BHC Pic of the Week Nr. 191

Source: civilengineering_photo via Instagram


This week’s Pic of the Week takes us to Japan and to a bridge which is a best kept secret in itself. This photo was taken at the Tsujun Bridge, a stone arch bridge located in the Kumamoto Perfecture in the village of Yamaoto. The bridge was designed and built in 1854 by  Yasunosuke Futa (1801–1873), who was the mayor of the village of Yabe. At 84.0 meters with the main span of 27.3 meters, this stone arch bridge is one of the oldest and longest of its kind in Japan. But when looking at the picture more closely, one wonders why water is being spat out at the keystone.

This question is easy to answer. The Tsujun Bridge may look like a typical stone arch bridge, and many people have crossed the bridge on foot, yet in all reality, it is an aqueduct- the longest in Japan as a matter of fact. As many as 41 stone masons and dozens of locals built the aqueduct using Futa’s model, which would later work with other aqueducts in the region with the purpose of providing water to areas needed for farming. In the case of the Tsujun Bridge, water was transported to the nearest Shiroito Plateau.

Nevertheless, the bridge is located in an unusual setting. Normally an aqueduct is built to provide water from a location on higher elevation to one that is lower than the bridge, just like a river or other stream flowing from its source in higher ground to its confluence downstream. What is unique about the Tsujun Bridge is that the aqueduct is located deep in the valley between two plateaus, which means sand, dirt and other debris can collect on the bridge. To relieve the pressure on the structure and free up the flow of water, the water is released through the keystone portion of the bridge, creating a spout that lands in the river below. This water release happens occasionally but mainly during the offseason for farmers, once the harvest is completed and during the time they plan for the next season.

This water release is a phenomenon that is seen by thousands of spectators and as you can see in the video below, it is one that a bridge lover must never miss when visiting Japan. Some have considered this bridge to be a wonder in the world as this originated from the Edo Dynasty (1603-1867) and the bridge was built 13 years before its fall and replacement with the Meiji Dynasty. That is true to a certain degree. Japan has a lot of fancy historic bridges, many can be seen in Instagram like the one mentioned here, yet the Tsujun Bridge represents a work of art that is considered Japan’s best kept secret and one that is worth a visit when experience Japan with its beautiful landscape, its delicious delicacies and meeting the Japenese and understanding their culture. If you are in Japan, pen in this bridge as one of your stops. Like Niagara Falls, you will not regret seeing this one, a once in a lifetime place.