The Nihonbashi Bridge marks the symbolic centre point of Japan. On the left is a historic picture from the early 19th century when the bridge wasstill made of wood. In the middle: the bridge in the 1930s. The picture on the right shows the present bridge with an expressway running over it.

Centre point ofJapan

Kärcher cleans the historically significant Nihonbashi

Bridge in Tokyo – Nationwide reports

If credence is given to a well-known
saying, all roads lead to Rome. In Japan, however, since the early seventeenth century all roads have led tothe Nihonbashi Bridge. In the days ofthe Tokugawa shogunate, it was thestarting point of all major trading routes.
The majority of goods were transported along these routes, but they werealso used by a large number of travellers because ships as a mode oftransport were reserved exclusively
for the ruling class. The bridge, built in
1603, was therefore the symbolic centre point of the country. On the roadway in the middle of the bridge, abronze plaque still marks the pointzero. The distances from and toTokyo shown on Japanese highway
signs are measured from here.

In 1911 the bridge was rebuilt in
fireproof granite
The original wooden bridge burnt
down several times over the centuries, so when the bridge was lastrebuilt in 1911 the material of choice
was granite. However, it was not dirtproof. As time passed, dust, mosses
and algae deposits built up on the52-metre long and 30-metre widestructure, forming encrustations up to2 mm thick in parts. Traffic emissions
from the expressway that runs acrossthe bridge did further damage.
In order to spruce up the stony Nihonbashi Bridge appropriately in time
for its 100th anniversary, a GermanJapanese team from Kärcher took it inhand. Application technician Thorsten
Möwes and his Winnenden colleague
Jörg Wagner were there, while Kenro
Otsuka and Hiroki Muraoka travelledto Tokyo from Sendai, where our Japanese subsidiary is located.
Before they started work, a traditional Shinto ceremony was held, as isdone in Japan to solicit support andgoodwill from the gods. The auspices

A Shinto ceremony and a press conference with Kärcher Japan’s Managing Director Hachiro Sato marked the start of the Nihonbashi Bridgecleaning works. The bridge was given a preliminary clean with pressure washers.

for the project were evidently good,
judging by the great public interest
shown in the subsequent press conference. Over fifty media representatives
came to hear about the cleaning operation and reported the project launchnationwide in print media and on TV.

Combined cleaning methods formost efficient gentle treatment
A combination of pressure washingand low-pressure particle blasting
had proven to be the most efficientand gentle beauty treatment for thegranite, which was already cracked
and flaking in places.
Our team started by giving thebridge a preliminary clean with pressure washers and water at around
100 °C. They then used GS blastingguns to carefully remove the remai-ning dirt and discolouration, using calcium carbonate and aluminium silicate as a blasting medium. “To subject
the environment to as little strain as
possible we used wet and dry vacuums to vacuum up the blasting medium again immediately,” said Thorsten Möwes. “Then we rinsed off any
residue on the surface with HDS
13/15 hot-water pressure washers.”

Sato: “Emblem of our country
for centuries”
After a six week work the cleaning ofthe bridge was finished. „As a symbolic centre, this structure has been anemblem of our country for centuries,“said Hachiro Sato, Managing Directorof Kärcher Japan. „So we are very
proud to have been involved with thehistory of the Nihonbashi Bridge.“The Tokugawa shogunate“Shogun” was a Japanese military title for leadersof the military aristocracy, the samurai. Originally, a shogun wasroughly equivalent to aEuropean duke. In theearly seventeenth century, the shogun Tokugawa Ieyasu rose to become the de facto rulerof Japan, holding power in place of the Emperor andsecuring it by military means. He set about uniting
Japan and established the Tokugawa shogunate,
which lasted nearly 270 years from 1603 until 1867.
During that era the country experienced the longest
period of peace in its history. Tokugawa Ieyasu moved
the capital from the old imperial city of Kyoto to Edo,
now Tokyo, where the Nihonbashi Bridge was built at
the beginning of his reign.

The Nihonbashi Bridge• The bridge survived US air raids inWorld War II unscathed and is now oneof just two remaining bridges built during
the reign of the Meiji Emperor Mutsuhito,1867–1912.
• The canal it crosses was once a castle
moat connecting the Shogun’s seat ofgovernment directly with the sea.
• Since Japan’s trading routes intersected at the Nihonbashi Bridge, a majorurban mercantile centre grew up aroundit. Many shermen, craftsmen and traders
worked there. Now, this area is one ofTokyo’s nancial and business centres.

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