Comments about technological history, system fractures, and human resilience from James R. Chiles, the author of Inviting Disaster: Lessons from the Edge of Technology (HarperBusiness 2001; paperback 2002) and The God Machine: From Boomerangs to Black Hawks, the Story of the Helicopter (Random House, 2007, paperback 2008)

Saturday, April 5, 2014

The Inhuman History of ROVs: Part 2

Continuing from Part 1, based on my history of ROVs for Invention & Technology:

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Setting aside military trials (such as the US Navy, which lowered an undersea TV camera to check on A-bomb blast damage to shipwrecks near Bikini Atoll, and the British Navy, which used another to look for a sunken submarine), credit for the first civilian ROV probably goes to Dimitri Rebikoff of France. Frustrated by the fact that some Mediterranean wrecks were too deep for divers to investigate, he installed a camera in a pressure-resistant housing, added a water-corrected lens, and mounted it on a tether-controlled vehicle that he dubbed Poodle.
For extra treasure-finding skills, he added a magnetometer and sonar set. (ROV experts credit Poodle as the world's ROV, albeit an unarmed one. Having recently built a diver-driven, one-man underwater scooter called Pegasus for use by the Submarine Alpine Club of Cannes, France, Rebikoff had a head start in building Poodle's controls and power train.) On its first use in 1954, Poodle sent up video of two previously unexplored Phoenician wrecks, one 700 feet down.

U.S. Navy labs and Navy contractors built other camera-carrying ROVs, one of which was Snoopy, notable for its reliance on direct hydraulic drive, transferred from tender to vehicle through a long tether-hose (today's ROVs all rely on electrical power, as did the successor, Electric Snoopy).

The first ROV to hit the water with manipulator arms emerged from a US Navy laboratory in Pasadena, California: Cable-Controlled Underwater Recovery Vehicle, or CURV.
Originally tasked with bringing back torpedoes that failed to rise to the surface after test shots, CURV-I made international news in 1966 off Palomares, Spain, where an H-bomb had plummeted into the Mediterranean Sea after a bomber collision. The bomb was resting precariously on the lip of a steep slope in a skein of parachute shrouds, which for a few terrifying moments had tangled with the manned submersible Alvin when that craft had tried to attach lifting shackles. Though at 2,850 feet the bomb lay well below CURV's rated depth, CURV reached the spot without imploding and finished the rigging job. Seven years later, successor CURV III helped rescue the two-man crew of a submersible stuck on the sea floor off the Irish coast.

The Navy's Remote Unmanned Work System, fielded after CURV, was directed at search and recovery work.
Challenges overcome in its development pointed the way to today's work-class ROVs. “The Idea was to go to 20,000 feet with all the tools you needed to recover a black box,” said Wernli. This would give access to the great majority of objects on the ocean floor, since abyssal trenches are rare. The great depth could have posed a serious problem in cable handling: If connected directly to a boat on the surface via a single, thick cable more than four miles long, the ROV would have been at the mercy of any deep currents pulling at the line.
The solution was to use two cables: a strong umbilical line reinforced with Kevlar fiber that plummets straight down from the tender to a base station (called the Primary Cable Termination), hanging above the sea floor; and a lightweight and neutrally buoyant tether that's paid out horizontally as the ROV ventures off to work nearby.
This arrangement has been very successful, because it keeps cables from dragging along the sea floors, where the slightest turbulence will stir up a cloud of talcum-fine silt that blocks visibility for hours.
Work class ROVs use the same arrangement today, and it's what I saw when shadowing an Oceaneering crew on a drillship in the Gulf of Mexico. Today, the umbilical terminates at a strong metal cage that serves as a garage for the ROV when not in use.

The North Sea turned the tide in favor of ROVs. With exploratory wells having proven large reserves of oil and gas by 1970, and with oil prices high after the first oil embargo, production began in 1975. The conditions – undersea wellheads far from shore, and frequent storms – were so novel that by 1980, development and installation costs outran American expenses for the Apollo moonshots. Reserves estimated at 70 billion barrels kept them going.

The early years saw dozens of manned submersibles and hundreds of divers at work, with ROVs at the margin, little more than a curiosity, of doubtful reliability. Typical was the “flying eyeball” model, which kept its camera trained on a diver to monitor his safety. But by 1980, as abilities expanded and reliability improved, ROV fleets surged.
Although the North Sea fields are shallower than waters off West Africa, Brazil, and the Gulf of Mexico, it was a proving ground for critical advances: connectors that didn't short out in seawater, acoustic beacons for precise navigation around a sunken structure, robust manipulators, and high-quality video. Some of the most important developments at this time had less to do with ROV hardware and more to do with wellhead hardware.

“That was the big turning point,” said Wernli. “When [oilfield engineers] accepted they had to go deep, they started designing the equipment for that: how the subsea equipment would be operated, how valves would be turned. The key is that whenever would be needing an ROV there had to be standard docking so it could plug something in or manipulate something. In other words, they got the tooling in place.” As an example, if a valve needs turning, it's better to provide handles designed specifically for powerful, rotating claws than to expect the ROV to wield a crescent wrench.
On the Deepwater Horizon emergency-response spillcam sites, viewers could see ROV claws wielding shears, circular saws, and diamond wire cutters. ROVs can also carry drills, abrasive wheels, and jets to cut steel with high pressure water and abrasive powder. Such tools will be handy for deepwater decommissioning work, that costly day at the end of a well's useful life when oil companies are obligated by federal regulations to cut away old pipes, valves, and other sea-bottom steelwork for hoisting to the surface. The idea is that nothing will be left above the mudline, except those structures approved to serve as artificial reefs.
Decades from now such work might be turned over to AUVs, or autonomous underwater vehicles. AUVs are now restricted to going off on relatively simple missions, and must find their way back or surface to open up a temporary link via satellite. An AUV's job might include seawater sampling, surveys of the ocean floor preparatory to pipelaying, or minehunting for the Navy.
If given the ability to recharge along the way, AUVs can work for many weeks before returning. Oil companies have great expectations that, with time, AUVs can be promoted from surveys to detailed inspection of underwater equipment such as checking valves for proper function, and then move on to routine maintenance jobs. This will allow the more elaborate ROVs to focus on the complicated jobs, such as “workovers” of aging wells, and replacement of corroded parts and leaking packers.

While deepwater technology is often compared to space shots, the most intriguing development, to me, is how experience from the oilfields suggests that humans can't compete with robots when doing high-stakes work in dangerous conditions, when figured on a business basis. Yes, today's underwater "robots" are really remote-control actuators, depending on humans to control the details of each job at a safe distance, via levers and knobs.
But artificial intelligence is advancing on a fast track, and with each passing year robots will be given more authority to exercise judgment, based on how they interpret instrument readings and video images.
From what I hear, some of the most advanced autonomous underwater vehicles (AUVs) today are devoted to minehunting. Their job is to seek out sleeper mines on the seafloor, an anti-ship tactic quite likely to be used in the next major conflict.

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