COMPANY INTRODUCTION Underwater Maintenance...

COMPANY INTRODUCTION

14 November 2019

Design of an Autonomous Underwater Maintenance Dredger

Rolph Hijdra, Stefan van der Harst

LNG – 5000 tons lifting capacityOrion – Offshore installation and decommissioning vessel

• Serving ship owners and shipyards worldwide

• 5 offices: • Hoofddorp• Rotterdam• Heerenveen• Nikolayev • Houston

• > 150 in-house engineers employed

COMPANY INTRODUCTION

Independent design and engineering company

CNG-Electric propulsionTexelstroom – Sustainable double ended ferry

Vox Amalia - 19000 m3 Trailing Suction Hopper Dredger

COMPANY INTRODUCTION

C-Jobs vision on Autonomous Shipping

Autonomous Shipping provides an enormous potential in operational and economical benefits.

The full potential will be achieved by fully utilizing the design-opportunities it provides.

CONCEPT DESIGNS

Why concept designs?

CONCEPT DESIGNS

MAKE IT HAPPEN!

BENEFITS

CHALLENGES

BENEFITS ASSESSMENT C-JOB

Benefits assessment Autonomous ShippingAdvantages Dredging Offshore Yachting Ferry1. Increased safety2. Reduced fuel consumption3. Reduction crew costs4. Reduced lightweight5. Fleet management6. “Fancy factor” – “Green image” Disadvantages Dredging Offshore Yachting Ferry1. Engine efficiency2. Investment costs3. Increased energy demand4. Expenses shore-based personnel5. Hijacking6. Risk of system failure

• Relevance for C-Job focus markets?

• Company wide questionnaire

Dredgers!

FIRST BRAINWAVE

New concept: Autonomous Maintenance Dredger

REDUCED OPERATIONAL COSTS

(No crew)

DECREASED DREDGING POWER(Reduced suction depth)

REDUCED PROPULSION POWER(Reduced resistance)

IMPROVED OPERABILITY(Submerged)

COMPARITIVE STUDY

Comparison Conventional versus Autonomous dredger

• Dredging capacity governing!

• Operational profile:• Port of Rotterdam• Eemshaven (port)• 12 hr Operation / day

• Functional decomposition

Autonomous Maintenance Dredger

Carrying platform

Provide buoyancy

Mobility

Propulsion

Balasting

Endurance

Navigate

Position keeping

Survivability

Provide redundancy

General support

Electric power

Hydraulic power

Fuel supplies

Dredging

Pump soil mixture

Store sediment

Discharge

Bottom doors

POWER

Power requirements

• Resistance prediction:• Transit: 11 knots• Dredging: 2 knots

• Propulsion power prediction

Rtotal = RF (1+ k1) + Rapp + Rw + RTR

RF (1+ k1) = Frictional resistance ↗Rapp = Appendage resistance ↔Rw = Wave making / -breaking resistance ↓RTR = Transom immersion resistance ↘

2200 kW (Conventional) 100 kW (AUMD)

POWER

Power requirements

• Resistance prediction:• Transit: 11 knots• Dredging: 2 knots

• Propulsion power prediction

Rtotal = RF (1+ k1) + Rapp + Rw + RTR

RF (1+ k1) = Frictional resistance ↗Rapp = Appendage resistance ↔Rw = Wave making / -breaking resistance ↓RTR = Transom immersion resistance ↘

∆ploss,tot = ∆psu,loss + ∆pdis,loss + pabs,dis - pabs,draghead

∆psu,loss = Frictional loss + suction head, suction side ↓∆pdis,loss = Frictional loss + pressure head, discharge side ↔pabs,dis = Absolute pressure, discharge side ↗pabs,draghead = Absolute pressure, suction side ↔

2200 kW (Conventional) 1000 kW (AUMD)

1350 kW (Conventional) 300 kW (AUMD)

16 MWh battery pack

• Dredge pump power prediction

• E-load balance

DESIGN

Key aspects of the design

Shallow water design

Flat bottom design

Highly manoeuverable

Redundant propulsion

Optimised hopper design

Discharge via bottomdoors

RESULTS

Main particulars

Length [m] 104.6 80.0

Breadth [m] 18.0 20.0

Depth [m] 8.0 8.5

Hopper capacity [m3] 3599 3430

Dredging depth [m] 35 35

Transit speed [kn] 11 11

Propulsion power [kW] 2x 1100 2x 500

Dredging power [kW] 2x 675 2x 150

RESULTS

DECREASED DREDGING POWER (Reduced suction depth)

REDUCED PROPULSION POWER(Reduced resistance)

IMPROVED OPERABILITY(Submerged)

REDUCED OPERATIONAL COSTS

(No crew)

CAPEX / OPEX STUDY

Total cost of ownership

• Feasible design if: Payback period < 10 years

• CAPEX:• High initial investment• Complex submarine hull • 16 MWh Battery package

• OPEX • Electricity main cost driver• Shore-based complement of 4 people

Payback period after 7 years

THE CONCEPTS FUTURE

Future works

Upcoming challenges

Legal aspects

Situational awareness

Decision making

algorithms

Maintenance

Port facilities

Redundancy

Data communi-

cation

Environmental awareness

Launching customer(s)

Rules / Regulations

AUMD ANIMATION

www.C-Job.comInfo@C-Job.com

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