This course introduces the principles, architectures and calculations behind marine powering, transmission and propulsion systems. It connects propulsion theory with machinery choices, emissions and real ship applications. It starts with resistance, effective power, shaft power and power-speed curves, then explains mechanical, electrical and hybrid propulsion configurations and the naming conventions used for combined plants. Marine diesel engines and gas turbines are examined in terms of cycles, performance and trade-offs, followed by emission formation, MARPOL Annex VI and abatement technologies. The course then compares propeller and alternative propulsors, works through propulsion sizing and specific emissions calculations using a frigate example, introduces induction motors and electric ship architectures, and closes with a shuttle tanker propulsion case study and exam-style preparation.
Course at a glance: Duration 20 hours · Self-paced online · 13 sections, 47 lessons, a 183-page downloadable course book
What you will learn
- Describe the main components of mechanical, electrical and hybrid marine propulsion systems.
- Apply effective power, shaft power and speed-law relationships to propulsion analysis.
- Compare common marine propulsion configurations and decode names such as CODAG, CODOG and COGAG.
- Explain the operating principles and characteristics of marine diesel engines and gas turbines.
- Explain how exhaust emissions form and how MARPOL Annex VI and abatement technologies control them.
- Evaluate propulsor and electric-drive options for different ship types.
- Carry out preliminary propulsion sizing and specific emissions calculations.
Inside the course: a high-level summary, section by section.
Powering fundamentals
The course starts with the basic chain of marine powering. Effective power is the power needed to overcome hull resistance at a given speed: resistance multiplied by speed. It is not the full machinery power, because losses occur in the propeller, the hull-propeller interaction, the shafting and the gearbox. Total resistance is made up of several components, mainly frictional, wave-making and form or viscous pressure resistance, plus air and appendage resistance, and the balance among them changes with speed and hull form.
Shaft power and the propulsive efficiency chain link effective power back to the engine. Speed laws, in which power rises roughly with the cube of speed over a limited range, are introduced as practical tools for estimating power changes. Power-speed curves show how required power changes as a ship accelerates, and they reveal how different hull forms, such as monohulls, trimarans and surface-effect ships on and off cushion, respond very differently.
Propulsion configurations
The third section reviews propulsion configurations. Direct-drive diesel plants, geared diesel plants, steam and gas turbine plants and electric drive are compared. Combined mechanical systems use more than one type of prime mover, and their names follow a deliberate logic: in a name such as CODAG or CODOG, the sequence describes the operating logic. AND arrangements use both engines together at high speed, while OR arrangements use one engine type for cruise and a different one for high-speed operation, but not both together. Similar conventions describe gas-and-gas and gas-or-gas arrangements, and electric variants. Electric drive in practice covers how electric motors deliver torque across the speed range and why combined electric and mechanical drives must manage torque limits carefully.
Marine diesel engines
The diesel engine section reviews the diesel cycle principles, including compression ratio and compression ignition, where fuel ignites because of the high temperature of compressed air. Four-stroke and two-stroke engines are compared in terms of cycle, speed, size, power-to-weight ratio and typical applications. Power and losses explain indicated, brake and shaft power, mechanical efficiency and the main sources of loss, linking engine performance to fuel consumption.
Gas turbines
Gas turbine principles are explained through the Brayton cycle, with compressor, combustion chamber and turbine working continuously. Performance and trade-offs show why gas turbines offer high power density and rapid acceleration but lower efficiency at part load and higher fuel consumption than diesels, which is why they suit warships and fast craft better than cargo ships. Advanced arrangements, such as intercooled and recuperated cycles, improve part-load efficiency at the cost of complexity.
Exhaust emissions and IMO rules
Emission formation explains how nitrogen oxides, sulphur oxides, carbon dioxide, carbon monoxide, hydrocarbons and particulates arise in marine engines. MARPOL Annex VI sets the regulatory framework, including tiered nitrogen oxide limits, fuel sulphur limits and emission control areas. Abatement technologies, such as selective catalytic reduction, exhaust gas recirculation, scrubbers and alternative fuels, are compared in terms of effectiveness, cost and operational impact.
Propulsors
Propeller fundamentals cover thrust generation, efficiency and the main design parameters. Alternative propulsors, including controllable pitch propellers, ducted propellers, contra-rotating propellers, waterjets and azimuthing thrusters, are compared. Selecting a propulsor is treated as a structured decision based on speed, loading, manoeuvring requirements and operating profile.
Sizing and emissions calculations
The sizing section sets out a logical sequence for estimating installed power from resistance and efficiencies. A worked frigate example demonstrates the method, and a specific emissions calculation shows how fuel consumption and emission factors are combined to estimate emissions per unit of work or transport. A calculation assignment lets you practise the method on your own.
Electric propulsion systems
Induction motor basics explain how a rotating magnetic field produces torque and how speed is controlled with variable-frequency drives. Electric ship architectures, including integrated full electric propulsion and hybrid systems, are reviewed, and the electric warship context shows why navies have adopted these systems for flexibility, survivability and quiet operation.
Ship case study and exam preparation
A shuttle tanker propulsion case study brings the course together. Shuttle tankers combine long transits with demanding dynamic positioning and loading operations, which makes propulsion choice a real trade-off. A case comparison contrasts alternative solutions, and the final section uses exam-style problems to consolidate understanding.
Why this matters in practice
Propulsion choices fix much of a ship’s fuel consumption, emissions, maintenance burden and operational flexibility for its whole life. Engineers who can move confidently from resistance to installed power, compare machinery configurations and estimate emissions are well placed to contribute to concept design, retrofit decisions and decarbonisation planning. The course also builds the vocabulary needed to read machinery specifications and engine maker data critically, to understand why naval and commercial vessels make such different propulsion choices, and to explain those choices clearly to non-specialist colleagues, owners and examiners. Its exam-preparation section makes it a useful revision resource for students as well.
Key takeaways
You leave able to calculate effective and shaft power, decode and compare propulsion configurations, explain diesel and gas turbine performance, interpret emission rules and abatement options, select propulsors and carry out preliminary sizing and emissions calculations.
How you study
The course is delivered fully online and is self-paced, so you can fit roughly 20 hours of study around professional commitments. Lessons combine clear explanation with examples, diagrams and short interactive checks, and the main sections end with graded quizzes (15 in total) so you can confirm you can apply each method before moving on. A 183-page course book can be downloaded and printed for offline reading and later reference.
Course contents
- Propulsion System Basics: Mechanical and Electric Drive
- The Propulsion Requirement: Resistance and Effective Power; Shaft Power and Efficiency; Power-Speed Curves
- Propulsion Configurations: Combined Mechanical Systems; Configuration Naming; Electric Drive in Practice
- Marine Diesel Engines: Diesel Cycle Principles; Four-Stroke and Two-Stroke; Power and Losses
- Gas Turbines: Gas Turbine Principles; Performance and Trade-Offs; Advanced Arrangements
- Exhaust Emissions and IMO Rules: Emission Formation; MARPOL Annex VI; Abatement Technologies
- Propulsor Types: Propeller Fundamentals; Alternative Propulsors; Selecting a Propulsor
- Sizing and Emissions Calculations: Sizing Logic; Worked Frigate Example; Specific Emissions Calculation; Calculation Assignment
- Electric Propulsion Systems: Induction Motor Basics; Electric Ship Architectures; Electric Warship Context
- Ship Case Study: Shuttle Tanker Propulsion; Case Comparison
- Exam Preparation: Past Exam Questions
- Summary: Key Takeaways
Who this course is for
This course suits engineering graduates, marine and mechanical engineers, naval officers and students preparing for marine engineering examinations, as well as technical staff who need a structured refresher on propulsion systems. A basic engineering background is assumed.
Frequently asked questions
How long does Marine Powering, Transmission and Propulsion take?
The course is designed for about 20 hours of study. It is self-paced and fully online, so you can spread it over a few weeks or complete it more quickly.
What is covered?
The course is organised into 13 sections with 47 lessons, moving from foundations to applied methods, as summarised above.
Is there material to keep after the course?
Yes. A downloadable 183-page course book accompanies the lessons for offline reading and later reference.
How is progress checked?
Each main section closes with a graded quiz (15 in total). The quizzes test understanding of the concepts and methods explained in the lessons rather than memorisation, and you can review the relevant lessons before attempting them.
Can I record this study for my own professional development?
Yes. The course notebook includes a self-assessment of the course objectives before and after study, a reflection page and a learning log, which you can use to keep your own record of professional development.
Duration: 20 hours
Related courses: B06 – Resistance & Propulsion; B13 – Marine Engineering — Propulsion, Auxiliary Systems & Control Engineering; B02 – Marine Engineering 1; B04 – Marine Propulsion Systems and Thruster Design
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Study at your own pace and work through the full course material, worked examples and section quizzes. Enrol in B15 – Marine Powering, Transmission and Propulsion →
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