5th International Symposium on

Ship Operations, Management and Economics

Athens, Greece

NEW PROPULSION CONCEPT (Patent Pending)

POWERHOUSETUG and BARGE (PTB) SYSTEM

Mizanur R. MajumderB.Sc. Naval Architecture & Marine Engineering, 1980

M.A.Sc. Mechanical Engineering, 2000Envirotech Products Development & Marketing

My Background in Tug-Barge Systems

• 1980-84: ITB system design & operations by Mitsui Shipbuilding & Engineering, Japan

• 1984-86: Paper on ITB system design and application for Bangladesh with James Finlay Shipping, Bangladesh

• 1989-2015: Design, operation and maintenance of tug-barge systems in Fiji Islands, Canada and USA

(Courtesy of Internet)

If ships could be designed like this

(Courtesy of Internet)

“Read something no one else is reading, think something no one else is thinking, and do something no one else is doing”.

What can

I do different?

Eureka,

I got it!!!

(Courtesy of Internet)

Current Configuration of Tug-Barge System(Courtesy of GoogleSketchUp)

(Courtesy of GoogleSketchUp)

What’s wrong???

Notch on the barge (added length with no virtual benefit)

Expensive/Robust connectionbetween tug and barge

Reduced Propulsive efficiencyTransitional loss between tug & barge

Reduced Propulsive efficiencySmaller propulsion gear on the tug than on the barge

(Courtesy of GoogleSketchUp)

ON THE TUG ON THE BARGE

Operational issues

• Line of Sight

• Connecting & Separating the tug & barge

• Tender/unstable tug when independent

• Reduced operational flexibility

(Courtesy of GoogleSketchUp)

Powerhouse Tug & Barge (PTB) System

Electric Propulsion

Gear on barge

No superstructure

& Notch

Powerhouse Tug at the bow

Soft articulation

(Courtesy of GoogleSketchUp)

Basically it providesPropulsive advantage of a ship

with Commercial advantage of a tug

(Courtesy of GoogleSketchUp)

Factors for Acceptability

• Technical Advantage

• Operational Advantage

• Commercial Advantage

• Regulatory Acceptance

Technical Advantage

• Increased propulsion efficiency:• Maximization of propulsive gear size on the barge than the tug

• Tug at forward end resulting in added length & better angle of entrance

• Reduced tug-barge transitional loss

• Better design of the stern of the barge

• Simpler articulation system;

Currently a small tug pushes a big barge.

(Courtesy of Internet)

Technical Advantage

• Increased propulsion efficiency:• Maximization of propulsive gear size on the barge than the tug

• Tug at forward end resulting in added length & better angle of entrance

• Reduced tug-barge transitional loss

• Better design of the stern of the barge

• Smaller and simpler articulation system

Big barge pushing a tug in proposed concept

• Applied to both existing vessels or new constructions

• Ease in environmental compliance

• Powerhouse tug with propulsion gears for independent operation

• Barge with wireless-controlled generators for emergency operations

(Courtesy of Internet)

Operational Advantage• No line of sight issue

• Flexible operation:• In ATB configuration or

• Quick switching to towing/pushing/berthing mode: • in rough weather or

• Failed propulsion on the barge

• Barge docking or other commercial operation

• Tug and barge as independent units

• Remote operation of barge from tug or shore

• Easy replacement of generators on the tug

Flexible OperationsNormal Operation

(Courtesy of GoogleSketchUp)

Flexible OperationsRough Weather Operation

(Courtesy of GoogleSketchUp)

Flexible OperationsPowerhouse Tug Docking its Barge

(Courtesy of GoogleSketchUp)

Flexible OperationsShore-side Operator Docking Barge

(Courtesy of GoogleSketchUp)

Commercial Advantage

• Smaller crewing need

• Lower freeboard, resulting in increased cargo capacity

• Smaller machinery space, thus increased cargo capacity

• Higher Propulsive efficiency, saving fuel

• Cheaper articulation system

• No notch needed saving significant investment

• Increased utility & reduced downtime from build-in flexibility

Commercial Advantage (cont.)

• Applied to both:• existing vessels; saving them from ending up in scrap yards

• new constructions, with high operational flexibility

• Additional fuel bunker in barge for higher tug endurance

• No superstructure on barge saving investment

• Low overall cost

• Quicker return on investment

• Cost effective in continued environmental compliance

Operational Expenses(Example Vessels)

• Example Vessels:• Self-propelled vessel : 35000dwt, 730ft Loa, 78ft B, 45 D• Tug & Barge system : 35000dwt, 730ft Loa, 78ft B, 45 D

• Standard for a self-propelled vessel:• Crew wage & benefits: 40 to 45%• Fuel cost: 40 to 45%

• Tug assist: 0.5%

• Standard for a tug & barge:• Crew wage & benefits: 25 to 30%• Fuel cost: 50 to 55%

• Tug assist: 1.0%

Crewing Need

• 35000dwt cargo vessel: 730ft Loa, 78ft B, 45 D

• Crew need: 22

• 35000dwt Tug & Barge: 730ft Loa, 78ft B, 45 D

• Crew need: 13

• 41% reduction in crew requirement

Lower Freeboard Assignment

Freeboard assignment for an unmanned barge is up to 25% less than that of a manned vessel. That means:

• The barge will be smaller in overall cubic size

• May be able to maximize its propeller size

• Cheaper in hull cost

• Increased cargo capacity

Cost Saving in Hull & Superstructure

• 25% reduction in freeboard assignment

• Around 6.4% of depth reduction

• Hull weight saving of around 3% (250Tons)

• Translates into additional cargo capacity

• 41% reduction in cost of superstructure

Cost of Propulsion and related systems

• May weigh as much as 900Tons for the example vessel

• PowerhouseTug will be around 7% in cubic volume of the example ship

• Expected a saving of over 500Tons in weight• Propulsion power transmission system: No gearbox needed

• Maneuvering system: Saving of bow thruster by using tugs azimuth

• Cost of Regulatory requirements• Bilge & Ballast system: 75% saving

• Navigational Equipment: Same

• Firefighting & Safety Appliances: 40% saving

Life-cycle Cost

• Crewing: Over 41% reduction than ship

• Fuel: Lower than ship; way lower than Tug & Barge

• Tug Assist: Virtually none

• Maintenance Cost: Less than 50% of ship

Cargo Capacity Increase

• Manned vessel: 730ft Loa, 78ft B, 45 D, 27.5ft d• 35000dwt

• Unmanned Barge: 730ft Loa, 78ft B, 45 D, 31.85ft d• 41400dwt

• 18.25% increase in cargo capacity

Typical Powerhouse/Tug

(Courtesy of GoogleSketchUp)

GeneratorsTrunk

Connection System

Electric Azimuth

Machineries for Tug & Barge6.6KVA system

(Courtesy of GoogleSketchUp)

Typical Control System

(Courtesy of Marine Automated System Technology)

Typical Control System (cont.)

(Courtesy of Marine Automated System Technology)

Any floating structure with portable drive(Extended utilization)

(Courtesy of GoogleSketchUp)

Portable Electrical Propulsion Gear

Powerhouse/Tug

Powerhouse Tug as Floating Mobile Power Plant(Extended Usage)

(Courtesy of GoogleSketchUp)

Generators

(Courtesy of GoogleSketchUp)

Regulatory Acceptance

• No new science or technology development will be involved in:• Propulsion gear design

• Articulation system design

• Electrical power transmission & quick disconnect design

• Control system design

• Higher flexibility in operations

• It is more safer than existing systems

• Virtually nothing to be added to existing regulations

• Invite companies or individuals for connection and propulsion system design

• Invite regulatory authorities to work on rules and requirements for this new concept

• Invite all to add your ideas and suggestions and make it a success.

Questions or Comments, Please.

Thanks for your patience