Transformation of Coastal Concrete
Barrier Installations into Artificial Islands

2009年8月 インゴギュンター


By 1993 55% of the Japanese coastline was barricaded with artificial concrete boulders or encased in concrete in order to preserve the shape of Japan.

There is a discrepancy between the desire and intent of the Japanese to support a sustainable and ecologically responsible environment and their opportunities to do so. (this issue is not confined to Japanese. Generally people would rather do good things if they would know how and where and when). Japan used more than 80 million tons of cement in 1991. In 2000 Japan produced about twice as much cement as the global average, and between 1920 and 2000 Japan was the world's third-largest producer of cement per capita, surpassed only by Switzerland and Italy.


Japanese construction companies have unique experience with submarine and marine architecture and construction.  A similar if different capacity is found among Dutch and French companies.  There is also great expertise in Israel with saltwater irrigation and salt water plants as part of the greening of the Negev desert. 

The goal is to identifyanddevelop viable, community based strategies for the re-naturalization of Japanese coastal erosion barrier systems in order to integrate them both functionally, culturally and ecologically -- and to improve them.


Everybody agrees that the ubiquitous concrete pods that litter the Japanese coast, especially the beaches are an eyesore, that they not only protect beaches but also ruin the beaches and our communication with nature. They limit the vision of the ocean, one of the most fundamental and substantial sources and representation of life, beauty, eternity, serenity... nature itself. They cause an aesthetic problem with nature perception and they present ultimately a perceptual and psychological barrier between our deep-seated need to connect with nature. They are a constant reminder of man's interference with nature and man's inability to live in harmony and in tune with nature.
Most everybody agrees that they fulfill a vital purpose of protecting the scarce Japanese homeland from erosion and literally being washed into the sea one wave at a time. Some people argue that not only are they ugly, they ultimately may not help to prevent nature from taking its course and actually having a negative impact on the ecological balance of the maritime ecosystem.

“Whether in pursuit of a "Beautiful Country" policy, or for ecosystem sustainability, Japan is sorely in need of a comprehensive coastal preservation and conservation policy.”
(Japan Times July 2007)

What is an Island?
Islands are disconnected. The are separated from land and from each other. Floating in the infinity of the Ocean.

Every one is a small universe onto itself.  Like Japan, Hawaii, Galapagos. The varying degree of isolation has determined and shaped their uniqueness. Each one of them has a particular flavor.

Too a degree, the smaller the island the more delicate its ecosystem.

Under the United Nations Convention on the Law of the Sea, an island is "a naturally formed area of land, surrounded by water, which is above water at high tide. Rocks which cannot sustain human habitation or economic life of their own shall have no exclusive economic zone.


People have tried to build and shore up islands throughout history. It is nothing new. Except today we have the technology (and need) to build them faster and more durable than ever before.

To mention a few types and notable examples: Oil Platforms, Fixed ocean buoys, Airports (e.g. Kansai International), Qatar's Gulf archipelagos, Mitsubishi's mining island near Nagasaki.

Small volcanic islands rising from the continental shelf have been shored up and fortified in order to remain constantly above water - in order to lay claim to an extended exclusive economic zone around that island.

As much as a tangible result is intended, there should be an aesthetic result as well.
The aesthetics component is not only a goal in itself. The aesthetics are also needed to help convey the project to an audience, to engage their imagination and help guide their motivation. But whatever visuals will be produced, they will also be regarded as a stand-alone result of the project that should be regarded as initially sufficient.

My work always wants to have a strong link to reality and at best even a positive influence on and interaction with real world issues.  In this case my personal obsession and experience with water and the Ocean contributes.

Japan has long been enamored of fortifying and excluding. Just as Japanese rulers toiled for centuries to build impermeable castles and maintain uncrossable borders, so too in the modern age the nation has sought to harden its coasts against waves and currents, loath to give an inch to the sea. (S.Hesse)

Fudo Tetra Corporation, has a line of 18 different blocks that range in size from half a ton (90-cm high and 1 meter in width) to 80 tons (5 meters high and 6 meters wide). TETRAPOD is a registered trademark held by Fudo Tetra, but it is also a generic term used, written in lower-case letters, to refer to any of the concrete blocks that come in a variety of configurations, with three to eight legs.

"Today's earthworks use concrete in myriad inventive forms: slabs, steps, bars, bricks, tubes, spikes, blocks, square and cross-shaped buttresses, protruding nipples, lattices, hexagons, serpentine walls topped by iron fences, and wire nets. "These projects are mostly unnecessary or worse than unnecessary. It turns out that wave action on tetrapods wears the sand away faster and causes greater erosion than would be the case if the beaches had been left alone,"
(A Kerr)

Tetrapod may be an unfamiliar word to readers who have not visited Japan and seen them lined up by the hundreds along bays and beaches. They look like oversized jacks with four concrete legs, some weighing as much as 50 tons. Tetrapods, which are supposed to retard beach erosion, are big business. So profitable are they to bureaucrats that three different ministries — of Transport, of Agriculture, Forestry and Fisheries, and of Construction — annually spend 500 billion yen each, sprinkling tetrapods along the coast, like three giants throwing jacks, with the shore as their playing board.











(ジャパンタイムズ 2007年7月)島とは何か?島は他から離れている。島は本土からも他の島からも隔離されている。永遠に海に浮かび続けている。島はそれぞれが小宇宙を成す。日本、ハワイ、ガラパゴス。孤立の程度によりそれらの特異性が決定づけられ、形成される。それぞれの島は固有の風土をもつ。ある程度言えることとして、島は小さければ小さいほど、そのエコシステムが繊細なものになる。











日本は長い間、土壌の補強と他者の締め出しに夢中になってきた。歴代の支配者たちが何世紀にも渡って侵入不可能な城をつくり、侵入できない国境線を維持することに懸命だったのと同じように、近代においても、日本国家は波や潮に対抗して海岸線の強化に余念がなく、ほんの少しでも海にさらわれてたまるものか、と努めてきたのである。(S・ヘッセ/Japan Times)







(A・カー/Japan Times)

ドラフト0.6 2009年8月25日

©2009 インゴ・ギュンター





Tsukuba University, 2013