The Incredibly Unique Japanese Manhole Covers Scattered Throughout Japan

Manhole covers have never been seen as more than a lid or a cover to holes found on streets all over the world. It is even often overlooked by the people who walk over them every day. This notion can clearly be seen in movies with scenes where people fall into manholes because they never notice or always look past these things. In the country of Japan, they have made a new way to give these manhole covers more important and it is something that has been gaining popularity in the past decades. This is because these manhole covers in Japan have been turned into unique artworks and it has become something that is sought out by both locals and tourists.

The History of Japanese Manhole Covers and How It Developed Into the Art It Is Today

It is a known fact that some of the earlier human civilizations were able to engineer their versions of sewage and drainage systems using the technology they had back then. Japan is among the places where the remnants of the old sewage and drainage systems are found. These remnants can be dated back to a period in time that is as early as the Yayoi period. Despite this fact of advancement with regards to the systems they had been using, the first modern sewer system implemented in Japan came during the late 19th century already. These modern sewer systems were the type to make use of sub surface canals that had access points they called manhoru, which is the Japanese word for manhole. The manhole covers used for these particular pioneering systems simply used the geometric designs that foreign countries used for their own manholes.

The manhole covers aren’t there to just cover the manholes on the ground. It is part of the road because vehicles pass over it during travel and that is why it should also provide the vehicles the proper traction on the road, especially during the rainy weathers when these streets and roads are a lot more slippery. The manhole covers are given the ability to provide this traction through the designs that are placed on it. You should know that multi-directional lines must be used for these manhole cover designs to provide the best traction for the vehicles which also pass over these covers in multiple directions. With this being the criteria, by the late 1950’s, a couple of Japan’s bigger cities had already started making the unique design type of cover for their manholes but it still wasn’t as flashy as the ones you can see in Japan today. There was, however, two main categories for the manhole covers of this period and those categories were the Tokyo design and the Nagoya design.

The Tokyo and Nagoya designs came to be a thing because the engineers who built the sewer and drainage systems in the larger cities of Japan were eventually given the task to expand these systems into the different parts of the Japan that have yet been touched or installed with it. When these engineers moved from project to project, they brought with them the designs they used for the covers in the larger cities. This is the reason why you see the pre-war Tokyo and Nagoya designs in cities aside from Tokyo and Nagoya.

Nowadays, you can see unique manhole cover designs in almost everywhere in Japan. You can easily see great looking covers in parts of the Shimane Prefecture as well as Tenpaku, which is one of the 16 wards found in the Nagoya, and other cities like Kyoto but it wasn’t until the decade of the 80’s though that these manhole cover designs were elevated to the next level and it is all thanks to a man named Yasutake Kameda. He is responsible for these elevated level because he was the ranking bureaucrat in the construction ministry of Japan that suggested the idea of developing unique designs that showcased the different finds to be found in a certain area or city of Japan.

You see, during those times, the majority of Japanese households were connected to the municipal sewer systems but the people were not willing to pay for the public works that had to be done to expand it. What Kameda did to address this issue was to devise his plan to allow municipalities to make custom covers that would raise the awareness for these costly sewages works. This was obviously a success because, despite the fact that custom covers cost nearly 5% more than the standard covers, almost 95% of all municipalities in Japan now make use of these custom covers. Its use has even widened in recent years because these designed covers are now also being used as covers for storm drains, telephone lines, fiber-optic cables, fresh water and electric supply pipes, gas pipes, and other parts of a city’s infrastructure that are essential to it.

The Engineering Used On these Japanese Manhole Covers

It might not have been in the past but more and more people nowadays know about the different themes and designs that these Japanese manhole covers make use of. A large portion of their designs use trees, plants, and flowers that can be found in that respective prefecture. They also use landscapes, animals, trademark tourists spots, food, and many other local symbols that are truly able to give a glimpse of the culture to be found in that particular city. Some symbols used also signify what the covers cover. An example of such a thing is a cover designed with an anime fireman which signifies that a fire hydrant is what is inside the hole.

While the information about these Japanese manhole covers is spreading, there are details about it that remain unspoken of. These details that are adjustments made by the Japanese engineers to improve, not only the look of these manhole covers but also their functionality and safety. There are a couple but the first main adjustment they made these Japanese manhole covers is one that addressed noise problems.

A common complaint about manhole covers, in general, is that they make so much noise due to the vibrations brought about by numerous things on the road. Since Japan initially just adapted the geometric configurations of manholes from other countries, it was also a victim to this irritating noise that these covers created. The regular manhole cover fits like a child’s puzzle toy does. It is flat and the hole that it covers is just slightly bigger than the cover itself to make sure that the cover fits the hole. Because of this design, when the covers are subjected to strong vibrations, these covers start to act like coins dropped from a high place. When this happens, the covers, like the coins, tend to rotate on its edges and the continuous grinding and rattling of the metal cover against the concrete or metal encasement is what creates this noise.

It’s quite ingenious how the Japanese fixed this problem with their manholes in the 70’s because what they did was so simple, it could honestly be used anywhere else in the world but they don’t. All they changed in the design was to make the manhole covers tapered instead of straight edged. Having these manhole covers tapered meant that the radius of these covers would lessen as you move along the axis of its thickness. The holes that were to be covered with these covers were also adjusted to be tapered in a sense and this made the fit of the cover into the manhole more stable and locked in. It limited the movement of the cover despite the external forces that regularly act upon it hence eliminating the problem of the rattling noise.

The second main adjustment they made with their manhole covers was to install advanced safety features to it as early as the late 90’s. There are a lot of areas in Japan that are quite steep and if the road is steep, you can be sure that the sewer line under the street is parallel to the steepness of the road. This creates problems because when heavy rains come, the velocity of the water in these sewage systems is increased by the high slopes created by the steepness. With this being considered along with the water pressure these conditions can create, the manhole covers can easily be shot out of its place by the strong water forces and pressure that act upon it from inside.

To prevent any accidents from happening, the Japanese engineers developed a hinged safety system that locks down the covers on the manholes despite the extreme pressure and forces the covers undergo. This system allows the pressure to be released by letting the manhole cover rise just enough for some pressure to be released and once the excess pressure is gone, the cover would settle back down into place. The Japanese, being the way they are, took further measures to ensure safety and they did so by installing safety grills inside the opening of these manholes so that if ever the hinged system fails and manhole covers are blown off, citizens will still be safe because if they fall into the manhole, the grills will keep them safe from falling any further down the hole.

If you wish to learn more about the designs used for these manhole covers, you can get a comprehensive guide called the “Nihon no Manhoru” which was published in 1997. Unfortunately, this book is not available online but if you are in Japan, you can ask local booksellers to order it from the publisher known as Suido Sangyo Shinbun-sha found in Minato, Tokyo. It is sold at around 6300 Yen but since it has been nearly two decades since it has been published, you can probably get it for cheaper nowadays.

How Japanese Manhole Covers Contribute to Japan’s Growing Popularity

To begin with, Japan already has a lot of attractions to explain why its popularity is constantly growing. From the natural beauties this land possesses to the innovative technologies and fun-filled establishments that they continue to develop, it can easily be seen and explained why things are the way they are. With this being said, these customized Japanese manhole covers boosted Japan’s popularity further by giving both local and foreign travelers something to look forward to.

Having the unique covers has created the phenomenon called “Drainspotting” as described by the writer, Remo Camerota, in his book. If you are wondering how artistic manhole covers scattered all throughout Japan is something to get crazy about, just think of it as “Pokemon Go” but instead of walking around looking for Pokemon through your smartphones, you are walking around looking for cultural Japanese urban art that holds and signify different things about a particular city. It has become like a treasure hunt to some. Looking at it from this perspective makes it clear how such a thing became colossal in Japan. In April of 2016, the Japan Ground Manhole Association even started to release collectible picture cards that can be purchased in certain shops around Japan. These cards showcase the different manhole covers as it as well as interesting information about it on the back of the card.

If you are headed to Japan soon and you find yourself having extra time on your hands, you should consider going on a manhole cover treasure hunt as well because there isn’t anywhere else in the world that you can experience such a thing. It’s a great and interactive way to see the different parts of Japan and because of the efficient metro or train system in this country, you can easily move around from city to city in a matter of minutes. You not only learn about the culture of the different parts of Japan by partaking in this “drainspotting” because you will surely make new friends considering the amount of locals and foreigners that are also looking for these artistic covers as well. New covers are still being produced presently and if you’re lucky, you might even be one of the first people to find the new designs they recently released.