Marine Module

What are the types of cargo ships?

Container, Liquid, Bulk, Passengers, RoRo, Offshore, Special Purpose (Ice Breakers, Pilot Boats)

What invention was made in the 1050-ies that revolutioned logistics of manufactured goods? Today, 95% of manufactured goods are transported this way.

Containers

What is HFO and why do most of the world’s fleet run on it?

Heavy Fuel Oil

HFO has a very high energy content (more energy per weight of the fuel) and is readily available and cheap

Makes it a convenient fuel to use in world shipping

What are the issues with running a ship with HFO?

HFO needs to be heated in order for it to be pumped.

Makes for a relatively complex fuel handling system onboard ships consisting of heat exchangers and purifiers before the HFO is used in the engine

Also produces emissions

What is MGO and what are its advantages and disadvantages?

Marine Gas Oil consists of distillates with shorter carbon chains, which makes it purer than HFO.

A: Pumpable at room temperature

D: More expensive than HFO

What is LNG and what are its advantages and disadvantages?

It is a mixture of mainly methane with parts of butane, propane pentane and hexane in it. It is extracted from gas fields and can be a byproduct of oil extraction.

A: It has a lower carbon footprint and can burn without SOx and PM

D: It needs to be cooled very low to be liquified making it more challenging to store than liquid fuels.

What are the benefits and drawbacks of ammonia as fuel?

A: No CO2 emissions, can be manufactured sustainably
D: Poisonous and corrosive, hard to combust, NOx emissions

Mention three important factors related to the operation of ships.

Range, maneuverability, redundancy

What operational factors are essential for passenger ships?

Safety and redundancy, comfort, environmental concerns

What operational factors are essential for offshore ships?

Safety and redundancy most important, cost of less importance

What operational factors are essential for icebreakers?

Power, robustness, propulsion system for varying loads.

What operational factors are essential for tugs?

Power, robustness, maneuverability

What are the efficiencies of each component?

Propeller: 60-65%

Bearing: 99%

Engine: 50-55%

Straight shaft 2-stroke system

Benefit: Very efficient, reliable,

Drawback: Poor maneuverability, poor redundancy, heavy

Straight shaft 2-stroke system + auxiliary generator

Benefit: Very efficient, reliable, better redundancy

Drawback: Poor maneuverability, heavy

4-stroke system

Benefit: Reliable, more versatile, can be expanded with more engines

Drawback: More complex

Diesel-electric system

Benefit: Very versatile, generators can be optimized for different operating conditions

Drawback: Many losses in transfer of electric current, complex system

Diesel-electric hybrid system

Advantage: Very versatile, Generators can be optimized for different operating conditions, peak shaving

Disadvantage: Many losses in transfer of electric current, complex system, novel and expensive

Describe the main balances to be made with designing the propulsion system of a ship.

Fuel efficiency vs. operational flexibility: highly efficient propulsion has low maneuverability
Reliability and redundancy vs. cost and complexity: adding multiple engines improves reliability and safety, but increases investment cost

Performance vs. space for cargo: propulsion system must provide sufficient power while minimizing the space and weight occupied by machinery

Describe the measures taken to reduce sulphuric emissions from shipping.

Exhaust gas cleaning systems known as scrubbers are used to reduce sulpher emissions
Wet scrubbers: Remove sulphur compounds by washing exhaust gasses with sea water

Dry scrubbers: Use chemical reactions involving solid absorbents