Green-hull Designs Ltd.

Green Technology Catamaran Sailboat

Project Outline• Concept of Operations / Scope

• Parametric Analysis

• Velocity Prediction Program

• Hull Form Development

• General Arrangement

• Propulsion Analysis

• Electrical Analysis

• Structural Design

• Weight Analysis

• Cost Analysis

• Financial Feasibility Analysis

Concept of Operation / Requirements

– Catamaran sailboat designed for a new green charter company.

– Design is to utilize green technology

– Able to cruise for 2 hours at 5+ knots under electric power including hotel loads

– 3 to 4 staterooms with 3-4 guest heads/showers

– 2 crew quarters

– One main level head/shower

– Galley• Electric stovetop

• Fridge/Freezer

– On-board laundry

– Operated in the Caribbean

Project Scope• Objectives

– Create an accurate design model

– Major components and systems, especially those related to the “green aspects” of the design will be fully defined

– Detailed cost and financial benefit analysis

• Assumptions– Constructed in North America

• Authority & Responsibilities– DNV-GL Class with RINA’s Green Plus Certification

• Budgets & Schedules– $800,000 - 1 million dollars per vessel

– $2.4 – $6 million total capital cost budget

Green Design Aspects

Methanol Fuel Cells

• By-products: H2O and trace CO2

Solar Energy• Solar cloth integrated into the main

sail

• Flexible solar cells on hull

Electric Drive System• Very low noise emissions

• Smooth electric drive with

variable speed

• Vibration isolation mounts

• No burning of fuels= no emissions

• Complete integrated system

• Shore power connection

• Battery bank

Summary of Performance vs. KPP’s

Parametric Study• 32 commercially available vessels investigated

• Analyzed: Length, Beam, Draft, Sail Area, Lightship Weight, Installed Power, Fuel Tank Volume, Water Tank Volume, Accommodation Spaces

Parametric Curves Developed

y = 16.995x - 115.29R² = 0.8208

y = 10.396x - 71.141R² = 0.7534

y = 6.6218x - 40.119R² = 0.7522

0

50

100

150

200

250

12 13 14 15 16 17 18 19 20 21

Sail

Are

a o

f th

e V

esse

l (m

2)

Length of the Vessel (m)

Vessel Installed Sail Area as a Function of Vessel Length

Total Sail Area

Main Sail Only

Genoa Sail Only

Linear (Total Sail Area)

Linear (Main Sail Only)

Linear (Genoa Sail Only)

Velocity Prediction Program Building from the parametric analysis an excel based VPP developed

Model Parameters• Resistance

– Bare hull resistance

– Hull roughness - Bowden-Davison & Townsin Equation

– Appendage resistance • Keel – Delft series using Horner relationships

• Rudder– Delft series using Horner relationships

• Centerboard– Delft series using Horner relationships

• Propeller and propeller supports - Offshore Racing Congress: Velocity Prediction Documentation 2013

• Sail Driving Forces

Bare Hull Resistance• NPL – Molland Series with Geurts extension

• Proposed new design range is within the series for all factors except for Fn

New Design

0 - 1

13 - 14

0.44 - 0.45

2.3 - 2.5

6.5-7

0.66

0.4

Bare Hull Resistance• Cf calculated using ITTC 57 and

• Molland Formulation

𝐶𝑇 = 𝐶𝑅 + 1 + 𝛽𝑘𝑚𝑜𝑛 𝐶𝑓

• Geurts Extension – Accounts for Froude number

Resistance Prediction for Fn<0.2

• Values found for the effective power at Fn=0.2

• Assumed form of:

𝑃𝑜𝑤𝑒𝑟𝐸𝑓𝑓 𝑅𝑒𝑞 = 𝐴1𝑉𝑠ℎ𝑖𝑝3

𝐴1 =𝑃𝑒𝑓𝑓 𝑎𝑡 𝑓𝑖𝑟𝑠𝑡 𝑐𝑎𝑙𝑐𝑢𝑙𝑎𝑡𝑒𝑑 𝑣𝑎𝑙𝑢𝑒

𝑉𝑠ℎ𝑖𝑝 𝑎𝑡 𝑓𝑖𝑟𝑠𝑡 𝑐𝑎𝑙𝑐𝑢𝑙𝑎𝑡𝑒𝑑 𝑣𝑎𝑙𝑢𝑒3

Curve fit provides smooth transition

(transition at about 5 knots)

0

2

4

6

8

10

12

14

16

0 1 2 3 4 5 6 7 8

Re

qu

ire

d E

ffe

ctiv

e P

ow

er

(kW

)

Vessel Forward Speed (knots)

Required Effective Power for Various Ship Speeds

Sail Forces

• Sail relationships taken from ORC VPP using the apparent wind angle

Velocity Prediction Program

• Iteratively solves for the:– Driving force (sails)

– Heeling force (sails)

– Lift from the hydrodynamics (keel, centerboard and rudder)

– Drag due to forward motion (u - component)

– Drag due to side slip velocity (v - component)

• Drive force = Drag due to forward motion

• Heeling force = Drag due to side slip velocity + lift from hydro

• Excel VBA macro written to modify the:– Forward velocity

– Slip angle (angle of attack of the hull)

• Continues iteration until assumed values equal calculated values for both with and without spinnaker sail

• Final step is selection of the sail design that provides the highest vessel speed and output of the speed polar plot

0.0

1.0

2.0

3.0

4.0

5.0

6.0

7.0

8.0

9.0

10.0

05 10 15

2025

3035

40

45

50

55

60

65

70

75

80

85

90

95

100

105

110

115

120

125

130

135

140145

150155

160165170175

180185190195

200205

210215

220

225

230

235

240

245

250

255

260

265

270

275

280

285

290

295

300

305

310

315

320325

330335

340345 350 355

Speed Polar Diagram 10 Knot Wind(Forward Velocity in Knots)

Wind Velocity 10 knots No Spinnaker

Wind Velocity 10 knots

Max Heel Angle:

2.2 degrees

Max Trim Angle

Under Sail:

0.6 degrees

Hull Form DevelopmentThe vessels has a round flat bilge hull form.

Lines Plans

Vessel Particulars

Green-hull Designs Ltd. Catamaran SailboatAll Hull Parameters Pertain to A Single Hull

Length Overall (m) 17.35LWL/LPP 1.06Length Water Line (m) 16.22L/B 13.52Length PP (m) 15.24B/T 2.11Breadth WL (m) 1.2CP 0.654Draught (m) 0.568Cx 0.907Wetted Surface (m2) 31.42Weight (kg) 17,035Sail Plan Area (m2) 433.5Water Clearance Height (m) 0.8

General ArrangementMain and Accommodation Deck

General ArrangementTanks and Machinery Deck

Sail Plan

Wire Rope Type 1 x 19

Metal Type 316 Stainless Steel

Diameter 7/16"

Breaking Strength 21,500 lbs

Maximum Load 13,500 lbs

Rigging Particulars

4 standing rigging wires

Propulsion/Endurance AnalysisOnce the resistance and electrical load analysis was completed a propulsions analysis was preformed.

Propulsion was analysed at three cruise speeds 7, 6 & 5 Knots. 7 Knot Cruising Speed

Required Forward Velocity V 7 Knots

Advance Velocity VA 3.60 m/s

Required Trust T 2,130 N

Propeller Torque Q 158 Nm

Shaft Power Ps 13.25 kW

Effective H.P EHP 10.13 h.p.

6 Knot Cruising Speed

Required Forward Velocity V 6 Knots

Advance Velocity VA 3.09 m/s

Required Trust T 1,574 N

Propeller Torque Q 102 Nm

Shaft Power Ps 8.54 kW

Effective H.P EHP 6.42 h.p.

5 Knot Cruising Speed

Required Forward Velocity V 5 Knots

Advance Velocity VA 2.57 m/s

Required Trust T 1,111 N

Propeller Torque Q 62 Nm

Shaft Power Ps 5.17 kW

Effective H.P EHP 3.78 h.p.

Propeller Selection

Utilized the Wageningen B-Series propellers.

Thrust Coefficient Torque Coefficient Advance Coefficient Open Water Efficiency

Preliminary Assumptions – 3 bladed

– 0.5 < Ae/Ao < 0.7

– 0.7 < P/D < 1.1

– Dmax = 0.5m

– RPMMAX = 800

Since the thrust required and advance velocity is known from the resistance estimate I was able to combined the Kt and J equations into a single equations with only one variable, propeller diameter.

Propeller Characteristics Chosen Propeller for 7 Knots

J 0.541 - P/D 0.9 - n 13.31 rps

KT 0.188 - Pitch 0.45 m N 799 RPM

KQ 0.0286 - Efficiency 57% - Thrust 2,135 N

D 0.5 m Ae/Ao 0.65 Torque 162 Nm

Chosen Prop DJ365 - Michigan 19.20 Lbs.

𝐾𝑇(𝐽) =𝑇∗𝐽2

𝜌∗𝑉𝐴2∗𝐷2

Endurance LimitEndurance Limits

• 2hrs cruising at 5 Knots only utilizing the battery bank,

• 8hrs cruising at 5 Knots with supplemental power from Solar Cells, Solar Sails

and Fuel cells.

Comparing the selected propellers and knowing the power required for the motor

and house loads for the vessel endurance limits were then calculated for the three

cruising speeds.

Therefore all three propellers selected for the three designs speeds are capable of

meeting the initial endurance limit.

Endurance Limits vs Cruising Speed Base Case

Available Power (Battery Bank) 38,880 Watt hrs.

7 Knots(per hr. Energy Required) 16,908 Watts

Endurance at 7 knots 2.30 hrs.

6 Knots(per hr. Energy Required) 11,953 Watts

Endurance at 6 knots 3.25 hrs.

5 Knots(per hr. Energy Required) 8,542 Watts

Endurance at 5 knots 4.55 hrs.

Endurance Limit Con’tFor the endurance limit with supplemental power from Solar Cells, Solar Sails and fuel

cells an additional assessment was completed.

For this case it was assumed that the fuel cells would be able to deliver their full rated

energy output but as for the solar cells a percent factor was multiplied by the power

generation to account for losses.

Therefore it was found that with a 32% solar power generation factor on the solar cells

the extended endurance limit at a 5 knots cruising velocity is achievable.

Endurance Limits vs Cruising Speed (w/ Power Gen)

Available Power (Battery Bank) 38,880 Watt hrs.

Assumed % Solar Power Gen. 32% -

Available Power ( fuel cells and %Solar Power Gen. ) 1,455 Watts

7 Knots(per hr. Energy Required) 14,680 Watts

7 Knots Net Energy Draw 13,225 Watts

Endurance at 7 knots 2.94 hrs.

6 Knots(per hr. Energy Required) 9,725 Watts

6 Knots Net Energy Draw) 8,270 Watts

Endurance at 6 knots 4.70 hrs.

5 Knots(per hr. Energy Required) 6,314 Watts

5 Knots Net Energy Draw 4,860 Watts

Endurance at 5 knots 8.00 hrs.

Propeller SelectionThe final propeller selection took into account the owners requirements as well as the most efficient propeller which could be selected.

Therefore the propeller selected was the 7 Knot cruising speed propeller

• Satisfies the base line endurance limit

• Satisfies the extended endurance limit at 5 knots, only requiring the solar cells to produce 32% of their rated power generation

• No Cavitation Issues

Stability – Intact and Damaged

• Intact Stability– DNV-GL does not require

traditional stability analysis

for multihulls

– Only requirement is:• a maximum GZ at 10 degrees or larger

– From ORCA:• Longitudinal GM 40.0 m

• Transverse GM 29.2 m

• Damaged Stability– Not required for multihulls less than 24m, performed anyways

– Penetration depth of 3.5m means one bulkhead flooded.

Damage CaseTransverse Heel

Angle

Longitudinal

Trim AngleTransverse GM Longitudinal GM

Undamaged 0 0 24.69 56.81

First Bulkhead

Flooded0.43 degrees 0.50 degrees 23.44 40.50

First Two Bulkheads

Flooded1.62 degrees 1.81 degrees 20.96 33.33

Electrical Load Analysis • Excel Spreadsheet with:

– the anticipated electrical loads

– The anticipated electrical generation• Solar

• Fuel cell

– The anticipated electrical storage capacity• Explored sealed AGM batteries and Lithium Polymer batteries

Electrical Generation• Solar cells on top of deck

• Solar cloth on sails

• Fuel Cell

Electrical Storage• Energy Storage

• Lithium polymer system 479 lbs compared to 1344 for AGM

• Cost of lithium polymer 43k compared to 11k for AGM

• Lithium polymer have about 2x the lifespan.

• Lithium polymer batteries chosen.

Structural Analysis• The midship structure of this vessel was designed to meet Det Norske

Veritas and Germanischer Lloyd (DNV-GL) regulations for Yachts

• Aluminum NV-5083 was chosen for the Hull and Superstructure– Composite materials were considered, however for this preliminary design stage with

the production of one vessel, aluminum is more economical

• Design Procedure:

– Determine the design pressures and global loads acting on the hull and superstructure

– Determine the scantling spacing and compute the plate thicknesses

– Calculate the section modulus requirement of local scantlings to satisfy DNV-GL rules

– Compute midship section modulus and verify it meets the section modulus requirements defined from the global loads

Structural Analysis

• Longitudinal Stiffener Spacing: 0.2m

• Longitudinal Girder Spacing: 1m

• Transverse Frame Spacing 0.75m

Plate

Thickness

Stiffener

Profile

Girder

Profile

Frame

Profile

Hull Bottom 4.0 mm T 60 x 4,

30 x 4

T 90 x 10,

60 x 10

T 110 x 10,

60 x 10

Cross Structure 4.0 mm T 50 x 4,

30 x 4

T 100 x 4,

60 x 4

T 100 x 10,

60 x 10

Side Wall 4.0 mm T 30 x 3,

20 x 3

T 80 x 4,

40 x 4

T 80 x 4,

40 x 4

Super Structure

and Deckhouse

3.0 mm T 30 x 3,

20 x 3

T 70 x 4,

40 x 4

T 70 x 4,

40 x 4

Accommodation

Deck

2.0 mm T 30 x 3,

20 x 3

T 50 x 3,

30 x 3

T 60 x 4,

40 x 4

Weight Analysis • Weight Estimation

– Preliminary Stage

• Basis for developing the vessel’s principal characteristics and predicting the possibility of achieving optimal performance

• Goal – To achieve a design weight of about 17000kg

– weight calculations• Multiple sources were used in determining the weights

• Format

– SWBS (Level 3)• The navy ship work breakdown structure was the standard used in

organizing weights, tracking items and record keeping

• Growth Margin• 5% margin was added to the design weight to account for

unexpected weights.

45%

10%

12%

28%

5%

Percentage of Weight Distribution

Structure

Electric / Propulsion system

Command and surveillance

Auxilary system andmachineryOutfit

Misc

GROUPWeight

(kg)

Structure 7,702

Electric / propulsion system 1,719

Command and surveillance 54

Auxiliary system and machinery 1,970

Outfit 4,777

Margin 811

Total Lightship weight: 17,035

• Structure and outfit represents about

75 percent of the total lightship weight

• Command and surveillance had the

least percentage of weights

• 5 percent margin of the design weight

was 811kg

Lightship weight summary

Cost and Labour Estimate• The cost estimate was built up at the same

time as the weight estimate

• The analysis was performed using a bottom up method by determining the cost of each individual part and assembly used on the vessel

• Each individual line item in the analysis was taken from online shopping sites and supplier catalogues

• The labour components for each individual task were estimated using the experience of the design team in the manufacturing environment

• The labour component of the vessel hull and superstructure was estimated using Product Oriented Design and Construction Cost Model (PODAC)

Cost and Labour Estimate Summary

Total Estimated Direct Labour 8453 man hours

Estimated Direct Labour Rate 28 $/hr

Labour Overhead Rate 30% of direct labour hours

Estimated Total Overhead Rate 36.4 $/hr

Estimated Total Labour Cost $307,707

Estimated Direct Material Costs $429,454

Material Overhead Rate 10%of direct material

costs

Estimated Total Material Costs $472,399

Total Estimated Ship Cost $780,106

Management Margin 5%to allow for change

orders and unexpected costs

Shipyard Profit Margin 10%

Total Estimated Contract Price

$897,122

Chartering Financial AnalysisManagement Fixed Costs

• Management, marketing and administrative salaries with allowance for benefits

• Office Space Rental

Fixed Annual Costs per Vessel

• Vessel Crew, salaries and benefits

• Maintenance Costs

– New sails and rigging every 4 years

– Bottom painting every 2 years

– Regular upkeep, cleaning and component replacement

• Insurance

• Marina Costs

Variable Annual Costs per Vessel

• Food and Alcohol

• Fuel for fuel cells (30L/week)

Financial Cost Summary

Purchase Price per Vessel $897,122

Management Fixed Costs (for all

vessels) $377,450

Fixed Annual Costs per Vessel $268,843

Variable Annual Costs per Vessel

$86,432-

$113,442

• 3 to 6 vessels operational in the Caribbean

• 32-week vs 42-week operating window

Charter Revenue

• Market research was done to determine the amount of revenue a high end Caribbean charter stands to make

• Trend between weekly price charged and catamaran length

y = 2281.9e0.1238x

$0.00

$5,000.00

$10,000.00

$15,000.00

$20,000.00

$25,000.00

$30,000.00

$35,000.00

0.00 5.00 10.00 15.00 20.00 25.00

Wee

kly

Ch

arte

r P

rice

(U

SD)

Catamaran Length (m)

Charter Price vs Catamaran Length

Length (m) Weekly Charter Price

17 $18,720

Operating

Window

Estimated Annual Charter

Revenue per Vessel

Low (32 weeks) $600,922

High (42 weeks) $788,125

Net Profit• To purchase the vessels

we will take out a 20 year 6.5% interest rate loan per vessel

• Net Profit = (Charter Revenue – Charter Costs –Annual Debt Service) x Number of operational vessels

$0

$200,000

$400,000

$600,000

$800,000

$1,000,000

$1,200,000

$1,400,000

$1,600,000

$1,800,000

0 1 2 3 4 5 6 7

Number of Vessels

Net Annual Profit Before Income Tax

32 Weeks

42 Weeks

Payback Period

3 Vessels, 32 Weeks

Payback Period 123.7

Annual Rate of Return 4.4%

4 Vessels, 32 Weeks

Payback Period 90.3

Annual Rate of Return 7.9%

5 Vessels, 32 Weeks

Payback Period 77.8

Annual Rate of Return 10.0%

6 Vessels, 32 Weeks

Payback Period 71.2

Annual Rate of Return 11.4%

3 Vessels, 42 Weeks

Payback Period 43.3

Annual Rate of Return 22.2%

4 Vessels, 42 Weeks

Payback Period 38.4

Annual Rate of Return 25.8%

5 Vessels, 42 Weeks

Payback Period 36.0

Annual Rate of Return 27.9%

6 Vessels, 42 Weeks

Payback Period 34.5

Annual Rate of Return 29.3%

• The business has potential from large profitability pending further market research

• Accurate estimation of the market demand is critical to the decision on how many vessels to build

Future Work

• Seakeeping analysis• Research of the Caribbean charter industry to determine

how many weeks per year vessels would be chartered and how many vessels should be built

• Perform hull fairing for the above the water hull extension to make the design easier to manufacture

• Model testing of the hull to verify the numerical models

Questions?

Methanol Fuel Cells

• By-products: H2O and trace CO2

Solar Energy• Solar cloth integrated into the main

sail

• Flexible solar cells on hull

Electric Drive System• Very low noise emissions

• Smooth electric drive with

variable speed

• Vibration isolation mounts

• No burning of fuels= no emissions

• Complete integrated system

• Shore power connection

• Battery bank