vol 6 issue 5

Towing icebergs to drought zones

16 May 2011
By Anne Harris
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Iceberg

Moving icebergs could provide much needed water to barren regions

Sky sail assisting iceberg movement

A sky sail (or giant kite), aims to use wind power to assist convoy progress while reducing fuel consumption

Iceberg simulation

Complex simulation can predict accurately the effects of transportation on an iceberg

There is nothing more valuable than water, yet much of the world is short of it. Could the answer be as simple as towing a icebergs to the drought-stricken tropics?

It's an idea that seems both impossibly simple and simply impossible. You tow the enormous ready-packed masses of the world's most precious commodity to the places in the world where it is most desperately needed. But surely it's an impossible mission – towing an iceberg?

Well, the idea of harnessing icebergs to produce fresh water is not a new one, and one man now thinks he is ready to put the theory into practice.

It was in 1970 that, after reading about an attempt to tow a small iceberg with a boat, Saudi prince Mohamed al Faisal began to muse on the possibility of transporting icebergs to desert regions. Keen to find solutions to the fresh water shortages in his region he joined forces with French polar explorer Paul-Emile Victor and Victor's graduate friend Georges Mougin and founded Iceberg Transport International.

Mougin was installed as technical director, and his first task was to demonstrate the feasibility – technical, ecological, practical and financial – of harnessing and transporting by far the biggest object ever hauled.

Mougin spent the 1970s and early 1980s modelling his ideas on a typical tabular iceberg weighing almost seven million tonnes. A tabular iceberg is stable and of regular shape, and presents minimum risk of fracturing or rolling over. For this purpose he would need to risk up to €10m equivalent.

One pressing concern was how the iceberg'could be prevented from melting, as well as what type of traction system was most suitable. Moreover, how could they make the transportation efficient, in order to consume the least amount of fuel without increasing the risk of the iceberg melting more quickly? These issues proved a major block on the proposal, and for years Mougin's dream foundered. He was convinced, however, that modern technology would prevail to refine and corroborate the concepts and the systems that he had devised for the project.

The project on ice

Jump forward to the end of the last decade and the plan was rekindled but with Mougin running the project himself – Victor having passed away three years earlier and the interest of the Saudi prince having waned. The rebirth was driven by progress made in meteorology and oceanography, particularly in terms of satellite data.

With forecasts now available in real time for all of the world's oceans, it was now possible to provide detailed information for each section of ocean in terms of temperature, salinity, currents and eddy. This information made it possible to predict oceanographic and meteorological conditions and enable towing operations to be optimised.

Advances in materials too now made sophisticated fibres reasonably affordable. Mougin's revised plan would employ a non-woven geotextile to minimise the melting of the target iceberg. A skirt made up of several ultra-long strips of geotextile, would envelop the immersed part of the iceberg and insulate it from the seawater.

Once skirted, the iceberg would be captured using a large net fabrication before being pulled by a tug. According to Mougin, one tug with 130 tonne traction would be enough. The most efficient solution for transporting icebergs – from both a financial and an ecological perspective would be to harness natural resources of the wind, waves and currents.

Virtualised pilot project

Mougin and the team chose the Canary Islands as the destination for the purposes of their pilot project. This region suffers from fresh-water shortages and already uses desalination plants, making it a suitable site for testing the iceberg solution.

Currents and prevailing winds make the waters to the east of Newfoundland the ideal location for selecting and capturing the iceberg before towing it away. For the last three decades, tugs have been re-directing icebergs that otherwise would have been on course to hit oil production platforms.

The main thrusts of the pilot project were decided: a tabular iceberg weighing around seven million tonnes, a tug with a traction force of 130 tonnes, and a race against time, before the iceberg melted travelling between Newfoundland and the Canaries.

It was at a 2009 screening of 'Khufu Revealed' – a documentary about Jean-Pierre Houdin's theory on the construction of the Kheops pyramid – that Georges Mougin met Mehdi Tayoubi of Dassault Systémes and discovered the potential of its 3D technologies.

3D techniques had made it possible to simulate the construction of an Egyptian pyramid, which simulated every detail of the project including labour, materials, processes and era-specific restrictions. 3D and virtual worlds can be used to test all aspects of a project and anticipate any issues before embarking on the real thing.

With the benefit of computer technology realised, the pilot project's budget requirements melted from €10m to an almost negligible amount. The ecological and human risks were also eradicated and, most importantly, the flexibility of 3D technology meant that the operation and logistics could be repeated as often as necessary.

Parameters that could be adjusted included the number of tugs required, the quality of the anti-melting system, the steering strategy to be used for different currents and any possible combination of oceanographic and meteorological conditions.

Mougin, his team and Dassault Systémes using scientific 3D simulation tools, assessed the technical feasibility of the project by tackling two major challenges.

The first was predicting how the iceberg would melt during its journey. To what extent would Mougin's protection system be effective and how would the convoy's travelling speed affect the rate of melting? Was there an optimum travelling speed? What ice mass would remain on arrival in the Canaries? What final shape would the iceberg be?

Secondly, the team needed to ascertain if it was possible to tow an iceberg from Newfoundland to the Canary Islands. How many tugs would be needed? How powerful would they need to be? How much fuel would they consume over how much time? Which route should they follow? What time of year? What should the steering strategy be?

As a safety and risk management precaution, the team also decided to simulate scenarios allowing them to analyse the consequences should an iceberg fracture to the point of breaking up completely. Using Dassault Systémes 3D simulation technology the team developed a digital iceberg weighing 7 million tonnes, measuring 163m deep, 236m long and 189m wide. Each simulation would build in all meteorological and oceanographic data actually recorded – with the help of satellites, balloons and other data capture systems.

Weight loss

Predicting the melt rate of an iceberg involves factoring in complex physical phenomena straddling a number of scientific disciplines. Using 3D simulation tools, it is now possible to model these phenomena with great accuracy. The first stage consists of simulating the interactions between the iceberg, protected by the skirt, and the environments through which it will travel.

Using thermal simulation the team observed how an iceberg behaves when it is melting. The simulations confirmed the need for an anti-melting system.

Using the software the team developed an integrated drift model, designed to consolidate all criteria involved in the iceberg transportation. The data set incorporated meteorological and oceanographic data with physical phenomena and characteristics of the iceberg's behaviour in various environmental conditions.

The team could enter the GPS coordinates corresponding to the start location for the iceberg off Newfoundland and the end destination (the Canary Islands) and develop optimised departure dates for the convoy.

Within the 3D simulation system it is possible to observe what happens at any instant, and analyse causes and effects produced by the changing parameters and circumstances. It can be seen, for example, that the power of one or even several tugs would not always be capable of withstanding the currents, rendering the convoy unsteerable.

After a series of simulations the team drew its initial conclusions. It decided that it would be possible to steer an iceberg weighing several million tonnes for thousands of kilometres with just one standard tug. In the Canaries example, the journey could be completed in 141 days.

With an effective anti-melting system it would be possible to minimise the extent to which the iceberg melts. In the Canaries example, the iceberg would lose an average of 38 per cent of its mass. Using several tugs over the entire journey makes very little difference to the overall journey time, and only serves to increase fuel consumption.

It is, the team concluded, pointless trying fight natural forces; they are too overpowering. The simulations highlighted the need to transport the iceberg at a speed of around one knot (1.8km/hr).

Icebergs can shatter without warning, as a result of the natural flaws that are embedded during their formation, as well as through environmental assaults such as temperature and erosion by sea currents and waves. Digital simulation has made it possible to accurately assess the physical risks and develop appropriate responses associated with the break-up of this large mass of ice while under tow.

Ice innovations

The innovations of Mougin and his team go far beyond the essential principles of the insulating cushion of water and assisted drift. For each major stage of the project (such as capturing the iceberg, transporting it and harvesting it on arrival at its destination), they have created a series of innovative technical systems designed to enhance its financial and technical viability while minimising ecological costs.

A sky sail (or giant kite), aims to use wind power to assist convoy progress while reducing fuel consumption. There's also an 'iceberg-cutting wire', designed to exploit the vast source of energy that is an iceberg, in line with the principles of OTEC (ocean thermal energy conversion).

There are no longer any major obstacles to understanding iceberg transportation for use as fresh water. Powerful simulation technologies combined with accurate knowledge about sea currents and other ocean and weather data have enabled complete and accurate study of the technical challenges without needing to invest in pilot projects or expensive, and unrealistic physical prototypes.

The integrated drift model demonstrates that the project is technically feasible and allows replay of the entire journey in less than two minutes – as many times as required. At the same time, the 3D virtual world recreated around the iceberg gives engineers the ability to place themselves at the heart of a realistic immersive experience that facilitates technical reviews and better informed decision-making, while also enabling anyone to enjoy an experience that is both interactive and educational.

For Mougin and his team, the next stage is to travel to the site itself and start full-scale operational trials. They still need to find a financial partner in order for the project to materialise.

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Georges Mougin, ice-dream man

Born in St Malo, France, Mougin grew up in a Newfoundland cod fishing community, where his father managed the local maintenance workshops for the boats. The youngest engineer in his year, he graduated from Arts et Métiers in 1944, and in 1945 helped to refloat ships grounded in the port of St Malo by the hostilities.

In 1947, with the help of a Danish naval architect, he coordinated work to transform a US surplus ship into a polar vessel that became the Commandant Charcot. It was at this time that he met Paul-Emilie Victor, beginning a friendship that would last 50'years, as well as members of the French polar expeditions organisation (EPF), and developed a fascination with Antarctica.

Mougin then developed self-propelled vessels for rivers in West Africa, where he was responsible for their installation. He even managed the operation of some of these vessels. In his role as director of the family business that became a shipyard in 1955, he oversaw the construction of around 40 ships up until'1963.

In 1964, he was the Polynesian director of an industrial architecture firm that built nuclear missile bases, including one in Mururoa. From 1967 to 1974 in the United States, he focused on peaceful applications of nuclear explosions, before becoming the manager of a Thomson subsidiary based in New York and Los Angeles, where he was in charge of prospective studies.

Upon his return to France, he founded ITI (Iceberg Transport International) with Saudi prince Mohamed al Faisal. Between 1975 and 1981, this company established the feasibility conditions for transporting and using tabular icebergs from Antarctica. In 1982, through his own personal company, Biostructures, a spin-off from an American company, he got involved in various projects, including the entrance hall at the Cit' des Sciences de la Villette and also developed a windbreak fencing system that was used by Eurotunnel, stadiums and projects in the UK, Germany and Brazil.

With satellite data resulting in the provision of ocean forecasting services,'coupled with the availability of maritime resources developed for the off-shore oil industry, Georges Mougin has been working since 2003 to revive the idea of harvesting icebergs. The trial transportation of a small tabular iceberg from Greenland within the northern hemisphere, less expensive than a similar exercise conducted in the southern hemisphere for a large tabular iceberg, has become the preferred option.

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