What's with this pipe?

[sylvar]

What's with this pipe?

Does anyone know why this pipe has its own bridge? What does it probably carry?

Comments

[cbustapeck.livejournal.com]

There were some pictures of CNG pipelines going into and out of Manhattan posted a while ago on cryptome.org. These appeared to be then same. Then I tried to find the photographs, and have not been able to, which is why I deleted my comment, because I'm not feeling so sure.