Cape Town is running out of water. It’s difficult to say exactly when the city will hit ‘Day Zero,’ the moment when the water runs out for good, but most experts predict it could happen as soon as next year. When that happens, thousands of people could lose access to clean water. Such a scenario would be disastrous to say the least.
The looming disaster has prompted a series of increasingly desperate solutions to delay the problem. The most recent proposal by Zambian-South African marine salvage expert Nick Sloane is to capture an iceberg from Antarctica and tow it to the city, using its melting ice as a source of fresh water. Could it work? In theory, yes. Will it work? That’s a much tougher question.
The idea itself, of towing an iceberg from the poles to provide fresh water, is not new. It’s been proposed over and over again for nearly 200 years, and nearly always amounts to nothing. Numerous groups over the decades have proposed towing icebergs everywhere from India to the Middle East to California, and in 1973 the RAND Corporation even wrote an 83-page study on the idea. Despite all the planning, there has yet to be a successful effort to capture and tow and iceberg for fresh water.
The good news is that in the decades since the RAND Corporation paper was published, towing large icebergs has actually become somewhat routine in one area: Arctic drilling. Oil companies operating offshore rigs in northern waters often worry about icebergs colliding with those rigs, so they’ve developed techniques for capturing icebergs and shifting them onto less hazardous trajectories.
Typically, to tow an iceberg a special towing vessel will surround the ‘berg with a towing rope. This rope is eight inches in diameter and attaches to the towing vessel with a three-inch diameter tow cable. The tugboat then moves the iceberg out of the way before it can cause any harm.
This sounds like great news for proponents of iceberg towing, but this specific application is very limited. The iceberg only moves at speeds up to a handful of knots and can take days just to get out of the way of an oil platform. In addition, towing icebergs can be hazardous because they can sometimes flip or break apart during the towing process.
The potential Cape Town project would utilize this same basic procedure, with two tugboats to pull the iceberg over 1,000 miles to Cape Town along prevailing currents, with it covered in an insulating blanket to try and delay its melting. The odds of success may be low, but with the city running out of water very soon this long shot might be its only chance. The fate of thousands might depend on Cape Town succeeding where everyone else has failed.
First published on Popular Mechanics USA