This CO2 Scrubber Killed Half the Crew

During a routine dive in Key West, Florida, a four-person submersible becomes entangled in the wreckage of a sunken warship, they are unable to free themselves and rescuers need to reach the men before their life support systems are exhausted. It is June 17, 1973 and the Johnson Cink

crew

are preparing to make a dive 50 nautical miles off Key West in Florida. They are diving into the wreck of the USS Fred T Berry to recover a fish trap designed to help scientists monitor fish populations. The Berry was a US Navy destroyer commissioned right at the end of World War II, after finishing her service in 1971, she was scuttled at

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Key West location to create an artificial reef for the Marine life.

One of the men aboard the research vessel. Robert Meek is an ethologist or fish biologist. studying the fish that inhabit the baya recess the Johnson cink is a submersible specialized in deep-sea scientific research. It is licensed to carry people and research equipment to a maximum depth of 305 M. It was built 2 years earlier and is designed to transport up to five

crew

the crew is divided into two separate compartments the pilot compartment is an acrylic sphere 1.5 m in diameter and approximately 10 cm thick that offers a panoramic view during the dive during the dive the pilot compartment remains at the same air pressure than the surface the rear The compartment is a diving compartment with capacity for three divers.

The dive compartment is designed for deep lock diving. It is an aluminum cylinder 2.5 m long and 1.5 m in diameter with welded hemispheres at each end. It is similar to the appearance of the Ocean Gates Titan. Except there is a hatch at the bottom for divers to exit and enter the ocean like a diving bell, the diver compartment can be pressurized to the same pressure as the depth of the ocean, allowing divers to exit to through

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hatch and carry out their activities. diving the two compartments are not designed for the crew to move between them they are confined to the pilot's compartment or the diver's lock compartment immediately behind the diver's compartment there is another sphere to contain the diving gas the gas in the cylinder is 86 .5% helium and 13.5% oxygen, that cylinder can withstand up to 130 bar of pressure, but I am not sure if it is full at the time of diving and I do not know the capacity of the cylinder.

The designer and builder of the roofs was Edwin Albert Link and he aboard the roof support ship, the research vessel Sea Diver, diver SE has transported the roof from Key West to the wreck during the course of the morning , members of the research vessel's crew will supervise the roof dive and, although there appears to be no formalized command structure Edwin Link is effectively in command of the diving operation aboard the Cink are the vessel's pilot Archal Mensy and scientist Robert Meek in the pilot's compartment two passengers Albert Stover and Edwin Clayton link are in the diving compartments Edwin Clayton link is the son of Edwin Albert Link and is known as Clayton, although these two are in the diving compartment, They do not plan to dive and, like the pilots' compartment, the dive compartment will be sealed and maintained at the same pressure as the surface on which it won.

Do not be pressured into performing a blocking dive, this is a routine dive and, according to the US Coast Guard's investigation into the dive, is the 130th dive the seink will perform. This Coast Guard report contains detailed information about the dive and is where I gathered most of the information for this account before the men departed. Everyone gets ready. The Coast Guard report gives me the impression that they are pretty casual about safety in the dive compartment. Stover and Clayton Link, who are there as observers of the investigation, are dressed only in shorts and T-shirts. It is very cold at the planned dive depth and your choice of clothing does not take into account delays or difficulties.

Meek, who will be in the pilot's compartment, warns them but they don't change their clothes. The pre-launch security check on the roof. The link is completed by a training pilot in place of Menes. Discover a potential problem. The training pilot discovers that one of the two fans in the CO2 purification units in the pilot's compartment is not working. The CO2

scrubber

unit is there to absorb excess carbon dioxide. Keep the air in the pilot compartment safe to breathe. It will work with only one fan, but if the second fan stops working, then there will be no backup.

Instead of fixing the faulty fan, the training pilot casually mentions the problem to the men as he enters the boat. The dive, the expedition continues without a backup fan, the boat is hoisted into the sea and at 08:36 the roof submerges below the waterline, it heads down and 9 minutes later the four men are at 104 M deep on the ocean floor, the Menses pilot turns off the engine in order to estimate the conditions of the underwater currents by observing how much the maritime link moves in the water. He estimates the drift to be about 0.4 knots and visibility is poor.

This is quite normal at 100 m depth in this area of ​​Key West. Before leaving, trim the The boat should have a slightly negative buoyancy, meaning that she will sink slightly in the water. He does this to have better control over the vessel and prevent it from floating up and touching anyone when it is closer to the sunken warship and then heads towards the wreck of the Berry at 09:04 the crew sees the anchor chain del Berry as they approach the ship. They are on the north side of the Berry. They have to climb up and over the boat to get to the other side where the fish traps are located. they pass over the berry and then the man drops the roof back to the ocean floor just past the fish trap, turns around and prepares to approach the trap.

Fish traps are located 4.5 m away from the berry. It is a good place to catch fish, but you have to be careful while they are so close to the wreck that you approach the trap slowly and carefully by manipulating your side engines, rear engines and both gut thrusters. They only have to travel 12M to reach the trap, which takes a few moments. The approaching men smell burning in the pilot's compartment and think there may be an electrical fault. They open the electrical covers to investigate but find no problem. I imagine the problem distracts the men and probably worries them, but they can't find the fault.

They continue and reach the trap, all they need to do is pick it up and bring it to the surface. It should be a simple procedure on the front of the roof link there is a 2.5M arm with a fork at the end for pick up. the trap, the fork is pushed onto the fish trap rope which is a line with two buoyant balls that keep the line up when the fork on the arm engages with the line, a mouse device locks the line in its place, as if a carbine were attached to a rope. Float balls prevent the line from falling out of the fork and the take-up procedure is complete.

Menes tries to lift the trap. He feeds the recovery line into the fork, but the mouse device fails and the line comes back out. He tries again. The arm is fixed. towards the roof it is not a robotic arm to be able to pick up the line the pilot must maneuver the roof until it is in position he goes back a short distance to try again he puts the line in the fork and again the mouse device fails he goes back he gets up and comes back to try the equipment fails with three failed attempts the crew decides it's not going to work and aborts the mission I guess they plan to return to the surface fix the passage device on the arm and then return to try again while he is moving the sink away from the trap allows the bow of the boat to drop and tilt slightly to port by about 5 to 10° the pivot point is in the center of the submersible when the men lower the bow to port the stern rises equally to starboard the backs of the men Next men move the roof further away from the trap so they can get far enough away from the berry to be able to climb to the surface.

They have been at the bottom of the ocean for an hour and it is around 09:45 when the men are behind the roof. up still tilted at a slight angle it stops with a sudden jerk the ship is caught in a cable from a flagpole on the sunken ship but the men cannot see that it is caught by a hook on the starboard side of the roof is what same type of hook they are using to try and catch the fish basket, but this one works, it is also stuck under some other parts of the roof sticking out on the starboard side, the men cannot see because their view of this area is obstructed for an air conditioning unit the vision from the pilot bubble is very good except for this particular blind spot, move the ship to try to get them out but they can't escape, they can move about 6m in any direction or turn through a marking around 270° but that's it, they are trapped 110 M deep with no obvious way to escape.

The four men on the roof begin to assess the situation they are in to determine what they can do to communicate between the pilot compartment and the dive compartment. goes through an intercom system. The men and meeks in the cockpit have to switch between listening mode and talking mode when communicating with the two men in the diving cabin. Stover and Clayton connect by simply talking or listening over the intercom without having to flip a switch. The dive compartment line is constantly open so pilots can monitor the divers' compartments. They can also be seen through a porthole in the front of the dive compartment the men try a few more maneuvers to free the roof but think they are just getting more entangled and decide to stop at 0953 men call the diver using an underwater phone to inform the dive command team about the situation after they are done After talking to the men on the roof they connected the command team to the diver's radio.

The Coast Guard reported the situation and asked them to send Navy divers. Looking at the Coast Guard report, it appears that neither the Coast Guard nor the diver's crew believe the danger is immediate. A request for divers may seem quite drastic, but perhaps no one is worried because they believe they have plenty of time to carry out a rescue, whether with divers or by other means. They hope that the life support system on the roof will keep the men alive long enough to plan and execute a rescue. They just have to find a way to rescue the ship.

They call the Coast Guard at 105. The information passes through the Coast Guard chain of command and reaches the US Navy. The Navy decides to send the submarine rescue ship USS Tringa from Key. To the west of the scene, this boat has Di div on board, as well as other diving support equipment, and she is the right boat to perform this type of rescue. The ship is scheduled to depart at 3:00 p.m. as the Coast Guard and Navy begin coordinating a rescue. There is a discussion. between the diving command team in the marine diver and the men on the roof link on the possibility of doing a blockage dive the proposed plan is for a man to exit the diving compartment towards the sea to untangle the roof from the steel cable This is a simple plan and may seem like an obvious and easy solution, but unfortunately things are not simple in lock diving, the dive compartment has two hatches, one that opens into the dive compartment and another that opens toward the sea to open the hatch and do a lock dive they need to increase the pressure inside the compartment until it is equal to the pressure of the water if the pressure is not equalized then the outer hatch will not open they have compressed gas in the supply cylinder gas they could use that gas to equalize the chamber pressure, but that's a gamble, the increase in pressure will create an increase in the partial pressure of oxygen in the diving compartment at a depth of 110 M, the surrounding pressure is 12 atmospheres, 13.5% oxygen will have a partial pressure of 1.62, men would have To breathe oxygen at this elevated partial pressure in the diving compartment, the air we breathe above the waterline has 0. 2 partial pressure of oxygen, the maximum level we can tolerate is 1.6 for a short period of time.

Dr. Youngblood, an expert in diving physiology who is aboard the A support diver estimates that spending more than 2 hours at that partial pressure could be fatal and advises against the attempt if the men dive butThey discover that they cannot untangle the boat and have to wait in the diving compartment. Rescuers on the surface. You will only have 2 hours to get them out shortly after they decide not to attempt a blocking dive around 10:30. Man detects a buildup of CO2 in the pilot compartment, informs diver SE, and then checks the CO2

scrubber

, which he finds. is that the fan motor that was running now stopped.

The CO2 scrubber works by blowing air through a container containing a substance called barrel lime. The barrel lime absorbs CO2 and the fan simply moves air through the barrel lime to encourage it to absorb CO2 without a fan. will not work and CO2 levels will rise to toxic levels. Exposure to high levels of carbon dioxide can be fatal fairly quickly, but Menses has an idea: He takes off his shirt and empties the Li barrel of the scrubber into his shirt and then holds his barrel. full shirt in front of the air conditioning fans in the pilot compartment works this system creates an artificial CO2 scrubber to replace the one they lost without this improvised solution the CO2 levels would increase to toxic and then fatal levels if the CO2 levels increase there are an emergency supply of oxygen that can be breathed through an oxygen mask, although the supply is limited and they don't want to end up depending on it, from the report it seems they only have a few hours of air in the pilot compartment, but for now all is well at 11:3 the men inform the diver that the CO2 levels in the pilot compartment are dropping, they exchange the men's shirt for a spare canister of barrel lime to create a more permanent solution and many save the barrel lime from the original container for later, in case they need it, the efforts on the surface begin to increase around noon, a small boat of the sea diver tries to carry a rope to the roof link.

The idea is that when the Navy divers arrive they will be able to use the line to descend directly to the accident ship, otherwise they will have to position the trer as accurately as possible and then lower the divers, which is not an easy task, At more than 100 m of water there is a buoy line that marks the berry but does not descend to the ceiling. They know the approximate position of the berry and they know the roofs on the south side, but getting an accurate position is difficult and they need an accurate position. Trer divers will use the surface.

They are supplied with gas, which means they have a long hose that goes down with them. If they land in the wrong place, they will have to drag 100m of hose through the water, or worse, if they land on the berry, they could snag their own supply lines in the water. ship the diver's ship tries to lower a line but the line marking the berry is in the way while this is underway Navy commanders in Key West called in the US Navy Submarine Development Group in San Diego, California, to ask for help and prepared a roving unit.

The diving bell with support personnel and equipment will be delivered by air to Key West. The diving bell offers an alternative if divers in the trer are unable to rescue. The ship just before the diving bell leaves California, the USS Trer arrives on site. Dr. Youngblood and the support crew aboard the fesal marine dive support diver estimate how long the CO2 scrubbers will last on the marine link. They should last the time necessary for the sea link to be rescued based on the assumption that the temperatures on the ship. will remain at 21° C. They estimate that the pilot compartment will have 42 hours and the diving compartment will have 61 hours, so although the situation is urgent at least they have plenty of time, now it is 4:15 p.m. and the sink is stuck in the bottom of the sea for 6 and a

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hours since the train arrived it has been trying to position itself precisely on the roof.

They have tried to determine the exact location of the submersible by lowering lights into the water for the men to see and the men flashing on the roofs. lights for the trer to see, they manage to see each other, but according to the Coast Guard report they cannot obtain an exact location, so they have to estimate as accurately as possible, the trer begins to maneuver to place a Ming of four points on the roof. position to send divers down need the stability of a four point Ming, but it takes time to establish by 2015 the trinker completes his Ming within 10m of the child's line marking the berry the hope is that the positioning will be precise and the divers descend close enough to the roof while the trer dive prepares to enter the water the CO2 scrubbers in the roof diving compartment begin to malfunction the temperatures have dropped inside the compartment to lower temperatures the capacity of the chemical lime to absorb CO2 significantly decreases temperature in aluminum dive compartment is falling faster than acrylic pilot compartment according to Coast Guard report temperatures in dive compartment could be as low as 7° C men dressed in shorts and t-shirts they suffer from the cold and the lime in the barrel is rapidly losing effectiveness on the surface, they have calculated the air supply based on temperatures of 21 °C, when the lime in the barrel stops working, the carbon dioxide on the roof will become toxic, they will have to switch to using the mask supplied with oxygen that comes from a High Pressure Cylinder, although it is not clear from Coast Guard reports exactly how much oxygen there is.

This is a limited supply around 22:00. Stover and Clayton report that the LI barrel in their CO2 scrubber has lost all effectiveness and at 22:25 they switch to using MKS oxygen according to the Coast Guard report, as CO2 levels in the diving compartment increase. , the internal pressure in the diving compartment also increases to around two atmospheres, the pressure continues to increase until it reaches three atmospheres at 22:45, the men breathe oxygen from a pressurized cylinder as gas moves from a cylinder of high pressure towards the diving compartment, the pressure in the diving compartment increases two divers with helmets from the trer begin their descent of 110 M to try to locate the men from a depth of 96 M, they see the roof link they can see it below water from the side of the berry and it is caught on something they are close enough to see the container but can't reach it their path is obstructed by the remains of the berry making it look like a satellite dish is in their way along with other obstructions, they cannot pass through the obstructions with their surface.

Gas supply lines, so they can't reach the men to free them. Going any further would mean taking a big risk of getting tangled. They abort the dive and return to the surface while the Tringa divers slowly ascend making decompression stops. Personnel aboard the diver support vessel SE review the possibility of a blockage dive. It is a fleeting discussion. Stover and Clayton in the diver's compartment don't want to risk leaving. the sea link the diver's crew accepts his decision at 23:11 the oxygen supply runs out in the diver's compartment Stover and Clayton switch to the helium and oxygen gas supply at the rear of the boat as the Tringas divers slowly return to the surface the boat tries to reposition itself to have free access on the next dive on the roof, the pressure in the diving compartment continues to increase, reaching 10 atmospheres at midnight and at 00:15 the hatch opens when it reaches the equivalent of 12 atmospheres in the surrounding water pressure again the team discussed doing a blocking dive the Coast Guard report doesn't give much information on this conversation but I imagine the sea diver command crew is getting pretty desperate now maybe they are trying to convince Stover and Clayton to make the dive, perhaps Edwin Link believes it is the only hope for his son and Stover, they have a dwindling supply of oxygen-rich gas and once it is depleted, CO2 levels will rise, they posited the idea of ​​a blockade dive with The two men in the diver's compartment, but according to the Coast Guard report they say they are too cold to try again, the diver's command crew accepts the decision of the two men in the roof link and wait for a dive rescue to be performed from the trer will operate at 0030 communications go silent with the men in the dive compartment as menes attempts to help the trer to position itself directly above him.

He is looking at the lights suspended beneath the trer to aid his positioning. It is unclear what is known about men in diving. compartment there is no contact with them after 0030, but we do not know if that is because they are unconscious or if communications stop working, it is very likely that the two men will slowly become incapacitated and unable to respond to any attempts to communicate with them. they. We don't know at what point their oxygen levels drop to the point of losing consciousness, it seems like they just go silent at 01:12 on the 18th. Menses informs the surface that Stover and Clayton Link are having seizures.

The two men are there. they are now suffering from carbon dioxide poisoning and there is a small chance that they can still be saved if the tringa divers reach them quickly Edwin Link hears the news that his son is about to die at the bottom of the sea 100 M below him, attention now Change to the two men in the pilot's compartment, its acrylic bubble is better insulated than the diver's compartment, but it is colder. Eventually the lime in their CO2 scrubber will stop working, so Manes and Meek will have to switch to their emergency oxygen supply as well.

Minutes pass and at 0135 the train divers begin their second dive to the roof link. It takes them 8 minutes to reach the bottom. They inform Menes that they have completed their descent. Men scan the ocean floor for diver lights. It is difficult to imagine a sense of panic rising among the men and the meek in the pilot's compartments. In the compartment behind them, their colleagues are convulsing. I'm sure they're worried not only about Stoker and Clayton, but they're also starting to think about the same fate for themselves. must be waiting for the divers to have landed close enough to rescue the seink, they might even save the men in the diving compartment if they bring them to the surface quickly.

He looks but can't see the lights from him once again. The divers have landed in the wrong place. side of the berry and have to dive at some point during the second dive, comes the roving dive. Bell flew from California to Key West, loaded onto a support ship and sailed to the location, transferring to the train at 0245 on June 18. Over the next few hours, the diving bell is prepared and an attempt is made to dive to the roof link at 0605. Two divers are in the bell, descend to 85 m in the bell and then begin their dive using the bell as a stopping point .

The diver leaves the Bell, he is immediately swept into a strong current, the current is so strong that he becomes entangled in his umbilical and cannot descend further. It takes him 15 minutes to untangle himself and return to the Bell, they abort the attempt and bring the Bell. surfaced, the USS Amberjack arrives on the scene. The rescuers then check the charts and discover that the current is tidal with the next low tide around 1200, there is another delay of a few hours at 0951, they send the Bell back with lights in place and no divers. so they can establish the correct location for the next dive when they lower the bell, the current pushes it towards the wreck and it gets stuck, they can't lower it or raise it any further, the rescue team regroups and formulates a different plan at 12:40 A.M.

The submersible ship called Perry Cub Marine that arrived aboard the USS Amberjack is sent to locate the cink. It has to return to the surface an hour and a

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later because its sonar is not working. It does not locate the seink. They have now been trapped for 30 hours, The two men in the diver's compartment, Stover and Clayton Link, have now been unresponsive for more than 13 hours, just before the Perry Marine Cup surfaces. The AB Wood 2 rescue ship reaches the sea just as the wood arrives. The lime barrel in the pilot's compartment runs out and the two men have to switch to using their oxygen masks.

They only have a few hours of oxygen left. I'm sure Menes and Meek hope they don't have to suffer the same fate as Stover. and Clayon's hopes now turn to the newly arrived ship. Timber. The ship has an underwater ROV with a camera that can be maneuvered by personnel on the surface. If they can get it down to the ceiling, they might decide what to do. The forest launches its ROV about an hour and a half after its arrival, shortly after, 1500 manage to lower the ROV's camera and for the first time get a clear image of the situation in which the seink is in the crew of the boatwood. see the cable that hooked the seink on its side looked after Dr.

Youngblood and the diver's crew miscalculated how quickly the barrel would deteriorate based on warmer temperatures. Now worried that the men in the pilot compartment have reached their last hours of breathable air, the clock is ticking, so the rescue party formulates a risky plan, they take the ROV back to the surface, attach a grael full tip with a 3 m long steel cable and lower it again with the camera guidance they managed. Attach a grael hook to the ceiling link. Meny sees the hook come in and reports it to the surfer in 1641 on the surface, the wood begins to rotate in the ROV which now has the marine link attached to the end of the cable in First, the submersible tilts at a steep angle held in the corner starboard rear by the safety hook that is hooked on the wreck, then the safety hook that holds the cable opens and the cable that holds them on the ocean floor is released, the roof rises to the surface while reeling the line in just 12 minutes later at 16:50 three the roof link finally rises into fresh air menes and meek will survive much like the diver's compartment when menes and meek started breathing from the oxygen tank the pressure inside the pilot chamber began to rise after they surfaced they are transferred to the tringas recompression chamber their decompression begins at 17:15 next The rescuers turn their attention to Stover and Clayton link there is still a small Possibility that they are unconscious but alive they tow the marine link out to sea and pull it aboard, they can see Stover and Clayton connect through the dive compartment windows.

There are no signs of life and it has been a long time since there has been a response from the men, but they will try to revive them anyway. goes next to the trinker and grabs a pressurized air hose from the boat, they use it to vent the dive compartment while it is still pressurized, they spray hot water over the sides of the El Al minimum compartment to try to raise the internal temperature, the hope is that if the men are still alive the air and heat will revive them the two men stay inside the diving compartment while it is filled with breathable air and heated at 1845 the ROV and camera are used to recover the menes diving bell and I complete their decompression at 19:15 and they are declared medically fit at 20,300 the diving bell is released and they climb to the ground everything is stowed and everyone is safe except Stover and Clayton Link in the seal diving compartments. 14 hours pass with no signs of life from the two men.

The doctors on board declare both men dead, stop operation of the ventilation and hot water, and begin depressurizing the compartment to recover their bodies. The autopsy shows that both men died of carbon oxide poisoning.