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          Van den Noort Innovations > RFA

 

Rotating Floating Airport - RFA

    

Floating Platform

The RFS’s platform consists of a Pneumatically Stabilized Basement Floor (PSBF)

Construction:

The basic construction method is to wet cast the individual cylinders with an integral top slab to be assembled into modules.These modules join with each other to form a complete platform structure as depicted below.  This modularity is a key aspect of the concept.

 

The economics of casting a complete module is under study. The number of components in a module will depend on the selected construction and launching environment. A nine component module is considered adequate for maintaining stability during deployment. Generally, the larger the module, the lower the offshore labour cost. All joining of the manufactured units is with post-tensioned cables resulting in a monolithic structure.

How It Works:

Most conventional floating platforms acquire their floatation forces by directly displacing the water with their hulls. A pneumatic floating platform utilizes indirect displacement, in which the platform rests on trapped air that displaces the water, see figure. The primary buoyancy force is provided by air pressure acting on the underside of the deck.

The PSP is a distinct type of pneumatic platform, one in which the platform is composed of a number of cylindrical shaped components packed together in a rectangular pattern to form a module. Each cylinder is sealed at the top, open to the ocean at its base, and contains air at a pressure slightly above atmospheric pressure. Modules can be of a size that are relatively easy to manipulate, as shown in the simplified drawing below Another aspect of the PSP design is that, when needed, air is allowed to flow from a cylinder to its neighbours through a manifold or connecting orifices. The airflow provides a mechanism to help reduce the peaks in the pressure distribution beneath the structure and provide platform stability as well as a mechanism for dissipating wave energy. Directing the moving air through turbo-generators to produce electrical energy is a capability that is now generating considerable interest. See the "Wave Energy" page.

An assembly of cylinders results in enclosed interstitial regions between cylinders, which may be filled with air, foam or other material. These regions are isolated from the air pockets within the cylinders to provide additional buoyancy and righting moment. In comparison to conventional floating platforms, the designers of a pneumatic platform can modify the distribution of the flotation force as needed to minimize the hogging moment or in response to large concentrated loads on the deck. Further, it is possible, for a particular sea state, to tune the oscillation of the water columns inside the cylinders to minimize the overall hydrodynamic loading to which the platform is subjected.

This brings up the fact that the PSP, as with other floating platforms, is sensitive to its environment in form and function, and must be designed taking that into consideration. There is not a "one size fits all" PSP. However, that said, they can be segregated in two broad categories, open ocean platforms, and protected water platforms. These differ markedly in component size and complexity as illustrated in the following examples, see

Features

  • A minimum required surface due to rotating platform and runway system
  • Wind conditions are in fact irrelefant 
  • Airplanes can land and take off in any direction
  • No restrictions to night flights
  • Environmental impact is significantly smaller
  • Only the central terminal must be constructed on the bottom of the sea, with floating parts prefab made
  • The RFA concept is a substantially lower cost concept

Transport

Transport of people and cargo by air has grown more than anticipated. Most airports are situated near densely populated areas limiting the needed expansion to meet future demand. In this context, the Dutch Government initially considered the feasibility of an airport serving as a twin for Amsterdam Airport planned to be built in the North Sea on an artificial island, some 15 – 20 kms from the mainland. Other examples: Krek Lap Kok in Hong Kong and Kansai International Airport in Japan. 

However, building an airport on an artificial island in open waters is a capital intensive affair and often harmful to the marine environment. An airport on a ‘fixed’ island needs runways in different directions to enable airplanes to take off and land against the direction of the wind, thus requiring a surface of a substantial diameter. 

For a much more cost effective and efficiently operating airport, Van den Noort Innovations BV in collaboration with Royal Haskoning Technical Engineering and the Technical University in Delft/Holland have developed the Rotating Floating Airport concept. This concept consists of a purely afloat platform and runway system rotating 360 degrees along  a "fixed" circular terminal solely constructed on the bottom of the sea. It is the ultimate solution to meet cost and environmental conditions. The central terminal has connection with the mainland through a tunnel tube line. The airport just needs  two parallel runways rotating into the wind direction. Hence, the total surface of such an airport demands minimum acreage.

Principle

As far as an airport has been constructed on an artificial island in open waters, it needs runways in different directions to enable airplanes to take off and land against the wind. The surface of such an airport therefore requires extensive acreage. Its construction normally implicates various environmental problems. Hence, construction cost are out of proportion.

 

The Rotating Floating Airport is a platform that rotates along a fixed circular terminal, constructed on the bottom of the sea and connected with the mainland by a tunnel metro line. The RFA always rotates according to the wind direction, enabling airplanes to take off and land comfortably in all wind conditions. This type of airport just requires only two parallel runways. Constructing an airport this way minimizes the surface required. In addition, its 'central' construction concept enhances minimal environmental implications. Its off coast location also facilitates night traffic.

RFA  Transport system

 

The fixed terminal is constructed in different levels to accommodate a departure and arrival hall with all required facilities along with a subway station  connected to the mainland through a 2-line tube. All decks have vertical connections by elevators, escalators and up- and down walkways.

 

 

 


 

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