On January 17, 1995, an unprecedented magnitude 7.3 earthquake struck the Hanshin area (between Osaka and Kobe) and Awaji Island in Japan. This disaster, known as the Great Hanshin-Awaji Earthquake, caused tremendous damage to infrastructure facilities such as transportation networks and port facilities, as well as lifelines including water, gas, electricity, and telecommunications. Approximately 1.3 million households in the affected areas had their water supply cut off,^*3 and in particular, many aging iron water pipes were damaged, including over 3,600 water distribution pipes laid under public roads and over 200,000 water supply pipes leading to households. This disaster brought into sharp relief the urgent need for Japan as a whole to develop an earthquake-resistant water infrastructure that can ensure safe water supply, even in times of emergency. But it also served to prove the effectiveness of Kubota’s earthquake-resistant pipes.

Ductile iron pipes, which boast high strength, durability, and corrosion resistance, are now the main pipe material used in Japan’s waterworks. Kubota began mass-producing these pipes in 1957. In 1964, when a magnitude 7.5 earthquake struck Niigata Prefecture, leaks were observed at several joints of iron pipes. Kubota turned its attention to these leaks. Through repeated interviews with experts and extensive research, Kubota worked to improve the earthquake resistance of ductile iron pipes.

In 1974, Kubota developed the S-type, an earthquake-resistant pipe with the joints capable of flexibly following the movement of the ground to withstand an earthquake. This was followed by the SII-type in 1977, and the NS-type with improved workability in 1993. In the Great Hanshin-Awaji Earthquake of 1995, there was no water leakage or damage to the approximately 270 km of ductile iron pipes with earthquake-resistant joints that were buried in Kobe City. Today, even after the Great East Japan Earthquake, the Kumamoto Earthquake, and numerous other earthquakes, Kubota’s ductile iron pipes continue to demonstrate their high performance with zero damage to the 3,650 km of water pipelines laid.

In 2010, Kubota’s earthquake-resistant ductile iron pipes evolved into GENEX. In addition to improved earthquake resistance, GENEX achieves reduced product and pipe installation costs, greatly improved workability with a view to saving labor and manpower, and extended service life through enhanced corrosion resistance. The quality of this product has been recognized overseas as well, such as on the West Coast of the United States. An earthquake-prone region like Japan, GENEX has been adopted there for use as water pipes. In addition to ductile iron pipes, polyethylene pipes, which are already widely used for water distribution in Japan, have also been certified as earthquake-resistant pipes under the Waterworks Business Guidelines. In order to meet diverse needs, Kubota will continue to protect the water infrastructure of Japan and the world from earthquakes with its earthquake-resistant pipes, which have evolved not only in terms of earthquake resistance and corrosion resistance, but also in terms of workability and durability.