Adapted from an article on the former Arquitectos Navales & Asociados website (2023); expanded and technically reviewed in October 2026.
Key points
- The vessel mission and owner requirements provide the basis of design.
- Stability, structural strength and compliance are checked throughout the design cycle.
- Construction documentation, inspections and trials complete the engineering process.
1. Define mission requirements and the owner’s design brief
Ship design starts with the vessel’s purpose: cargo transportation, passenger service, fishing, research, offshore support or recreation. Intended trading area, endurance, speed, loading capacity, operating conditions and service restrictions must be identified before geometry is fixed.
These requirements form a basis-of-design document defining principal expectations, constraints, materials, main equipment, safety criteria and the likely flag-state or classification framework. Early ambiguity can lead to substantial rework at the detailed design stage.
- Vessel type, operating area and duty cycle
- Capacity, service speed and required endurance
- Applicable legal and classification requirements by vessel and service
2. Preliminary design and feasibility assessment
The preliminary stage brings together candidate principal dimensions, approximate displacement, weight budgets, propulsion requirements and general arrangements. Initial assumptions cover hull geometry, compartment subdivision, operating draughts and centers of gravity.
Options should be evaluated against measurable criteria such as payload, stability, fuel consumption, maintainability, shipyard feasibility and life-cycle cost. A visually appealing arrangement is not sufficient if it cannot be built and operated under the stated constraints.
3. Hull form, hydrostatics and stability
Lines plans and hull surfaces provide the geometry used to determine displacement, buoyancy centers and hydrostatic characteristics for loading analysis. Resistance, propulsion, maneuvering and seakeeping can be included depending on vessel type and contractual scope.
Intact stability and, where required, damage stability should inform decisions about freeboard, tanks, superstructures and weight distribution well before the final stage. IMO identifies SOLAS chapter II-1, the Load Line Convention and the 2008 Intact Stability Code among relevant international design instruments for covered vessels.
- Traceable hydrostatic model
- Representative loading conditions and relevant criteria
- Weight and center-of-gravity tracking throughout design
4. Structural design and material selection
Hull, deck, bulkhead and primary member scantlings are developed using anticipated service loads, selected materials and applicable design rules. Longitudinal strength, local stress and connection details must be considered together; finite element or fatigue assessment may be useful in critical locations.
In conversions and repairs, reliable as-is data should come first. Ultrasonic thickness measurements and 3D surveys help reduce uncertainty when legacy drawings do not reflect the current vessel condition.
5. General arrangements and marine systems
The project develops arrangements for propulsion, power, electrical distribution, bilge and ballast, ventilation, navigation, communications and other essential systems. Access, emergency escape, maintenance and fire safety are considered according to the vessel’s operational profile.
Coordination between structure, equipment and piping reduces clashes during construction. Models and coordinated drawings can support interface reviews, provided their intended level of detail is agreed in advance.
6. Detailed engineering and technical submissions
Detailed design turns concepts into fabrication drawings, material specifications, assembly details, equipment schedules and calculation reports. Engineering packages require consistent revision control, assumptions, source information and the relevant dimensional tolerances.
When formal approval is required, the documentation is prepared for review by the competent flag administration or classification organization. Preparing an approval package does not guarantee approval: that decision remains with the responsible organization.
7. Construction control, testing and handover
During construction, supervision checks drawings, materials, workmanship and the agreed installation sequence. Depending on project requirements, tests may cover tightness, machinery and systems, lightweight verification or an inclining experiment.
Harbor and sea trials provide evidence against the specified performance and operational criteria. The final technical package should include as-built information, test records and manuals appropriate for safe operation and maintenance.
How Arquitectos Navales & Asociados can support the process
Our scope may include feasibility studies, hull and stability calculations, structural assessment, detailed engineering and construction or repair supervision. For vessel modifications, ultrasonic measurements and 3D LiDAR surveys can support the engineering inputs.
Project scope is defined by vessel type, available records and owner priorities. An initial technical review helps identify the essential deliverables before major commitments are made.
