Page 126 - Marine Structural Design

102 Part I Structural Design Principles

of hulls and deck, tendon system design, foundation design and analysis, riser systems,
facilities design, fabrication, installation and inspection as well as structural materials.
Recently API RP 2FPS (2001) was issued for floating production systems. It gives a high level
specification for the design and analysis of floating production systems such as semi-
submersibles, spars, FPSO and conversionheuse of existing structures. The guide defines
design environmental criteria, accident loads, fire and blast loads and specifies design
requirements with respect to design load cases, structural design of hull and deck, fatigue
assessment, weight control, watertight and stability, transit condition and fabrication
tolerances. The API RF’ 2FPS (2001) also provides general guidance on station keeping and
anchoring systems, well and production fluid control, transportation system and export system,
facilities, fabrication, installation and inspection, material, welding and corrosion protection as
well as risk management.
6.1.6 Other Technical Documents
When performing the design or reassessment of steel marine structures, reference may be
made to specialized documents. These maybe in the form of:
Company specifications and procedures that are based on specific expertise or test results
developed in-house by the designer, a subcontractor, or the client manuals that give
support to finite elements, risk and reliability, or other engineering tools.
Reports, conference proceedings, or technical journals in the public domain covering a
particular design aspect in-depth.
Books on steel designs that allow hndamental stresses and strains to be estimated.
The above documents will need to be referenced in the Design Basis and made available to the
design team members as required.

6.2 Project Planning

6.2.1 General
It is essential that adequate planning be undertaken at the initial stages of the design process in
order to achieve a good design within the estimated cost and time schedule.
The main output of the planning process is a ‘Design Basis’, describing the criteria and a
‘Design Brief‘, describing the procedure to be followed and software to be used. For smaller
projects in particular, it may be preferable to gather all the information into one concise
document.
Ideally, the Design Basis and Design Brief will be written to and agreed with the Client prior
to the design phase. However, in practice this is not always possible. In such cases, it is
strongly recommended that these documents be issued in draft format with, as much detail as
possible or with relevant items labeled as ‘Preliminary’. This will enable the project team to
begin developing the design with some understanding of the criteria that will be the most
critical throughout the design.
The Design Basis and Design Brief may be updated throughout the project as particular
problems arise. It is important that all-relevant team members are aware of such changes.