Going through the news flow of LinkedIN, I saw a home experiment for kids. The mother used a simple experiment to show her kids what a suction bucket was. She had an aquarium with sand covered by water. She inserted a coke can with the top cut off. Then she inserted a straw into the bottom of the can and sucked out the air trapped inside the can.
Visually, I could see the can descend deeper into the sand. When she tried to pull the can out of the sand, it was very difficult. As I watched, I thought, “This is all very interesting. But what’s it for?” I thought I understood the basic concept. But, not knowing anything about suction buckets, I couldn’t see what the application would be.
I put a comment (always a scary thing to do) saying that while I thought the experiment was very interesting I had no idea what it was for. “What’s the point?” I was asking. I had this vague feeling that after all there must be a point. Just educating the kids about sand and coke cans or how to be careful not to inhale water when removing air through a straw didn’t seem sufficiently significant for all the effort involved. After all, she had posted a video!
Other viewers came to my rescue, sort of. They supplied comments in reply to my ignorance. Which by itself was a real lesson in the bane and blessing of the Internet. One response commended the originator for being so clear, as if to say, “Can’t imagine why others don’t understand, I did!” The mounting evidence of “significance” was overwhelming. But my comment couldn’t be removed. Besides, there was another response.
The second response explained. “Ray, when you scale up the coke can, you can pop the world’s largest offshore wind turbine on top (with a little bit more engineering).” This video illustrated at a larger scale the simple home illustration. Damian Carrington, head of offshore wind at the Carbon Trust, used a tin can and a large fish tank to illustrate a new technique for building offshore windfarms.
They called the technique “new” in 2013. Old stuff now. Except that some of us hadn’t heard about it. Carbon Trust, along with Danish company Universal Foundation are the originators of this technique. Predictably, some people feel that the many offshore wind turbines disturb the beauty of the seascape, citing money in the pockets of billionaire developers, rather than surplus electricity in consumer homes.
This video link – full sized suction buckets in play – helped me to see how wind turbines could take advantage of off-shore winds to generate electricity. Driving iron down into the sand to create a firm foundation for building a platform is expensive. Expense in terms of time, iron used and man-hour effort. There is also the consideration of extent, in terms of creating a platform strong enough to hold a wind turbine exposed to some powerful wind currents.
The size of the final “coke can” is huge. But the simple principle of the power of suction to pull the bucket down into the sea bed is riveting. Especially buckets of this size. Huge buckets with long necks to rise above the water level for the platform. Amazing engineering. Powering thousands of homes and saving billions of pounds.
Here’s the engineering.