Spiralling underwater cities could make oceans inhabitable by 2030
News: underwater cities with infrastructure networks spiralling down into the depths of the oceans could be a reality as soon as 2030, according to a Japanese construction company.
![Ocean Spiral by Shimizu Corporation](https://static.dezeen.com/uploads/2014/11/Shimizu-Corporation-Ocean-Spiral_dezeen_468_sq.jpg)
The conceptual Ocean Spirals could descend by up to 2.5 miles below the oceans' surface to create self-sustaining underwater communities that could be home to up to 5,000 people each, says Shimizu Corp.
![Ocean Spiral by Shimizu Corporation](https://static.dezeen.com/uploads/2014/11/Shimizu-Corporation-Ocean-Spiral_dezeen_468_10.jpg)
The helical structures would be made up of resin components, produced using huge industrial 3D printers.
![Ocean Spiral by Shimizu Corporation](https://static.dezeen.com/uploads/2014/11/Shimizu-Corporation-Ocean-Spiral_dezeen_468_9.jpg)
Each one would be topped by a watertight floating dome containing businesses, homes and hotels, which would submerge underwater during bad weather conditions.
![Ocean Spiral by Shimizu Corporation](https://static.dezeen.com/uploads/2014/11/Shimizu-Corporation-Ocean-Spiral_dezeen_468_7.jpg)
Beneath this, the nine-mile-long spiral would wind its way down to the seabed to allow scientists to create an "earth factory" of natural resources that could be harvested for energy and materials.
![Ocean Spiral by Shimizu Corporation](https://static.dezeen.com/uploads/2014/11/Shimizu-Corporation-Ocean-Spiral_dezeen_468_4.jpg)
According to the Tokyo-based company, micro-organisms could be used to turn carbon-dioxide into methane.
![Ocean Spiral by Shimizu Corporation](https://static.dezeen.com/uploads/2014/11/Shimizu-Corporation-Ocean-Spiral_dezeen_468_5.jpg)
This would fuel power generators along the spiral, which would also take advantage of differences in seawater temperature to create additional energy.
![Ocean Spiral by Shimizu Corporation](https://static.dezeen.com/uploads/2014/11/Shimizu-Corporation-Ocean-Spiral_dezeen_468_6.jpg)
Hydraulic pressure would be used to produce desalinated drinking water.
![Ocean Spiral by Shimizu Corporation](https://static.dezeen.com/uploads/2014/11/Shimizu-Corporation-Ocean-Spiral_dezeen_468_1.jpg)
Shimizu – whose other projects include a space hotel and a floating city – predicts that the first spiral will take five years to build at an estimated cost of ¥3 trillion (£16 billion). The company says the technology to sustain underwater life will be ready in 15 years, meaning residents could move in as early as 2030.
![Ocean Spiral by Shimizu Corporation](https://static.dezeen.com/uploads/2014/11/Shimizu-Corporation-Ocean-Spiral_dezeen_468_3.jpg)
The concept was developed in partnership with Tokyo University and the Japan Agency for Marine-Earth Science and Technology (Jamstec).