Snow is one of the few things that can delay the Shinkansen in Japan. To combat it there is a solution as simple as it is effective.

Japanese bullet trains are known for their extreme punctuality. However, when the snow appears, neither the most cutting-edge railway system of the world is saved. And to combat it, the country’s railway institutions developed a solution as simple as it was ingenious: sprinklers installed along the tracks that spray water during snowfall. This is done to prevent snow from accumulating and wreaking havoc on the trains. We explain in detail how these systems work. Why is it important. Snow not only causes the system to stop being as punctual as usual, but it can also cause serious damage to high-speed trains. And at speeds above 200 km/h, the snow on the ground rises due to the air current generated by the train, which can cause it to compact under the cars forming ice balls that, upon impact with the ground, throw gravel into the air. This can end up breaking windows and damaging train components if left untreated. Japan has spent decades perfecting systems to eliminate this problem without sacrificing speed or punctuality. The origin of the problem. When the Shinkansen began regular operations in 1964, according to explains JR Tokai (the operating company of the Tokaido Shinkansen), construction was carried out in a hurry and “there was not enough time to consider” alternative routes that would avoid areas of heavy snowfall. In January 1965, just three months after launch, snowfall in the Sekigahara region caused serious incidentsincluding broken windows and shattered water tanks. The investigation revealed that the real culprit was speed, since the wind generated raised the snow, which ended up turning into ice projectiles under the carriages. The solution: sprinklers. To prevent the snow from rising and forming those dangerous ice balls, it was installed a sprinkler system along the tracks that sprays water during snowfall. There are currently sprinklers deployed in a stretch of more than 70 kilometers, covering the lines most affected by the snow. In 2009, the nozzles were improved so that the water reached areas that were not reached before, melting the snow more effectively. The system does not completely remove snow, but changes its consistency to prevent it from compacting and flying, thus reducing the risk of damage. It is not the only solution. The water system is complemented by other resources. During non-service hours, snow plows work at dawn to remove accumulated snow. Since 2003, rotary snow plows have been used that use rotating brushes capable of cleaning up to five centimeters below the surface of the rails. In addition, since 2013, devices with optical sensors have been used to monitor weather conditions, and there are cameras installed under the carriages to detect snow accumulations. When a snow-covered train arrives at stations like Nagoya or Osaka, there are also specialized teams waiting under the platforms with high-pressure washers to quickly remove stuck-on snow. The results speak. All of this operation has radically transformed the Shinkansen’s defenses when the snow arrives. According to JR Tokaiin 1976 there were 635 train cancellations due to snow, a figure that has been reduced to zero since 1994. The average delay due to snowfall has also improved dramatically, dropping to just a few minutes. Beyond the trains. In the northern regions of Japan, where snowfall can exceed three meters, many roads have sprinklers integrated into the asphalt. The system, known as ‘shosetsu’ (disappearing snow) or ‘yuusetsu’ (melting snow), was developed in 1961 in the city of Nagaoka by Yosaburo Imai, founder of a century-old confectionery. Imai was inspired by observing that snow did not accumulate where thermal water gushed from underground. Since then, underground pipes transport geothermal water (at about 13-14°C) to pavement sprinklers that melt snow during winter storms, avoiding the use of salt or snow blowers. Cover image | KUA YUE In Xataka | The straightest road in Spain is located in a place whose name I don’t want to remember: between El Provencio and La Roda

The Japanese Shinkansen was the fastest train in the world until China defeated it. The reason: the “piston effect”

In a very summary way, the piston in a four stroke engine It is responsible for moving the air inside to compress it and facilitate the burning or explosion of the fuel or to push it out of the combustion chamber. That is, it is dedicated to pushing the air up or down. Now imagine a train arriving in a tunnel at more than 300 km/h. Suddenly, the train goes from being outside to moving the air inside the tunnel. To push it to the bottom. Your movement It would be very similar to that of a piston. The train moves in a straight line and around it the tunnel would behave like a combustion chamber. That doesn’t seem like a problem. It doesn’t seem like it if we think that the air is simply pushed to the outlet where it is released without further problem. It’s also not a problem if your high-speed lines run over a bridge more than 100 kilometers long. But if you are a mountainous country and you have made the railway your star medium to move millions of people hundreds of kilometers an hour. Yes, you have a problem. Because the piston effect is pure physics and solving it to gain speed is not being easy. When they were the best In 1964, while Spain began to open up to the world, Abebe Bikila won his second Olympic Marathon in the streets of Tokyo. He did it wearing Puma Osaka shoes.nothing to do with the famous 42,195 meters that he covered barefoot in Rome to win four years before. We do not know if Bikila took that first Shinkansen that linked the cities Tokyo and, precisely, Osaka. The bullet train had begun to operate in Japan that same year, promoted by the Olympic Games in the Japanese capital. Then, the two cities were linked by a train that reached peaks of 210km/hbecoming the first high-speed line in the world. More than 60 years later, Japan is no longer the country with the highest number of high-speed kilometers of the world. Today it is China. It makes sense, taking into account that the country is huge, so if this means of transportation were promoted, sooner or later they would surpass their neighbors. Spain, by the way, also surpassed Japan in this area years ago. But it is very likely that something else has hurt Japan more. China is making the bullet train its flag. Its latest advances with the maglev, which levitates thanks to very powerful magnets to avoid friction with the track, has reached a combined speed of 896 km/h at the intersection of two CR450 trains. The problem for Japan is that China has a lot of money. And if it is necessary to build eight of the 10 longest bridges in the world to solve geographical accidents, they get to work. Japan has to deal with a lot of mountains and a more traditional system: tunnels. And that when you want to make a train pass at very high speed is quite a problem. When a train fully crosses the threshold of a tunnel, what is known as piston effecta problem that prevents increasing the walking speed further. The consequences are as simple as they are serious: loud explosions, breakage of equipment… and the eardrums of passengers. Upon entering the tunnel, the air is compressed and the movement of the train moves it towards the exit. However, some of that air rebounds and generates pressure changes that can be especially painful for passengers, even affecting their middle ear. When moving outside, a pressure wave is created that moves at the speed of sound and when the train leaves the tunnel, a shock wave and a sound explosion are created that, it is calculated, can be heard 400 meters away. It is known as tunnel boom. Japan is now experiencing a problem carried over from the past. Their trains are wider than the European ones but their tunnels are narrower. This was to reduce infrastructure costs but also to run less risk of landslides in the event of an earthquake. At first this was not a problem but when the speed of the trains increased they realized that they could not continue moving. In China, trains also use wide tracks like their neighbors but since they do not preserve inherited structuresthe new tunnels built are wider. This reduces the void effect produced with the entry of the train into the tunnel and, therefore, mitigates the problems for passengers. Furthermore, as less resistance is generated when the train passes, energy expenditure is also reduced. The solution for the Japanese is not simple. On the Tokaido Shinkansen, the first high-speed line (the one that connects Tokyo with Osaka), 13% of total kilometers They run inside tunnels. But the Sanyo Shinkansen line runs through tunnels half of the time. and he Hokkaido Shinkansen which is under construction (this line is only partially open) contemplates the roofing of 80% of the layout. The most effective solution that has been found to the problem is to produce trains with a very long and sharp nose. The aerodynamics tries to imitate the beak of the Kingfisher that can dive into the water generating minimal splashes. Following the same concept, the longer and sharper the nose of the train, the less resistance the train encounters at the entrance and the more gradually the pressure wave is generated. The other solution has been expand the section of the tunnel at its entrance. The “door” is wider and also has side openings that allow part of the air to escape. air moved by the train. This escape route generates a lower pressure wave, allowing the train not to cause unwanted discomfort to passengers and to travel faster. It has even been thought of hermetic trains with controlled pressure. During its tests, Japan continues to search for trains that can reach a top speed of 400 km/h. However, the structures inherited from … Read more

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