Pressure? What Pressure?
June 8, 2004
The ROV Hercules went dead in 12,500 feet of water over the wreck of Titanic early 6/7/2004 and was brought to the surface for repairs. Pictured are IFE engineer Mark DeRoche (right) and Dr. Robert Ballard.
Photograph by Bert Fox (c) National Geographic Society
Cheers and applause filled the control van on the stern of the Ronald H. Brown as the flashy, flawless live video from Titanic's bow ended the National Geographic Channel broadcast Monday night.
"Wow! Yes!" exclaimed Dr. Robert D. Ballard, who burst from the van a minute after 10 p.m. and began shaking hands and hugging everyone. "We set a new standard."
It was a thrilling end to a challenging day.
Hercules and Argus gave the science team a scare before the remotely operated vehicle and its towed relay sled were ready for the Return to Titanic broadcast.
The vehicles ended their marathon fifth dive before dawn Monday when signals from Herc abruptly stopped. The ROV had to be hauled, powerless, from the Atlantic.
"I forgot what the vehicles looked like," joked Institute for Exploration engineer Brennan Phillips. They had been underwater for 65 hours, which probably set an endurance record for Hercules, ROV designer Jim Newman said.
When the vehicles finally were brought on board, two problems became evident.
First, a fiber-optic connection inside Hercules had gone dead. The connection, which links the tow cable to the ROV's main "bottle," a pressurized container for electronics, had to be replaced. The bottle itself, pressure-tested to operate at one-and-a-half times Titanic's depth, remained intact.
Second, the mechanical termination of the cable that suspends Argus from the stern of the NOAA ship Ron Brown showed signs of wear. The cable end is designed to allow Argus to pitch, meaning its front and back ends can swing up and down, but not to roll, a motion in which its sides rise and fall. Surface swells had made Argus act like a 4,000-pound yoyo and caused enough of a rolling motion to abrade the cable's metal fibers. The worn end was hastily rebuilt.
Dr. Ballard said he didn't feel fazed by the problems as the time for the live portion of the broadcast approached.
"There's no point [getting anxious]," he said. "It doesn't do any good."
By Monday afternoon, both vehicles had been repaired and tested. A winch raised Hercules and dropped it over the stern rail.
But no sooner had the ROV splashed into the North Atlantic than its signal to the control van went dead ? again.
The deck crew retrieved the stricken Herc and parked it on the fantail for diagnostic tests. The ROV was powered up, and ? zap! ? its tether began to smoke.
The engineers decided they had to replace the entire tether. They fetched Hercules's third and final leash, one that had served them well during a Black Sea expedition in 2003.
Time began to work against them. In order to get Hercules and Argus to the bow before the 9 p.m. ET/PT broadcast, which had been advertised as including live images from the shipwreck, the vehicles would have to leave the Ron Brown no later than about 6 p.m. for the three-hour trip to the bottom. And even if they arrived on the ocean floor at the appointed time, there would be no guarantees, given the unpredictability of ocean currents and a 2.5-mile (4-kilometer) cable, that Hercules would drop close enough to swim to the bow before showtime.
"That's the A-Team out there," NOAA Capt. Craig McLean said as the clock ticked down. "They'll make it."
A flock of gulls watched calmly from the still waters behind the stern as the crew raced to fix the problem. Dr. Ballard cut his hand while helping to connect and reinforce Hercules's end of the tether, but he continued to work.
Hercules finally went into the water at 5:20 p.m. Argus followed a few minutes later. The blue water and white bubbles outside their cameras, which normally bore those watching the bank of monitors, proved a welcome sight as the pair descended. They meant Herc was still working.
Only two-and-a-half hours later, in the fastest descent yet, Herc and Argus reached bottom. Incredibly, navigator Justin Manley and the rest of the team in the control van landed the vehicles less than 50 meters from the bow. A few minutes later, their live video of the shipwreck appeared topside, ready to be shared with the world.
(Note: nationalgeographic.com does not research or edit dispatches.)
