Blackburn was asking, in his Chipmunk falsetto, “Where’s Barth?”
Minutes seemed to pass before Cannon regained his composure enough to respond. He didn’t know where Barth was. He had left the habitat without informing Barth, an uncharacteristic breach of buddy diving etiquette. Fearing that Barth might be in trouble, Blackburn quickly strapped on a diving rig and dropped fins-first through the hatch onto the cage. No sooner had Blackburn jumped in than Barth appeared, breathing hard like Cannon. Blackie and Barth climbed back up into the PTC. Barth kept repeating something but Blackburn couldn’t understand. Distortion from helium speech was more pronounced at six hundred feet, where they were breathing a gas mixture that was more than 90 percent helium.
The topside commanders, via a camera monitoring the Sealab III hatch area, had watched a grainy black-and-white image of Barth as he struggled with the hatch and then silently swam off screen. The divers had no voice communication in the water, so no one could know exactly where Barth went, or whether he was in trouble. But topside soon heard from the PTC that everyone was back in the capsule. A voice over the intercom told the divers to stay put. They were going to be brought back to the surface. Barth and the others closed the hatch and buttoned up the PTC for the return trip to the Elk River. The foursome left the bottom at 7:25, about an hour after they had arrived. Inside the command van, a converted trailer on the main deck of the support ship, assorted Chipmunk utterances, often incomprehensible, could be heard coming over the intercom. It was clear, though, that the four divers were all cold, too cold to say much of anything during their ride up. As on the way to the bottom, the four divers were again chilled by the lack of heat and the frigid breeze from the scrubber fan. The return trip to their decompression chamber on the Elk River took about ninety minutes. The actual passage through the water took less time than the process of raising the pod through the moon pool, moving it with the gantry crane and mating it to the chamber hatch with the crucial airtight seal, as on the Berkone.
All four divers in the PTC were shaking badly from the cold by the time they reached the Elk River. It was almost nine o’clock that night when they finally lifted the hatch in the floor and left the PTC. One by one, they climbed down through a short connecting trunk into the deck decompression chamber below, a horizontal cylinder twenty-four feet long, with a bathroom, a couple of bunks, and just enough headroom to stand upright. The contrast in temperature as they entered the chamber was so great it felt as though they were dropping into a blast furnace.
On the opposite side of the continent, in Caribbean waters as clear and balmy as the Red Sea, things were going much more smoothly on the first day of Project Tektite I, an undersea habitat run by the Office of Naval Research, Sealab’s former lead agency, along with NASA and the Department of the Interior. The $2.5 million project’s duration was to be sixty days, the same as Sealab III, but Tektite was not nearly as deep, or as expensive, although news reports barely differentiated between the barrier-breaking six-hundred-foot target depth of Sealab and Tektite’s markedly less perilous forty-three feet, a depth similar to Cousteau’s early trials. A direct swim for the surface was unlikely to kill anyone. There was no ultralight helium in the Tektite atmosphere to complicate matters and decompression would take less than a day, compared to nearly a week for Sealab III. The Tektite habitat, a pair of interconnected vertical tanks two stories tall and twelve feet in diameter, sat on a rectangular base, like upside-down bell jars on a shoebox. In a secluded cove on the south side of St. John in the Virgin Islands, four aquanauts, all Interior Department scientists, shared roomy quarters pleasantly reminiscent of Cousteau’s Starfish House. They planned to make scuba dives and carry out marine studies, while NASA’s interest was in observing the effects of isolation to help predict human behavior on long-duration space flights.
Back on the Elk River, as the four chilled Sealab aquanauts recuperated in the chamber, about a dozen topside commanders gathered at about midnight in a small conference room to decide on their next move. Jack Tomsky, George Bond, Walt Mazzone, and Scott Carpenter were among those hashing over a variety of possibilities, including halting the project to raise the habitat, fix the leaks back at the shipyard, and start over again. They decided that another dive to open the habitat could and should be made. Once inside the divers should be able to plug those leaks and the sixty-day quest could proceed on schedule.
Barth had gotten as far as blowing the skirt and twisting the levers to unlock the hatch. The main problem seemed to be that when he tried to push the hatch open, the pressure inside the lab was higher than outside. Tomsky and the topside commanders had kept their eyes on the gauges in the command van and ordered more gas be pumped to the habitat to keep the pressure up and the water out—the finger-in-the-dike scenario. Equalizing the inside pressure with the outside could be tricky from six hundred feet away and there was a tendency to err on the side of maintaining a higher pressure inside the lab to stave off the leaks. The steel hatch was heavy to begin with and proved to be a bear even during practice openings in shallow, less debilitating conditions. Blowing the skirt, as Barth did, should have helped equalize the pressure above and below the hatch, but it didn’t take much additional internal pressure to turn the four-foot-square hatch into a two-ton beast that only Superman could have lifted. As Barth was trying to get in, the lab had become overpressured by as much as eight pounds per square inch; the hatch might as well have had a Sherman tank parked on it.
Timing an intentional drop in Sealab’s pressure with the exact moment a diver went to open the hatch could be difficult, especially without any voice communications once a diver was in the water. One suggestion was to have the diver give a thumbs-up, or some such sign, into the closed-circuit TV camera outside the hatch. Topside could then shut off the gas flow and allow a deliberate drop in the lab’s internal pressure. The diver should be able to pop open the hatch and the topside crew could then crank up the pressure again to minimize the flooding. But should Barth and Cannon be the ones to try again? What about Blackie or Reaves? By now the aquanauts to make up the rest of Team 1, the five who were put under pressure more gradually, were ready in the second chamber nearby. Why not send some of them to open the lab?
The topside commanders turned to Captain Bond for an estimate of how long Barth and Cannon should have to wait before they could safely get back in the cold water. Research into adequate recovery times from thermal stress was lacking, Bond said, but his best guess, with a few caveats, was that the recuperating divers should be able to make another dive by one o’clock in the morning, about four hours after they had returned from the first dive. They would be cold and they would be very uncomfortable, Bond said, but they could get through it.
Tomsky said he would prefer that Barth take Blackburn to open the hatch. He reasoned that Blackburn was bigger and stronger than Cannon, but Mazzone pointed out that Barth and Cannon had trained together and Cannon, as team engineer, was most familiar with the internal electrical system and how to get at the leaks. Carpenter agreed that Barth and Cannon ought to dive again but not until the following morning. They needed time to rest. If the commanders wanted the best out of the divers, they shouldn’t send them back to the bottom at two in the morning, Carpenter said. Others argued that it made more sense just to send fresh divers. The skirt had been blown and virtually all that remained to be done was to open the hatch. Tomsky ultimately sidestepped the issue and asked Mazzone, the diving operations officer, to talk over the matter with Barth, who as team leader would have to decide whether his foursome should go down again, and who should make the opening dive.
Inside the decompression chamber, Barth, Cannon, Blackburn, and Reaves had stripped off their gear and were trying to warm themselves. Reaves hadn’t even gotten wet, but like Barth he had never been colder in his life, colder even than on a salvage dive he once made under several inches of ice. As the four divers regrouped, there wasn’t much conversation among them. Barth and Cannon talked a little about the troubles t
hey had had on the first dive, and the feeling that they weren’t getting any good satisfaction from the breathing rig. They agreed that cold was the likely culprit—severe cold could cause disorientation, among other things—but they also reasoned that their own nerves may have been in overdrive as they went about their work, a whopping six hundred feet down. They had practiced the unbuttoning procedures before, but never in deep water or such daunting conditions. Cannon said he was sorry about having gone back to the PTC without telling Barth, but Barth said there was no need to apologize. They had both been busy. Nothing all that drastic had come of it anyway.
From inside the chamber, Barth spoke with the topside commanders, mainly Mazzone, and shared a few observations but didn’t dwell on what happened to him and Cannon as any kind of insurmountable problem. Barth was typically unfazed. He had come to expect the unexpected. The difficulty with the breathing rig and the entry hatch were just the latest examples of Murphy’s Law underwater.
When Blackburn asked Cannon what had been wrong, why he was so dazed upon returning to the PTC and breathing so hard, Cannon shrugged off the question. He said it was likely just the cold. Working divers were not apt to complain about discomfort or hardship, and neither Cannon nor the others would have wanted to miss out on the opportunity to take a historic place on the deep frontier. Blackburn understood; he had had to work the system to get himself a coveted spot on this third Sealab venture. The three other divers had all been on Sealab II.
To help restore the divers’ core body temperature, it was recommended that they eat, drink hot fluids, take hot showers—long enough to make them sweat—and get some rest. Soup and steak were passed in through the oven-sized medical lock, but with the possibility of a second dive looming there was a lot to do—setting up the PTC, running through a long checklist of valves, and changing all the power supply batteries. No one seemed to eat much or get more than an hour of sleep, and only Blackburn got around to taking a hot shower.
After catching an hour-long catnap, Blackburn checked over the two Mark IX rigs that Barth and Cannon had used on the first dive. Blackburn’s years of diving with explosive ordnance disposal teams made him more familiar than most with the mechanics of this type of gas-recycling rig, which were frequently used in the kind of underwater work he did. In the early 1960s Blackie was on the Navy team responsible for testing and refining the Mark VI, which was subsequently chosen for use on the first two Sealabs, and the Mark IX was similar to the Mark VI, with similar peculiarities that meant a diver had to be alert to subtle signs of danger, without the benefit of warning lights or alarms.
As Blackburn checked over the rigs it occurred to him that a restriction in the inhalation hose might have been to blame for Barth’s and Cannon’s breathing difficulties. Among the recent refinements to the Mark IX, a stiffener had been inserted to strengthen a section of the inhalation hose, but it also narrowed the passageway, possibly impeding the gas flow. Blackburn scrawled a note with this concern and put it and the rigs’ two used Baralyme canisters into the oven-sized medical lock, through which they could be passed to the crew working outside. Replacement canisters were soon sent back into the chamber through the lock, and Blackie put the two rigs back together.
About half past one in the morning, several hours after the first dive and with Sealab III’s gas supply dwindling, barges arrived with a backup supply of helium. In the meantime a flooding alarm had gone off, signaling that seawater was finding a way in around the edges of the entry hatch. A camera inside the habitat showed at least six inches of seawater covered the floor of the dive station. Once the new helium supply was hooked up, they cranked up the pressure inside the lab and forced the water out.
After the conference room meeting Mazzone went down to the two decompression chambers, which were shoehorned into dusky, low-ceilinged quarters below the main deck, and discussed the situation with Barth. Barth assured Mazzone and the topside commanders that his group was in good physical and mental shape. There was no reason to change horses in midstream, as Barth put it. He and Cannon were ready to make the opening dive again. They had already done most of the unbuttoning and should be able to swim quickly to the hatch, open it, get inside the habitat, and get to work fixing the leaks. Mazzone gave them one other instruction: “Don’t be a hero. If you have any problems return to the capsule. Don’t take any unnecessary chances to get into the habitat.”
To fend off the cold on the second dive Barth and Cannon were supplied with a new type of hot-water wet suit, known as the Wiswell suit. It looked something like a standard neoprene wet suit but was looser fitting, with little plastic tubes running like blood vessels throughout the rubbery material that bathed the diver in hot water delivered through an umbilical. It had proven to be effective and was certainly an improvement over the electrically heated suit they tried out during Sealab II. Because the suit was designed only for use from Sealab III, and not from the PTC, the commanders decided to jury-rig an umbilical to pump hot water to the PTC. Then Barth and Cannon could grab the hoses and attach them to the Wiswell suits. For all Sealab III’s more generous funding and expanded army of personnel, there was still room for jury-rigging, just as in the program’s early days.
Once they had all wriggled back into their suits and gone through the final check-offs, they climbed up the short ladder leading into the PTC still mated to the top of their chamber. They took seats around the periphery, squeezing in with the Mark IX rigs amid the pipes and valves inside the pod. They secured the circular hatch in the middle of the floor and could feel the temperature falling almost as soon as their capsule was cut off from the chamber’s heat.
The PTC was detached from the decompression chamber shortly after three o’clock in the morning on Monday, February 17, 1969. As on the first dive, the gantry crane on the Elk River lifted the white pod from its perch, just behind the ship’s gray superstructure, and rolled aft over the moon pool. The divers had all been on the job for twenty hours straight. With Captain Bond’s approval, another Navy doctor had locked in some amphetamine tablets—pep pills—to combat fatigue, but none of the four divers opted to take them. The PTC blowers again chilled them with an unrelenting arctic breeze. Barth put a foul-weather jacket over his head and shared a blanket with Cannon. They all felt even colder than they had on the first ride down. By the time they reached the bottom they were shaking badly. It was four-thirty in the morning, and they had been sealed inside the frosty PTC for more than an hour.
The water was surprisingly clear, and through the PTC’s little portholes they could catch glimpses of the bubbling lab, lit up like a monument in a deserted town square after nightfall. Barth and Cannon, shaking like the others, were eager to get hold of the hot-water hoses and hook them up to their Wiswell suits. They pulled open the hatch in the floor of their pod and reached down to grab the jury-rigged hoses outside, but out of the hoses came only a cool trickle. Without hot water, their loose-fitting suits would afford less protection from the cold than a standard wet suit. Still, they shouldn’t have to be in the water very long. Barth and Cannon went ahead and donned their diving rigs. From just below the open hatch, they also grabbed the ends of the umbilical hoses that would supply each rig with the proper mix of helium and oxygen. Cannon wore no hood or gloves, as was his custom. Barth plunged through the open hatch. The water creeping down his neck felt warm. The sensation puzzled him, but even at temperatures in the mid-forties, the water felt warm because he was so cold. Cannon followed Barth, dropping fins-first into the trunk and onto the cage. As Cannon hit the water his head bobbed up and he made such a desperate gasping sound that Blackburn thought he might decide not to dive after all. But Cannon dropped back through the looking glass and met up with Barth on the winch cage, their stoop below the PTC. It was now shortly after five in the morning, two hours after this second bone-chilling ride to the bottom began. Barth felt a tap on his shoulder and Cannon pointed toward the floodlit habitat nearby. Despite the cold and the ticking clock, the two
paused for a moment to admire the oasis of light on the seabed and the impressive structure that would soon be their home in the sea.
With their umbilicals trailing them like garden hoses, Barth and Cannon swam the rest of the way to Sealab III, another thirty feet down to the bottom. Cannon split off from Barth, apparently to check on something else before swimming to the hatch. Barth went straight to the hatch, as Mazzone had instructed, to give it another try. Watching on a TV monitor, those in the command van on the Elk River saw Barth swim into view, step up the short ladder, and push on the hatch. The recent flooding had broken the seal, the skirt was still blown, and with the plan to coordinate a drop in the lab’s pressure, Barth should be able to get in this time. Barth gave it a try, but the damn hatch wouldn’t budge. In training, Barth had found that a little extra leverage could help pop a stubborn hatch and he had had a crowbar installed nearby, just in case. A little plaque with instructions on how to use the crowbar was even posted, as if an aquanaut might need to study it before proceeding.
Tomsky, Bond, Mazzone, Carpenter—everyone watching the topside TV monitors saw Barth swim off screen. They figured he was going for the crowbar this time. Fatigue and frayed nerves contributed to a subdued tension, as did conflicting opinions as to what they should be doing topside as they watched Barth struggle with the hatch—Hold pressure steady? Shut off the gas? Allow some water to flood the dive station? Whatever suggestions were made by those present, Commander Tomsky had the final say. Gauges in the command van seemed to be showing that the pressures inside the lab and out had equalized. Given those readings, Tomsky could not understand why that hatch was still stuck. It took Barth about a minute to undo the two wing nuts holding the crowbar in place—a clumsy method, Carpenter thought, and another example of something that more time and money could have improved.
No sooner had Barth grabbed the crowbar than he heard a strange grunting sound. At that moment Blackburn and Reaves were startled by a yell, or maybe it was a scream, that came from somewhere outside the capsule. Barth turned and saw Cannon on the opposite side of the habitat. At first glance his buddy looked like a man jumping rope—legs pumping, arms jerking. Barth dropped the crowbar and the topside commanders saw him reappear on their monitors, but then swim away, stirring up silty clouds as he vanished into stygian darkness. Bond immediately sensed trouble.
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