The New York City subway car reef experiment demonstrates that material properties critically determine artificial reef success: carbon steel subway cars (Redbirds) created thriving marine ecosystems with 400-800 times more biomass than natural sand, while stainless steel cars (Brightliners) failed due to galvanic corrosion and structural collapse, spreading debris 10 miles from permitted sites. Florida's refusal to participate was vindicated by its 1972 Osborne Reef disaster, where 2 million tires destroyed natural coral reefs, leading to strict regulations that prevented similar failures.
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They Sank 2,500 Subway Cars Into the Atlantic — What's Inside Them Now Wasn't Supposed to HappenAdded:
On a calm morning in August 2001, a hydraulic arm closed around an 18-ton New York City subway car, swung it out over the Atlantic Ocean, and dropped it.
If that sounds like the beginning of an environmental disaster, it was not entirely wrong. But what happened next on that sandy ocean floor 80 ft below was not what anyone expected. Over the next [music] 9 years, more than 2,500 subway cars would be deliberately sunk into the Atlantic off five different states. [music] Marine biologists called it a controlled experiment. Environmentalists called it using the ocean [music] as a landfill.
Florida refused to participate entirely.
Therefore, this is the story of who was right, who was wrong, and what 2,500 [music] subway cars look like after two decades on the bottom of the Atlantic.
The idea.
In the late 1990s, the New York City Metropolitan [music] Transportation Authority faced an expensive problem. The MTA was retiring an entire generation of subway cars. The Redbird fleet, the R26 [music] through R36 series painted vermilion red, had been running the A division of the New York City [music] subway for roughly 40 years. There were thousands of them. Too old to keep running, too costly to scrap [music] on shore, too large for any conventional disposal channel.
So, the MTA proposed something [music] different. They would dump them into the ocean. If you had proposed this on a street corner in 1999, it would have sounded insane. In practice, it was based on decades [music] of marine biology that most of the public had never heard of.
The Atlantic [music] Ocean floor along the eastern seaboard, particularly off the coast of Delaware, New Jersey, Virginia, and the Carolinas, is a vast [music] expanse of featureless sand.
More than 99% of New Jersey's seafloor is in ecological terms a desert. There is nothing for marine [music] life to attach to, no structure, no shelter, no vertical relief.
The water column above it is a highway with no rest stops.
Marine biologists [music] had known for decades that almost any solid object placed on a sandy bottom would rapidly become [music] a thriving ecosystem.
The hard substrate gives algae something to grow on.
The algae attract invertebrates. [music] The invertebrates attract small fish.
The small fish [music] attract larger predators.
Within years, a single sunken structure can become a dense underwater city in the middle of an ocean desert.
The subway cars were by accident nearly perfect for this.
Each Redbird measured [music] 51 ft long, 9 ft wide, and 9 ft tall.
They weighed 9 tons. They had massive [music] interior volumes. They had windows and doors that let water flow freely through the structure and gave fish [music] multiple entry and exit points.
The carbon steel they were built from was heavy enough to stay put through hurricanes. And there were thousands of them available for free. The first deployment happened in August 2001 [music] at a permitted site 16 mi east of the Indian River Inlet in Delaware, designated site 11 and named Redbird [music] Reef.
The state received more than 1,300 subway cars over the following years, >> [music] >> the largest concentration anywhere on the eastern seaboard.
The marine life arrived faster [music] than anyone expected. Within weeks, the metallic surfaces were coated with algae and encrusting bryozoans.
Within months, [music] barnacles, blue mussels, and small invertebrates had established dominant communities across [music] every surface and inside every cabin. Within a few years, soft corals, deep-water sponges, and large predatory [music] fish had taken up permanent residence.
By 2008, the Delaware Department of Natural Resources documented that the amount of marine food per square foot in the immediate [music] vicinity of Redbird Reef had increased 400 times compared to the original sandy bottom.
Artificial reef structures [music] along the New Jersey coast were holding 800 times more biomass than equivalent areas of natural sand seafloor. In the year 2000, [music] anglers caught 4,800,000 fish on New Jersey artificial reefs alone.
Nearly one in [music] five fish caught in all of New Jersey's salt waters that year.
Delaware's reef program manager Jeffrey Tinsman described a 300-fold increase in the number of people fishing on site 11 compared to before the subway cars were placed there.
The MTA [music] expanded the program to New Jersey, Virginia, South Carolina, and Georgia.
By the middle of the decade, more than 2,000 cars had been sunk.
Then in September 2007, the MTA approved a $6 million contract Weeks Marine to send another 1,600 cars to the bottom.
That was the contract that would destroy the program when it collapsed.
By 2007, the MTA had run out of Redbirds. The carbon steel Redbird fleet had all been retired.
The cars now coming out of service were a different generation, the Brightliners, the R32, R38, R40, and R42 series.
They had been engineered to be lighter, more fuel-efficient, [music] faster on the rails.
To achieve that the MTA's engineers [music] had built them from corrugated stainless steel, thinner than the carbon steel of the Redbirds, [music] better for transit operations.
As it turned out, completely wrong for the ocean.
The first sign of [music] trouble came within months of the Brightliner deployments.
Marine biologists arrived at dive sites [music] expecting to see 30-ft steel boxes resting upright on the seafloor, slowly being colonized.
That was not what they found. The Brightliners had crumbled. The thinner stainless steel could not handle the combination of salt water corrosion, current pressure, and wave [music] oscillation.
The structural integrity that had been adequate for 40 years above ground failed within months below it. The combination of stainless steel [music] and remaining carbon steel components in salt water triggered galvanic corrosion, an electrochemical process where [music] two different metals in salt water create a tiny battery and the more reactive metal eats itself.
The weld points [music] went first, then the panels, then the entire structure. Within a year of deployment, the Brightliner cars had collapsed [music] into flat twisted piles of metal.
The vertical relief that made [music] them useful as habitat was gone.
The interior cavities where fish sheltered were gone.
And the wreckage did not [music] stay where it was supposed to be. Commercial fishermen reported subway car debris snagging in their [music] nets at distances of 10 to 15 miles from the original permitted reef sites.
The pieces [music] were sharp. They were tearing expensive fishing gear apart.
The debris field [music] had spread across miles of ocean floor. At the same time, a separate political crisis had been building. The Redbird cars [music] contained small quantities of non-friable asbestos locked into solid wall panels.
The EPA had [music] studied this and determined it posed no detrimental effect on the marine environment. Water testing near the sunken cars >> [music] >> showed asbestos concentrations statistically indistinguishable from background levels in [music] seawater.
The science said the asbestos was contained.
The optics said [music] something else.
Environmental groups protested at public hearings.
Maryland's Ocean City Reef [music] Foundation rejected the subway cars outright. By April 2010, [music] the New York City Transit Authority officially discontinued its reefing program.
The carbon [music] steel Redbirds had vindicated the concept. The stainless steel Brightliners had ended it. And throughout all nine years, one state [music] on the Atlantic coast had refused to accept a single subway car.
Why Florida [music] said no and indeed what had happened there before?
Florida's official reason for rejecting the subway cars [music] was dry and technical. The sheet metal failed to meet the state's minimum thickness standards for artificial reef materials.
>> [music] >> That sentence is true. It is also a euphemism.
The reason Florida had thickness standards at all, the reason its fish and wildlife conservation commission >> [music] >> was the most rigorous artificial reef regulator in the United States, was that 30 years earlier Florida had run its own artificial reef experiment. And it had produced [music] one of the worst environmental disasters in the history of the Atlantic coast.
In 1972, off the [music] coast of Fort Lauderdale, a coalition of boosters, marine engineers, and environmentalists launched a project [music] called Osborne Reef. The premise was even more ambitious than what New York would attempt 30 years later.
Florida was [music] not going to dump subway cars. It was going to recycle America's discarded automobile tires.
More than 2 [music] million of them. The logic was elegant on paper.
Used vehicle tires [music] were a growing waste disposal nightmare in the 1970s.
They did not degrade, could not be easily [music] recycled, and were filling landfills. They were also in theory an ideal reef [music] substrate.
Lightweight enough to transport in massive quantities.
Resistant to corrosion.
With interior volumes that [music] could shelter fish. Bundle them with steel clips, drop them on a permitted section of seafloor [music] off Fort Lauderdale, and let nature do the rest.
The project received endorsement from the United States Army Corps of Engineers, support from Broward County government, and even a ceremonial launch when Goodyear dropped a gold-painted tire [music] from the Goodyear blimp to christen the site.
More than 2 million tires were deposited over approximately [music] 36 acres of seafloor at a depth of 65 ft.
The first sign of trouble was that nothing colonized them. Vulcanized rubber is a poor substrate for marine life. Algae barely grew on it. Barnacles avoided it.
The corals the project's organizers had hoped for simply did not arrive. The tires sat on the ocean floor biologically inert.
Then the steel clips that bound the tire bundles together began to corrode. As the clips failed, the tire bundles separated.
Individual tires, now free, began to move with the current.
>> [music] >> And here is where the disaster happened.
Ocean currents off Florida's southeast coast [music] are powerful, running along a corridor containing some of the most ecologically valuable natural coral reefs in North America. [music] Reefs that had been growing slowly for thousands of years. The free-floating tires drifted into those reefs >> [music] >> and smashed into them. 2 million tires, each weighing approximately [music] 20 lb, propelled by tidal forces. Soft corals were torn from their substrate.
>> [music] >> Hard corals were chipped, gouged, and shattered. By the late 1980s, the scope of the [music] disaster was clear.
The tires had spread across the ocean floor for miles beyond [music] their permitted area.
The cleanup that began in the early 2000s and has continued ever since has involved military divers, contracted [music] civilian operations, and combined federal state task forces.
As of April 2023, [music] Florida DEP confirmed that 640,777 tires had been removed. Cleanup operations continue under active contracts through [music] at least February 2028 with an estimated hundreds of thousands still remaining on the seafloor.
The Osborne Reef disaster fundamentally rewrote how Florida [music] approaches artificial reef construction.
Minimum material thickness.
Minimum weight.
Mandatory environmental [music] impact assessments. Absolute prohibition on materials that could be displaced [music] by current.
These were the standards that the MTA's subway cars failed to meet.
And these [music] were the exact standards that saved Florida from a second catastrophe when the Brightliner [music] debris was spreading across the ocean floor of every state that had accepted them.
What's down there now?
More than 15 years after the last [music] subway car was sunken to the Atlantic, the program's surviving structures continue to do what they were designed to do. Delaware's [music] Redbird Reef at site 11, 16 mi east of the Indian River Inlet, 80 ft down, holds 714 [music] Redbird subway cars alongside retired military tanks, armored [music] personnel carriers, tugboats, and thousands of tons of ballasted truck [music] tires.
Together they form 1 and 3/10 square nautical miles of dense artificial habitat >> [music] >> in what used to be sand.
Divers who visit Redbird Reef describe something that [music] feels less like a wreck site and more like swimming through a sunken city.
The exterior surfaces of the cars are coated [music] in soft corals, sponges, and dense beds of blue mussels.
Schools of black [music] sea bass move through doorways and window frames.
Tautog defend territories inside the cabins. Scup, summer [music] flounder, and juvenile fish use the interiors as nurseries.
Above the cars, [music] in the upper water column, tuna, mackerel, and mahi-mahi use the reef below as a hunting ground. South Carolina's [music] 200 Redbird cars, deployed in 2002 and 2003 at depths between [music] 90 and 120 ft, have weathered multiple hurricane cycles across more than a decade.
South Carolina [music] Department of Natural Resources survey data documents that more than 90% remain intact and upright, supporting some of the densest [music] invertebrate colonies and fish assemblages anywhere in the state's coastal waters.
In December 2023, [music] the program quietly resumed in a different form.
The Georgia Department [music] of Natural Resources received two decommissioned heavy rail cars from the Metropolitan [music] Atlanta Rapid Transit Authority, stripped of hazardous materials, inspected by the United States Coast Guard, and deployed at [music] Artificial Reef L 23 nautical miles east of Ossabaw Island.
Within a year, Georgia DNR documented [music] soft coral growth across the rail car surfaces and at least nine distinct species [music] of game fish using them as habitat.
What comes next? And further south [music] off the Florida Panhandle, the next chapter of America's artificial reef story [music] is already in motion.
In October 2024, Okaloosa [music] County, Florida paid $10 million for one of the most famous ships ever built, the SS United [music] States.
1,000 ft long, the fastest [music] passenger ship to ever cross the Atlantic, she had sat decaying at a pier in Philadelphia for nearly 30 years with no buyer and no future.
Florida bought her [music] to sink her.
Modern artificial reef construction has fully absorbed that lesson.
Purpose-built concrete modules, decommissioned military vessels scuttled [music] deep enough that storms cannot move them, engineered ecological infrastructure rather than repurposed waste. 2,500 [music] subway cars sit at the bottom of the Atlantic. 2 million tires are being lifted [music] out of the ocean one dive at a time.
The program that put the subway cars there is finished.
The disaster that [music] explains why Florida said no is being undone slowly, carefully, and expensively. And in the warm water off the Florida panhandle, a thousand-foot [music] ocean liner is being prepared to become the largest reef on Earth.
They dropped the first [music] car into the Atlantic in August 2001 and watched it sink 80 ft to a sandy bottom that had supported [music] almost nothing for thousands of years. Today, that bottom is a city.
The cars that held [music] their shape built something extraordinary. The ones that did not left a debris field 10 mi wide. And the lesson between [music] those two outcomes is the entire history of what humans put into the ocean and what they get [music] back. Subscribe and hit the notification bell so you never miss a story like this one.
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