keep the
channel navigable year around. The importance of having the dredge available for that work each year poses some
limitations for completion of such a large scope of work.
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It was determined that the time available in the off-season is inadequate to complete the entire scope of the
construction work for this project in one off-season shipyard event. As a result, it was decided to split the
construction work into two separate seasons, with the Dredge OREGON to be dredging during one regular season in
between the two shipyard events that are needed to accomplish all construction work.
Even though there are certain advantages in having a fixed dredge season and a clearly defined off-season during
which the refit work can be performed, it also poses additional challenges. One consequence is that there are very
hard deadlines by which any refit work must be started in order to be performed, which can mean that if the
schedule were to slip by even a few weeks, the work would have to be postponed a full year.
A related challenge is that a relatively large part of the funding originates from grant programs, which often have
strict requirements for timing and completion of the funded projects. Due to those requirements, a one-year delay in
construction could possibly undermine the funding package and could, in the worst case, put the total project at risk.
Obviously, with the shipyard work split between two off-seasons, it will still be important to complete the shipyard
work on schedule, and there is little to no flexibility to move work scope between the two shipyard events.
And finally, splitting the work between these two shipyard events poses a technical challenge in dividing the work.
The dredge is required to be functional between the two shipyard events. A combination of old and new control
systems must be able to control the remains of the existing and new systems between the two events.
Moving Targets
Several aspects of the project became moving targets because of the dynamic situation of several outside factors
impacting the repower project. Examples are discussed below:
Production Capacity
There was great uncertainty about required future production amounts. Although the Port has more than 100 years
of experience in fulfilling its mission to maintain the Lower Columbia River channel depth, the specifics of this
mission have changed over time. An excellent example is the increased dredge amounts that have to be dealt with
each year due to Mt. St. Helens alluvial flow into the Columbia. Initially, this alluvial flow was prevented from
reaching the lower Columbia River by establishing a sediment catch dam on the Toutle River (a tributary of the
Columbia). The basin filled in a shorter time span than anticipated and the sediment overtopped the dam, leaving
this material flow as a direct sediment source to the Columbia River channel and eventually impacting the workload
of the dredge. Mt. St. Helens also remains an active volcano, with the most recent eruption in January of 2008.
Should a larger eruption occur, the Oregon will again be tasked with responding to ash flows in order to keep the
navigation channel open.
Other examples of uncertainty of target capacity include the changing insights and directions over time as to upland
versus in-water placement of dredged sediments as the preferred channel maintenance method, and the
consequences of that for the long-term dredge volumes for the Dredge OREGON. This is due to not only changes in
total volumes to be dredged, but also the possible split between hopper and pipeline work.
Predicting and planning for the changing mission was beyond the scope of this project. As a result, a separate
discussion took place with the Army Corps of Engineers to solidify the anticipated future dredging needs that should
form the basis for this project. All involved stakeholders agreed to these requirements as documented.
Emission reduction target
Another moving target was the EPA requirement for emissions reductions. The National Clean Diesel Campaign
described above involves complex timing for a tiered implementation. The timing is based on engine size, power
produced per cylinder, application, and how the manufacturer decides to comply with the rule. For example, if a
manufacturer commits to offering a Tier III marine engine early, then they can delay the implementation of Tier IV
for the rail segment of their business. This rule directly impacted the Port and resulted in a Tier III solution being
provided where a Tier II had been anticipated. The resulting changes in engine design have resulted in delays in
obtaining design information for the final foundation design, and in increased costs due to redesign.
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Stakeholder audience
This project is anticipated to take multiple years to accomplish. As with any project with a multi-year timeline,
there are bound to be personnel changes that lead to different stakeholders and changes in requirements. It is
important that requirements and their backgrounds be properly documented. Even with this documentation, newer
stakeholders are bound to question assumptions.
Uncertainty as to Obtainable Objectives
Fuel efficiency – As noted earlier, engine manufacturers cannot define the fuel economy of their engines under
operating conditions over which they have little control. The cutter suction dredge cycle presents such varying
conditions that, on a practical basis, defining average fuel efficiency is impossible. Because of this, engine
manufacturers are of little help in defining fuel usage under actual loads.
Pump performance
The slurry effect on pump calculations presents another uncertainty that can only be estimated using industry
guidance gained from past experience. Predicting pump performance using water is a well-defined science.
Unfortunately, these analytic and empirical relationships break down when slurry is substituted for water. As a
result, fully defining a pump’s performance at the full range of anticipated operating conditions has proven difficult.
It follows that, on a practical basis, firmly quantifying any increase in production or cavitation is also impossible.
There is confidence within the team that the Port will realize an increase in pump performance, but defining it or
even characterizing it has proven to be effectively impossible without undertaking a financial burdensome study that
would add little effective value to the overall project. As a result, a fully engineered production estimate is not part
of the scope of this project.
Noise
Noise levels of newer engines are a concern because they are anticipated to be louder by an undetermined amount.
Newer engines generating similar horsepower to older ones generally run at higher comparative speeds. This has
benefits in size, since crank torque loads are less, but the downside is an increased noise level caused by the
increased engine speed. While the noise limits on the dredge are governed by OSHA 1910.95 and USACE EM 385,
these maximum allowable levels do not provide for crew comfort. The OREGON has no fully defined separate or
enclosed engine room, and crew pass through the areas where the engines operate on a regular basis. The project
may have unfunded or unaddressed scope from its adapted goal of reducing engine noise to “acceptable levels”.
Working with stakeholders, an acceptable level has been determined to mean “no louder than current operations”.
In order to define whether this has been achieved, or if additional mitigation is required, it is vital that accurate,
repeatable measurements of the existing operation be taken with a calibrated decibel meter through a strictly defined
protocol. Contingency plans are in place to deal with noise mitigation as needed, but due to its uncertainty this issue
remains a concern.
Repower versus Replace Decision
A final hurdle to initiation of this project was the financial comparison of repowering vs. replacement. Since its
mission of the dredge is regulated by the Jones Act, the Dredge OREGON is required to have a keel laid in the US.
With this requirement, the cost of functionally-equivalent replacement for the Dredge OREGON comes to an
estimated $35M, based on market surveys and fitting-out estimates. This is more than double the total project cost
of the repower effort.
The comparison made was straightforward, since for the alternative of a new dredge, a dredge of similar size and
production capacity as the existing Dredge Oregon was assumed. In reality, the repowered Dredge OREGON will
be capable of increased production capacity with lower fuel usage.
Had the increased production and fuel economy been considered the baseline for a new dredge alternative, a less
powerful plant would have been a real consideration. It proved difficult to obtain stakeholder buy-in for this option.
The stakeholder-perceived need for horsepower had traction that defied engineering analysis. The positive effect of
this decision to repower was that defining a truly comparative plant, including defining efficiencies and losses, was
made unnecessary.
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Stakeholder Involvement
Human interface issues
The crew of the dredge initially voiced vocal opposition to the repower effort. Replacing 1960’s technology with a
modern dredging system poses training challenges that require a heavy training budget, open communication with
the crew and minor design compromises. These compromises include limiting the use of touch screen displays and
retaining key controls in a format that is familiar to the crew. This requires a delicate balance and careful choices, as
the refitted dredge should well outlast the current crew’s careers; therefore, the refitted dredge will be operated not
only by the current crew but also by future new crew who may have different preferences and comfort levels
regarding use of technology. Overall, an important factor in the ultimate decision was based on the anticipated labor
pool from which dredge crews will be recruited now and in the future, which for the Dredge OREGON in general is
more aligned with local operating engineers than with highly specialized (international) dredging operators.
Stakeholder Communication
Oregon Department of Transportation (ODOT) and Department of Environmental Quality (DEQ) – Since some
funding has been secured via state and federal programs, regular updates and communications to these key
stakeholders are required. These funding programs require proposals that were impacted by the subsequent change
from a Tier II to a Tier III solution, by the decision to spread the construction work over two off-seasons, etc. These
types of interconnected actions have been typical in this repower project. Changes in one area impact other areas,
and if not properly communicated and coordinated, stakeholders who were allies in the early stages can have a major
issue or problem with the project based on the revised course or scope.
The Port’s main customer, USACE, is quite interested in all aspects of this program. The potential threat to the
operational readiness of the dredge is constantly evaluated throughout the project, and Corps staff is actively
engaged on issues they consider possible risks to the dredge’s operation.
The Port’s environmental staff has been a key stakeholder, and has assisted the project in securing grants and other
financial incentives. These funding sources are conditional on the anticipated emission reductions, so it’s crucial to
keep this staff involved in any project developments that may impact those factors.
Procurement Planning
The Port is a quasi-public agency, which requires the organization to adhere to public contract and procurement
rules. These rules are generally based on the use of competitive processes for procuring services and goods. The
entire list of planned procurements includes the following:
 Naval Architect Design Services – Includes design and integration of the mechanical systems and an initial
electric power requirements analysis.
 Control System Design Services – Includes the design of the control system and low power distribution
systems. A harmonics analysis is included due to the use of a 600 kW (800 hp) VFD.
 Pumping System – Main engine, driveline, gear reduction, and pump.
 Generator sets – Two primary power generator sets, ~1500 kW each.
 Cutter head System – One 600 kW (800 hp) synchronous AC TEAO cutter head motor and associated
variable frequency drive.
 Switchgear and Power Distribution System – Includes main switchgear to operate the generator sets and
480V power distribution system.
 Control System – Includes the components for a fiber optic based distributed control system. These include
remote I/O boxes, control panels and programmable logic controllers.
 Shipyard Services – Includes two shipyard events, separated by one year.
The current procurement plan is to install all systems over the course of two shipyard events separated by one year,
with the Port acting as General Contractor. The procurement strategy described above has gone through a large
amount of changes. This is due to multiple causes. Grant funding sources have terms which require protection of
those sources from liability. Some suppliers have been reluctant to accept those terms. Some suppliers have also
been reluctant to accept design responsibility, necessitating the insertion of outside design services into the process.
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Timing of the project imposed by the grant funding and a desire to avoid using new, less efficient, untested and
costly Tier IV technologies has required that some procurements start before the design is complete. Each of these
changes impacts other aspects of the project, requiring a flexible and creative approach to the overall procurement
strategy.
CONCLUSION
Repowering an older dredge is a task that can quickly overwhelm the unprepared. There are many interrelated
factors, causing the project to constantly evolve and change. These include schedule, budget, performance goals,
scope definition, stakeholder involvement and changing state and federal mandates.
This paper represents just one possible path for a repower project. The options available present a daunting and
nearly limitless array of variations. By including stakeholder involvement, defining performance goals early and
remaining aware of the changing emissions requirements, a repower project can be successfully undertaken.
REFERENCES
Anonymous,( 2009), “A Radical Proposal.” Dredging and Port Construction Magazine, March, 50-52.
CITATION
Parker, C.O., Haynes, W. H., and Hermans, M.A. “Dredge OREGON: Repowering and Refit,” Proceedings of the
Western Dredging Association (WEDA XXXII) Technical Conference and Texas A&M University (TAMU
43) Dredging Seminar, San Antonio, Texas, June 11-13, 2012.

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1A-4 Parker

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