Kintaikyo

Iwakuni's treasure - the Kintai bridge!

Iwakuni’s symbol and one of the most famous bridges in Japan.

 In 1601 Iwakuni was assigned to feudal lord Kikkawa Hiroie. Since it was only a year after the battle of Sekigahara, Japan was going through an unstable time. Due to that, Hiroie decided to build a castle on top of the mountain and had his senior samurai live in the Yokoyama area to utilize the Nishiki river as a natural moat. Lower class samurai and others had to cross the river to get to the Yokoyama area where everything was held back then. While there is no evidence, it is said that there was a bridge that was built concurrently with the city. The architects and the technicians were not very experienced back then and many times the first bridges were washed away. The only stable commute to cross the river was a ferryboat, which could not get people across the river when there were storms or floods. The city was divided in two and in need of a stable bridge.

 

After several years of researching bridges outside the feudal domain, they came to a conclusion that an arched bridge would not need a pier that typically caused the prior bridges to wash away.  The Kodama brothers that were well-known technicians in Iwakuni were deployed to Nagasaki to do some research on Meganebashi (another famous arched bridge made of stones). The research went well, though the width of the river was too wide to build an arched bridge at that time. A Dokuryu Chinese (naturalized as Japanese later) doctor who was treating Hiroyoshi Kikkawa (3rd Feudal Lord) told him about his hometown in Hangzhou, China and also mentioned that he had a book about it. Hiroyoshi was interested in a lake mentioned in Hangzhou, and he sent one of his vassals to bring the book. The book contained a drawing of the lake that had 5 small islands and each island was connected with arched bridges. Hiroyoshi then had an epiphany of building islands on the river so that he could connect the arched bridge.

 

On October 1st 1673, the first Kintaikyo was built, however it got washed away only 7 months later. The second Kintaikyo was built immediately after doing some few modifications such as putting rocks on the river bed to slow the current. The 2nd Kintaikyo lasted for 276 years until a flood caused by Typhoon Kizea washed it away again. After the typhoon the City decided to renovate and rebuild the bridge and the third bridge was retired after 50 years. The current one that we see today was finished in 2004.

 

The fees that are collected for the bridge are used to preserve and maintain the bridge. The current Kintaikyo cost ¥2.5 billion to build, and over 25% came from the fees that were pooled in the previous 5 years. The trees that are used are Japanese Red Pine, Japanese Cypress, Japanese Elm, Hiba Arborvitae, Japanese Chestnut and Oak. You might have heard that the Kintaikyo was built without using a nail. But if you ever walked on the bridge you will notice, that is a false statement. In fact 20,000 nails are used and you can see lines of Japanese nails on the surface of the bridge. However, unlike western wooden structure that utilize nails to connect wood, the main framework of Kintaikyo is built with a traditional wood jointing technique. Nails are only used to stick the surface (where we step) on to the frame.