The document presents a final report on the design of a serial hybrid propulsion system for the 'Tara', a diesel-powered boat owned by Tidelines Institute, aimed at reducing fossil fuel dependency while transporting students between their campuses in southeast Alaska. The propulsion system utilizes a combination of a diesel generator, lithium battery, and electric motor, with detailed deliverables including CAD models, lifecycle assessments, and operational analysis. This innovative solution is intended to leverage local hydro power resources and promote environmental sustainability in marine transport.

1. Final Report
Submitted in partial fulfillment of the requirements for
ENGS 90: Engineering Design Methodology and Project Initiation
Tara Hybrid Conversion
03/07/2022
Sponsored by
Tidelines Institute
Project Team #17
Emily Martinez, Barrett Noone, Hana Ba-Sabaa,
Agon Hoxha, Jackson Danis
Faculty Adviser
Douglas Van Citters

2. Abstract
Marine transport is a critical means of moving people and goods around the littoral waters of Southeast
Alaska. Unfortunately, it also generates significant harmful emissions. Tidelines Institute, a Southeast
AK-based leader in environmental education and research, requires a more environmentally friendly
propulsion system for their vessel, Tara. This project designed a serial hybrid propulsion system for
Tara, furnishing Tidelines with a bill of materials, design documentation, implementation diagrams, CAD
drawings, operational analysis software, and a life cycle assessment. This design will take advantage of
the substantial hydro power resources in the region and help Tidelines be an agent of structural change.
Executive Summary
Tidelines Institute needs to transport students between their two campuses located on the Inian Islands
and in Gustavus, AK – about 25 nautical miles from each other. To reduce Tidelines Institute’s depen-
dence on fossil fuels and facilitate ease of transportation of students between their two campuses, we
designed a diesel electric series hybrid propulsion system for their recently purchased diesel boat, Tara.
The system consists of three primary components: a Bollard MG42 diesel gen-set, a Lithionics
GT102V75A lithium battery system, and an Elco EP-70 electric induction motor. The batteries, which
will be pre-charged through a renewable charging station in the home port on the Inian Islands, will
power the electric motor which drives the propeller to move the boat. The diesel generator will be serving
as a range extender, providing the battery charger with power to charge the batteries when pre-charge
runs out. Due to the fact that Tara is out of the water, we interpolated datasets for two other similarly
shaped hulls – the Woodstock and the I Gotta – in order to build an operational MATLAB model
which was used to size components. Furthermore, we conducted a marine vessel survey by exchanging
sketches with Tidelines; the survey data was confirmed through a photogrammetric analysis and used to
construct a CAD model which was utilized to determine component placing and to conduct buoyancy
and structural load analyses.
As our deliverables, we have produced a Bill of Materials (BOM) listing the main components
needed for the retrofit; design and implementation documentation consisting of a circuit diagram, a
state diagram, and CAD drawings; analysis documentation consisting of buoyancy and structural load
analyses; the operational MATLAB model (transferred to Octave for portability); and a Life Cycle
Assessment for the new propulsion system.
ii

3. Contents
1 Introduction 1
1.1 Background & Significance . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1
1.2 Problem Statement . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1
1.3 Specifications . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2
1.3.1 Description of Operation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2
1.3.2 Quantified Specifications . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2
1.4 Proposed Solution . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2
2 Methods & Methodology 4
2.1 Data Collection . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4
2.1.1 Photogrammetric Analysis . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4
2.1.2 Internal Measurements . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4
2.2 Operational Model & Parametric Analysis Development . . . . . . . . . . . . . . . . . . 4
2.3 CAD Modeling . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5
2.4 Design Verification . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5
2.5 Life Cycle Assessment . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7
3 Deliverables 11
3.1 Operational Model & Parametric Analysis Results . . . . . . . . . . . . . . . . . . . . . 11
3.2 Design . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13
3.2.1 Motor Selection . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13
3.2.2 Battery Selection . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14
3.2.3 Generator Selection . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14
3.2.4 Bill of Materials . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15
3.2.5 Financial Analysis . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16
3.3 Installation Guide . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16
3.4 CAD Models and Drawings . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16
3.5 Circuit Diagram . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17
3.6 State Diagram . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18
3.7 Design Verification Results . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18
3.7.1 Buoyancy Analysis . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18
3.7.2 Structural Load Analysis . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20
3.7.3 Limitations . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 21
3.8 LCA Results . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 21
4 Conclusions & Recommendations 24
A Supplementary Materials
A.1 Description of Operation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
A.2 Sketches and Dimensions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
A.3 Generator Comparisons . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
A.4 Quotes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
A.5 Net Present Value . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
A.6 Verification Methods . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
iii

4. List of Figures
1 Block Diagram for Propulsion System . . . . . . . . . . . . . . . . . . . . . . . . . . . 3
2 Interpolated power curve for Tara showing required continuous shaft power to maintain
corresponding speed . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11
3 Sample of parametric analysis outputs showing a) trip fuel use as a function of throttle
power over a predefined 50 mile trip, b) trip fuel use as a function of throttle power
using all available fuel and charge aboard, c) range as a function of throttle power over
a predefined 50 mile trip, d) range as a function of throttle power all available fuel and
charge aboard, e) range as a function of generator output power over a predefined 50
mile trip, f) range as a function of generator output power all available fuel and charge
aboard . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12
4 CAD Model of exterior of boat . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17
5 Interior view of CAD model with each component labeled . . . . . . . . . . . . . . . . . 17
6 Calculation of waterline . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18
7 Buoyancy test: State where fuel tank is empty . . . . . . . . . . . . . . . . . . . . . . . 19
8 Buoyancy test: State where fuel tank is full . . . . . . . . . . . . . . . . . . . . . . . . 19
9 FEA Static test - Stress results . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20
10 FEA Static Test - Stress results for individual component loading . . . . . . . . . . . . . 20
11 Factor of Safety Results from FEA analysis . . . . . . . . . . . . . . . . . . . . . . . . . 21
12 Impacts by SBOM inputs: Carbon footprint [CO2 eq. kg/func unit] . . . . . . . . . . . 22
13 Impacts by life cycle stage: Carbon footprint [CO2 eq. kg/func unit] . . . . . . . . . . . 23
14 Impacts by life cycle stage: Total [mPts/func unit] . . . . . . . . . . . . . . . . . . . . 23
15 Tara’s home port on the Inian Islands and her primary ports of call in Gustavus and Elfin
Cove. The red arrow shows her expected trip. . . . . . . . . . . . . . . . . . . . . . . .
16 FEA Study - Displacement of loading on hull . . . . . . . . . . . . . . . . . . . . . . .
17 FEA Study - Strain of loading on hull . . . . . . . . . . . . . . . . . . . . . . . . . . .
18 FEA Study - Displacement of individualized components . . . . . . . . . . . . . . . . .
19 FEA Study - Strain of individualized components . . . . . . . . . . . . . . . . . . . . .
List of Tables
1 Breakdown of Guiding Specifications . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2
2 Components for Diesel Electric Series Hybrid Refit . . . . . . . . . . . . . . . . . . . . . 3
3 Parameters for buoyancy testing in SolidWorks . . . . . . . . . . . . . . . . . . . . . . . 6
4 Loading forces on the hull . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6
5 Material content of typical marine diesel engine . . . . . . . . . . . . . . . . . . . . . . 8
6 Material content of a Lithium Iron Phosphate battery . . . . . . . . . . . . . . . . . . . 8
7 Material content of typical electric motor . . . . . . . . . . . . . . . . . . . . . . . . . 9
8 Material content of a typical diesel gen-set . . . . . . . . . . . . . . . . . . . . . . . . . 9
9 Bill of materials including three main propulsion components and ancillary components . 15
10 Quoted prices for each of the three main systems . . . . . . . . . . . . . . . . . . . . . 16
11 Overall Results from both design studies for testing buoyancy . . . . . . . . . . . . . . . 19
12 Current specifications of Tara . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
13 Average operating conditions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
14 Most severe operating conditions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
15 Comparison of available diesel genset specifications . . . . . . . . . . . . . . . . . . . .
iv

5. 1 Introduction
1.1 Background & Significance
Tidelines Institute is an environmental and educational organization co-founded by Zachary Brown and
Laura Marcus in early 2021. Tidelines has two campuses: the Good River Campus, located in Gustavus,
AK, 50 miles northwest of Juneau, AK, and the Inian Islands Campus, also known as ”The Hobbit
Hole,” located about 25 nautical miles southwest of Gustavus. Tidelines has purchased Tara, a diesel-
powered 29-foot Rawson boat built in 1967, that had been used around the Icy Strait region as a halibut
fishing vessel for decades. The boat was acquired to help Tidelines transport students between their
two campuses.
Currently, Tidelines Institute charters other boats and planes in the area to transport students
between their two campuses. They spend an estimated $5000 per year on fuel running their gasoline
boat, the Magister, in addition to chartering costs. Not only does Tidelines have a financial interest
in this project, but they also hope to move towards full independence from fossil fuels. Most of their
remaining fossil fuel use is from transportation between their two campuses, so the retrofit of Tara would
make Tidelines take a significant step towards energy independence.
Due to the central role of the ocean in the local geography, boats that use antiquated and inefficient
diesel or gasoline propulsion systems prevail in this part of Southeastern Alaska, both as means of
transportation and for commercial fishing. Juneau has the most active port in the state, issuing 2028
launch ramp permits in 2019 as well as having 213 active fishing boats ported there [4]. Tidelines
Institute is concerned with environmental threats related to boat emissions and sees an opportunity to
reduce their own environmental footprint while also inspiring the local population to adopt a similar
change. Tidelines hopes to use this project as a proof of concept of marine electrification for the entire
region of Southeast Alaska. There is an opportunity to drastically reduce the total emissions produced
by boats, and the people at Tidelines hope that Tara can serve as an example to convince the local
population that there are viable alternatives to fossil fuel powered boats. This is why the choice of
using Tara for this project is especially significant. She has been used for halibut fishing in the region
for decades and is a familiar sight. Locals who may be uncertain about the reliability of an electric or
hybrid engine will recognize Tara as one of their own. Therefore, proving that Tara can become a hybrid
electric vessel would have far more impact than if we built a state-of-the-art boat from the ground up.
1.2 Problem Statement
In pursuit of these goals, Tidelines wants us to design a more environmentally friendly propulsion system
for Tara that allows them to reduce their dependence on fossil fuels and simultaneously facilitate the
ease of transportation between their two campuses. Because we do not have access to the boat itself,
this project is an exercise in design feasibility. Our aim is to provide Tidelines with enough information
and specifications to demonstrate that, if they choose to move forward with the project, that we have
produced a viable design for the retrofit of Tara. We will provide them with a bill of materials, a
3D model of Tara post-retrofit, a Life Cycle Assessment evaluating the performance of the existing
system against that of the proposed design over its entire life cycle, and supporting documents for the
installation of the main components.
1

6. 1.3 Specifications
1.3.1 Description of Operation
To begin systematically developing specifications, we first created a thorough Description of Operation
document. This document, appended in A.1, was developed in conjunction with our sponsor over
the course of several meetings and details known information about the vessel. It includes known
specifications of her current physical plant and operation, profiles her operator, specifies her intended
use, and includes geographical and meteorological summaries of her area of operations.
The process of creating this document revealed a number of important insights about the project.
First, that Tara would primarily be used as a passenger vessel for transporting students between Tidelines’
Good River campus in Gustavus, AK and their Inian Island campus, a 50-nautical mile round trip, meant
that her design had to meet particular safety and comfort requirements. Tara’s cruising speed, power,
and range needed to far exceed the minimums required to make the trip, and only propulsion systems
with advanced monitoring and automatic shutdown capabilities in the event of an emergency were
considered. Completing this trip under very low throttle would enable greater energy savings but would
result in an agonizingly long trip for students, so maintaining or improving upon Tara’s original cruising
speed of 6 knots was also paramount.
Second, Tara’s areas of operations: Glacier Bay, Icy Strait, and Cross Sound present a number of
significant hazards. Tidal currents can often exceed 3 knots, and Tara will frequently experience currents
greater than one knot, even if traveling during slack tide simply due to the length of her trip. Therefore
her propulsion system was designed to provide additional power able to push her hull beyond cruising
speed. This region is also known for rough and unpredictable sea conditions, so a higher-than-standard
sea margin of 20% was employed to account for sea state and hull roughness.
Third, since existing charging infrastructure in Tara’s area of operations is insufficient for fully
electric operation of the vessel, and her size limits her possible battery capacity, it became necessary
to consider hybrid solutions employing a conventionally fueled range extender. Her ports-of-call reliably
offer only diesel, so only diesel generators were considered. Diesel, a nonvolatile fuel, has the added
safety benefit of decreasing fire and explosion risk. These considerations appear in the following list of
initial specifications.
1.3.2 Quantified Specifications
Specification Value
Cruising Speed (in calm water conditions) ≥ 6 knots
Sea Margin = 20%
Power Source for Range Extender Diesel
Table 1: Breakdown of Guiding Specifications
1.4 Proposed Solution
In line with the specifications derived from the description of operation, a diesel electric hybrid propulsion
system was proposed. Furthermore, in the interest of limiting excess drivetrain complexity, which would
drive installation complexity, the team settled on a series topology for the hybrid solution. A high-level
block diagram for the proposed system is shown in Figure 1.
The solution consists of three main subsystems, which are highlighted above: the diesel genset, the
battery system, and the electric motor. The motor is driven by the batteries, which are in turn charged
2

7. Figure 1: Block Diagram for Propulsion System
either through shore power or the diesel genset. The bulk of the team’s work focused on selection of
these three components as well as integration details. The specific components that were ultimately
chosen are detailed in Table 2
Genset Bollard MG42
Battery System Lithionics GT102V75A
Motor Elco EP-70
Table 2: Components for Diesel Electric Series Hybrid Refit
3

8. 2 Methods & Methodology
2.1 Data Collection
2.1.1 Photogrammetric Analysis
To better understand Tara’s hull shape, a photogrammetric analysis was conducted. Several hundred
photographs of her exterior were sourced from Zach, capturing at least three quarters of the hull in each
and wrapping around the entire vessel above and below the waterline. These photographs were then
imported into Metashape and aligned automatically in three dimensions. A point cloud was generated by
the software and scaled manually with the length, stem to stern, set to 29 feet. A mesh was generated
from this point cloud and exported as an .stl file. Further processing of the mesh was conducted in
MeshLab, such as resampling the mesh to smooth irregularities. Because of the high density of the
mesh and the fact that some irregularities remained post processing, the photogrammetric mesh was
not used directly in the CAD model or in buoyancy and loading simulations. Instead, it was used as a
reference model to ensure that the dimensions of the CAD model accurately represented those of the
actual vessel.
2.1.2 Internal Measurements
Internal measurements and layouts were also gathered for Tara to aid in the placement of the components
in her hull. A series of hand sketches and a spreadsheet tabulating marked dimensions, both included in
Appendix ??, were sent to Tidelines, and Tanner, a member of the staff, measured and recorded each
of the marked dimensions in the spreadsheet, noting qualitative details and corrections where needed.
This dataset was used to propose an interior layout that would minimize the relocation of bulkheads
and the inclusion of additional structural supports, thereby minimizing labor costs.
2.2 Operational Model & Parametric Analysis Development
Measuring Tara’s expected performance in the water was critical for determining the proper size of
components. Since Tara has been out of the water for years and lacks any substantial operational
data logs, these specifications had to be developed using models. A fully parameterized operational
model was constructed in MATLAB. This model performs a number of analyses on different aspects of
Tara’s operation: examining apparent speeds and effective trip durations, interpolating a power curve
to determine power and energy specifications, and conducting an electrical load analysis.
Matrices containing Tara’s apparent speed over bottom were calculated across a predetermined
range of actual speeds over water and velocities of tidal currents using the Law of Cosines and an
angle of incidence between Tara’s direction of travel and the direction of current. Four matrices were
calculated, one for each condition: Tara heading eastbound with a rising tide, Tara heading eastbound
into a receding tide, Tara heading westbound into a rising tide, and Tara heading westbound with a
receding tide. Because the angle between Tara’s heading and the primary direction of current flow
differs for eastbound and westbound travel, two angles of incidence were used: one each for eastbound
and westbound. Matrices containing trip durations were calculated by dividing a predetermined trip
length, in this case 50 NM, by each apparent speed.
Lacking a sufficient drag curve from literature, Tara’s power requirements remained a broad estimate
for many weeks. Fortunately, our team was provided with datasets from two larger but similarly shaped
vessels, Woodstock and I Gotta, that included measurements of shaft power at a range of speeds [8,
9]. These power curves (power vs speed) were reduced to dimensionless drag curves (drag coefficient
vs Froude number) via the calculations shown below. A wetted area ratio calculated as the square of
4

9. the waterline length ratio was used to scale the drag values to a boat of Tara’s size [21]. This method
assumes that the measured hull has the same shape as Tara (i.e., that they are scale models of each
other). This dimensionless drag curve was then interpolated at known Froude number values from Tara
and multiplied back into a power curve. Tara’s maximum (rated) power specification was determined
using a conventional method of applying a sea margin to the power required to reach hull speed, and
the energy requirement for a trip was calculated by multiplying the power required at six knots by the
duration of the trip at six knots.
An electrical load analysis was also conducted using the forward Euler method to construct a time
series of battery loads. The battery discharge rate was calculated as the efficiency-adjusted throttle
power, and the battery charge rate was calculated as the efficiency-adjusted generator output power.
Two versions of the Euler loop were developed – one using a for loop that would run for the duration
of the trip, and one using a while loop that would run until the fuel tank and batteries were empty.
For each of these, a timestep of 1.5 minutes was used, and at each timestep, the battery level was
calculated. Within the Euler loop, a control algorithm applying a simple hysteresis method toggled the
generator on or off at the bottom or top of a battery level deadband and kept it on or off within the
deadband. From this time series, outputs including generator runtime, range, fuel use, and fuel cost
were calculated and reported.
Manually changing parameter values to understand the behavior of a single component proved too
arduous to be practical, so a parametric analysis script was developed. This secondary script defines a
range of test values and single default values for each parameter. The user manually selects a particular
parameter to iterate over, and the script calls the operational model for each value of the user-selected
parameter, using default values for all other parameters. Outputs are then tabulated and graphed.
2.3 CAD Modeling
In an effort to visually illustrate the retrofit of Tara, we designed a CAD model. The dimensions of the
CAD model are based on the dimensions of Tara in its current state, obtained as described in sections
2.1.1 and 2.1.2. With this data, we produced a number of iterations of CAD models to ensure the most
accurate design.
In developing a CAD model of Tara, our goals were threefold: to visualize the retrofit, to prove the
buoyancy of the boat, and to test to the stability of the hull with the new components. To produce a
CAD model, we primarily used the software SolidWorks, as it would also allow us to be able to conduct
studies, such as buoyancy testing and Finite Element Analysis (FEA). To be able to conduct such studies,
we required information on materials of both the hull and each of the components. The hull is known to
be made of fiberglass. Since there is no complete information for fiberglass material in SolidWorks, we
outsourced that information from a technical forum [3]. Material and dimension information for each
component was obtained from each of the three quotes contained in Appendix A.4.To better illustrate
the different views and dimensions of the CAD model, we also developed 2D drawings of the design.
See Supplementary Materials A.2 for drawings.
2.4 Design Verification
Once each of the new components were selected and the CAD model of Tara produced, we then needed
to verify that implementing a hybrid-electric propulsion system in Tara is technically feasible. To do
this, we ran two tests. The first test determined if the boat will be buoyant and float even with the
additional loading. The second test looked at the distribution of load across Tara and checked if there
was an imbalance in load on one side, causing stability issues.
5

10. For the first test, we first approached it analytically. We began by solving for the buoyant force
acting on the boat. This was done by considering that the buoyant force will be equal to the weight
that the boat displaces while in the water. Since the weight of the hull is a known parameter, we found
that the buoyant force acting on the boat is equal to approximately 1600 lb. Moreover, according to
Archimedes Principle, the volume of the boat underwater will equal the volume of the water displaced
[20, 13]. We used this principle to solve for the volume of water displaced, which can be considered as
the water line on the boat. To solve for the waterline of the boat, we did so by taking into account the
following parameters:
Parameter Value
Weight of the hull 1600 lbs
Volume of the hull 36.953m3
Specific gravity of salt water 1020kg/m3
Loading on the boat 4256 lbs
Table 3: Parameters for buoyancy testing in SolidWorks
Analytically, we solved for the buoyancy of the boat without considering any loading on the boat.
We did this to verify our computational method, which was to run a design study in SolidWorks. For
the design study, we needed to account for total loading on the boat, weight of the hull, and volume of
the hull. Considering loading on the hull, we mainly focused on the following factors:
Loading Factors Weight (lbs) Dimensions (in3)
Genset 1922 10,388.35
Motor 650 12,679.975
Batteries 6 batteries + 3 controllers: 984 Battery: 3,463.2
Fuel tank (full) 700 352,512
Table 4: Loading forces on the hull
For this test, we mainly focused on seeing how an empty fuel tank would affect the stability of the
boat versus if it was a full fuel tank. To do so, we ran the design study twice. For these studies, we
ran a cutting line across the length of the boat. For every 0.025 in. step size, it would cut the volume
of the boat by that much. We set the cutting line to cut the volume of the boat by 0.025 in. until the
mass of the hull equaled the actual total mass of the boat. The aim of this study is to figure out how
far down is the waterline from the top of the boat, as we wanted to test how much the waterline would
change if the fuel tank were empty or full. Thus, for the first test, we set the mass constraint to be the
total mass without including the load of the fuel (700 lb.). Once it reaches this point, then we have
identified the waterline and consequently the center of buoyancy as well. We then run this study again
while changing the mass constraint to include the 700 lb. of fuel.
To perform the structural loading analysis, we conducted a finite element analysis (FEA) to determine
how the distribution of loading affects the stability of the boat. For this, we identified the forces acting
on the boat. Knowing the waterline from the buoyancy tests, we set fixed structures along the part of
the hull that will be underwater. From there, we included forces such as from total loading and gravity.
We then ran this static study to solve for the displacement, strain, and stress distribution. These results
will allow us to visually determine if there are any instability issues.
To identify which tests and simulations to conduct to verify our design, we consulted with experts
such as Professor Vicki May and Machine Shop technical instructors Scott Ramsay and Joseph Poissant.
After consulting with them, we identified our approach for determining that the retrofitted Tara will
6

11. be stable and float. Each step of our testing and simulations was verified and looked over by Joseph
Poissant.
2.5 Life Cycle Assessment
Life Cycle Assessment (LCA) is a technique for assessing the possible environmental impacts associated
with a product’s lifecycle by compiling an inventory of relevant inputs and outputs of a product system.
LCA results are then interpreted according to the goal and scope of the project to investigate the
sustainability of the system. LCA examines the environmental impacts throughout a product’s life (i.e.,
cradle-to-grave) which includes raw materials extraction, manufacturing, use of product, and end of life
treatment. For the LCA that was conducted on Tara’s propulsion systems, we collected the data for
the different parts’ bills of materials through literature values, estimations, and similar products. Actual
values were not possible to obtain due to either the termination of manufacturing of the product (such
was the case with the old Tara engine) or due to the unavailability of model-specific data online. It is
important to note that LCA is a process that is driven by assumptions. Despite its existence as a tool
that influences and verifies the decision-making process, it is not meant to be an absolute driving factor
of the process.
Conducting an LCA includes several steps: System Definition, Modeling, and Optimization. During
the first step, the goal and the scope of the system are defined. The goal of our LCA is to assess
the environmental impacts for a diesel propulsion system and to compare it to its hybrid diesel-electric
counterpart. Our two systems focus on three stages: Manufacturing, Usage, and End-of-Life. Raw
materials info was included during the manufacturing stage; the materials libraries include the extraction
and transportation data of raw materials in the entries automatically. There is no need for the user’s
manual input. Maintenance was out of scope for this project as we did not have enough information
about the maintenance of the old system. Transportation was treated similarly because the old system
is already installed in Tara. Therefore, we primarily focused on the usage stage of the product because
that was the stage that we wanted to optimize and we had the largest influence on. We wanted to
look at how our system’s fuel consumption compares to the old one and the effect of the electric power
source on the system’s environmental impact.
For Tara’s powertrains, we decided that a comparison of the life cycles of the old system and the
new hybrid one will show us how sustainable our solution is and any modifications that might better
our LCA results. The old system consists of the Sabb 2JHVP Marine Diesel Engine. The new hybrid
system consists of the Elco-70 motor, six Lithionics GT102V75A batteries, and the Bollard MG42 diesel
genset. The LCA was conducted on a web based tool called Sustainable Minds which uses single scores
to evaluate the environmental performance of a product. According to Sustainable Minds’ website, the
results of each product concept represent the contribution to one person’s share of the environmental
impacts of the entire United States in one year. As a summary of the set of the 10 environmental impact
categories, millipoints represent a total impact score in one number.
For Tara’s old Sabb diesel engine, the motor’s life span was assumed to be around 30 years. The
yearly fuel consumption was estimated to be around 192 gallons per year. The BOM for the motor
production was compiled according to “An Effective Framework for Life Cycle and Cost Assessment for
Marine Vessels Aiming to Select Optimal Propulsion Systems” which lists several motors and the weight
ratios of the constituent materials. This data was taken and then scaled to the weight of our motor.
Only raw materials were added and no materials processing was included due to the negligibility of the
estimated impact and the unavailability of data. Steel and cast iron were the primary materials, with
around 40 and 46 percent of the motor’s weight ratio respectively [6]. The rest of the BOM is included
in table 5 .
Similarly, data for lithium iron phosphate batteries was taken from “Update of Bill-of-Materials and
7

12. Engine Material Weight Ratio Weight (in kg)
Steel 40 152
Cast iron 46 174.8
Aluminum 8 30.4
Copper 0.1 0.38
Zinc 0.1 0.38
Lead 0.1 0.38
Plastic 0.9 3.42
Rubber 0.9 3.42
Paints 0.9 3.42
Oils and Grease 3.0 11.4
Total 100 380
Table 5: Material content of typical marine diesel engine
Cathode chemistry addition for Lithium-ion Batteries in the GREET® Model”. The list of materials was
simplified because Sustainable Minds’ library of materials is very outdated and not nearly comprehensive;
it did not include most of the materials necessary for the batteries. Some of the table entries that were
in the article were also too vague for us to infer the constituent materials, for instance, electronic parts.
The final table is included below. The active material (lithium iron phosphate in our case), copper,
and aluminum were the main contributors to the weight of the batteries with 14.92, 29.65, and 25.81
percent respectively [22]. The rest of the BOM is in table 6. We are using six batteries in our solution;
therefore, these values were scaled in the LCA model according to that number. The lifespan of the
batteries was estimated to be around 15 years.
Battery Material Weight Ratio Weight (in kg)
Lithium Iron Phosphate 14.92 11.34
Carbon 7.96 6.05
Copper (and ½ of electronics) 29.65 22.53
Aluminum (and ½ of electronics) 25.81 19.62
LiPF6 1.75 1.33
Polypropylene 13.14 9.99
Steel 2.59 1.97
Thermal Insulation 0.66 0.50
Coolant: Glycol 3.52 2.67
Total 100 76kg
Table 6: Material content of a Lithium Iron Phosphate battery
The data for the electric motor was taken from “Lifecycle Analysis of Different Motors from the
Standpoint of Environmental Impact”. The life span of the motor was estimated to be 50 years. This
estimation was based on similar products. Also, inboard motors have one moving part. Therefore, they
are more likely to last for longer. Steel (electric and other) and aluminum were the primary materials
contributing to the weight of the motor, with around 60.19 and 17.2 percent of the motor’s weight ratio
respectively [19]. The rest of the BOM is included in table 7.
8

13. Motor Material Weight Ratio Weight (in kg)
Electric steel 47.62 140.48
Other steel 12.57 37.08
Aluminum 17.2 50.74
Copper 8.47 24.99
Insulation material 0.26 0.77
Impregnation resin 1.32 3.89
Paints 0.66 1.95
Packing material 11.9 35.1
Total 100 295kg
Table 7: Material content of typical electric motor
Finally, the data for the genset was taken from “Life cycle energy assessment of a standby diesel
generator set”. Ferrosilicon and low alloy steel were contributing 27 and 25 percent of the weight of
the motor [1]. The rest of the BOM is included in table 8.
Generator Material Weight Ratio Weight (in kg)
Aluminum Alloy 2.5 21.8
Cast Aluminum 2.5 21.8
Cast Iron 12 104.64
Copper 3 26.16
Ferrosilicon (Fe-Si) 27 235.44
Low Alloy Steel 25 218
Low Carbon Steel 16 139.52
Nickel 1 8.72
Steel 10 87.2
Epoxies 1 8.72
Total 100 872
Table 8: Material content of a typical diesel gen-set
For the use phase of the Sabb diesel engine, the amount of service delivered is estimated to be
around 30 years. For the fuel consumption of the engine, we know that Tidelines Institute expects these
trips to occur weekly (4 months × 4 weeks = 16 trips) during times of the year when student groups are
present (May-September) and monthly ( 8 months = 8 trips) during the off-season (September to May).
A round-trip duration is around 8 hours. We also know thatTara supposedly burns 1 gal diesel/hour at
6 knots.
1 gal diesel/hour × (16 + 8) trips × 8 hour/trip× = 192 gal diesel
192gal diesel = 618360.64 gram
On the other hand, for the new hybrid system, we assumed that Tara would be running half of the
trip on diesel and the other half on the electric power. Tara burns 2.7 gal diesel/hour at 6 knots using
9

14. the new genset.
2.7 gal diesel/hour × (16 + 8) trips × 8 hour/trip× = 518.4 gal diesel
However, we expect to run the generator only for half of the trip, so we will be burning 259.2 gallons of
diesel.
259.2 gal diesel = 834786.87 gram
The other half of the trip would be running using the stored electric power source from shore power.
15 A × 120 volt = 1800 watts
1800 watt × (16 + 8) trips × 8 hour/trip× = 172.8 kWh
10

15. 3 Deliverables
3.1 Operational Model & Parametric Analysis Results
The operational model and parametric analysis scripts revealed a number of insights about Tara’s
operation. Tara’s power curve, shown in Fig. 2, reveals that above Tara’s hull speed of 7.5 knots, her
power requirements increase exponentially, however, her planned cruising speed of 6 knots requires much
less power to maintain. Taking into account that she will often travel in currents near or greater than
1 knot, the power required to maintain 6 knots will often look like that at 7. Her motor was spec’d to
meet hull speed, allowing for safer operation in significant currents. Additional outputs beyond Tara’s
hull speed and her power requirement include the trip duration at six knots, her total trip energy, the
generator runtime for one trip, her range, her total fuel use for one trip, her apparent fuel consumption
per hour, the total cost of fuel for one trip, her total fuel use in one year, and the total cost of fuel for
one year.
Figure 2: Interpolated power curve for Tara showing required continuous shaft power to maintain
corresponding speed
The parametric analysis logs those outputs for each iteration of the operational model. One example
of a pertinent study that can be conducted using the parametric analysis scripts is balancing the size
and demands of the motor with the size of the generator, shown in Fig. 3. This is often a difficult
endeavor to complete with heuristics alone – running a motor at higher throttle reduces the time of the
trip but increases the fuel use and decreases the range; increasing the size of the generator increases
range but increases fuel use as well.
11

16. a) b)
c) d)
f)
e)
Figure 3: Sample of parametric analysis outputs showing a) trip fuel use as a function of throttle
power over a predefined 50 mile trip, b) trip fuel use as a function of throttle power using all
available fuel and charge aboard, c) range as a function of throttle power over a predefined 50
mile trip, d) range as a function of throttle power all available fuel and charge aboard, e) range
as a function of generator output power over a predefined 50 mile trip, f) range as a function of
generator output power all available fuel and charge aboard
Figure 3 reveals that not only do these heuristics occasionally fail to hold true, the existence of a
demand/supplied power threshold becomes clear examining the dynamics of these parameters. In Fig
3.a) and 3.c), throttle demands exceeding 25 kW result inTara not being able to make the round trip
from Gustavus to the Inian Islands. A similar situation appears in Fig 3.b) and 3.d) wherein the rate
at which the generator is charging the batteries does not meet the rate at which the motor is draining
them, preventing Tara from using all available fuel and charge onboard and drastically limiting her range.
Conversely, in Fig. 3.e), a larger genset supplies more charging power, ensuring Tara will make the trip.
This holds true for the unbounded analysis in Fig 3.f) as well, though interestingly, once Tara has a
sufficiently large generator to reach maximum range, higher powered generators that burn more fuel
12

17. actually begin reducing her range. This is only one example of a possible analysis using this software
package. The parametric analysis scripts also allow for a user to examine motor efficiency, generator
efficiency, generator fuel consumption rate, battery capacity, and deadband thresholds for generator
operation as inputs and generator runtime, apparent fuel consumption rate, true boat speed during a
single trip, and trip time for a single trip as outputs.
Included in our deliverables package are six scripts that perform all of the modeling and analysis
functions described in Section 2.2. Four are configured to take direct user input: a single trip model,
a whole tank model, and a parametric analysis for each. Two more are configured to be called by
the parametric analysis scripts and do not take user input. This package was designed for use by
inexperienced coders: all of the functionality is embedded in functions that aren’t abstracted into
individual files, making the package readable and reducing the number of files. Additionally, all of
the tunable parameters exist at the top of each script, and scripts don’t require function calls in the
command line interface. The operational model and parametric analysis scripts constitute an important
product of this project towards the goals of education and proliferation. These analyses enable Tidelines
to apply what our team learned from Tara to future projects on other vessels and to spearhead conversion
efforts in Southeast AK.
3.2 Design
3.2.1 Motor Selection
The motor chosen for the proposed solution is the Elco EP-70. The primary consideration that went
into selecting an electric motor was rated power: if the chosen motor was too small, it would not be
capable of driving the boat to the specifications laid out from the description of operation; if the chosen
motor were too large, it would run well under its rated load and thus operate at an inefficient bias point,
as well as be wasteful of the sponsor’s funds.
The plant that is currently in Tara is a 30hp Sabb diesel engine, which was known to be severely
undersized from the testimony of our sponsor. Thus said, the team was aware that a significant step-up
in power was needed. Our MATLAB model allowed us to narrow down our power specification: the
replacement motor would need to be capable of a maximum output of approximately 50kW, as well as
a continuous output of approximately 25kW. The Elco EP-70 is rated to a peak power of 51.5kW, and
a continuous power of 29.75kW, so it adheres to these sizing criteria.
Two other similarly-sized motors were shortlisted along with the Elco EP-70: the Bellmarine Drive-
master 50A and the Electric Yacht QuietTorque 45.0. The reasons that we chose the Elco EP-70, as
opposed to the other two, were threefold. First (and primarily), Bellmarine and Electric Yacht did not
have the desired motor sizes (that is, the 50A at 50kW and the QuietTorque 45.0 at 45kW, respectively)
in stock, and lead times for both were in excess of 20 weeks, which would not allow a timeline featuring a
summer installation; second, the Elco is an induction motor, so it should prove to be much more rugged
(with its 50000 hour periodic maintenance time) than the permanent magnet motors of Bellmarine
and Electric Yacht; and third, documentation and integration details (i.e. installation manuals, motor
characterizations, controller details, etc.) for the Elco were much more available to us compared to the
other two manufacturers.
The main integration considerations with the EP-70 are its operating voltage of 108V and its max-
imum current draw of 495A (which tie into battery selection and configuration), as well as its rated
RPM of 1800 (which, with a direct drive configuration, will entail a significant reduction in pitch for
Tara’s propeller).
13

18. 3.2.2 Battery Selection
In order to utilize the abundance of renewable energy that is generated in Southeast Alaska, mainly
hydroelectric, Tara will need a battery bank that could be pre-charged at the Hobbit Hole. The Hobbit
Hole has its own mini hydroelectric generator and a new solar array, so Tidelines hopes to be able to
harness this electricity and power Tara’s propulsion. Ideally, Tara would have a large enough battery
bank so that the trip from the Hobbit Hole to Gustavus and back could be made using all electric drive.
However, we determined very early on that the weight and cost of a battery bank this size would make
that infeasible.
After deciding on a hybrid drivetrain, the main selection criteria for the battery system was the
operating voltage of the motor. Since we selected an Elco EP-70 that is rated for 108V, the batteries
would have to be at approximately that voltage. Many of the marine batteries on the market operate
at lower voltages like 24V or 48V, which constrained our options to two manufacturers: Lithionics and
Valence (produced by Lithion). Recommended by Bob Varness, our technical lead, the Valence XP
series of batteries was very modular, allowing multiple 12V battery modules to be strung together in
series to get the desired output voltage. These strings could then be placed in parallel to increase the
overall capacity. On the other hand, the Lithionics system consisted of large, 102V battery modules that
were already at a compatible voltage for the EP-70. Similarly, several of these modules could be placed
in parallel to increase the total capacity of the battery bank. Both systems come with a sophisticated
battery management system (BMS) that allows for fine control and monitoring of the state of the
modules as well as peripherals like the chargers. The BMS of our chosen system had to be able to be
integrated with the genset so that the system could toggle it on and off depending on the state of the
charge of the battery, and both BMSs are able to do this function using a digital high/low pin.
Over the course of the project, repeated attempts were made to contact Valence through a variety
of channels, yet the company never engaged in conversation with our team. We were, however, able to
get in contact with OceanPlanet Energy, a dealer for Lithionics based in Portland, ME. They were able
to provide us with a quote for a 45.9 kWh system that consisted of six 102V, 75 Ah battery modules
arranged into three groups of two, each group with their own combiner box, BMS module, and charging
setup. The BMS modules communicate with the other ancillary components through Controller Area
Network (CAN), as serial protocol. The generator auto-start is controlled by a digital high/low line.
Each of the individual phase lines coming from the genset would be connected to one or more chargers
for each group. As currently laid out, the design will be bottle-necked at the chargers when operating
at full genset load. However, this can be remedied by either adding more chargers in parallel or by using
higher powered chargers.
This configuration can be seen in the circuit diagram included in additional files.
3.2.3 Generator Selection
After it was clear that both weight and cost precluded a fully electric solution for Tara, a number
of marine gensets were explored. We considered diesel, gasoline, propane, gas turbine, and fuel cell
solutions, but due to safety concerns and fuel availability, diesel was a clear winner: as a nonvolatile
fuel, diesel has a far reduced fire and explosion risk, and marinas in Southeast AK only reliably provide
diesel dockside.
Modeling efforts revealed that gensets with a continuous power of approximately 30kW would be
required for continuous operation at cruising speed in tidal currents. Additional research and design
efforts indicated that 240 V 3-phase output would result in the fastest charging and easiest integration
with battery chargers. Reducing total weight, fuel consumption, and emissions were also considered
important to project goals, but available specs, included in table 15, were found to be approximately
14

19. standard across manufacturers. A wet exhaust configuration with raw water cooling was specified for all
models under consideration for a number of reasons: one, Tara already has seacocks installed for raw
water cooling; two, increased cooling with this configuration allows for a sound shield to be used; and
three, a lack of external keel coolers decreases hull drag and simplifies installation.
Diesel gensets are available from a number of manufacturers, and contact was made with dealers
for Kohler, CAT, Cummins, Northern Lights, and MER representing all major purveyors with gensets
in our size range. Kohler, Cummins, and CAT were excluded after consultation with dealers revealed
lead times (40, 50, and 72 weeks, respectively) that exceeded Tidelines’ desired timeline for the project.
The MER Bollard MG42 was selected over the Northern Lights M944T3FG due to it’s additional 4kW
of output power and stellar 50,000-hour overhaul time, an industry leader in that category.
3.2.4 Bill of Materials
The bill of materials is included below:
Motor
EP-70 with controls and cabling 1 $15,995.00
Deluxe display and controller 1 included
Motor mounts 4 $275.00
Shaft couplings 2 $190.00
Battery connection cables and hardware 1 $275.00
Shipping crate 1 $285.00
Shipping 1 $1,736.23
TOTAL $18,756.23
Batteries
GT102V75A-F24-DIN battery modules 6 $45,343.80
Combiner box 2-1 3 $3,021.30
ND-SC-UL-102V-300A BMS 3 $7,449.30
NCC-2500 charger 3 $2,832.30
System consulting - configuration 4 $800.00
System diagram 4 $800.00
System consulting - commissioning 8 $1,600.00
Freight 1 TBD
TOTAL $61,846.70
Generator
42 kw Marathon Mariner generator 1 $36,000.00
Oil drip pan 1 $400.00
Pedestal mount control panel 1 $650.00
Bollard sound shield 1 TBD
Low coolant Murphy alarm 1 $450.00
Low oil Murphy alarm 1 $550.00
Oil change valve and hose 1 $250.00
Test run coolant system 1 $350.00
Shipping crate 1 $650.00
Shipping 1 $980.00
TOTAL $40,280.00
Switches
Genset/Shore Power: FA2-B0-22-825-2DA-CG (or equivalent) 4 $1200.00
Motor cutoff: FA3-P0-14-870-22A-BT 1 $129.77
PolyCase WQ-42 2 $55.64
Breaker knockouts 2 $30.00
Table 9: Bill of materials including three main propulsion components and ancillary components
15

20. 3.2.5 Financial Analysis
Combining all of the quoted prices together, we get the following for the total projected cost of the
main motor, batteries, and genset and their respective ancillary components.
Component Model Price
Motor Elco EP-70 $18,756.23
Batteries Lithionics GT102V75A $61,846.70
Genset Bollard 42 $40,280.00
Total $120,882.93
Table 10: Quoted prices for each of the three main systems
This proposed budget represents a very significant capital investment on the part of Tidelines, yet
it is close to the upper range of the estimate put forward in the project proposal. During the design
process, there was never a firm cap on the budget, so the team spec’d out the most robust, well-
engineered system to satisfy the objectives put forth by Tidelines. We know that the project itself is
well funded, but this final quote may have exceeded Tidelines’ expected price range. Potential ways in
which the budget could be reduced are discussed in Section 4.
There are some additional important perspectives to consider when evaluating this value proposition.
Not only is Tara receiving a more environmentally-friendly propulsion system, but the resulting system
will be a significant upgrade over the existing system This gives Tara vastly improved capability and
performance in a variety of operating conditions. Also, performing a Net Present Value calculation
(Section A.5) we can see that if the costs of chartered flights, fuel, and maintenance are considered for
the next several years, the retrofit of Tara actually has a positive value.
3.3 Installation Guide
We have acquired the installation guide for the Elco EP-70 motor already (included in additional docu-
mentation). Installation guides for the Lithionics battery package and Bollard generator will be obtained
upon purchase of the batteries and genset. The installation guides will provide general instructions,
information on the minimum system requirements, and installation methods and detailed notes. The
guides should also include the electrical schematics and the physical layouts. They should prove to be
comprehensive for the mounting and installation processes.
3.4 CAD Models and Drawings
To produce an illustration of the retrofit, we designed a CAD model. This model includes the dimensions
of the existing boat along with the changes to the interior. Figure 4 shows the exterior of our model.
16

21. Figure 4: CAD Model of exterior of boat
Considering the configuration of the main components, we can take a look at the setup below the
deck. At the back is the fuel tank, followed by the batteries, motor, and at the front is the genset.
The decisions of the placement of each component was based on space available as well as the existing
setup currently onTara.
Figure 5: Interior view of CAD model with each component labeled
From the interior of the boat, we can see that there is sufficient room for each of the components
to fit well. Moving forward, we conducted testing to verify that the loading of each of the components
would not cause instability in the boat and that the hull would be able to sustain the weight of the
added components comfortably.
3.5 Circuit Diagram
To aid in installation efforts, we constructed a circuit diagram for our proposed propulsion system which
is included as a separate PDF file under the name “circuit diagram.pdf”; the schematic details the main
connections between the Bollard genset, the Lithionics battery system, and the Elco motor. All of the
switches are Carling F-series. Note that the genset/shore power switch will be physically implemented
17

22. using four 2-pole switches (with 2 connections left open) and the motor disconnect switch will be
physically implemented using a 3-pole switch (again, 2 connections are left open); switches with more
appropriate numbers of poles did not possess desired current and voltage ratings. Final configuration
of the system is contingent upon component availability.
3.6 State Diagram
A state diagram, included in attached files under the name ”state diagram.pdf”, was also developed for
Tara’s operation. It includes three docked states (prefix B) and two underway states (prefix C), each
individual state separated by charging status. In this diagram, the generator is set to turn on and off
automatically at predetermined thresholds, and when docked, Additional error states are noted on the
diagram, but those function as placeholders for the 70 error states contained in the motor controller and
BMS firmware. This diagram is intended to inform configuration of the controllers during installation.
3.7 Design Verification Results
3.7.1 Buoyancy Analysis
To calculate buoyancy, we first solved for the waterline by calculating the water displaced. We took
the total weight of the boat and divided it by the specific gravity of saltwater and found the water line,
which shows where the volume at which the boat will be underwater. We obtained this relation by
considering the Archimedes Principle.
Figure 6: Calculation of waterline
After calculating the water line we did this computationally for a more robust analysis. For this
analysis, we found the location of the water line to be the same as the one we calculated. The volume
of the hull shown in the image is the volume of the hull that would be underwater. The circle in the
middle that you see represents the center of buoyancy of our boat.
Computationally, we conducted two design studies in SolidWorks to test the buoyancy of the boat
and find the center of buoyancy. To do so, we ran this study by removing the shell of the boat and
having it be a filled-in solid hull. By making the hull a solid body as opposed to a hollowed shell, we
can say that the mass of the solid body is the mass of the water displaced by the boat being submerged.
Once we did that, we then added a sensor to locate the point at which mass of the solid body (water
displaced) was equal to or less than the total mass of the boat in its normal state. Considering the
loading on the boat and the weight of the hull, the total mass equals 13774.3 lb. As this boat will be
18

23. used mainly for transportation purposes, we are running two design studies, one where the fuel tank is
empty and another where it is full. From these two studies, we will be able to know how the buoyancy
of the boat changes. Thus, for the case of the empty state, we set the mass limit to equal 13074.3 lb,
as the average weight of 100 gallons of diesel fuel is equal to approximately 700 lb. After setting the
mass constraints for both, we ran the tests and came up with the following conclusions.
Figure 7: Buoyancy test: State where fuel tank is empty
Figure 8: Buoyancy test: State where fuel tank is full
Buoyancy Test Total Mass (lbs) Waterline (inches away from the deck)
Boat with Empty Tank 13074.3 41.503
Boat with Full Tank 13774.3 41.553
Table 11: Overall Results from both design studies for testing buoyancy
As expected from Archimedes Principle, the boat with an empty tank will float at a higher volume
than the boat with a full tank. Yet, as we see from the study, the difference for the water line from
the first and second test is a factor of 0.050 inches. This is a rather small difference, which suggests
that even when the tank is completely empty, the center of buoyancy is still similar to when the
tank is full and the boat is therefore buoyant in both cases. Data for these analyses are included in
19

24. ”TARABuoyancyFinalTest fulltank.xlsx” and ”TARABuoyancyFinalTest emptytank.xlsx” in the folder
of additional documentation.
3.7.2 Structural Load Analysis
After proving the buoyancy of the boat, we then conducted an analysis to check that the loading on the
boat would not be enough to cause stability issues. For that we conducted a static study and added
the forces acting on the boat. The purple arrows represent the loading on the boat. The green arrows
represent fix points on the boat. And the red arrow is the force of gravity acting on the boat. In running
the simulation, we found the stress to be evenly distributed throughout the hull, which shows that the
boat will be stable even with the additional loading.
Figure 9: FEA Static test - Stress results
From this figure, we can see that most of the stress is distributed evenly across the boat and is
relatively small so it causes minimal stress on the boat. To attempt to identify how each component’s
loading influences the stress on the hull, we also conducted an FEA study where we distributed the
loading of each individual part. In running the simulations, we found there to be no significant stress
from any of the individual components. There is shown to be some stress along the hull where the fuel
tank is, but aside from that, no other visible stress from any of the other components.
Figure 10: FEA Static Test - Stress results for individual component loading
20

25. Aside from stress, we also calculated displacement and strain and found the results to be consistent
to that of our stress results. See Supplementary Materials A.6 for displacement and strain results.
Another result from the FEA study was in obtaining the Factor of Safety from the design. Figure 11
shows the Factor of Safety to be greater than 1 for most parts, which suggests that our design and
placement of components shows no clear places of failure.
Figure 11: Factor of Safety Results from FEA analysis
Given the limitations for the FEA study as a result of the difference in material, we are not able
to provide sufficient information on how each individual component affects the stress and strain on
the hull. To be able to provide a deeper understanding of just how the drivetrain, motor, and battery
packs will be integrated into the hull structure, we would need more data on the hull material and hull
construction.
3.7.3 Limitations
In an effort to demonstrate the distribution of loading on Tara, we aimed to conduct a structural loading
analysis that would determine if the boat is stable along with the ideal configuration of components
in the interior. While we succeeded in conducting an FEA analysis that demonstrates how the total
loading on the boat affects the stability of Tara, we were unable to complete the testing of how each
individual component loading affects the stability of the hull. After consulting with Thayer Machine
Shop Technical Instructor Joseph Poissant, we concluded that there were limitations to successfully
completing those simulations due to issues with the large size of the CAD assembly model. In order
to successfully run the FEA study, we concluded that we needed to compromise on material due to an
elastic strain error when using fiberglass as the material [10]. Thus, instead of selecting fiberglass as
the material for the FEA of the boat, we went with the material Aluminum Alloy 6061-T6 instead.
3.8 LCA Results
LCA results of the diesel and hybrid diesel-electric systems were compared in Fig. 12, Fig. 13, and Fig.
14. Although the new hybrid system did not outperform the old diesel one when it comes to the carbon
footprint of the individual parts, this can be attributed to the particular nature of Tara’s old engine.
Not only was it severely undersized, it was severely underpowering Tara. It was an old engine that is
out of production now. The maintenance of the engine, we are assuming, although not included due to
21

26. the lack of available information, would have contributed a lot in the LCA. It’s also important to note
that our new system is much more powerful than the previous one, so a comparison of two equivalent
systems would be more realistic. We still believe the retrofit is more sustainable for similar vessels with
different diesel engines, ones with equivalent horsepower as our solution.
Figure 12: Impacts by SBOM inputs: Carbon footprint [CO2 eq. kg/func unit]
Looking at the impacts by life cycle stage, which is a better metric, considering we are more
concerned with how the two systems perform during the usage stage, we notice that our hybrid system
produces only 5.73 kg more of CO2 per year. Again, emphasizing the small size of our motor, this
implies that other current diesel motors will definitely be outperformed from a sustainability perspective
by our solution.
22

27. Figure 13: Impacts by life cycle stage: Carbon footprint [CO2 eq. kg/func unit]
Looking at the impacts by life cycle stage of all emissions of chemicals into the air, water and soil,
we notice that our hybrid system outperforms the old one, scoring 0.037 mPts less per year. This value
increases significantly to 0.35 mPts per year when we assume that our batteries will be running for three
quarters of the trip and the diesel genset only for a quarter of the trip. This implies the use of more
batteries, which will increase the costs of this project but also will make the trip more sustainable. This
is a trade-off that Tidelines might have to make. Therefore, as the batteries are used longer to power
Tara during the trip, the propulsion system performs better when it comes to several impact categories
including ecological damage, resource depletion, and human health damage.
Figure 14: Impacts by life cycle stage: Total [mPts/func unit]
23

28. 4 Conclusions & Recommendations
Though there was no hard cap on the budget given by Tidelines, creating the most well-engineered
design for the retrofit of Tara ended up costing a considerable amount. This is discussed in Section
3.2.5 As a result, we have identified a few different ways in which the total cost of the retrofit could be
reduced. First of all, the most direct path towards cost reduction comes from cutting back on the specs
for the motor, genset, or batteries. For example, if the motor was reduced in size from an Elco EP-70 to
an EP-40, that would create some slight savings. A smaller motor would also allow for a smaller genset
to be used. Together, these changes would create about $15k in savings. However, this would greatly
impair Tara’s functionality and limit the conditions in which she can be used. The factor of safety in
tidal currents would be reduced, making Tara unnavigable in all but the lightest currents. Reducing the
batteries would have a similarly deleterious effect on Tara’s utility, as the generator would have to run
far more frequently to the point where the vessel is basically just running on diesel fuel. This would
eliminate a lot of the environmental benefits of a hybrid drivetrain, and would also minimize some of
the qualitative advantages like the low volume during all-electric drive
Another way to reduce the total budget would be to buy used components instead of purchasing
them brand new. This would really only work for the battery system, as there are not very many options
on the second-hand market for electric motors or marine gensets.There are, however, vendors that sell
used lithium ion batteries for a fairly substantial discount. One such vendor, Greentec Auto, lists pre-
owned Valence batteries at approximately 75% of the brand new price. Accordingly, the batteries are
only rated to have about 70-75% of their original capacity. These would likely work just fine as a
battery bank for Tara, yet it is difficult to recommend this as a path forward. First of all, there are
considerably more risks incurred when working with pre-owned components. We have no way of knowing
how many charge cycles the batteries were put through or the environment in which they were stored,
so the batteries may be more degraded than advertised. This likely shortens the lifespan of the battery
bank, making it so that the system may need to be replaced sooner, for an additional significant sum.
Secondly, it would be unlikely that we would be able to have a pre-owned system covered under some
type of warranty or receive support from the manufacturer. This poses a significant financial risk, as it
makes Tidelines responsible in the case of an unforeseen accident.
Finally, it is possible that funds could be saved by simply delaying the project. Availability ended
up being a fairly significant factor in choosing the main components of the design. Lead times for
motors and gensets varied significantly from different suppliers, and in many cases were in excess of 40
weeks. Part of these significant lead times can almost certainly be attributed to the supply chain issues
stemming from the global pandemic. Therefore, there is a chance that in a year or two, many of these
issues will have been resolved, making it possible to consider cheaper components that were eliminated
due to availability concerns. For the batteries, Lithionics was the sole manufacturer with whom a dialog
was established over the course of the project. Though the Lithionics system is a good candidate for use
with Tara, it would be ideal to have multiple options and price points to compare, considering that the
batteries alone are the single biggest cost in the current budget. Additional time reaching out to battery
manufacturers may yield more competitive quotes that could lower the price of the battery system while
retaining the capacity that is desired. However, this would obviously derail Tidelines’ stated goal of
performing the retrofit over the summer of 2022.
Beyond budget considerations, there are significant steps that still need to be taken in order to
complete the retrofit. There needs to be improvements made to Tara’s superstructure and deck in order
to make the vessel safe and seaworthy. Tidelines has already begun this process, having contracted Mike
Svensson, a shipwright based out of Hoonah, AK, to perform the necessary improvements. Beyond that,
should they decide to move forward with our proposed design, Tidelines will need to actually acquire
the selected components. All contact information for the dealers with whom we have communicated so
24

29. far will be passed on, and the necessary introductions will be made to facilitate a smooth transition.
After these upgrades are made, a group of Dartmouth students will travel to Southeast Alaska over
the summer of 2022 to help perform the retrofit. We look forward to joining that team and getting
Tara back out to sea to help Tidelines be an agent of structural change and a harbinger of the future
of marine transportation.
25

30. References
[1] Kelly Benton, Xufei Yang, and Zhichao Wang. “Life cycle energy assessment of a standby
diesel generator set”. In: Journal of Cleaner Production 149 (2017), pp. 265–274. issn: 0959-
6526. doi: https://doi.org/10.1016/j.jclepro.2017.02.082. url: https:
//www.sciencedirect.com/science/article/pii/S0959652617302962.
[2] CAT. C4.4, C4.4 ACERT, C2.2 Product Specifications. 2021.
[3] Firasf1dream. Fiberglass composite study in SolidWorks, Help ! 2015. url: https://www.
f1technical.net/forum/viewtopic.php?t=22303 (visited on 03/07/2022).
[4] Anjuli Grantham. Juneau’s Climate Change Solutionists: Electrifying marine transportation
with Bob Varness. 2021.
[5] Hans Hersbach et al. “The ERA5 global reanalysis”. In: Quarterly Journal of the Royal
Meteorological Society 146.730 (2020), pp. 1999–2049.
[6] Byongug Jeong et al. “An effective framework for life cycle and cost assessment for marine
vessels aiming to select optimal propulsion systems”. In: Journal of Cleaner Production 187
(2018), pp. 111–130. issn: 0959-6526. doi: https://doi.org/10.1016/j.jclepro.
2018.03.184. url: https://www.sciencedirect.com/science/article/pii/
S0959652618308552.
[7] Michael Kasten. Sabb 2JHVP Marine Diesel Engine. Oct. 2001. url: http://www.xsw.
com/boojum/Sabb30/index.html (visited on 11/18/2021).
[8] Chandler Kemp. “Electric power systems for fishing vessels : Feasibility , fuel savings and
costs Sponsoring organizations : Prepared by : Corresponding Author”. In: (2021).
[9] Chandler Kemp. “Woodstock Summer Operations”. In: (2021).
[10] Ketul Patel. SOLIDWORKS Simulation: Causes of Incremental Strain Error. 2018. url:
https://www.cati.com/blog/2018/12/solidworks-simulation-causes-of-
incremental-strain-error/ (visited on 03/07/2022).
[11] Kohler. “Model : 28EFKOZD, 32EKOZD, 33EFKOZD Marine Generator Set Generator
Weights and Dimensions Engine”. In: 195 (2021), pp. 1–4.
[12] Anna Karina Magnussen. “Rational calculation of sea margin”. MA thesis. NTNU, 2017.
[13] Grant D. McKenzie. How to Calculate The Underwater Volume. 2017. url: https : / /
sciencing . com / calculate - underwater - volume - 6345342 . html (visited on
03/07/2022).
[14] MER. “Bollard MG28, MG42 Marine Generator Specifications”. In: (2021).
[15] NOAA. “Coast Pilot 8: Alaska-Dixon Entrance to Cape”. In: 1 (2021), pp. 119–135.
[16] NOAA. “Current Tables, Pacific Coast”. In: (2021).
[17] Northern Lights. “M944W3FG, M944T3FG Specifications and Dimensions”. In: (2021).
[18] Onan. MDKDU, MDKDS Marine Generator Specifications. 2021.
[19] Svetlana Orlova et al. “Lifecycle Analysis of Different Motors from the Standpoint of En-
vironmental Impact”. In: Latvian Journal of Physics and Technical Sciences 6 (Dec. 2016),
pp. 37–46. doi: 10.1515/lpts-2016-0042.
[20] University of British Columbia. 14.4 Archimedes’ Principle and Buoyancy. url: https://
opentextbc.ca/universityphysicsv1openstax/chapter/14-4-archimedes-
principle-and-buoyancy/ (visited on 03/07/2022).

31. [21] USNA. “Resistance and powering of ships”. In: Resistance and powering of ships. 2002.
Chap. 2.07, pp. 1–46.
[22] O. Winjobi, Q. Dai, and J.C. Kelly. “Update of Bill-of-Materials and Cathode Chemistry
addition for Lithium-ion Batteries in GREET 2020”. In: Systems Assessment Group, Energy
Systems Division, Argonne National Laboratory (2020).

32. A Supplementary Materials
A.1 Description of Operation
[see below]

33. Vessel Information
Background
First launched in 1967, the F/V Tara (formerly F/V Angel Lilly, call sign WX9698) has served as a halibut
longline fishing vessel in the waters of Southeast Alaska for decades. Her hull is a semi-displacement deep-v with
dimensions given in Table 12. Her main deck has a center cockpit helm and a small forward cuddy cabin with a
raised cabin top in lieu of a foredeck. She has two fish holds amidships with a six ton total capacity, and an engine
compartment aft of the holds. Additional smaller lockers to hold fishing, deck, and docking gear are located on
the deck. Tara’s current power plant is a 30 horsepower diesel engine, the specs of which are also listed in Table
12 [7].
Part Dimension Units
LOA 28’11” feet/in
Beam 10’3” feet/in
Draft 4’6” feet/in
GRT 10 tons
NRT 8 tons
Hold Capacity 6 tons
SABB 2JHVP diesel motor 2 cylinders, water cooled, 4 stroke
Engine max power 30 horsepower (at 1900 rpm)
Engine bore/stroke 3.93”/4.72” inches
Engine displacement 114.7 in3
Fuel consumption 0.4 lb/hph
Engine weight 838 lbs
Table 12: Current specifications of Tara
Planned Systems
Hybrid conversion of Tara will replace her current diesel power plant with a series hybrid electric propulsion system.
This system will employ an electric drive motor with a battery power supply. Since current charging infrastructure
(§Home Port, §Ports of Call) is insufficient for fully electric operation of the vessel, a conventionally-fueled range
extender – an internal combustion motor running a generator – will charge the batteries in port and en route,
however, the vessel will recharge with renewable energy sources when available
Sea Margin
A sea margin of 20% will be used for initial calculations and will be revisited after preliminary CFD simulations
are completed [12].
Vessel Operator
Background: Tidelines Institute
Tara will be operated by the Tidelines Institute, an experiential education and research organization located in
Southeast Alaska. As a former fishing vessel, conversion of Tara will offer a benchmark for performance and cost
of hybrid vessel construction and will serve as an inspiration to take on such projects, advancing the institute’s
mission of climate responsibility.

34. Planned Use
Tara will serve as a passenger shuttle, moving student groups and institute affiliates between the institute’s Inian
Island Campus and their Good River Campus in Gustavus, AK. Student groups visit the Inian Island campus during
the late spring, summer, and early fall months – May, June, July, August, and September – so primary operation
of Tara will occur at that time of year. Tara may be used for shoulder season trips outside of that window if the
need arises.
Home Port
Tara’s home port will be at the Hobbit Hole on Inian Island (Fig. 15, 58°14’50”N 136°20’29”W). The Hobbit
Hole is situated in a lagoon, called ”the Gut,” with a narrow and shallow mouth, rendering it inaccessible within
1.5 hours of low tide. At low tide, the Gut has a depth of approximately 1.5 meters and a width of approximately
3 meters with several submerged rocks on the sides of the channel. Tidal currents in the Gut can reach 4-5 knots.
The facility has two docks – one offshore on pilings in deep water outside the Gut and one connected to the
campus by a long gangway inside the gut.
Current charging infrastructure on Inian Island consists of a Type B extension cord connected to the 120
V/15 A domestic mini-grid. The grid has a usable energy storage capacity of 24 kWh and a maximum generating
capacity of 10 kW from the micro-hydro plant and 3 kW from the PV solar array for a total of 13 kW. These
power sources are fully renewable and will serve to further Tara’s mission of demonstrating independence from
fossil fuels for maritime transport.
Figure 15: Tara’s home port on the Inian Islands and her primary ports of call in Gustavus and
Elfin Cove. The red arrow shows her expected trip.
Ports of Call
Tara will operate between Inian Island and Gustavus, AK. Gustavus has two docks – a municipal dock with the
Alaska Marine Highway ferry terminal and a National Park Service dock at Bartlett Cove in Glacier Bay National
Park. Both docks are in deep water, and shore power (120 V/15 A) is available at the municipal dock. Tara
will also operate between Inian Island and Elfin Cove, a port 5 miles to the south of Inian Island Fueling services
(diesel) and shore power (120 V/30 A) are provided at Elfin Cove.

35. Area of Operations
Planned Route
Tara’s planned route will take her from Inian Island to Gustavus and back, a round-trip distance of approximately
50 miles excluding the effects of currents. Apparent speed over water and effective trip duration with maximum
currents are shown in Tables ??, ??, ??, and ??. Other areas of operations include Glacier Bay, Icy Strait, and
Cross Sound.
Expected Conditions
Typical Operating Conditions
Tara’s primary operating season is May through September. Tara may also operate in shoulder-season conditions
outside of that window for non-critical transport of Tidelines Institute staff and equipment. Typical meteorological
and maritime conditions for these periods in the northern Icy Strait are summarized in Table 13 [15].
Parameter Units May June July August September
Air Temperature °C 8.3 11.7 13.3 13.3 10
Water Temperature °C 8.8 11.3 13.4 13.9 12.1
Wind Speed mph 6.1 5.6 5.5 6.2 7.9
Wind Direction N/A SE S S S S
Table 13: Average operating conditions
Most Severe Operating Conditions
Tara’s primary operating season is May through September. Tara may also operate in shoulder-season conditions
outside of that window for non-critical transport of Tidelines Institute staff and equipment. The most severe
meteorological and maritime conditions for these periods in the northern Icy Strait are summarized in Table 14
[15, 16, 5].
Parameter Units May June July August September
Air Temperature (min) °C 4.4 7.8 10 10 7.2
Air Temperature (max) °C 13.3 16.1 17.2 16.7 13.9
Wind Speed mph 25.2 22.8 21.7 21.9 26.4
Sea Height % > 9ft 2.8 1.8 1.0 1.8 3.5
Tidal Current kts 3.1 3 2.9 3 3
Table 14: Most severe operating conditions
Storage Conditions
Tara will be taken out of the water each winter, covered, stored outdoors in Gustavus. Sea conditions at this time
are thus irrelevant, but storage temperatures will average between 25° and 35° Fahrenheit and may reach as low
as 0° F [5].

36. A.2 Sketches and Dimensions
[see below]

40. Drawing Dimension Value Units Description Questions Notes
1 ‐ Hull A 29 ft LOA approximate
B 10 ft Beam approximate ‐ actual is 10.3
C 4.5 ft Depth approximate
D 27 to keel, 34 to bottom of rudder skeg in Draft
approx. from estimated waterline. Remeasure from
painted?
E 41.5 in Depth to chine Hard or soft chine? soft.
F1 14 in on center Distance between keel and first stringer
What are the cross‐sectional dimensions (and shape)
of the keel beam
No keel beam. Only two stringers, each 14 inch on
center from centerline. Stringers are 8.5" deep by 3"
wide rectangular in cross section.
F2 Distance between first and second stringer
What are the cross‐sectional dimensions (and shape)
of the stringers n/a
F3 Distance between second and third stringer n/a
F_n… Distance between additional stringers
How many stringers are there? Are there lateral
frames or just fore‐aft stringers?
Lateral frames under holds and tanks, to establish flat.
Undecked.
2 ‐ Bilge G 105 in Length (along keel) of cuddy cabin
Feel free to correct layout as needed (Measured cabin
forward of pilot house)
H 68 in Length (along keel) of open bilge
It is assumed that the forward bulkhead separating
the fish holds from the bilge lines up with the rear wall
of the pilothouse ‐ how will this change with the
I 54 in Length (along keel) of fish hold
How are the fish holds separated from the bilge? By a
full bulkhead? Planks? Is there a flat bottom? Planks. There is not a flat bottom.
J 103 in Length (along keel) of fuel tank
Ok so the fuel tank is actually a hold that contains a
tank with dimensions 24"x 10"x105" lying athward the
stringers directly behind the fish holds. The total "fuel
hold" is 103" along the keel, with approx 21" of
headroom
K 44 in Width of fish hold How far from keel does hold start? 16 inches either side of centerline
L 54 in Clearance at tallest part of hold Where does this occur?
from lowest part of fish hold to underside of fish hold
cover
L ‐ min 36 in Clearance at shortest part of hold
between edge of hold and underside of deck (hold
curves upward)
M 48 in Clearance at tallest part of engine compartment This is under the engine hatch in the pilothouse
M ‐ min 16 in Clearence at shortest part of engine compartment
Any qualitiative descriptions of engine compartment
access? How will this change with the superstructure
rebuilds?
I don't know about how this will change. This
dimension is the narrowest access to the rest of the
area under the pilothouse floor. In terms of qualitative
description, there is good access of the size indicated
directly over the engine, and the engine is also
accessible from the bilge/fish hold area, as the planks
N 16 in Distance from stern to rudder post
P 4 in Distance from rudder post to end of prop shaft Please also note distance to end of prop itself 6 inches to the end of the prop itself
3 ‐ Deck Q 181 in
Distance (along keel, from stem) of forward edge of
fish hold access
This is an inside dimension, i.e. from the forwardmost
part of the cuddy cabin. There is very little space
forward of the forwardmost part of the cuddy cabin,
but it is difficult to estimate. Perhaps six inches at
R 47.5 in Length (along keel) of fish hold access
It is assumed that fish hold access hatches are equal in
size and symmetrical over the keel
S 29 in Width of fish hold access
T 105 in
Distance (along keel, from stem) of forward edge of
helm
Helm is on the wall dividing the pilothouse from the
cuddy cabin
U 18 in Length (along keel) of helm
It is a standing helm, the depth of the area along the
keel that contains the wheel and controls is 18 inches
deep.
V Distance from port gunwhale of port side of helm
Is the helm on the port or starboard side of the
pilothouse? Will it remain there after the remodel? Helm is 8 inches port of the centerline of the boat.
W 32 in Width of engine compartment access
X 38 in Length (along keel) of engine compartment access

41. 96.00
117.01
30.00
18.82
26.70
11.22
10.48
4.38
4.92
35.00
19.25
55.81
29.00
24.00
13.00
348.00
117.0
1
A A
B B
C C
D D
E E
F F
G G
H H
J J
K K
L L
M M
N N
P P
R R
T T
24
24
23
23
22
22
21
21
20
20
19
19
18
18
17
17
16
16
15
15
14
14
13
13
12
12
11
11
10
10
9
9
8
8
7
7
6
6
5
5
4
4
3
3
2
2
1
1
DRAWN
CHK'D
APPV'D
MFG
Q.A
UNLESS OTHERWISE SPECIFIED:
DIMENSIONS ARE IN MILLIMETERS
SURFACE FINISH:
TOLERANCES:
LINEAR:
ANGULAR:
FINISH: DEBURR AND
BREAK SHARP
EDGES
NAME SIGNATURE DATE
MATERIAL:
DO NOT SCALE DRAWING REVISION
TITLE:
DWG NO.
SCALE:1:20 SHEET 1 OF 1
A0
Material <not specified>
WEIGHT:
TARA BOAT drawings

42. A.3 Generator Comparisons
[see below]

43. MAKE
MODEL
UNIT
COST
VOLTAGE
POWER
(MAX)
OUTPUT
FREQUENCY
WEIGHT
L/W/H
FUEL
CONS.
EMISSIONS
Kohler
[11]
28EFKOZD
-
120/480
28
three
phase
50
1339
51/26/30
2.57
32EKOZD
-
110/380
32
three
phase
60
1339
51/26/30
2.99
EPA
Tier
III
33EFKOZD
-
110/416
33
three
phase
50
2260
64/30/40
2.7
CAT
[2]
C2.2
$12,560.00
12/24
18
single
phase
50/60
1027
46/24/31
EPA
Tier
III,
IMO
NST,
EU
IW
C2.2
$15,320.00
12/24
27
single
phase
50/60
1027
46/24/31
EPA
Tier
III,
IMO
NST,
EU
IW
Cummins
[18]
Onan
QD
29
$24,876.66
220/208
29
three
phase
60
1380
54/25/30
2.8
EPA
Tier
III
Onan
QD
17
$18,788.32
220/208
17
three
phase
60
930
44/24/28
2.2
EPA
Tier
III
Northern
Lights
[17]
M944W3FG
$34,958.00
120/208
30
three
phase
60
1329
56/29/32
2.8
EPA
Tier
III
M944T3FG
$53,241.00
120/208
38
three
phase
60
1443
60/29/32
3.26
EPA
Tier
III
MER
[14]
Bollard
MG42
$40,280.00
120/208
42
three
phase
60
1922
62/31/40
3.53
EPA
Tier
III
Bollard
MG28
$29,480.00
120/208
28
three
phase
60
1147
52/22/31
2.3
EPA
Tier
III
Table
15:
Comparison
of
available
diesel
genset
specifications

44. A.4 Quotes

51. A.5 Net Present Value
[see below]

52. Year
0
1
2
3
4
5
6
7
8
9
10
Flights
$-
$50,760.00
$50,760.00
$50,760.00
$50,760.00
$50,760.00
$50,760.00
$50,760.00
$50,760.00
$50,760.00
$50,760.00
Fuel
(now)
$-
$5,000.00
$5,000.00
$5,000.00
$5,000.00
$5,000.00
$5,000.00
$5,000.00
$5,000.00
$5,000.00
$5,000.00
Maintenance
(now)
$-
$1,000.00
$1,000.00
$1,000.00
$1,000.00
$1,000.00
$1,000.00
$1,000.00
$1,000.00
$1,000.00
$1,000.00
Refit
$(120,882.93)
$-
$-
$-
$-
$-
$-
$-
$-
$-
$-
Fuel
(later)
$-
$(347.45)
$(347.45)
$(347.45)
$(347.45)
$(347.45)
$(347.45)
$(347.45)
$(347.45)
$(347.45)
$(347.45)
Maintenance
(later)
$-
$(1,000.00)
$(1,000.00)
$(1,000.00)
$(1,000.00)
$(1,000.00)
$(1,000.00)
$(1,000.00)
$(1,000.00)
$(1,000.00)
$(1,000.00)
Discount
Rate
0.2
NPV
$179,509.78

53. A.6 Verification Methods
Figure 16: FEA Study - Displacement of loading on hull
Figure 17: FEA Study - Strain of loading on hull

54. Figure 18: FEA Study - Displacement of individualized components
Figure 19: FEA Study - Strain of individualized components