The 1,289-meter long, 7.3-meter wide breakwater protects Otaru Port from the rough waves of the Sea of Japan. At the time of construction, Dr. Isamu Hiroi made more than 60,000 concrete specimens to test. This test, which is still being conducted and is known as the “100-year test” is attracting attention of concrete engineers all over the world.

photo courtesy: Japan Society of Civil Engineers Hokkaido Branch