Classification and Damage Stability of Flotel Ships

Abstract

This paper considers the mono-hull vessels (i.e. ships) used today in the maritime and ocean industries to accommodate people in semi-permanent accommodation at sea: the floating hotels, or flotels ships.
Together with other type of marine structures (mono-hull and semisubmersible barges, jack-ups,...) they have mainly been developed to support the activities of the offshore oil & gas industry. But there is a dilemma when the Classification Societies try to give a Class Notation to this type of vessels as they are a very recent concept. We can find two main options: as Passenger Phip (same as cruises of ferries) or as Special Purpose Ships (used by most of the offshore support vessels). The objective of the paper is to show how the market and the Classification Societies are responding to this dilemma. We will show that with the new 2008 SPS Code the recommendation of DNV is the better option: to design this flotel ships as passenger ship from the very beginning of the shipbuilding project.
And in relation with that, the paper also enters in the problem that these different ways of classifying the flotel ships suppose for their design, as the rules applied when calculating the damage stability are totally different.
Offshore ships (i.e. flotel ships) industry is one of the greatest developments and activity has occurred in recent times within the naval sector. For this reason, all the movements in the market and the rules governing the technical aspects of it are very important to anticipate the problems that may arise. Recently, the Maritime Safety Committee of IMO (International Maritime Organization) adopted a new Code of Safety for Special Purpose Ships covering most of the vessels in this industry. This new code includes the obligation to perform a probabilistic damage stability study.