Offshore engineering process

Offshore engineering process

Each offshore project is planned according to your needs and preferences. Whether the outcome is a full classification design or a feasibility study, we pay special attention to careful project planning and successful execution of the offshore engineering process.

The offshore engineering process descriptions and project phases below are just examples of how a project can be structured. This means that they describe a typical project. However, each project is different, and the goals and scope of your project may vary from these.

Our research and development (R&D) function has carried out around 700 application studies exploring various markets, project feasibility, product applicability, machineries and systems. These also serve as an excellent basis for developing state-of-the-art concepts.

Offshore engineering process by Deltamarin

Feasibility Study

One of the first steps in the offshore engineering process is a feasibility study. The purpose of the feasibility study is to develop the first design(s) for the owner in order to be able to make a preliminary estimate of the required investment and the feasibility of the intended service. The starting point for the feasibility project is the client’s business plan or basic description of the vessel or service. At the end of the feasibility phase, the client is in a position to discuss further with other parties involved, and to decide whether to go ahead with the concept.

Outline Project

The purpose of an outline project is to develop the concept to a level where the inquiry material can be sent to shipyards and the main equipment suppliers for tendering purposes. The main focus in this phase is to create reliable design material describing the design to a sufficiently detailed level for the shipyard’s pricing purposes. An interactive 3D model can also be developed for the client’s own use.

With a prototype vessel, it is essential that the project is well-defined before approaching yards. All yards can then start from the same basis, the owner receives comparable proposals and gets the desired design at an affordable price. Not all yards have the capacity or the experience to produce the necessary design by themselves. In China,  for instance, an owner’s outline project is practically always required to receive a proposal from the yard.

If the project is for a conversion FPSO, the candidate hull should be known in this phase so that the design is based on the actual hull to be converted. The condition of the candidate hull should also be evaluated in order for the tendering yards to be able to take into account the extent of the required steel modifications and new equipment.

At the end of the outline project, the owner can send yards invitations to tender.


The purpose of the FEED phase is to utilise the time period between the tender request and contract negotiations. The vessel concept will be developed to a more defined level enabling the owner to evaluate the cost of the unit, get firm pricing from the building yard and to show the end customer the technical feasibility and safety of the vessel. The main focus in this phase is to further refine and verify the developed design principles with more detailed calculations and design activities. In the case of an FPSO, the interface between the topside contractor and the marine engineering company becomes critical and Deltamarin deploys interface managers to take care of information exchange.

On the basis of the first proposals from a number of yards and an evaluation of their proposals, a short list of yards is typically made and more detailed discussions are started with the selected yards. At the end of the project development work, a Letter of Intent (LoI) with the shipyard is signed, or at least a project performance clarification is made.

As a result of this phase, the shipbuilding or FPSO lease-operate contract will be signed.

Basic Design

The purpose of the basic design is to develop the project in order to achieve approvals from the classification society, national and other related authorities as well as to define the project to meet the owner’s requirements. This means that an efficient basic design class and flag should be decided upon. At the same time, the project will be technically defined to allow the procurement of the main equipment. Basic design cannot proceed without the selection of makers for the main systems, as makers’ data is required for the design to proceed.

Basic design is typically ordered/carried out by the yard but can be carried out on behalf of the owner as well, even before signing the shipbuilding contract. This, however, means that the owner may have to make the classification agreement as well as select the main makers, subject to the shipbuilding contract.

Basic and detail design schedules are often overlapping. The basic design is finished when all approvals have been received.

At Deltamarin, we typically carry out 4-6 basic design projects a year, including technical procurement handling.

Hull form development

Deltamarin’s strong team of hydrodynamic experts are highly experienced in optimising hull forms for the actual operating conditions of ships. By careful optimisation with state-of-the-art tools, we can reduce needed propulsion power while maintaining good manoeuvring and seakeeping characteristics. With hundreds of model-tested vessels as a reference and the cutting-edge RANS CFD solver STAR-CCM+ as a tool, we optimise vessels to the highest efficiency level.

In addition to CFD simulations, we carry out 10-15 model test series a year at different European model basins. Successful execution requires experience and knowledge of developing the hull form, and the model tests need to be carried out to verify that the optimisation targets have been achieved. We have very good experience in managing this process to a successful end result.

Detail Design

Space reservations will be checked and necessary definitions for the location of various major items will be accomplished. The ship-wide routing of piping, ducting and cabling will be made to prevent any discontinuity in design at areas of interface.

The basic design diagrams for piping, main cable trays and ventilation ducts will be brought on top of the space arrangements and layouts, taking into consideration the structural arrangement as well.

Detail design and engineering are carried out in accordance with the selected building method. Normally hull, machinery and piping are taken care of by the yard, and the rest by the topside contractor and system suppliers. However, this depends on the selected shipyard. Detail/production design is typically carried out by the yard alone and/or together with the designers. In China the practice is different as, in detail design, only the final vendor data is implemented while the production design is carried out by the yards with their own 3D programmes.

Basic and detail design schedules often overlap in the offshore engineering process. The detail design ends in production start-up.

Ship in Operation

During the operation, Deltamarin can store and update your documentation, and offer conversion engineering, assessments and studies. Our environmental efficiency evaluations and safety assessments will assist you in improving your operations.

Our products and services during operation include the following:

  • Conversions
  • Training
  • Specialist services
  • Finite element analysis (FEA), hydro, stability, etc.
  • Energy management program
  • Environmental services
  • Total safety assessment
  • Consulting services
  • Market studies
  • Product applicability studies
  • Machinery and system studies
  • Technical information management
  • Document update service for the lifetime of a vessel

You can find a list of our offshore references here.

For more information, please contact

Esa Jokioinen
Sales, offshore
Tel. +358 2 4336 344
Mobile +358 40 834 8112


Kristian Knaapi Deltamarin
Kristian Knaapi
Sales, cargo ships
Tel. +358 2 4336 453
Mobile +358 40 7006 905