Gigantic floating water bags
Transporting large amounts of fresh water by sea, from regions that have a lot, to regions that have little, is the aim of the European XXL Refresh project, which enjoys the support of the European Commission.
We have already mentioned Refresh a few years ago, the European project aimed at transporting large quantities of fresh water by sea using enormous water bags able to hold up to 200 m3 of water.
That was three years ago. Since then, the idea has gained traction, the project has grown, and Refresh became XXL Refresh!
To increase the capacity of the water bag, the consortium's five European partners designed an enormous water bag – 65 metres long by 11 metres wide and 4 metres deep- which is both rigid and flexible, made from an extremely durable and waterproof plastic. The PVC bag is extensible because it is composed of several modules attached to each other with zippers, enabling the container to be given the desired size. The zippers are crucial for ensuring that the water bag remains watertight, with a sealing joint specially designed to make the bag fully modular: it consists of two layers of material that are sealed like a sandwich inside the fabric that forms the bag, and in the middle of the zipper, a polyurethane membrane that ensures that the sealing joint is watertight.
To ensure that the water bag was resistant and the zippers were infallible, a test was conducted in Tarragona, Spain, in December 2015: the prototype which contained 2,000 cubic metres of fresh water, for a weight of 2,000 tonnes, withstood the towing, despite the swell of the waves and the speed. It naturally floated to the surface as fresh water is lighter than the salty sea water.
The member companies of the XXL project are currently seeking potential investors, whose contributions would enable them to multiply the bags' capacities by a factor of ten or twenty, and to consider water transport to the Middle East, the Caribbean, South American and even Southeast Asia.
These giant devices could then become an ecologically and economically interesting alternative to tankers or submarine pipelines for the emergency (or otherwise) transport of fresh water to regions suffering from water shortages.
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