Retractable tsunami wall being tested off coast of Wakayama


Late last year we reported on the development of a completely new kind of breakwater to prevent a tsunami from hitting the coast with its full might. Unlike other breakwaters that would otherwise hinder sea transportation and the aesthetics of the ocean, these remain at the ocean floor until called upon.

If a tsunami warning is in effect then they can rise up in a matter of minutes and disrupt the coming wave. Last week, the first nine-meter segment of this system was constructed and successfully tested. Below is a video of the test.

Looking at the video, you might suspect some complex machinery making the steel pillars rise up 13 meters from the bottom of the ocean to seven meters above it. However, all it takes is some air.

Air is pumped in from the shore when the alarm is sounded which creates and air pocket inside the pillar causing it to become buoyant and rise to the top. When the emergency has passed, the air is simply let out and the pillar sinks back to the bottom.

This eliminates a lot of the maintenance that mechanical pillar would require.

It’s a clever solution but this segment is only nine meters of a proposed 230-meter line around Wakayama Prefecture’s peninsula. The entire breakwater is expected to be completed in 2020 at a cost of around 730 million yen.

Source: Naver

Read more stories from RocketNews24. -- Tsunami Survivors Share Their Stories -- Outbreak of Rare Phantom Squid May Herald Imminent Earthquake -- New Rising Barrier System for Japan’s Stations

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"Unlike other breakwaters that would otherwise hinder sea transportation and the aesthetics of the ocean."

I never thought the aesthetics of anything was a consideration, especially round the coastline, when a public works project was implemented.

3 ( +5 / -2 )

Great if it works in a real tsunami situation (and maybe it will). But I have to say that you can never, ever underestimate the power of the ocean.

3 ( +3 / -0 )

However, all it takes is some air.

Yeah, and all it needed was some electricity at Dainichi. Hope they have some backup air supplies here.

2 ( +3 / -1 )

some details are missing, i hope that wall works good !

1 ( +1 / -0 )

It is a little late to start worrying about the aesthetics of the ocean. There is little coastline left that has not already had its aesthetic value destroyed by tetrapods.

1 ( +3 / -2 )

Very cool, though of course it won't stop the big ones. I hope they are taking various safety elements into affect -- power outages, earthquake damage, etc.

2 ( +2 / -0 )

Sounds great, as long as it works as cited!

1 ( +1 / -0 )

The start of the Japanese Delta works!

1 ( +1 / -0 )

I hope it works well. I also hope there are no serious tsunami in the next seven years while it's being built.

And I hope that it is built to withstand the earthquake that's likely to precede the tsunami.

Yes, even the "beyond imagination" type that TEPCO still seems to be maintaining didn't damage their NPP before the 3/11 tsunami hit.

Maybe, just maybe, they'll plan this project for what's possible rather than what they deem plausible.

And is it only me that finds the cost unusually low?

1 ( +1 / -0 )

One can only try these things to Protect from Nature. But beware , The First Usage Will be the Real test at What nature can throw at it. Id Rare it as Excellent .

0 ( +0 / -0 )

Why build it in the will take longer to build under water and second the ground under water is not a stable as dry land. They should build it along the shoreline instead of a break-wall...

0 ( +0 / -0 )

Cool in a Thunderbirds kinda way BUT that wall wont stop ANYTHING of size WTF!

Havent these people learned what a tsunami even is, all the water behind a tsunami will topple that thing or blow it out the bottom pronto, I for one would NOT count on that protecting much of anything more than a typhoon or a small tsunami.

Hasnt anyone learned by now that breakwaters were pretty much epic FAILS mother nature packs too much power, simple as that, DO NOT WASTE MORE $$$ ON THIS CRAP!

If you want to rack up more debt Japan invest in routes & methods that get people to higher gorund!!!! DOH!

2 ( +2 / -0 )

If this really works, well gosh golly I'll be happy for the good people of Wakayama! If this wall just stays under water?? Many people will simply die.

0 ( +0 / -0 )

Remember, its nature! You cant stop the wind with your hands.

0 ( +0 / -0 )

Unlike existing seawalls it is not trying to hold back the rising water level. It is only trying to stop the "wave" part. Is the idea then that it doesn't need to be as strong as a traditional sea wall? It certainly doesn't look as strong. It tend to agree with GW it doesn't seem like it would stand up to the task when REALLY needed. Perhaps by spending only $10 million they feel it won't be such a waste even if fails.

0 ( +0 / -0 )

I've been reading about this for a while. Great idea and if it can block a surge or two from a tsunami, great.

But what pumps the air? A bunch of tanks and gear, both underwater and on the surface, apparently. What if this connection and/or power goes out in a big one? A really expensive Lego project that does nothing.

0 ( +0 / -0 )

What happens when the water recedes? Will the wall lay down long enough to let the wave pass, then rise afterward? Or will the water rise back up prior to the wave in time for the wall to float and have some effect?

0 ( +0 / -0 )

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