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New York Underground (nationalgeographic.com)
283 points by sehrope on Aug 10, 2012 | hide | past | web | favorite | 83 comments

So, there are two of those deep underground water tunnels, one which runs down from the Bronx through Manhattan and another that runs from the Bronx through Queens and Brooklyn. These tunnels were completed in 1917 and 1935 respectively. How they managed to do this then is beyond me.

Currently a third tunnel is being built and apparently it's "the largest construction project in New York history". The project was begun in 1970 and won't finish until 2020. It cost 6 billion. When the third tunnel comes online, it will allow for the other two tunnels to be shut down for repairs for the first time in their history. Scenes from Die Hard were filmed in Tunnel 3.

This is big, long-term stuff folks. Makes me feel kind of proud of civilization.

It is an amazing achievement.

3 men per mile died digging tunnel number 1 - 25% of the workers.


>Generations of sandhogs have accepted anonymity and danger as part of the job: 25 percent of those working on a tunnel in 1890 lost their lives; during a three-year stretch excavating Tunnel No. 2, 60 died. That’s three men for every mile of tunnel. Although the introduction in 1970 of a 13,200-volt pneumatic drill that sinks 10-foot holes into the rock has reduced the dangers facing the sandhogs, excavation of the first 25 miles of City Water Tunnel No. 3 cost the lives of 23 workers.

The way the work is done is mind blowing[0].

The divers have to go so deep they need to live in helium tanks for more than a month, to make sure that their blood is sufficiently saturated with the gas. The helium is the only way they can dive deep enough, and yes, it does make their voices high pitched the entire time they are in there.

[0] http://www.nytimes.com/2008/11/23/nyregion/23tunnel.html?pag...

That's amazing - I wonder how the work is progressing now? I didn't even know you could breathe any inert gas as long as it has enough oxygen in it until I read this article...

What are those tunnels and whats the purpose behind them? Also -- why so deep -- 800ft? I think (and may be wrong) digging them shallower would be cheaper. 6B vs f.e. 4B -- that's a lot of cheddar.

Also, someone mentioned "garbage" being underground citizen. I think that's wrong. While we have water, electricity and sewage running underground, the fact that garbage is not a part of this rail is really dissapointing. If you live upper west side, try to walk some broadway on a very hot day, before Thursday's garbage pickup. Your eyes will run wet from all the stink from garbage mountains packed everywhere. Literally there are streets where kids are forbidden to be outside because of all the smell and I assume airborne crap. Note, of course you won't see it downtown (the tourist area) where trash is picked up every day. Why there is no major garbage shute system across the city, no idea...

They're water tunnels. They deliver water from the Reservoir to the New York Metro Area. They're so deep underground for two reasons (1) imagine you have to build a tunnel that should last for the next 150 years – it needs to survive nuclear war, new technologies you've never heard of, meteor strikes – any risk of contamination is unacceptable and (2) more importantly, because the terminals of the tunnels are so low with respect to the reservoir, 95% of the pressure needed to deliver water from the reservoir to all of the buildings in New York is provided by gravity. Only 5% of the pressure comes from pumps. Which is pretty amazing.

> Also, someone mentioned "garbage" being underground citizen. I think that's wrong.

It's true. Roosevelt Island has an underground network of "trash-sucking tubes".


This is amazing! I had no idea that such a thing existed.

There are a few reasons -- upstate portions of the aqueducts are larger and built in trenches. As you approach the metropolitan area or mountainous area, the trench method becomes impractical, so the drill narrower tunnels with a steeper slope to force the water to flow more quickly.

To me, $6 billion seems really cheap for a project that seems pretty vital to the city's long term health, safety and security.

Compare this to the ~$10 billion for the California High Speed Rail project, which doesn't seem nearly as important as this NYC project.

Economically linking the SF Bay and LA metropolises could have tremendous importance over the next 100 years (which is the time scale a project like this should be evaluate on).

Having lived the last 2 years in NYC and the previous 7 in CA I can say that high speed rail is the more valuable project. The water here is fine, and no one is suffering because there isn't a 3rd tunnel. But the transportation situation in California is archaic and frustrating.

Have you ever been trapped in traffic on the grapevine for 4 hours trying to get to/from LA? Or shelled out $300 for an hour flight to SFO? Its maddening.

I drink water out of the tap here in NYC and it tastes great.

California rail is a crisis, the water supply to NYC is not.

Perhaps, but consider what happens if something does go wrong with the water supply--this is not something that can be patched overnight.

A rail system is well and good, but you can at least take a car or bus if you need to. If your water infrastructure stops working, there aren't many other games in town.

How much will train tickets cost? Taking the high speed rail from DC to NYC costs about the same as flying.

The importance of a project has little correlation with how expensive it is to execute.

This is not really true since cheap, highly important projects tend to get done pretty early on. That means the marginal project we are now embarking on does tend to have a relatively high cost-importance correlation.

> The importance of a project has little correlation with how expensive it is to execute.

Right, but it should be the primary factor on whether to undertake it or not.

I think you mean more like $100-150b for Cal-HSR.

A must-read on the water tunnel project underneath NY is David Grann's article for the New Yorker 'City of Water'[1]. Mind-blowing engineering project, especially the two old tunnels and their inability to repair them. It is one of the most read and most requested stories in the recent history of the New Yorker.

The article was syndicated in his book, The Devil and Sherlock Holmes, which is worth a read[2].

[1] http://www.newyorker.com/archive/2003/09/01/030901fa_fact_gr...

[2] http://www.amazon.com/The-Devil-Sherlock-Holmes-Obsession/dp...

The greatest depth shown in that graphic is 800 feet. At 10-12 feet per floor, that's equal to the height of a 67-80 story skyscraper. This means Manhattan has a 'mirror-image' city under the ground -- its 'citizens' are electric power, water, gas, and trash.

I can't help but be in awe.

What is even more amazing is that this mimics nature. Most trees have a root structure that is a rough mirror image of what's above ground!

The roots are generally much closer to the surface than the canopy is to the ground.

Like within a meter versus dozens of meters.

Having lived in a very hurricane-prone area of the southeastern US for most of my life, I can verify that tree roots are not a mirror of the above-ground portion.

Any pictures?

I grew up in south florida and have witnessed a bunch of root walls, but It really depends on the tree.

Palm trees for examples have deep root structures and small canopies which is how they survive the strong tropical winds.

Correct, there are certain exceptions.

I believe the point of this rabbit trail was to correct that notion that root formations are mirrors (or otherwise similar) of the tree trunks/canopies. At least, that's what I was hoping to show.

Yeah, absolutely. Just providing some additional info.

Pines too often have a big and strong main root. It's for collecting water from deep layers. It can be all-most as thick as the tree itself.

Link about architecture here: http://en.wikipedia.org/wiki/Root#Root_architecture

Most interesting thing in my opinion is how roots serve the part of the tree that they're on. If left roots die, left side of tree may die too.

That's true in grasses, but not in trees. In grasses, if the aboveground leaves get shortened/killed, from fire or mowing, the belowground roots die back, then both regrow in a similar manner.

If you like this, you'll love Kate Ascher's The Works: Anatomy of a City (http://www.amazon.com/The-Works-Anatomy-Kate-Ascher/dp/01431...). It's slightly out of date (but much more up to date than the OP!).

And if you like that, you'll REALLY love Brian Hayes' Infrastructure: A Field Guide to the Industrial Landscape (http://www.amazon.com/Infrastructure-Field-Guide-Industrial-...). It's porn for people who like to try to figure out what the random towers in a chemical plant do, or how the electrical station you just passed on the interstate works.

> try to figure out what the random towers in a chemical plant do

Tangential, but that phrasing reminds me of this article: http://news.ycombinator.com/item?id=3390719

Woah. The water mains are 800 feet down? How does that work? How did they even get there?

It's closer to an underground version of an aqueduct than to a normal water main, a long-distance tunnel being bored to bring water from upstate reservoirs: http://en.wikipedia.org/wiki/New_York_City_Water_Tunnel_No._...

I'm not 100% sure why it's that deep (and can't seem to find a solid explanation). What I can glean suggests that it's partly due to wanting it to be in more geologically stable bedrock that passes below any bodies of water and geological aberrations in the area. And partly so that it can be fed by gravity along a continual downwards slope, which causes it to be fairly deep by the end (then at the end the tunnel narrows, increasing pressure sufficiently to push water up a vertical shaft to the surface distribution network).

I'm guessing they probably got there before everything on top was built, but how do they get down there now for repairs and such?

From Wikipedia:

"[New York City Water Tunnel No. 3] was authorized in 1954. A third tunnel was needed so tunnel one and tunnel two could be closed for repairs. Stage One was begun in 1970 and completed in 1993 and put into service in 1998."[1]

This seems to imply that the later stages of the old two tunnels have never seen repairs.

[1] https://en.wikipedia.org/wiki/New_York_City_Water_Tunnel_No....

They don't. That's why they are building a third water tunnel. For backup, and so they can do repairs on the other two.

Very hard, apparently, as jontas pointed out: http://www.nytimes.com/2008/11/23/nyregion/23tunnel.html?pag...

No - they're still building out these tunnels.

My uncle worked briefly on the project in the 60's but its very much active


The water has to get in somewhere, and come out somewhere, so you go to those places and put a robot vehicle in.

Nice image, but if you want to really have fun with a kid dig up the book "Underground" by David Macaulay. It peels back the layers beneath our feet and was a real eye-opener for me when I was younger. Actually grab anything by the same author and have fun...

Tunnelling under cities has a number of odd problems.


I read an article, some years ago, about the problems of getting subterranean tunnels at a depth greater than 100 foot approved. As part of the process the plans get submitted to the security services, who then say "yes" or "no"; and you only get three attempts. I can't find the article (or anything similar) so maybe it's just myth.

The Moscow subways are beautiful, but when I went (April '86) you were not allowed to take any photographs.

I'm fascinated by the complex networks of public tunnels, secret tunnels, and abandoned tunnels.

Now taking photographs in Moscow subway ('metro') is allowed, and groups of tourists with cameras could be seen on most picturesque stations when I last visited it in 2011.

Next to all the granite and marble, large bulkhead doors can be seen in many passages there. Currently all are open and not very visible, but certainly intended to insulate stations in a case of emergency, such as a nuclear attack.

These fascinating Web 1.0 pages prove that content is king. I miss Geocities.

I'm no civil engineer, but why are the sewage tunnels above the clean water tunnels? If there were a leak, wouldn't the sewage seep into the clean water? Or is the clay thick enough to provide a good barrier?

I feel safer about it when looking at the scaled version: http://www.nationalgeographic.com/nyunderground/docs/scale.h...

The water tunnels operate at great pressure. Intrusion is extremely unlikely.

It doesn't matter much. Clean water tunnels have high pressure and good walls to keep anything out. Just plain soil getting into clean water tunnel can make loads of people really sick. If there is a clean water leak, they know it from pressure drop.

If there would be a leak in sewage, the biggest problem would be ground water getting into the sewage tunnel, and flooding the water treatment plant. There is probably larger pressure in ground water than in the sewage. Ground water pressure drop can also make foundations of buildings to get looser, so they try to monitor leaks to the sewage (little leaking is btw quite common in older ceramic/concrete pipes).

Sewage system works by gravity. That makes it sometimes really difficult for positioning the pipes. They must have either 2 - 7 % slope or they must be vertical. Uphill inside a sewage tube will gather all the shit and get stuck. With more than 7% slope the water runs too fast away from the pipe and leaves the shit behind, so again it will get stuck eventually.

PS. I used to study civil.

Like my mom always says, "Keep your poop close."

This is a very old article. One of the pages links to this page - http://www.nationalgeographic.com/nyunderground/docs/myth000... - which suggests using RealPlayer 3.0 and Shockwave 5.0.

The oldest version the Wayback Machine has of it is from 1999, and at that time it had a (c) 1997 in the header: http://web.archive.org/web/19990508090930/http://www.nationa...

Oddly they've taken out the (c) 1997 part, maybe to make it not seem as ancient? I suppose it's still reasonably relevant; not much of this basic information has changed. Heck, Water Tunnel #3 is still under construction.

There's still a copyright notice at the bottom left:

> © 1996- National Geographic Society. All rights reserved.

So is it safe to guess it's from 1996 or later?

I'm pretty sure the audio is RealAudio encoded though can't confirm as I don't have the codec installed (does anyone anymore?). This is just a guess based on the .ram file extension.

Still cool to see how engaging you can make a site using 10-15 year old technology. Content is king.

The .ram file points to a real media rtsp-precursor streaming server that no longer exists (pnm://real.nationalgeographic.com)

It's from 1997

Its a fascinating picture. I'd love to see one of the Bay Area, one of the cable technicians installing yet another fiber down the road outside our office joked that if you put big rockets at PAIX and MAE-WEST and launched, they would lift 'silicon valley' [1] into space on a net of fiber optic cables.

Of course no mention of "Beauty and the Beast" [2] which took place in a pretty fanciful world under New York city.

Given the expense these days of tunneling I wonder if we've reached a peak of complexity underground for now.

[1] Actually only the parts between San Jose and Palo Alto but it was the imagery not the accuracy they were going for.

[2] https://en.wikipedia.org/wiki/Beauty_and_the_Beast_%281987_T...

Naive question, but are things like power, gas, water, TV cables and steam always buried like this (requiring digging to make repairs or modifications), or are there cities/systems where they are laid in human-accessible tunnels? Seems like it would be more practical, albeit more expensive.

In Helsinki they have human accessible tunnels because the whole city is on bedrock and there is not much soil above it. It's just way too hard to make tunnels to rock so small that people can't go there, so they're forced to be more accessible.

Tv, gas and power can be digged relatively shallow and I have not hear of maintenance tunnels for them when there is no solid rock to deal with.

With sewers they usually put vertical wells to it in every corner. That makes the whole system more accessible.

Often they put empty plastic tubes to new buildings just in case. It's not very hard to get something crawling there when new Internet comes to house.

For those interested in this sort of stuff, there is a documentary called Dark Days that's all about the homeless people who live in the NYC subway system. It was available on iTunes the last time I checked.

The most interesting I found was the steam pipes.

Indeed. There's is such thing where I live and I find it quite interesting.


Steam pipes are pretty common and can be quite economical. Besides New York, you'll find them in Seattle, San Francisco, and a number of other large cities in the US, as well as all over Europe. On a small scale, a number of institutions run them as well - IIT in Chicago, for example, has a central steam plant.

Here is an interesting Subway chart from 1904 with a depth chart.


This was absolutely fascinating. It reminds me of Tokyo's underground sewage system--considered the largest in the world: http://surfwithberserk.com/the-largest-sewage-system

I love how this is both informative, very cool and a complete Internet relic. I can't remember the last time I saw a message where I had to choose whether I had Shockwave or not to continue. Nice find!

A friend of mine made a very cool documentary called Under City that you'd probably like if you're into this kind of stuff.


This isn't accurate for the entire city. At Astor Place, you can look through the sidewalk grates directly onto the tracks.

Well, of course. The subway system varies in depths from above-ground to hundreds of feet in the ground (I think Roosevelt Island, on the F line, is the deepest subway station).

Possibly the A train at 168th St. in Manhattan.

BLDGBLOG is a gold-mine for these kind of things.


For the record I first got a link to this page in 1997 or 1998.

Its a timeless page.

this is incredible!

This has already been posted several times.

First time I've seen it.

yeah, seems to be a lot of old links getting shared lately. please stop. Maybe start using http://isitold.com/ before posting.

Who cares if it's old? The information is still as relevant as it is interesting.


"On-Topic: Anything that good hackers would find interesting. That includes more than hacking and startups. If you had to reduce it to a sentence, the answer might be: anything that gratifies one's intellectual curiosity. "

You know, I'm glad I got rid of all my encyclopaedias, the information had been in there for ages!

Hmm, now see I find this interesting (at your company?)


(I just posted this.)

How old are you? If you are older than 1 year, please stop commenting!

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