We solve structural problems at sea

naval architecture


Ships and other marine structures are exposed to various environmental loads, such as those from wind, wave and current. The interaction between a marine structure and the environmental loads must be understood in order to optimize design and develop groundbreaking concepts. To ensure that your marine assets can withstand extreme or changing environments, we offer a range of services.

General Services

Structural analysis

  • Global and local FEM analysis
  • ULS, ALS and FLS analysis
  • Main scantling analysis and optimization
  • Lifting and transportation analysis
  • Conversion, life extension and FEEDs for FPSOs and FSOs

Structural design

  • Typical structure design of FPSOs, semi-submersibles, wind carriers, crane pedestals, etc.
  • Sea fastening design and concept development
  • Design fo tower grillage, blade stacks and nacelle supports for wind carriers
marine engineering

Hydrodynamic analysis

  • Site specific hydrodynamic motion and load analysis
  • Motion and wave load analysis
  • Mooring and green sea analysis
offshore wind

Survey inspections

  • Vessel valuation reports
  • Sales and purchase inspections
naval architecture

Hull design

  • Weight distribution and stability studies
  • Concept design and layout
  • Steel optimization
  • 3D modelling and 2D structural drawings
naval architecture

Sector Specific Services


  • Selection and inspection of candidate vessels for FPSO conversion projects
  • Sales and purchase inspections
  • Vessel valuation reports
  • Planning and costing for FPSO lifetime extension campaigns
  • FEED studies for FPSO’s and FSOs
  • FPSO conversion projects
  • Project management services for rig and FPSO construction projects
  • Design and management for local content integration
  • Hull and topside structural engineering
  • Hull/topside and turret/mooring interfacing
  • Technical documentation
  • Structural drawings 
  • Class approval 
  • Main scantling approval
  • Real time monitoring of topside structural integrity
  • Developing SRBI (structural risk-based inspection program) for hull and topside 
  • Flare tower strength assessment 

Offshore fish farming

  • Global structural and hydrodynamic analysis
  • Local and global ULS, ALS and FLS studies
  • Technical documentation for class approval
  • Structural drawings
  • CFD analysis
  • Calculation of RAO (response amplitude operator) and DAF (dynamic amplification factor)
  • Wave motion analysis

Offshore wind energy

  • Lifting analysis
  • Sea fastening and green sea analysis
  • Technical documentation of tower grillage, blade stack and nacelle support
  • Transport studies
  • VIV (vortex induced vibration) fatigue assessment 


  • Scantling design and optimization according to DNV GL Rules and Standards
  • Production of structural drawings, 3D Autocad model, GeniE and HydroD analysis model
  • Topside integration with hull
  • Technical documentation
  • ULS, ALS and FLS analysis
  • Main scantling and class approval
  • Lifetime extension projects

Offshore Structural Analysis and Hydrodynamics

Visualize stress analysis results

Improve stress analysis validation and assessment by combining traditional stress reporting with stress analysis visualization. Display your structural member stress results graphically and perform post-analysis member and tubular joint code checking to international design codes. Display shear force and bending moment diagrams.

Analyse offshore structures

Predict behaviour of a platform or topside structure with comprehensive analyses of the global response, linear static analysis, estimation of dynamic amplification factors, time domain simulations in Riflex or SIMA, frequency domain analysis, hydrodynamic analysis in Wadam. Use integrated models to calculate the wave, wind and current effect. 

Analyse structural stress

Import real time offshore structural motion data and then calibrate numerical design tools to comply with the full-scale vessel motions. 7Waves also perform static structural analysis featuring automatic model generation and steel code checking for a range of design and loading conditions. Produce detailed stress analysis reports to verify the structural integrity. Improve offshore structural design, quality, and design code compliance.

Calculate and improve fatigue life

Comply with offshore design codes by calculating complex variable stress concentration factors (SCF). Assess wind and wave fatigue using standard or user-defined S-N curves. Re-design fatigue hot spots by strengthening surrounding area or soften the critical detail. 

Typical fatigue projects are to ensure the structural integrity of a flare tower, offshore wind tower grillage, global fatigue calculations of ships and other marine structures, and local fatigue calculations of structural details. 

Ensure compliance to offshore design codes

Ensure structural compliance using DNV GL’s built-in code checking tools. Filter results for critical conditions. Optimize design and configuration for compliance to numerous current and past international codes including API, AISC, EC, ISO, DNV GL, and NORSOK. Deliver compliance documentation. 


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