Hacker News Board Hacker News, browsed like a classic message board
Live data from Hacker News

The underground cathedral protecting Tokyo from floods (2018)

bbc.com

Post reply on HN
Print view View original

21–30 of 67 posts

Re: The underground cathedral protecting Tokyo from floods (2018)

#21

Post by NaOH »

gnabgib wrote: post #2

(2018) Discussion at the time (127 points, 30 comments) https://news.ycombinator.com/item?id=18570076 There was also a good NYT article in 2017 (293 points, 210 comments) https://news.ycombinator.com/item?id=15436943

More:

Tokyo Metropolitan Area Outer Underground Discharge Channel - https://news.ycombinator.com/item?id=43816183 - April 2025 (6 comments)

Tokyo expands underground 'temple' complex to counter climate change rains - https://news.ycombinator.com/item?id=41727317 - Oct 2024 (2 comments)

Tokyo's Underground Discharge Channel - https://news.ycombinator.com/item?id=19785044 - May 2019 (42 comments)

That second listing links to a piece with lots of good photographs.

Re: The underground cathedral protecting Tokyo from floods (2018)

#22

Post by hollerith »

acyou wrote: post #20

22 meters underground, built in 1950s, Tokyo, 5-7% of GDP - yeah the gigantic underground vaults serve as flood protection, to those who have a good understanding of Japanese history, it's understandable to believe these were rather primarily built as bomb and nuclear shelters.

It would easy to tell: (unless they were occupied by only a handful of people) they would be useless as fallout shelters without a lot of ventilation, and you can't rely on the wind: you'd need big fans and ducts, and the fans would need to keep running after most of the electricity-generating capacity available in Tokyo is destroyed, i.e., this ventilation system would need its own hardened electricity supply.

Re: The underground cathedral protecting Tokyo from floods (2018)

#24

Post by bobthepanda »

hollerith wrote: post #22
acyou wrote: post #20

22 meters underground, built in 1950s, Tokyo, 5-7% of GDP - yeah the gigantic underground vaults serve as flood protection, to those who have a good understanding of Japanese history, it's understandable to believe these were rather primarily built as bomb and nuclear shelters.

It would easy to tell: (unless they were occupied by only a handful of people) they would be useless as fallout shelters without a lot of ventilation, and you can't rely on the wind: you'd need big fans and ducts, and the fans would need to keep running after most of the electricity-generating capacity available in Tokyo is destroyed, i.e., this ventilation system would need its own hardened electricity supply.

Also, using this as a shelter would have a pretty obvious downside if torrential rainstorms happened.

Re: The underground cathedral protecting Tokyo from floods (2018)

#25

Post by bobthepanda »

realo wrote: post #8

I have to mention here that 1,500 years ago the same was done in Istanbul: https://en.m.wikipedia.org/wiki/Basilica_Cistern

Cisterns aren’t really the same thing; cisterns store drinking water for long term whereas these caverns are only supposed to hold water until the treatment plant can handle it.

Re: The underground cathedral protecting Tokyo from floods (2018)

#28

Post by tharkun__ »

bobthepanda wrote: post #24
hollerith wrote: post #22

Earlier quoted context omitted.

It would easy to tell: (unless they were occupied by only a handful of people) they would be useless as fallout shelters without a lot of ventilation, and you can't rely on the wind: you'd need big fans and ducts, and the fans would need to keep running after most of the electricity-generating capacity available in Tokyo is destroyed, i.e., this ventilation system would need its own hardened electricity supply.

Also, using this as a shelter would have a pretty obvious downside if torrential rainstorms happened.

Never mind all the wasted space above peoples' heads. The picture further down has people walking. They're tiny.

Re: The underground cathedral protecting Tokyo from floods (2018)

#30

Post by bschwindHN »

srvmshr wrote: post #3

I have been to this place. It is limited viewing, requires a reservation & the slots run out practically in seconds. Tough for us residents to get it as well. My wife could snag it in her third try, as a late birthday trip last year. It is gargantuan & having massive holding capacity. To give semblance with something familiar, it was like standing in NY Grand Central station, except it was felt bigger, empty, damp &…

Weird, I visited last year and don't remember having a hard time getting tickets. Maybe I got lucky.

Here are a couple photos I took with people for scale:

https://imgur.com/a/DPYYou4

Post reply on HN