OK, so why are there giant steam pipes under New York City?

[friedo]

@OtakuLoki

Using it to heat steam kettles, sometimes even direct heat via pressure cookers - of course that requires that the steam meet cleanliness standards.

ConEd says their steam meets all FDA standards for cooking and sterilization.

[Bosda_Di_Chi_of_Tricor]

OK, so why are there giant steam pipes under New York City?

That’s how the Mole Men get their Pepsi.
What?

Nobody delivers down there!

Except for Pizza…

[MrFloppy]

Baltimore still has a steam system run by Trigen Energy which I’m sure is an offshoot of BGE/Constellation. The grates keep the bums warm in winter.

Almost every US college campus I have been to in the past 20 years (as an engineer, not a student) has a steam system.

[Washoe]

An entire page devoted to college tunnel systems.

[NinetyWt]

Mississippi State University has an old steam system - parts of which are no longer in use. It is making the ongoing storm system rehab very interesting.

When I visited Parris Island for Marine Graduation it was most interesting to see that their steam system is apparently above ground. In this photo you can see them criss-crossing the grounds.

Disclaimer: that is not my photo album.

[Washoe]

From here.

From MIT (which some believe has the second-largest tunnel system in the world) to UCLA (reportedly the tidiest) nearly all U.S. universities–along with hospitals, hotels and other complexes with multiple buildings–employ a system of utility or steam tunnels. Colleges found that using tunnels to pump heat to all the buildings on campus from one central underground boiler was a much cheaper option than putting separate boilers in each building. Later, with the tunnel system already in place, schools began using them for electrical wiring, phone lines and fiber optic cables.

[DesertDog]

For Phoenix, it’s the other way – not steam but chilled water being delivered in tunnels (Read the Infrastructure paragraph on page 2). They got all the heat they can use.

[Princhester]

@friedo

Cecil also wrote a bit about the steam system

This column really doesn’t answer the question that the mailbag asked. The question was why do you often see steam rising from manholes in US cities? The answer given only really goes partway towards answering, if you ask me.

I suppose the answer to the unanswered part of the question is “… and the pipes leak” or something.

[asterion]

@Washoe

An entire page devoted to college tunnel systems.

I don’t know how much of a steam system NMSU has (it does get cold enough here in the winter for heating to be needed and the university is old enough) but I know that at least some of the chemistry labs have steam available for steam baths. I don’t know anybody that uses steam baths and the things leak and whenever you open a valve for the steam it smells like something (kinda like fish to me) died.

[El_Kabong]

@Princhester

This column really doesn’t answer the question that the mailbag asked. The question was why do you often see steam rising from manholes in US cities? The answer given only really goes partway towards answering, if you ask me.

That ‘steam’ is actually condensed water vapor. The answer is in one of the links in this thread. From the article linked by robardin:

@Gotham Gazette

The steam coursing under Manhattan is not to be confused with what is popularly called steam rising from many city manholes. The steam in the pipes is invisible, while the so-called steam wafting up from the streets is often vapor produced when underground water hits hot equipment and escapes from beneath the streets. It can also be condensed steam leaking from the Con Ed system.

Great responses from everyone. Thanks again.