1. How To Build The Next
Generation of Greener
Hopper Dredges
Vinton Bossert, P.E.
Stephen Wright
Ethan Wiseman
Presentation for:
IMarEST
New York, NY
November 2015
2. How To Build Greener Hopper Dredges
Dredging Efficiency (Hopper Dredge Design 101)
►Least Cost vs. Maximum Production
3. How To Build Greener Hopper Dredges
Dredging Efficiency
►Least Cost
• Most Efficient Hull
• Most Efficient Propulsion System
• Most Efficient Pumping System
• Crew Size Matched to Automation
• Least First Cost
• Least Maintenance
4. How To Build Greener Hopper Dredges
Dredging Efficiency
►Maximum Production
• Largest Hopper
• Most Maneuverable
• Highest Density Excavation
• Most Efficient Hopper Loading
• Fastest Loaded Speed to Disposal Site
• Fastest Unloading
• Fastest Speed Returning Empty
5. How To Build Greener Hopper Dredges
Best Available Technologies (BAT) Today
• Hull Technologies
• Dredging Technologies
• Machinery Technologies
6. How To Build Greener Hopper Dredges
Hull Technologies
• Minimum Lightship Weight
• Maximize Hopper Size for Hull
Envelope
• Reduced Freeboard Loadline
• Hydrodynamic Improvements
Around Recessed Hopper Doors &
Propulsion
• Balanced Trim Without Ballast
• Better Maneuverability – Z-Drive
Propulsion
8. Maximize Hopper Size for Hull Envelope
Less Sloping Plate
Larger Hopper Doors
2012 Hopper Plan
9. How To Build Greener Hopper Dredges
Better Maneuverability – Z-Drive Propulsion
Drawing from Thrustmaster of Texas
10. How To Build Greener Hopper Dredges
Machinery
• Least Weight, Lowest Cost
• Tier IV Engines
• CFD Analysis To Optimize Propulsion
• Shared Power Systems
• Environmentally Acceptable Fluids
15. How To Build Greener Hopper Dredges
Machinery
• DC Grid
• No Synchronization of Generators
• Minimize Harmonics
• Gen RPM Matched to Load
16. How To Build Greener Hopper Dredges
Machinery
►Power Management System:
• Optimize number of generators and feeds connected to the bus
relative to fuel efficiency and provide a sufficient reserve capacity of
power based on user defined presets.
• Provide proportional load sharing in a symmetrical & asymmetrical
plant configurations.
• Automatically manage Large Loads
• Automatically control Load Shedding.
• Automatically Restart Engines Generator/or Storage to restore
power following a Black Out Condition.
• Automatically provide Load Limiting integral to the CPP system.
17. How To Build Greener Hopper Dredges
Machinery
► Dual Fuel – LNG/CNG:
• No Urea Injection, No Sulfer, No Particulates
• U.S. Reserves are Huge
• Significant Op Cost Savings - Increase as Oil Price Rises
18. Broader Applications for Hybrid Power System
• Permanent Magnet Motors: Smaller and Lighter compared to
Induction Motors and Alternator.
• Further Improves Efficiency Difference between DE and
Conventional system
• Battery Banks: Battery banks provide Peak Shaving, so
Generator Power managed more efficiently.
19. How To Build Greener Hopper Dredges
Machinery
• Environmentally Acceptable Fluids
Water Fluid Power Applications
Hopper Door Operators
Hydraulically Operated Valves
Draghead Davits/Swell
Compensators
Draghead Visor Actuators
CPP Servo System
Engine Coolants
Lubricants
20. How To Build Greener Hopper Dredges
Dredging
• New Dredge Pumps
• Over-The-Bow Pumpout Systems
• Shallow Draft
• Active Dragheads
• Large Hopper Doors
• Automated Dredging Process Control
VOSTA LMG Bow Coupling
21. How To Build Greener Hopper Dredges
Dredging
• New Dredge Pumps
• High Efficiency > 87%
• Better Wear Characteristics
• Hi Chrome White Iron
• Diverter Technology
• Better Suction (NPSH)
Characteristics (skewed vanes)
22. How To Build Greener Hopper Dredges
Dredging
• New Dredge Pumps
23. How To Build Greener Hopper Dredges
Dredging
• Active Dragheads
More Pump NPSH is available for
Density
Jet-assisted
Excavating Teeth
Adjustable Visor
IHC’s Wild Dragon® Draghead
VOSTA LMG Draghead
24. How To Build Greener Hopper Dredges
Dredging
• Automated Dredging Process Control
Free Up Officers to Optimize Operations
Operate 24-7 Without Fatigue – One Man Bridge
Algorithms Continuously Learn/Adjust/Improve -
Maximize Production without Plugging Pipeline
Variable Hopper Fill Rate Reduces Overflow Losses
Replacement Every 7-10 Years
28. Water Hydraulic Technical Considerations
• Design Approach – Typically lapped spool type
designs; Internal Leakage is part of design;
rely on internal leakage for lubrication
• Practical Realities – Plunger floats; minimal
metal to metal contact, no requirement for high
strength/anti corrosive materials
• Physics – Oil allows for higher pressure drops
and higher velocities, creating smaller
components, but at a price of energy loss
• Economic Impact – Manufactured in volume,
price points relatively low given large market
size (several $Billion per year)
• Design Approach – Zero Leakage – internal
leakage damages base materials; water is a
cutting agent at high pressure and velocity.
Avoidance of internal leakage is key to success
• Practical Realities – Given zero leak
requirement, most valves use ‘soft’ packers;
lack of lubricity and difficult application
environment often requires high strength, more
exotic materials such as stainless
• Physics – Water does not compress, makes it
more efficient to pump; zero leakage makes it
more energy efficient
• Economic Impact – Manufactured in low
quantity, price points higher, much smaller
market ($100 M)
Oil Hydraulics Water Hydraulics
Zero Leakage – Environmentally Friendly – Higher Efficiency – Lower Total Cost of Ownership
29. Water Hydraulic Fluid Additives
• Purpose - Many Biodegradable additives aid the use of water as a hydraulic
fluid. Water is limited in its ability to lubricate (low viscosity). It also can be a
media for biological growth, and it freezes at a relatively high temp.
• Corrosion Control – Synthetic additives bond to the internals of the system and
prohibit or slow corrosion
• Algae Control – Algaecides mix with the fluid and prevent growth of biologics
which can degrade system performance
• Lubricity Assistance – Other additives are design to add lubricity to the fluid
making it slippery and enhancing life of components
• Freezing Control - Additives such as Propylene glycol (FDA approved food
additive) lower the freezing temperature of the water
Additives Serve Many Purposes
31. Fluid Cost - Water Hydraulics vs Oil Hydraulics
Description Tank
Volume
EAL Cost WH Cost
Reservoir 350 Gal $13,300 $350
Storage Tank 2000 Gal $76,000 $0
Fluid Makeup $38/Gal $1/gal
Fluid
Contamination
350 Gal $13,300 $350
Notes:
•Water Hydraulics is filled directly from potable water system.
•No clean up cost or fines associated with Water Hydraulics.
•No storage or handling costs for Water Hydraulics.
