Ship construction: structure, piping routes & technical zones __

In the modern maritime industry, a ship is far more than just a means of transport. Its construction is comparable to that of a highly complex floating industrial power plant. For shipyards and designers, the vessel’s structure forms the physical framework that determines the efficiency of the technical infrastructure, while the piping routes act as its nervous system, ensuring all vital functions operate reliably.

One of central challenges in modern projects is integrating these systems within highly confined spaces while maintaining maximum reliability and minimising maintenance costs (OPEX). Furthermore, it is essential to meet the increasing requirements of IMO regulations and efficiency standards such as EEXI through integrated piping engineering.

From hull and deck to the superstructure: the construction of a ship

The architecture of a ship follows a functional logic that extends from the keel to the upper deck. To master the complexity of onboard building services, the load-bearing structure must be understood as the foundation. The hull serves as the primary protective barrier while also providing the vessel’s internal volume. Whereas the bow and stern define the hydrodynamic performance, the interior is divided into watertight compartments by bulkheads.

• Internal layout: Bulkheads provide structural stability and create fire compartments. Every pipe penetration through these boundaries requires fire-rated sealing systems, increasing the complexity of installation and compliance requirements.
• Horizontal levels: The decks and the upper deck form the primary distribution levels. The lower decks typically accommodate heavy technical infrastructure, such as ballast water systems and bilge management, while the upper superstructure — including the bridge and the cabin blocks — contains the highly concentrated drinking water installations and HVAC systems.

Sectional construction dominates modern shipyard practice. Individual blocks, including their piping segments, are prefabricated and ‘joined’ in the dock. This process requires millimetre-precise planning of the ship’s superstructure. Components such as the funnel or the mast act as central vertical shafts in which supply lines are bundled. Only through detailed structural expertise can systems for drinking water supply or ballast water treatment be efficiently integrated within the highly limited available space. 

Ship design: Where pipes can run in a ship

Ship design is a multidimensional puzzle in which the piping infrastructure serves as the vessel’s essential supply system. Unlike stationary building construction, piping systems on board must withstand constant dynamic loads, vibrations and extreme spatial confinement. Pipe routing is therefore directly influenced by the ship’s structural layout: it primarily follows the main axes along the decks and utilises vertical trunks (trunkways) to efficiently connect the various levels.

The routing of piping is largely determined by the structural constraints of the ship’s design. Bulkheads and deck boundaries must be treated as active design elements. Every penetration must be statically checked in advance and certified for fire safety. Transition areas between sections are particularly critical: as modern ships are built using modular construction, the piping interfaces at the section boundaries must have a tolerance that accommodates both installation and thermal expansion during operation. Here, modern piping design uses digital twins (BIM/CAD) to rule out collisions with other systems such as ventilation (HVAC) or electrical infrastructure as early as the design phase.

Strategic zones and key coordination areas

Within the ship’s structure, specific zones can be identified, each placing distinct demands on the piping design.

• Engine room: As the energy hub housing the ship’s propulsion system and other utility systems such as adsorption chillers , it has the highest installation density. Here, large-diameter pipes for cooling, fuel and lubrication converge with finer control lines.
• Cabin blocks and sanitary areas: In these zones – particularly in the construction of a cruise ship – a linear layout is the norm. The challenge here lies in the efficient bundling of drinking water, wastewater and sprinkler systems within the confined space above the ceiling panels.
• Service areas (galleys & laundries): These areas require high flow rates and often need to be supplied from the central tank farm over long distances.

Maintenance Accessibility and Total Cost of Ownership

An often underestimated aspect in ship construction is accessibility during operation. Bottlenecks and hard-to-reach service spaces make inspections difficult and drive up maintenance costs. The aim of effective planning is therefore to bundle media in such a way that maintenance corridors remain clear.

Pipe systems made from corrosion-free materials such as PP-RCT are particularly advantageous in this context, as they do not suffer from scaling compared to metal pipes and are resistant to pitting corrosion. As a result, the need for invasive maintenance work is significantly reduced – a decisive factor for a ship’s long-term profitability.

Ship types and their differences in piping layout

 Piping design is considered a critical component of asset integrity. The differences between the various ship types are primarily reflected in the redundancy strategy, the material’s resistance to the medium, and the structural integration into the ship’s design. Whilst cost-efficiency is the primary focus for standardised vessels such as bulk carriers, highly specialised vessels such as LNG carriers or cruise liners require engineering that goes far beyond conventional standards. 

• Cruise ships: High-density MEP and ‘Safe Return to Port’ (SRtP)

The design of a cruise ship represents the pinnacle of building-services density. With a cumulative pipe length exceeding several hundred kilometres in modern vessels (e.g. the Oasis class), the pipe network is the central nervous system. In accordance with IMO guidelines on Safe Return to Port, critical systems (fire-fighting water, propulsion cooling, bilge systems) must be physically separated in such a way that they ensure manoeuvrability and basic services even in the event of a total failure of a fire- or flooding- affected compartment. This results in highly complex routing through multiple vertical fire bulkheads. As the metacentre (stability) is critical on cruise ships due to their tall superstructures, weight reduction on the upper decks is essential. The use of polymeric materials such as PP-RCT instead of CuNiFe or steel systems enables a significant reduction in top weight, which directly improves fuel efficiency (CII rating).

• Giant container ships and bulk carriers: structural mechanics and ballast water management

In large cargo ships, the piping layout is inextricably linked to the longitudinal strength of the hull. Long container ships are subject to enormous torsional and bending stresses. Piping that runs the entire length of the ship (e.g. fire-fighting lines or ballast water routes) must compensate for these deformations via expansion joints and flexible material properties to prevent fatigue failure in the structural components. Retrofitting ballast water management systems often requires major modifications to the existing structure. Here, the prefabrication (spooling) of piping modules is crucial to minimise time spent in the shipyard.

• Tankers and gas carriers (LNG/LPG): Cryogenic requirements and Ex zones

The design of a ship for transporting liquefied gases is characterised by the principle of the double barrier. Piping for LNG operates at cryogenic temperatures (-162 °C), which requires special insulation systems and materials. At the same time, the associated auxiliary systems (cooling, nitrogen inerting) must withstand extreme corrosion conditions. The strict separation into gas-hazardous and gas-safe zones dictates the routing of the piping. Pipe penetrations through bulkheads must be designed to be both watertight and gas- and explosion-proof.

• Megayachts and sailing vessels: Acoustic design and space efficiency

When building a sailing vessel or a megayacht, the focus shifts towards NVH engineering (Noise, Vibration, Harshness). To maintain luxury standards, pump vibrations must not be transmitted into the cabin structure via the pipework. Whilst metal pipes act as excellent sound conductors, plastics offer natural damping due to their lower elastic modulus. The organic hull shapes of modern yachts leave little room for right-angled routes. Material-bonded welding (fusion welding) allows for more compact fitting geometries here than traditional flange or press-fit connections.

• Inland waterway vessels and specialised fleets: modularity and Stage V

The design of inland waterway vessels is undergoing radical changes due to Stage V emission regulations and the trend towards hybrid repowering. Additional exhaust after-treatment systems (SCR) and battery storage must be integrated into existing hull structures. This requires a highly flexible redesign of the cooling water circuits. Due to shallow waters and frequent groundings (shallow-water operations), the intake systems and internal piping must be particularly resistant to sedimentation and cavitation.

Material selection: a strategic decision regarding life-cycle costs

Regardless of the asset class, it is clear that ship construction is a dynamic environment. Whether it is a matter of complying with the EEXI (Energy Efficiency Existing Ship Index) through weight reduction or minimising OPEX through corrosion-free systems – the choice of piping material is a decision affecting the life-cycle costs of the entire ship.

In the context of increasingly complex ship design and stricter environmental regulations (EEXI/CII), the material integrity of technical building services (TBS) is becoming a key focus of strategic decisions. The replacement of conventional metallic systems with high-performance polymer solutions represents a fundamental optimisation of operational asset performance. aquatherm addresses these requirements with material-specific piping solutions based on the modern material fusiolen® PP-RCT.

The core of this technological superiority lies in the modified crystal structure of the polypropylene random copolymer (PP-RCT). Whilst conventional materials are prone to pitting and scaling under constant exposure of seawater and aggressive media, aquatherm blue is completely corrosion-resistant.

Another significant risk factor in ship construction is mechanical joints (flanges, press fittings), which are prone to leaks under vibration. aquatherm solves this problem through fusion technology: the pipe and fitting are fused into a material-bonded unit by thermal fusion. The result is a permanently tight connection that requires no additional sealants or adhesives.

Material advantages meet process advantages

The combination of the fusiolen® PP-RCT material and the joining technology creates a synergy that metallic systems can hardly match.

• Elimination of hot work: Whilst steel systems on board often require time-consuming welding work (including fire watch), aquatherm systems are joined by fusion welding, which increases onboard safety and does not hinder parallel trades.
• Hydraulic superiority: The smooth inner surfaces of the polymer pipes often allow for a reduction in nominal diameters whilst maintaining the same flow rate. This reduces material costs and saves valuable installation space within the ship’s structure.

Engineering 4.0: Digital planning and prefabrication as a strategic standard

The construction of a ship today is a highly synchronised industrial process in which the time window for installing technical building services (TGA) is becoming ever smaller. In this environment, value creation is shifting away from manual installation on board towards digitally supported prefabrication models. aquatherm sees itself as a system partner, facilitating the transition from traditional pipework installation to industrial modular construction. Instead of welding thousands of individual joints under adverse conditions in the cramped hull or cabins, aquatherm relies on the principle of ready-to-install units.

• Complex pipe harnesses, distribution stations and technical modules are prefabricated under controlled industrial conditions. These units are delivered to the shipyard as ‘plug-and-play’ solutions.
• Every prefabricated module undergoes a certified quality control process prior to delivery. This virtually eliminates the risk of leaks, which in conventional onboard installations are often only discovered late in the project.
• Thanks to the ships’ sectional construction, these units can be hoisted directly into the open blocks. This significantly reduces assembly time on board.

Conclusion: How a ship’s structure determines the routing of pipes

Maritime engineering combines physical ship construction with digital system integration. A ship’s structure is more than a static framework; it is the defining matrix for the entire technical infrastructure. From the massive structure of the hull, through safety-critical segmentation by bulkheads, to the highly concentrated building services in the superstructure – every structural decision has a direct impact on the complexity and efficiency of the piping layout.

The routing must anticipate the geometry and dynamic loads of the vessel type in order to minimise mechanical stresses and spatial conflicts. The shift to corrosion-free, weight-optimised polymer systems such as PP-RCT is the answer to stricter efficiency requirements (CII/EEXI) and the need to significantly reduce operational life-cycle costs (OPEX). Industrial prefabrication transforms the piping into ready-to-use modules, shortening construction time and raising installation quality to a new level.

Setting the course for your next project together

Are you facing the challenge of integrating a complex piping system into a demanding ship design? Our experts support shipyards, designers and shipowners in realising the full potential of modern polymer solutions and digital design methods – from initial feasibility study through to prefabrication.

Contact us for specialist advice and let’s work together to optimise the efficiency of your maritime assets.