Ship Stability Course

Lesson 1 • Centres of Buoyancy and Gravity

Defines the centre of buoyancy (B) and centre of gravity (G) and their roles in equilibrium. Students locate B and G for simple loading conditions.

Lesson 2 • Righting Lever and Static Stability

Explains the righting lever (GZ) and its relationship to the righting moment. Students interpret basic static stability curves for upright vessels.

Lesson 3 • Ship Geometry and Hull Form

Introduces hull form terminology, lines plans, and geometric coefficients. Connects hull shape to displacement and waterplane characteristics.

Lesson 4 • Transverse Metacentre and Metacentric Height

Introduces the metacentre (M) and metacentric height (GM) as primary stability indicators. Students calculate GM and interpret its sign for initial stability.

Lesson 1 • Hydrostatic Tables and Curves

Explains the content and use of hydrostatic tables provided in ship's stability booklets. Students extract displacement, KB, BM, and TPC values at given draughts.

Lesson 2 • Draught Survey Procedures

Covers the systematic reading of forward, aft, and midship draughts to determine true mean draught. Students apply corrections for hog, sag, and density.

Lesson 3 • List and Heel from Off-Centre Loads

Explains static list caused by transverse weight imbalance and distinguishes it from loll. Students calculate listing angle using the wall-sided formula.

Lesson 4 • Displacement and Deadweight

Distinguishes lightship, deadweight, and loaded displacement. Students calculate deadweight from manifest data and verify against hydrostatic displacement.

Lesson 1 • Effect of Adding and Removing Weights

Quantifies how loading or discharging cargo shifts G vertically and longitudinally. Students recalculate KG and LCG after each weight change.

Lesson 2 • Ballast Operations and Planning

Covers ballast tank selection, filling sequences, and their effect on stability and trim. Students design ballast plans that maintain positive GM throughout.

Lesson 3 • Free Surface Effect

Explains how slack tanks reduce effective GM through the free surface moment. Students calculate the free surface correction and apply it to GM.

Lesson 4 • Shifting Weights and Cargo

Analyses transverse and vertical shifts of existing cargo on list and stability. Students apply the shift formula to correct list and optimise stowage.

Lesson 1 • Weather Criterion Assessment

Applies the weather criterion to evaluate resistance to beam wind and rolling. Students calculate the wind heeling lever and verify the required area ratio.

Lesson 2 • Stability Curve Analysis

Teaches construction and interpretation of the complete GZ curve for a loaded vessel. Students identify range of stability, maximum GZ, and dynamic stability area.

Lesson 3 • International Stability Standards Overview

Summarises the intact stability criteria established by international maritime regulations. Students identify the key parameters: GM, GZ, and area under the stability curve.

Lesson 4 • Compliance Reporting and Documentation

Explains the documentation required to demonstrate stability compliance before departure. Students complete a stability compliance checklist for a sample voyage.

Lesson 1 • Emergency Response to Flooding

Covers immediate actions to control flooding, restore stability, and prevent capsize. Students develop a flooding response sequence for a given damage scenario.

Lesson 2 • Floodable Length and Subdivision

Explains floodable length curves and their role in determining watertight subdivision. Students read floodable length diagrams and verify subdivision adequacy.

Lesson 3 • Effect of Flooding on Draughts and Trim

Calculates changes in draught, trim, and list resulting from a single compartment flood. Students apply the added weight method to determine post-flooding condition.

Lesson 4 • Damage Stability Criteria

Applies regulatory damage stability criteria to determine if a vessel can survive flooding. Students verify residual GZ, range, and freeboard against required standards.

Lesson 1 • Operational Measures to Reduce Motion

Presents course and speed changes, ballasting, and anti-roll devices as motion control tools. Students select appropriate measures for given sea and loading conditions.

Lesson 2 • Synchronous and Parametric Rolling

Explains resonance conditions that amplify rolling to dangerous angles. Students identify sea states and headings that trigger synchronous and parametric rolling.

Lesson 3 • Ship Rolling and Natural Period

Defines the natural rolling period and its dependence on GM and beam. Students calculate rolling period and relate it to comfort and stability margins.

Lesson 4 • Pitching, Heaving, and Coupled Motions

Covers longitudinal motions and their interaction with rolling in oblique seas. Students assess combined motion effects on cargo securing and crew safety.

Lesson 1 • Tanker Stability and Free Surface

Analyses the large free surface effect in tanker cargo and ballast tanks. Students calculate effective GM for a tanker with multiple slack tanks.

Lesson 2 • Liquefied Gas Carrier Stability

Addresses the unique stability features of LNG and LPG carriers including insulated tanks. Students assess stability for partial-fill and full-load conditions.

Lesson 3 • Bulk Carrier Loading and Stability

Covers hold filling sequences, density variations, and structural loading limits for bulk carriers. Students produce a compliant loading plan for a multi-hold bulk carrier.

Lesson 4 • Chemical and Product Tanker Considerations

Covers multi-grade loading, segregation, and stability implications for chemical tankers. Students verify stability compliance for a complex multi-parcel loading plan.

Lesson 1 • Stability Monitoring During Voyage

Covers continuous stability monitoring using fuel and ballast consumption data. Students update the loading condition at sea and verify ongoing criteria compliance.

Lesson 2 • Integrated Voyage Stability Plan

Synthesises departure condition, sea passage, and arrival condition into one stability plan. Students present a complete stability assessment with contingency actions.

Lesson 3 • Stability Assessment for Heavy Weather

Applies weather routing principles and stability margins to heavy weather passage planning. Students select safe speed and heading corridors for a given forecast.

Lesson 4 • Stability in Port Operations

Addresses stability risks during cargo operations, dry-docking, and lightering. Students calculate critical GM during a cargo transfer sequence.