More than 1.7 billion people ride the New York City Subway every year. In the dead of winter you will overhear people complaining about how frigid stations are. Even more people dread riding the trains at the height of heatwaves in the summer time. Nevertheless, New Yorkers would have a much harder time navigating the greatest city in the world without the subway, which is the most affordable and (most of the time) safest way around.

What's almost more fascinating about the machines, and how New Yorkers depend on them, is how they are disposed of.

As photographer Stephen Mallon found out and documents in his project "Next Stop Atlantic,"
retired subway cars are dumped into the ocean.

"I had read in the NY times about the Artificial reef project with the red birds but thought it had stopped with those trains," Mallon told HNGN.

Knowning of that story, Mallon was intrigued when he stumbled upon a barge of old subway cars.

"I found the barge in 2007 in Bayonne, N.J.," he said. "I had just started working on a long-term project titled 'American Reclamation' which focused on space and material re-use in the 50 states. I contacted Weeks Marine, who was the contractor hired to put the subway cars in the ocean, and told them about the project. They introduced me to the MTA, which was happy to allow me to shoot the project."

Starting in 2008, Mallon and his camera chronicled the disposal of subway cars along the eastern seaboard from Delaware to South Carolina to the bottom of the ocean. The cars do have a purpose in the water -- they "help rebuild underwater reefs along the eastern seabed," according to Mallon.  

Mallon is not done with "American Reclamation" just yet. His next portion of it will also focus on something New Yorkers, specifically Staten Islanders, are familiar with.

"My next chapter in the project is going to be photographing the Fresh Kills landfill, which is in the process of being converted to a city park."

Mallon's next exhibition, "Patterns of Interest," opens on Feb. 6 at New York University's Kimmel Galleries and will be on display until March 15.

Check out all of the pictures from "Next Stop Atlantic" below.

Retired Subway Cars
(Photo : Stephen Mallon)
Retired Subway Cars
(Photo : Stephen Mallon)
Retired Subway Cars
(Photo : Stephen Mallon)
Retired Subway Cars
(Photo : Stephen Mallon)
Retired Subway Cars
(Photo : Stephen Mallon)
Retired Subway Cars
(Photo : Stephen Mallon)
Retired Subway Cars
(Photo : Stephen Mallon)
Retired Subway Cars
(Photo : Stephen Mallon)
Retired Subway Cars
(Photo : Stephen Mallon)
Retired Subway Cars
(Photo : Stephen Mallon)
Retired Subway Cars
(Photo : Stephen Mallon)
Retired Subway Cars
(Photo : Stephen Mallon)
Retired Subway Cars
(Photo : Stephen Mallon)
Retired Subway Cars
(Photo : Stephen Mallon)
Retired Subway Cars
(Photo : Stephen Mallon)