The dimensions of the float should be defined in such a way asto minimize draught during towing, so as to allow shipyardconstruction, while guaranteeing sufficient stability in the towing phase in case of unfavourable weather conditions.An alternative structure for depths superior to 80 metres has also been studied a floating platform anchored by cables (see Marinarium 02).
The platform has been designed to withstand the most severe winds, tides, and waves, in its final location, as well as the effects of earthquakes.
Description of the "Mannarium 02" platform
The current project concems a floating offshore leisure complex which can be installed close to the coastline and linked to it by a floating enclosed walkway , or can even become an autonomous island
The "Marinarium 02" platform, covering an area of 175 000 m2 (plus 61 000 m2 of accessible deck space), comprises:
- accommodation in a five-star hotel, hotel-appartments, and flats
- two marinas (4- and 5-room houses with private port and roof-gardens)
- fully-f urnished office space with integrated logistical services
- shops and restaurants
- "sports and leisure" areas (beaches, pleasure port, watersports and swimming pools, tennis and squash courts, golf courses, table tennis, billiards, and computer games rooms etc.)
- health and beauty treatment (thalassotherapy. gymnastics, saunas. massage and beauty parlours)
- a floating dyke to protect the port from the waves
The originality of the design rests in the fact that the hotel is built around a tropical garden and circular sports complex 108 metres in diameter, topped by an air-conditioned glass dome.
This allows the visitor to play different sports throughout the year, in an exceptional environment and with unique leisure facilities Developed by the author, the "Marinarium 02" project uses construction techniques for floating oil platform anchored with tensile cables (TLP ) The anchoring for "Marinarium 02" will be the same as that developed by the author in 1972 for the "TLP" study (CDP 2000) for deep-sea drilling Comprising several groups of vertical pulley cables, this mechanism guarantees the stability of the platform at all times in the harshest weather conditions, such as storms.
Each group of vertical pulley cables is joined to the winch at the top, and to the submersible dead weights at the bottom.
The three anchoring winches in each pile enable the dead weight to be lowered and raised, as well as allowing control of the tension and the length of the cables.
A special mechanism to change the cables has been provided. According to the weather conditions, and the depth of water, the cables can be positioned vertically or slightly inclined in a curve.
Two alternatives have also been studied for water depths between 10 and 80 metres:
- A platform on submersible floats positioned on the sea-bed - A platform on sunk piles
"Marinarium 02" can be adapted to different water depths between 10 and 2000 metres.
The dead weight floats have several roles:
- they facilitate assembly of the prefabricated elements in a shipyard (the platform disc will be prefabricated in triangular sections)
- they will act as floats in the towing phase and during maintenance (air gap = 4 metres)
- they will act as counter-weights to guarantee the anchoring of the cables
The platform will have 13 independent dead weights
The dead weights will be joined to the platform by flexible tubes (compressed air to drive out the ballast), and will have ballast tanks.
"Marinarium 02" will be shell-shaped, built from steel (or aluminium, so as to minimize the weight, and so that the draught will not therefore exceed 9 metres). It will be constructed and fully equipped in the shipyard, and the installation (or eventual dismantling) can be carried out in a very short time, without disturbing the environment:
- towing to the final site
- positioning
- partial ballast-filling of the dead weights
- submersion and lowering of the dead weights using the winches and pulley cables
- complete ballast-filling of the dead weights, and setting of the cable tension using the winches
Feasibility studies on these two complexes have attempted to discover:
- the development possibilities of the projects
- feasibility on different levels
The development possibilities of the projects
If Marinariums primary role is as a tourist complex, it could also appeal to other sectors.
Firstly, the installation of marinas, appartments, offices, and shops at the site, will attract the real estate market.
Also, the presence of a 1330 room hotel, with a conference centre and fully furnished offices, in an attractive and tranquil setting, will offer the possibility of holding seminars, exhibitions, and conferences.
Finally, the architecture of "Marinarium 01" itself, a 300 metre beacon situated just off the coast, with views up to 80 km away, is a considerable bonus.
In effect, it is entirely likely that many visitors will be drawn to this site, symbolic of our own civilization, and bringing together in one place a number of different centres of interest (oceanographic museum, aquarium, etc.)
Equally, it will be seen that Marinarium perfectly meets the demands of the exceptional events (sports competitions, son et lumiEre shows, concerts) that will be organised there.
Different implantation sites have been studied
MARINARIUM 01
Franc.: French Riviera GOLF JUAN
Japan: KYSHOU ISLAND
Singapore: SENTOSA ISLAND
MARINARIUM 02 , a floating and mobile platform can be installed in differents sites as a semi-submersible plateform or a cruiser ship.
Feasibility studies on different levels show:
- at the technical level : tried and tested offshore oil platform technology.
- at the market level : increasing needs of a growing clientele.
- at the economic level : strong economic development of the region, and the creation of jobs ("Marinanum 01" = 3000 jobs and 3 to 4 million working hours for the shipyards).
- At the financial level : a strong potential market offering rapid retums on investments (7 to 8 years).
Marinarium could therefore be the first in a long line of ocean cities accommodating the leisure activities of the third millenium.
Bibliography
R. Dziewolski : "Offshore gravity-type leisure complexes"
IABSE Congress, Helsinki, June 1988.
R. Dziewolski : "Marinarium floating islands"
IABSE Congress New Delhi, March 1992
(IABSE = Intemational Association for Bridge and Structural Engineering )
R. Dziewolski: "Cites marines A vocation touristique " OCEAN
