Marine / Naval Engineering


Our Marine/Naval Engineers thrive on providing solutions to the most complex problems. Our field experience and project management skills complement our technical expertise in order to provide our clients with safe and robust solutions.

The Marine / Naval Department uses the following software licenses: 

  • Orcina Orcaflex / Orcawave
  • Bentley Moses
  • Bentley SACS
  • ANSYS Mechanical + AQWA


Vessel Operations

Modelling the dynamic behaviour of a floating body fundamentally governs every part of the installation analysis. We are able to model floating systems using 3D radiation diffraction solvers on at least two different software packages (MOSES, Orcaflex incl. Orcawave and ANSYS AQWA).

Additionally, we are capable of performing “bollard pull” assessments, design of safe mooring and anchoring systems, and providing detailed mooring analyses to produce workability summaries. This gives you insights into the risks associated with each operation, allowing you to be confident during operations offshore.

Our Marine / Naval department performs local capacity assessment analyses of varying ship’s structures for structural integration of deck safety equipment, winch platforms, sea fastenings, and other equipment. Analyses are carried out against Ultimate Limit State (yield and buckling checks). Depending on the project, environmental loads (sea pressure and accelerations) are been obtained from direct calculation or rule-based empirical values.


Additionally, we carry out the global structural assessment of ships and offshore structures from 3D FE models. We perform global hull structural analyses following both direct methodologies (ABS Direct Loading Approach / DNVGL Computational Ship Analysis) and simplified methodologies (ABS Total Strength Assessment / 3 cargo holds). This includes yield and buckling checks.

  • Vessel Hydrodynamics
  • Mooring Design / Verification
  • Anchoring Operations
  • Bollard Pull Calculations
  • Workability Analysis
  • Vessel Modifications / Structural Works

Pipeline Installation

Storing, transporting and laying subsea pipelines is a critical engineering task. OI has extensive experience with both the analysis and the offshore operation of laying large diameter pipelines in the most onerous of conditions. 

We are happy to unleash our static, dynamic and fatigue analyses by utilising our in-house dedicated computer. We can run every possible load case to ensure the most onerous case is realised, allowing you to be confident during operations offshore.

We can not only support you as a design house, we can also provide you with offshore analysis in the field (for real-time conditions, fatigue, update lay tables for specific A&R operations) and provide typical field engineering services with our strong offshore engineering team.

  • Pipe Stacking Calculations
  • Static / Dynamic Installation Analysis
  • A&R Analysis
  • Fatigue Analysis
  • Above Water Tie-In Analysis
  • Workability Analysis
  • Tension Schedules & Lay Tables for Offshore Operations
  • Installation, Project & Field Engineering Support

Track record


Modular Pipelay System Offpipe Support

  • Installation project engineering
  • Somewhere, The World
Undisclosed client

Pipelay Analysis long

  • Pipeline Engineering and Design
  • Somewhere, The World
Van Oord

Mozambiques LNG Umbilical Mooring Analysis

  • Marine / Naval Engineering
  • Africa

Cable Installation

At OI, we support you in every phase of the cable lay project with clear and concise engineering analysis and operational support.


Our activities typically include; SURF / cable lay static and dynamic analysis including normal lay, first and second end pull-ins. We provide you with workability summaries to aid go/no go decisions and determine, with certainty, that the operation can be completed safety.


We can also provide support for mobilisation, procedures, deck-layouts, tender & feasibility studies and operation and equipment specification support.

  • Normal Lay analysis
  • Pull-in Analysis
  • AWTI Analysis
  • Workability Analysis
  • Lay Tables

Track record


Hornsea Export Cable Platform Pull in Analysis

  • Marine / Naval Engineering
  • North Sea

Hornsea Export Omega joint overboarding Analysis

  • Marine / Naval Engineering
  • North Sea
Tadek Offshore

Racebank OWF Orcaflex Support

  • Marine / Naval Engineering
  • North Sea

Structure Transport & Installation

OI has strong experience in the transportation, lifting and installation of jackets / topsides, PLEMs, suction piles and other offshore subsea structures. We also have experience with the decommissioning of these assets.


We can support you with analysis, procedures and offshore operational support as well as with tender and feed design work scopes.


You can be confident that your assets get to where they need to go safely!

  • Grillage & Seafastening design
  • Marine Transport Analysis
  • Load-out Analysis
  • Static / Dynamic Lifting & Upend Analysis
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