Seiji learns about the importance of “positive pressure.”
On his recent trip to Hokkaido, our Japanese-language reporter Seiji Nakazawa experienced some of the most wide-open scenery the prefecture has to offer. Today, though, he’s going the opposite route, with a visit to Japan’s number-one maker of disaster and emergency shelters.
World Net’s headquarters is in Tokyo, but Seiji paid a visit to the company’s showroom in Yaizu, Shizuoka Prefecture.
His guide for the day was none other than the company’s president, Hiroki Nakajima. World Net is the only company in Japan that handles both emergency shelter design and assembly, and the impetus for their shelters came when Nakajima visited Ishinomaki, one of the worst-hit towns in the 2011 Tohoku tsunami. “After that, I wanted to make something that could protect people” Nakajima says, and the first shelters World Net built were tsunami shelters.
▼ Hiroki Nakajima
World Net has since expanded its line to include earthquake shelters, flood shelters, and nuclear shelters, and it’s an example of that last category that Nakajima would be showing Seiji on this day.
“For a nuclear shelter, it’s critical that it be able to achieve positive pressure quickly,” Nakajima explained, referring to a condition in which the air pressure inside the shelter is higher than the environmental air pressure outside it. “You can’t achieve positive pressure unless the shelter is completely sealed, so when you do have positive pressure, the interior is protected against radioactive material outside.”
“From the time between when a missile is launched somewhere and the Japanese government can sound an alarm for the civilian population, it takes about five minutes, and then there’d be about another five minutes before the missile hits Japan. So unless you can achieve positive pressure in that amount of time, allowing for the time it takes to get into the shelter too, there’s no point, so that’s why the speed of creating positive pressure is so important.”
It all made sense to Seiji’s layman ears, but he also couldn’t help wondering what being in a space with positive pressure does to your body. Would it put your lungs in a vice grip, rendering you incapable of drawing breath? Would it make your eyes explode?
Both curious and terrified, he decided to find out.
Stepping into the shelter, there was about as much floor space as a king-sized mattress would take up. At 165 centimeters (65 inches) tall, Seiji had enough room to stand up straight, and Nakajima informed him that World Net can make shelters of different dimensions by customer request.
Looking to his left, Seiji saw an air conditioning unit and a TV. The TV is probably so that you can watch news reports and government announcements, but it’d also probably come in handy if Seiji wanted to pass the time while watching some anime until it was safe to come back out of the shelter. The shelter has its own power supply, but you can also hook it up to the electrical grid and even attach a Lan cable for Internet access.
On the opposite wall was some sort of machinery with a serious cyberpunk aesthetic to it. This, Nakajima explained, is the positive pressure-producing apparatus.
“Let’s turn it on,” Nakajima said, closing the door and activating the device. Seiji, still anxious about what sort of effects the extra air pressure would have on his body, began thinking of all the things he still wanted to do in life, as long as he survi-
Without warning, a fan mounted in the ceiling began to spin.
“OK, that’s it, we’ve got positive pressure,” Nakajima nonchalantly explained.
Wait, what? Seiji didn’t feel any different. He could still breathe, and neither one of his eyelids had ruptured.
“Feels pretty normal, doesn’t it?” Nakajima said, apparently knowing what Seiji was thinking. “It’s just three percent higher than the outside air pressure, so the most you might feel is a little bit of extra pressure in your ears, but even then it’s less noticeable than driving into a highway tunnel.”
▼ It was comfortable enough that if he’d had his laptop with him, Seiji could have typed up his report right there inside the shelter.
So how much does a shelter like this cost? The one Seiji tried out, which is listed as a two-person shelter, is 8.8 million yen (US$63,300), but a one-person shelter of the same type would be 6.8 million yen. Another factor is the thickness of the walls. The shelter Nakajima had shown him has 3.2-milimeter (0.13-inch) thick walls, the thinnest World Net offers but still strong enough to withstand the air pressure impact of a missile hitting 10 kilometers (6.2 miles) away. On the other end of the spectrum, the maximum-thickness 36-millimeter walls are calculated to be effective against an impact five kilometers away, and Nakajima is confident that even a tank smashing into the walls won’t break them.
A 36-millimeter-wall two-person shelter will run you about 12.8 million yen. Seiji couldn’t help thinking that with that much money, he could buy a Porsche, but if a missile is ever headed his way, he figures he’ll probably want to be inside something sturdier than a sports car at the time.
Related: World Net
● Want to hear about SoraNews24’s latest articles as soon as they’re published? Follow us on Facebook and Twitter!