by Peter Maas
Momsen was privately critical on another count. But there was nothing he could do about it now, so he kept silent. Once the Sculpin had arrived on the scene, he would not have shared in the general reluctance to use the lung. His faith in it was based on something more than sentiment. Following its adoption by the Navy, Momsen had overseen the construction of two ingenious lung-training tanks, at New London and Pearl Harbor. The tanks themselves were a hundred feet high with intermediate locks fifty and eighteen feet from the top. Nearly a thousand men had mastered his artificial lung in them when suddenly two deaths were reported in rapid succession, both in only eighteen feet of water.
Momsen was filled with misgivings. It was incredible to think that a person could kill himself coming up at a depth a swimmer of ordinary ability could reach without harm. He had always been worried about some hidden danger during the lung’s early development. “Have I,” Momsen wrote with bitter self-reproach in his diary, “been lulled into a false sense of security by the success of my own personal experiments?”
Since the Navy was publicly committed to the lung, the matter was kept under wraps while the Bureau of Medicine and Surgery began an urgent study of the fatal accidents in collaboration with Harvard University’s School of Public Health. But once again the lung itself was not at fault. Instead, another secret was uncovered regarding the mysterious forces man faced in the sea. The two men had died simply because they had held their breath.
The answer—common knowledge today, so unknown then—was that a swimmer diving from the surface starts with a lungful of air that contracts in the increased water pressure he encounters. But someone only eighteen feet down who fills his lungs with air or oxygen takes in over half as much as he would on the surface even though it occupies the same amount of space. If he holds his breath, it immediately begins to expand as he rises. Specialists at Harvard discovered that just two pounds of excess pressure against human lungs were enough to drive deadly air bubbles into the bloodstream and thence to the brain. At eighteen feet this pressure would amount to more than eight pounds. After he got the news, Momsen recalled the stories he had heard about men lost at sea in great depths “blowing up” when their bodies came to the surface. Maybe, he reflected, they were not fables after all.
From then on, however, everything went smoothly. And, like every submariner, each Squalus crewman had to qualify with the lung before being accepted for undersea duty. Not even the frigid waters in which she plunged, of such concern to Cole and Naquin, would have swayed Momsen had he arrived sooner. After he had completed his dramatic trials with the lung off Key West, his old nemesis, the Bureau of Construction and Repair, noted that “we might be remiss” if he was not prepared to say how his new device would fare in chillier climates. “It was,” he once remarked, “the most subtle directive I ever received during my naval career.”
So the following January found Momsen on the Falcon as she towed the S–4 to a point a hundred feet deep off Block Island. The day was fiercely cold, the sky sullenly overcast, the ocean temperature an inhospitable thirty-three degrees. Just as he and his favorite diving partner, Edward Kalinoski, boarded the S–4 for the trip down, it started snowing. As a test of endurance he could not have asked for worse—which is to say, better—conditions.
Attired only in bathing suits, the two men waited until the icy water rose high enough to balance the pressure so they could swing open the hatch of their escape trunk. Momsen went first, Kalinoski right behind, holding one of Momsens feet. The only anxious time they had was when they reached the surface. It was snowing so hard that the Falcon was nowhere to be seen. But a small boat quickly moved in to pick them up, and once they were back on the Falcon Pete Yarbrough, the same doctor whom Momsen had brought with him on the flight to Portsmouth, provided a special treat—a healthy jolt of grain alcohol in a mug of black coffee. It also made something of a legendary character out of Momsen. Though the service was sternly teetotaling at sea and Prohibition was still the law of the land, a memo from him extolling the virtues of what he dubbed “Coffee Royal” resulted in an official change in the Navy’s Supply Manual, which allowed an issue of grain alcohol to all divers operating in cold water. “Here’s drinking to you!” one grateful beneficiary wrote him.
But now—with the trapped Squalus crewmen already on the bottom for some fifteen hours, their strength inevitably sapped by the cold, the foul air, the intangible tensions of their plight—he agreed that they should fall back on the lung only as a last resort. So they would wait for the Falcon—and the rescue chamber.
That it was available at all was entirely Swede Momsen’s doing. Despite his preoccupation with the lung, he had never abandoned his original concept of a diving bell. The chance to revive it came on the heels of the lung’s first spectacular demonstration in the Potomac. Summoned to explain its workings before a special presidential board on submarine safety belatedly set up following the loss of the S–4, Momsen finished his presentation of the lung and promptly launched into a pitch for the bell as well.
When a startled member of the civilian-dominated board demanded to know why the proposal had not previously been submitted to the Navy, there was an awkward pause before Momsen replied, “It was.”
Given a green light at once, Momsen continued to test the lung while simultaneously developing the bell. He remembered the experimental tank for carrying a seaplane on his old command, the S–1. The project had never really come to much, and the tank, as it happened, was then being removed from the submarine. Momsen decided that cut in half it would make a perfect pilot model for what he had in mind.
At his request the tank was shipped to the Brooklyn Navy Yard, where a bright young officer in the Construction Corps, Lieutenant Morgan Watt, began to transform Momsen’s rough plans into detailed drawings. But there was more to it than that. With nothing more to rely on than their own speculations, they always had hanging over their heads the challenge of trying to anticipate all the uncharted perils of an actual rescue, where even the slightest factor overlooked now meant death later.
One of the bell’s drawbacks as initially conceived by Momsen was getting it rapidly and precisely in place over a submarine hatch. His solution was to have it do the work. A diver would be sent down to attach two cables to the hatch. The cables in turn led up to reels inside the bell, so that when the bell was lowered into the water with just enough ballast to keep it lightly afloat, it would wind itself directly down to the hatch. As many trips as necessary could be made to get the men out and up.
The idea of using a diver first led to the realization of still another danger. A diver would be necessary in any event. A piece of debris, a loose line lying over the hatch would block the watertight seal that was so essential.
More refinements were added along the way as Momsen, busy preparing for his lung tests off Key West, commuted back and forth from Florida. A hatch was put in the bell’s top to make it easier for its operator to enter and rescued submariners to exit. Since partial or complete immersion of the motors running the reels could be expected, they would be powered by compressed air instead of electricity. To help solve the delicate problem of maintaining positive buoyancy—so that the bell would always be free of water by keeping the air pressure inside it equal to the sea pressure below—a green stripe was painted near its bottom edge. If the sea stayed below the stripe the bell would have positive buoyancy, but if it rose above the stripe negative buoyancy would result and the bell would sink.
The finished product looked like a huge inverted tumbler, five feet in diameter and seven feet high. Watt was so excited that he decided on a test of his own in a flooded dry dock at the yard. He discovered to his chagrin just how important the guide cables to the hatch were going to be. Without them it was next to impossible to control the bell. First he vented out the air that was in it. This, of course, made the bell heavier, and it started to drop. But after Watt opened the compressed-air hose to stabilize his position, it didn’t come in fast enough. Then
when he hastily built up the pressure, the bell shot to the surface, promptly tipped over and sank again. Luckily it landed upright and he missed drowning. By this time he’d had enough and a yard crane ignominiously hoisted him back on dry land. Still, the test had not been a total loss. As Momsen told Watt, “You’re wetter and I’m wiser.”
He delayed putting the bell through its paces until he had concluded all the lung trials that culminated in his dramatic 207-foot ascent. Then more time was spent arranging for the mass production of the lung and in designing the lung-training tanks. A steel collar, meanwhile, had to be carefully constructed around the escape hatch over the S–4’s motor room to receive the grooved rubber gasket on the bell.
The strange contraption was sent by rail to Florida and placed on the Falcon. With the S–4 in tow it was taken out to a shoal area about seventy-five feet deep in the Gulf of Mexico. Once the submarine was on the bottom, a Falcon diver attached the guide cables to eye-bolts that had been welded inside the hatch collar. Then Momsen and Chief Torpedoman Charles Hagner, an S–4 crewman, entered the bell. On the trip down through the clear water they could easily spot their target below. Landing with a thud, the two men were able to stand in about a foot of water on the deck, their bodies still inside the bell, and maneuver into position over the hatch without difficulty.
Now came the critical moment. Neither man said a word. They didn’t have to. They both knew only too well that if something went wrong with the seal, if some flaw in concept or engineering had occurred, they would be dead in a matter of seconds. Theoretically, just by reducing the air pressure inside the bell, the sea itself ought to press them firmly against the hatch collar. To backstop them, Momsen had Hagner turn down four bolts he had devised to help hold the bell fast to the collar.
Next he spun a wheel valve to let the air out of the bell, watching the water level with, as he later put it, “lively interest.” But the seal was complete. The water level stayed stationary, and mist, caused by the drop in pressure of the saturated air, was still another indication that the test was proceeding as planned.
His customary composure betrayed by a trembling hand, Momsen slowly opened the hatch on the S–4. He had warned her commander, Lieutenant Norman Ives, to expect some water, and about twenty gallons ran into the hatch trunk. Then he looked down to find Ives staring back up at him. And despite all the work he had done with the lung, he was suddenly overcome by an emotion that left him speechless. But at last he pulled himself together and uttered the historic words never before heard beneath the surface: “Request permission to come aboard.”
Ives selected two members of the S–4’s crew to be “rescued.” The hatch was closed and the restraining bolts removed. Air pressure was admitted until it matched that of the sea outside, and with the seal broken the bell started up. Although this first demonstration was conducted under rigidly controlled conditions, the point had been made, the principle proved. The dream spawned in the days and nights after the S–51 went down had finally been fulfilled.
To perfect the bell, Momsen continued test after test. When he arrived above the S–4, he discovered that his twin down-haul cables had inexplicably crossed. Right then he decided that one such cable would suffice in the final design. Another time he took on board a bigger load than usual and found the bell barely able to rise. This led him to the idea of portable ballast that could be dumped to compensate for the additional weight of rescued submariners. The ballast would be seawater itself, carried in cans that the men who were being brought up could also sit on. The plan worked perfectly except for one thing. As Momsen wrote in a deadpan memo to the Bureau of Supply: “The ballast cans you sent have been received. The elaborate handles on their covers, however, detract materially from their utility as seats.”
Twice he was nearly killed. Under certain conditions the bell might have to empty a flooded submarine compartment or at least blow the water down low enough for its operators to go inside. So the S–4 settled down at sixty feet, her motor room flooded and the flood valves left open. Momsen and Hagner in the bell proceeded normally to the hatch. After the seal was made, the bolts were given an extra turn. Momsen was not sure how much pressure he would meet in the flooded compartment, but he suspected that it would be the same as the sea outside.
That was precisely the case when he started to open the hatch and he quickly increased his air pressure to keep the bell from being flooded, too. Building up even more pressure, he forced most of the water out of the compartment through its open valves. Then he and Hagner entered the motor room. In a real disaster they could have closed the valves or rendered whatever other assistance might be required. Momsen sent a message over the bell phone to be relayed back down to Lieutenant Ives in the S–4’s control room that all had gone well. Ives could pump or blow out the rest of the water in the compartment as he desired.
But when Momsen and Hagner closed the hatch and tried to unfasten the bolts, they jammed. That was just the beginning. Too light to withstand the immense force placed on them, the bolt threads started to strip. If they pulled free altogether, the bell would soar to the surface.
Swede Momsen never moved faster in his life. Instantly he reduced the air pressure in the bell, compressing the gasket against the hatch collar again and relieving the strain on the bolts. Then he and Hagner managed to wrench them out. On the way back up Hagner made a tactful suggestion. “Mr. Momsen,” he said, “I think we ought to use heavier bolts.”
Far worse was a later trial in eastern Long Island Sound, the S–4 placed at 130 feet. For Momsen’s companion, Chief Gunner Francis Church, it would be his virgin ride in the bell. Reeling down on positive buoyancy as usual, they were suddenly caught in one of the brutal currents that rip through that part of the Sound. Even with the cable connecting it to the Falcon, the bell was swept away so that the down-haul cables were at an angle some fifteen degrees from a vertical descent. The extra strain caused one of the air motors to conk out. Momsen stopped the second motor to see if he could fix the first one. As he did, he momentarily took his eyes off the water level. When he looked back, it had already risen past the green warning stripe.
He increased the air pressure at once. But it was too late. The bell was falling on its own. And it had happened so swiftly that the crewman handling the retrieving cable leading back to the Falcon continued to let it out. The deeper the bell sank, the more the air in the bell was compressed by the rapidly rising water. Miraculously, the bell not only missed the S–4 by less than ten feet but also avoided at least a dozen boulders scattered on the bottom around them that Momsen could see through his glass eyeport. Thus far the sole injury either of them had suffered was the blood dripping from Church’s nose because of the sudden change in pressure.
The bell’s telephone was still working. He asked the officer in charge on the surface to transfer the retrieving cable to a capstan and to follow his instructions closely while hauling them up. It would be a ticklish operation. Momsen had to keep the bell this time at exactly the right degree of negative buoyancy or the whole problem would occur in reverse. Then, just as they reached the point where the trouble had begun, the errant motor that caused it all abruptly started working. Momsen forthwith informed the Falcon to slack off on the cable. He shifted the bell to positive buoyancy and reeled back down to the S–4 to complete the practice rescue. “Anyhow, you’ve learned a lot,” he consoled Church, “mostly in what not to do.”
Despite such mishaps and some obvious design shortcomings, the bell had been a huge success. The next step was to improve on the original, and a report incorporating the best ideas of everyone involved in the tests was prepared that would essentially transform what had been a diving bell into a rescue chamber. The new chamber had two compartments divided by a horizontal bulkhead equipped with an access hatch. The upper compartment would carry passengers seated on a circle of adjustable ballast cans, each holding seventy pounds of seawater that could be emptied as an equivalent weight of men came on board. I
t would also have a telephone, lights and fast-action valves for admitting and releasing compressed air. The lower compartment would include the air motor and reel for a single down-haul cable. Normally this compartment would be filled with water. If it had to be cleared, however, it was enclosed by a ballast tank capable of containing the same volume of water so that accurate buoyancy control could always be maintained.
Before Momsen could put these recommendations into effect himself, he was detached from the Bureau of Construction and Repair to train submariners in using the lung. Meanwhile Lieutenant Commander Allen McCann, who had arrived in Key West while the bell tests were in progress, was assigned to follow through on them.
When the revised rescue chamber was completed in the fall of 1930, Momsen and McCann tried it out in the same flooded dry dock at the Brooklyn Navy Yard where poor Watt had had his narrow escape. The chamber did everything asked of it, even landing on a symbolic hatch tilted thirty degrees and more. After this, it was loaded on the Falcon for a final checkout off New London. It was sealed and lowered to 400 feet for an hour. Next Momsen tested it on the S–4. Over and over he descended into swirling currents, into cold water, discolored water, deep water and shallow water. It functioned flawlessly, and one was ordered for each U.S. submarine command around the world.
But there was an ugly aspect to the story. Momsen in his stubborn drive to save submariners had stepped on too many toes, reddened too many faces, bypassed too many bureaucratic channels. Even the name “Momsen lung” had been a creation of the press. Its official name was the “Submarine Escape Appliance.” This time no chances would be taken. Although Momsen had conceived of the bell, fought for it and personally pioneered its development, putting his life on the line much of the way, it was publicly unveiled as the “McCann Rescue Chamber.”
Nine years later, as he sat in the Sculpin’s wardroom, only a hint of the hurt he had felt still tugged at him. What counted now was whether or not all his work would meet this unforgiving test.
