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Offshore top additional class notation

​​In a market in continuous development, cutting the edges of technical excellences always seeking to protect the environment and the human life, RINA SERVICES is the best partner to choose.
Our experience with key players of the market and our involvement in innovative projects brought us to develop dedicated sets of rules for units operating in Oil and Gas sector:
  • Rules for the Classification of Offshore Support Vessels
  • Rules for the Classification of Floating Offshore Units at Fixed Locations and Mobile Offshore Drilling Units.
Along with the above mentioned rules, it has been created a number of dedicated additional class notations also developed in cooperation with the shipping industry and they may be assigned to ships with enhanced characteristics in terms of safety, environment or quality of the service provided.


Dynamic Positioning (DYNAPOS)
A dedicated class notation based on the evaluation of the machinery automation, the power management system and the capability of the unit to maintain its position during operation of diving or offshore structures installation.

Fatigue life assessment FATIGUELIFE (Y) or RESIDUALFATIGUE (Y)
Assigned to units after a local stress analysis of the most critical areas of the structures in order to Identify & Monitor the hull hot spots during the units design life (Y) in order to prevent possible failures. The aim of this analysis is to assign a number of years during which we guarantee that no major structural repairing job will be requested.

Polar Class
Assigned to ships constructed of steel and intended for navigation in ice-infested polar waters, except icebreakers.

Winterization (temp)
Assigned to ships intended to be operated in cold climate over long periods. The value temp, in brackets, is the design temperature in °C and is to be taken as the lowest mean daily average air temperature in the area where the ship is intended to operate.


RINA SERVICES’ experience in Offshore Support Vessels (Ie: diving support vessels, subsea umbilical risers and flowlines installation vessels etc)and floating offshore units (ie: FSRU, FPSO etc) makes us a partner of choice for high technology and customized services.

Our partners can:
  • have dedicated and self-standing set of rules and tailored additional class notations capable to describe syntactically the specific features of the unit
  • obtain a class and statutory certificate issued by a third party organization recognized by most of the word wide flag Administrations
  • have an adequate certification approach of critical safety components such as for diving system, pipe layers.


During the new building and conversion phases, RINA SERVICES has got a high capability of mobilizing experts in various disciplines. Therefore RINA SERVICES appoints one experienced Project Manager, acting as single contact point for client and shipyard, will be appointed to coordinate the plan approval engineers, the team of surveyors involved at shipyard’s premises and the team of worldwide technicians involved in testing activities of materials, components, machineries.

Additional class notations are managed along with the classification process and are therefore granted upon plan approval and onboard verifications with dedicated surveys and tests.


When is the right time to involve RINA SERVICES during the construction or conversion project?
The right time to involve us is the very beginning during the pre-feed or feed stages, because already during these phases the main features of the Units and their critical safety equipment will be defined.
Aspects that are normally highly influenced by international and national regulations, therefore it is always important to involve our experts in order to identify the applicable international and national rules.

Is the mooring system of process and storage Off-shore units (SPM or Spread type) certified by RINA SERVICES? In which extent?
Yes, RINA class rules are covering also the mooring systems. Our approach of certification is covering the structural requirements applied to devices pertaining to the mooring system, which are devoted to the mooring function and are interested by the transmission of mooring loads. Such structures are located between the sea bed foundations (excluded) and the structural reinforcements or the mooring equipment (included), depending on the arrangement of mooring system, interfacing the unit and the mooring system itself.
The application also covers the load carrying mechanical components of turret.

Do additional class notations have an expiry date?
Additional class notations are always connected to class certificate of the vessel, therefore are subject to annual and renewal audits aligned with class periodical surveys.

Are additional class notations costs included in the newbuilding or upgrade classification fees?
Additional class notations generally require the involvement of highly specialized teams and are therefore quoted separately from the classification fees.

Will additional class notations periodical verifications imply additional stops for my ship?
​All verifications can be carried out during regular class periodical surveys with virtually no impact on the ship’s operativity.
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