At 15,000 feet deep, the wreck of the El Faro sits in one of the least explored places on earth, a lonely grave as deep as the Rocky Mountains are tall, with no light, crushing pressure, temperatures just above freezing and little life beyond microbes, giant worms and strange, tube-eyed fish.
Even the most advanced submarine can’t venture this deep.
In such daunting conditions, federal investigators have turned to a sophisticated unmanned submersible as they continue to search for clues to the sinking off the Bahamas during Hurricane Joaquin. The remotely operated vehicle, or ROV, is equipped with high-def cameras to survey the ship’s hull and robotic arms able to cut cables and grab important evidence, like the ship’s critical black box.
First developed by the Navy, the boxy ROV may be the last best hope for unraveling the El Faro’s fateful voyage and determining exactly why it sank last month, apparently within minutes of a final distress call, killing all 33 crew members.
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They’re very capable, but very complex to operate
“They’re very capable, but very complex to operate,” said Justin Manley, an MIT-trained ocean engineer who piloted the same cutting-edge ROV, called a CURV 21, for the National Oceanic and Atmospheric Administration when it mapped the Titanic, perhaps history’s most famous shipwreck, in the icy North Atlantic 12,500 feet down.
Last week, after sonar detected the El Faro resting upright on the ocean floor north of Crooked Island in the Bahamas, the U.S. Navy ship Apache deployed the deep-diving robot to document the condition of the ship and locate the black box, called a voyage data recorder. The NTSB has so far released little information about its findings, other than to report that the ROV has inspected the port and starboard sides of the vessel and that the bridge, which contains the critical recorder, is no longer attached to the ship.
Finding the recorder is critical because, in addition to navigation data, it contains audio that could let investigators, and families, hear what the crew said during the ship’s last moments. Efforts to track its “pinger” signal across a 260 square-mile search area have so far failed.
There is also a possibility of recovering something that may bring some measure of comfort to families — bodies of the crew that went down with the ship.
“It’s a strange world of reality that has hit these families,” said Michael Moore, a Coral Gables attorney who is representing the families of two crew members. “They would like to have closure. I think recovering their loved ones is a step in that direction.”
But the chances of that happening are remote. NTSB spokesman Peter Knudson said investigators do not plan on trying to enter the vessel and search teams have not yet located the bridge of the ship, where the captain and a portion of the crew would have been stationed during the El Faro’s battle with Category 3 Joaquin. Surveys of a large debris field continued this week in hopes of locating that important part of the ship.
So far, good weather has allowed the crew manning the CURV 21 and running sonar to work around-the-clock in 12-hour shifts, Knudson said. However, forecasts for stormy weather and rough seas over the weekend may hamper the search, which Knudson initially expected would take 15 days.
20,000The depth, in feet, at which the ROV can operate
Capable of diving to 20,000 feet, the CURV 21 is the latest model of the cable-operated vehicle developed by the Navy decades ago. Fewer than 50 exist, Manley said. They are regularly employed by the offshore energy industry but also have increasingly been used to try to unravel the mysteries of deep sea wrecks, including the Malaysia Airlines Flight 370 that crashed in the Indian Ocean in March 2014 and a U.S. Air Force F-16 that plunged into the North Pacific six years ago after the pilot ejected.
Capable of withstanding the harsh conditions in the ocean’s Abyssopelagic zone — the abyss part comes from the Greek word for bottomless — the CURV 21 can still be a bear to pilot. Manley compared it to standing atop the Empire State building and using a camera the size of a yo-yo, dangled from a string.
“It can be incredibly frustrating,” he said.
Investigators will likely start by sweeping the outside of the ship, something called “mowing the lawn,” to look for clues about the hull’s condition when the El Faro sank.
Ships as big as the El Faro — at 790 feet, it is twice the length of a football field — often have airtight compartments. They are designed to float, even if water starts leaking into one or more compartments, Moore said.
In his final message from the ship, Capt. Michael Davidson reported that the ship had lost propulsion and a hatch, or scuttle, had blown open, allowing water to enter one compartment. Davidson, who knew he was approaching a worsening hurricane and told his bosses at Tote Maritime Puerto Rico that he planned to sail 65 miles south of the storm, likely would have secured all the hatches.
“In this case, you have a crew that is well-trained judging from their maritime backgrounds and licensing. All evidence points to the ship itself as having deficiencies,” said Moore, who plans to fight a ruling this week in Jacksonville federal court won by Tote to cap liability at about $15 million and set a December deadline for families to sue.
While the ship may have suffered some damage when it landed on the ocean floor, Moore said “a good forensic failure analysis expert” should be able to determine whether damage occurred from impact or on the surface as the listing ship drifted powerless within about 35 miles of Joaquin’s eye.
Investigators may also try to determine the condition of the ship’s life rafts or locate a life boat that remains missing. Both contain equipment to send distress calls. Moore believes video taken of the wreck might also help explain why the three distress signals — the Ship’s Security Alert System, a security measure added in 2002 to combat piracy; a pre-programmed Inmarsat-C Alert that communicated the ship’s identity, time of alert, course and speed; and a mayday call from the ship’s Emergency Position Indicating Radio (EPIRB) — essentially sounded at once.
“That effectively means all three were in contact with sea water at the same time,” he said. “It’s not like weather or rain. They’re in the ocean at that point.”
But if weather off the Bahamas worsens as predicted, ongoing search efforts may slow.
At such depths, the crew piloting the ROV must account for shifting currents — different depths can have their own currents moving in different directions — as well as movement of the surface ship. Often a team of two to five pilot the craft with one person serving as pilot, another manning the arms and someone else overseeing navigation, said Manley, whose consulting firm Just Innovation deals with the emerging technology of underwater drones.
It’s this delicate ballet of controlling the ship, controlling the robot and controlling the winch
The CURV 21 also comes equipped with a rack of tools that can be attached to the robot arms and used for cutting or other maneuvers. The tools are strong enough to cut cables and wires, said Navy spokeswoman Colleen O'Rourke, but not doors or the ship’s hull.
As the ROV moves alongside the ship, and more than two miles of cables loop and twist in the alternating current, the pilot also needs to be careful not to create another wreck.
“The hardest part is you have this robot that is thousands and thousands of feet deep and connected by a cable to the ship and there’s current between you and the bottom. There’s also current,” on the surface, Manley said. “It’s this delicate ballet of controlling the ship, controlling the robot and controlling the winch.”