Blast In Manhattan
 

Just heard it on the news, came up as breaking news, i couldnt find nothing on any news channels so i logged it on a blog:

http://manhattanbomb.blogspot.com/

Sad News :(

Umm, that says a steam pipe burst and caused a transformer to blow. This does not constitute a 'bomb blast' where I come from.

Yes, of course it certainly is sad news for the people who were injured. On the other hand, bloggers posting speculation posing as fact doesn't exactly help anybody out.

Just my opinion.

As Diggers would say: Probably Faux News.

I just reproduced what the BBC said, alot of people are also saying that a burst pipe cannot cause a building to be in danger of collapsing. I dunno, lets wait and see.

I worked for ConEd in NYC in the late 1980's when a steam line burst under the street at gramercy Park. The description sounds very similar. It makes a crater as it blows up thru the street. These are BIG pipes. It can take a long time to shut off, because they have to close multiple valves upstream of the leak to get good isolation.

In a day or two, we'll begin hearing about the asbestos. The Gramercy park cleanup took months.

Nevermind.

asbestos is lethal :o

Same thing happened to me when i herd it on the news.

The mechanical reality of steam pipes in a city. But boy oh boy did that look like a massive explosion.

They say the one in 89 killed three, I think we were lucky enough to avoid any fatalities this time through.

I'm still trying to figure out what a "water hammer" is though. Asked my geology buddy, he said that it's like air in an organ, it reaches some harmonic resonance, creating a small pocket where water can condense, then it releases, the water expands into steam and the pipe bursts under the high PSIs.

Yeah...it still looks like gibberish to me. But that's what he said.

PS- Just to save jj07 any more grief (and stave off any more panicking) could a moderator be so kind as to change the title to "Pipe Burst in New York" as opposed to the current "Bomb Blast in New York".

Two relatively good descriptions of steam/water hammer:
http://www.kirsner.org/pages/condInduceWatHamText.html
http://en.wikipedia.org/wiki/Water_hammer

You really need to drain and pre-heat the steam lines.

The 1989 burst happened when utility workers were re-opening a valve in a section of line they'd been doing maintenance on. What they are SUPPOSED to do is open a tiny bypass valve first, to pre-heat the downstream line. Instead, they just opened the main valve. The hot steam hit the cold piping and quickly condensed. More steam came along behind and flung the big slug of water around, causing it to "chug". The chugs tore the pipe open.

That one killed the utility workers that were in the tunnel (2-3), plus a small number of inhabitants that lived in the apartment building next to the street on the 2-5 floors. Fortunately it was during the day, when the apartment building wasn't very occupied. The steam jet did blow bricks off the front of the building, up to like the 5th floor.

Some other useful links about steam hammer...

http://www.kirsner.org/pages/articlesAlt.html
http://www.coned.com/steam/kc_ot.asp
http://www.bellgossett.com/Press/BG-good.asp

I removed the word 'bomb' from the title...

Thanks for helping to put a tragic accident into perspective!
It’s all to easy to conclude "bomb" when there is a huge explosion like this.

And thanks, Craig, for correcting the thread title.

If you've ever turned off a water tap and heard a thump in the walls, or listened to an old steam radiator banging, or heard all the pipes in a house rattle when a dishwasher or washing machine stopped filling, you've experienced water hammer in a 1/2" pipe.

Rushing water has a lot of momentum - think about the forces acting on you when you ford a swift brook, or the blast of a fire hose blowing in windows - and in those examples the water is not confined to a conduit.

A slug of water propelled by steam down a long run of straight pipe at high speed will hit a corner like a freight train - the elbow doesn't survive.

from the sketchy description on CNN, the pipes might have gotten wet (on the outside). Removing insulation or getting the outside wet will turn the whole pipe into a great condenser, condensing LOTS of the steam inside, and creating the slug of water for the steam to slam around.

Wow. The physics of this accident are fascinating. The news is sad, don't get me wrong. I live in SoCal, so there is no need for a steam heating system, so I was unfamiliar with its use in NY. Man, the power of steam!

I used to work for a water fittings company and saw many instances of water hammer demolishing water meters and other fittings at the receiving end.

Forgive my ignorance, but what are the steam pipes for? Where does the steam come from/go to?

Around the "turn of the century" (1900's), Manhattan had power plants on both the east and west sides, all up and down the river. Some are still there, some are gone. Because the island is small, and electricity back then was still kind of a new thing, many buildings were built to use "district steam". Some of the excess steam from the power plants (that would have just been condensed in the river anyway) is piped the 1-2 miles towards the center of the island, and used for heating (and cooling!) those big office buildings. Because the distances involved were relatively short, it was a pretty good way to do things.

Im just glad that the media didnt blame terrorism and alkeada straight away, with all the bomb scares in england, community relations with muslims are at a low :(

It’s praiseworthy responsible public relations that people in charge with insight debunked the idea of a terrorist cause, as soon as it became apparent that this was an accident. Same goes for other situations; there’s enough fear out there.

Don't know about NYC, but in Boston Trigen provides steam heat and power for more than 230 businesses. More that I don't know about steam: Trigen also provides cooling for business with that steam and also steam for food prep and sterilization.

Info on "New York Steam" (as ConEd used to call it)...

http://en.allexperts.com/q/New-York-...team-Pipes.htm
http://en.wikipedia.org/wiki/District_heating
http://en.wikipedia.org/wiki/Con_Edi...eam_Operations
http://www.coned.com/history/steam.asp

Wouldn't it be great to harness the steam to run steam engines that pull cables for street cars? Seems there some neat potential for all that power.

One of my favorite toys as a kid was a Wilesco steam engine.
http://www.yesteryeartoys.com/cgi-lo...cfm?view=SJE60