Non-Metallic Shipbuilding Materials and International Maritime Regulations

Timber and Wood-Based Materials

• Timber remains a popular material in shipbuilding due to several advantageous characteristics:

  • Low cost and low volume weight.

  • Substantial strength and ease of processing.

• It generally comprises roughly $15\%$ of a ship's total body weight.

• Applications of timber in ships include hulls, decks, cladding, bulkheads, insulation battens, and equipment detailing.

• Shipbuilding utilizes two main categories of wood:

  • Coniferous woods: Cedar, fir, pine, larch, and spruce.

  • Deciduous woods: Ash, bakaut, birch, mahogany, oak, and teak.

• Bakaut is specifically favoured for stern-bearing shells. It is exceptionally hard and possesses the unique ability to operate effectively in water without the need for additional lubrication.

• Many types of timber undergo industrial impregnation processes before use:

  • Antiseptic solutions: Applied to prevent the material from rotting.

  • Antipyrine: Applied to enhance the fire resistance of the wood.

Synthetic Plastics and Resins

• Ships employ various organic and synthetic plastics, frequently enhanced with filler materials to improve properties like heat resistance and overall strength.

• Foaming agents are introduced to some resins to create gas-filled structures. These are utilized primarily for noise and heat insulation.

• Common applications of plastics on vessels include structural finishing, furniture, cladding, and corrosion protection.

• There are notable disadvantages to using plastics:

  • Low thermal resistance.

  • Low thermal conductivity.

  • Low modulus of elasticity.

• Resins are hard, brittle, and water-insoluble substances added to polymers before curing. While the term is often used colloquially for any synthetic plastic, it specifically refers to these additives.

• Epoxy Resins: These are liquid-state materials that can be poured and cured at room temperature. Once cured, the material is solid, tough, durable, and resistant to sea water and oils. It is frequently used as a chocking material for winches and engines.

Specialized Non-Metallic Components

• Asbestos: A mineral capable of withstanding extreme temperatures. It is resistant to steam, paraffin, petrol, fuel oils, and lubricants. It is common in gland packing, gaskets, and jointing materials, though it is recognized as a health hazard in certain forms.

• Cotton: A natural fibrous material used primarily as a backing for rubber in rubber insertion jointing and in specific types of gland packing.

• Glass Reinforced Plastics (GRP): Composed of thin glass fibers mixed with resin. Upon curing, it creates a chemically inert and strong material used for general repairs.

• Lignum Vitae: A hardwood used for lining stern bearings. It can be lubricated with sea water but is prone to swelling.

• Nylon: A synthetic polymer that is chemically inert. It resists erosion and impingement attacks, making it ideal for valve seats, orifice plates, and coatings for salt water piping.

• Polytetrafluorethylene (PTFE): A fluoropolymer with high heat resistance and chemical inertness. It features a very low coefficient of friction. It is used in dry and sealed bearings. When impregnated with graphite, it serves as a filling material for guide rings and glands.

• Polyvinyl Chloride (PVC): A vinyl plastic found in two forms:

  • Rigid form: Used for ducts and pipework.

  • Plasticised form: Used for various mouldings, cable covering, and sheeting.

• Rubber: A solidified tree sap that is elastic and waterproof but susceptible to attack by steam and oils. It is used for water-lubricated bearings and pipe jointing for both fresh and sea water.

  • Ebonite: A hard material formed when rubber is vulcanized with Sulphur. It is used for bucket rings (piston rings) within feed pumps.

  • Synthetic Rubbers: Materials such as neoprene and nitrile are utilized when the application requires resistance to mild chemicals, oil, or higher temperatures.

The International Maritime Organization (IMO)

• The International Maritime Organization is the primary regulatory body for the shipping industry and a specialized agency of the United Nations (UN).

• Its central purpose is to establish intergovernmental regulations for maritime trade, safe shipping, ocean access, and the prevention of accidents and ocean pollution.

• The IMO sets global rules that are implemented and controlled by national and regional entities, including:

  • EMSA: European Maritime Safety Agency.

  • FMC: Federal Maritime Commission (United States).

  • CMSA: Maritime Safety Administration of the People’s Republic of China.

• The governing body of the IMO, known as the Assembly, meets every $2$ years. The first meeting occurred in $1959$.

• The organization currently includes $175$ member states and $3$ associate members.

• Funding: The IMO is funded by member state contributions, voluntary donations, partnership agreements, and commercial activities such as conference hosting and book sales.

• Enforcement: The IMO does not enforce its own policies. Once a government accepts a policy, it must be enacted as national law, and the responsibility for enforcement lies with that national government.

Objectives and Challenges in Global Maritime Regulation

• Maritime regulations are designed to coordinate stakeholders, improve safety/efficiency, and reduce the carbon footprint.

• Current industry challenges requiring regulatory response include:

  • Minimizing $CO_2$ emissions.

  • Adopting Environmental, Social, and Governance (ESG) strategies to maintain investor and customer confidence.

  • Integrating digital technologies such as Artificial Intelligence (AI), Cloud computing, Internet of Things (IoT), Machine Learning, and Software as a Service (SaaS).

  • Improving cybersecurity and operational efficiency.

  • Training and educating future leaders and the current workforce.

  • Securing capital for necessary investments and cutting operational costs.

Major International Maritime Conventions

• International Convention for the Safety of Life at Sea (SOLAS), 1974: Specifies minimum standards for the construction, operation, and equipment of merchant vessels to ensure safety.

  • Flag States must ensure ships comply and issue prescribed certificates as proof.

  • Port State Control: Allows governments to inspect foreign ships if there is reason to believe they do not comply with convention requirements.

  • The convention consists of administrative Articles and an Annex containing $14$ Chapters.

• International Convention on Standards of Training, Certification and Watchkeeping for Seafarers (STCW), 1978: Sets international qualification standards for all personnel working on commercial vessels.

• International Convention for the Prevention of Pollution from Ships (MARPOL): Originally adopted on $2$ November $1973$. Following tanker accidents in $1976-1977$, the Protocol of $1978$ was adopted.

  • The combined instrument entered into force on $2$ October $1983$.

  • Annex VI: Introduced in $1997$ (entered force $19$ May $2005$), it limits sulfur levels in fuel to $0.5\%$.

  • Currently includes $6$ technical Annexes covering accidental and operational pollution.

• Maritime Labour Convention (MLC), 2006: Protects seafarer rights by requiring ship-owners and operators to provide decent living and working conditions, fostering fair market competition.

• United Nations Convention on the Law of the Sea (UNCLOS), 1982: provides a comprehensive legal regime for all ocean uses and resources.

• International Convention on Load Lines: Established to regulate the draught to which a ship can be loaded, expressed as freeboards.

  • $1930$ Convention: Focused on reserve buoyancy, stability, and avoiding hull stress from overloading.

  • $1966$ Convention: Introduced provisions for damage stability and subdivision calculations. It accounts for potential hazards in different geographic zones and seasons. It ensures watertight integrity below the freeboard deck through measures regarding hatchways, doors, and freeing ports.