Chapter 28: The Emergency Procedure

The alarm sounded at 16:47, and the sound was wrong.

The alarm in the chamber was a tone — a sustained electronic note that the intercom delivered at a volume calibrated to wake a sleeping diver but not to startle a diving one, the volume a compromise between urgency and safety, the sound designed by engineers who understood that a man breathing heliox at fifteen atmospheres could not tolerate the adrenaline spike that a louder alarm would produce, the heart rate acceleration dangerous at depth, the blood pressure response amplified by the pressure, the body's reaction to alarm more volatile in the hyperbaric environment than at the surface, the physiology of fright different at 150 metres.

The tone was the general alarm. It was not the fire alarm, which was a different pitch. It was not the gas contamination alarm, which was intermittent. It was not the decompression alarm, which Kwame had never heard outside a drill and which he hoped, with the particular hope of a man who understood what explosive decompression meant, never to hear inside one.

The general alarm meant: something has happened. Stand by for information.

Gary's voice came through the intercom seven seconds after the alarm. His voice was controlled, the control itself a form of information — the voice of a man who was managing a situation rather than reacting to one, the professionalism a signal that the situation was serious enough to require professionalism and not so serious that professionalism had failed.

All stations, Gary said. DP anomaly. The vessel has experienced a thruster fault on DP thruster number three. The DP system is compensating. The vessel is currently within position limits. Bell is at depth with two divers deployed. We are initiating the bell recovery contingency. Divers, return to the bell immediately. Bellman, prepare for emergency recovery. This is not a drill. Confirm.

Kwame was in the chamber. He was not on the bell run. Mac and Sean were the divers. Fraser was the bellman. Kwame was in the chamber with Tomasz and Davy, and he could do nothing except listen to the intercom and stand in the living chamber and feel the vessel move.

The movement was the thing. The vessel had been stationary — held in position by the dynamic positioning system, the four thrusters maintaining the Highland Endurance directly above the work site, the position fixed to within two metres, the vessel a stable platform from which the bell descended on a wire that assumed the vessel would not move. When the vessel moved, the wire moved. When the wire moved, the bell moved. When the bell moved, the umbilicals that connected the divers to the bell moved, and the divers were pulled, and if the pull was large enough the umbilicals could be damaged or severed, and if the umbilicals were severed the divers had the bailout bottles — ten minutes of emergency gas — and nothing else.

Kwame felt the movement through the chamber hull. The movement was lateral — a slow, grinding shift to port, the vessel sliding across the surface of the sea as the remaining thrusters fought to compensate for the failed thruster, the DP computer recalculating the thrust vectors, the system attempting to maintain position with three thrusters instead of four, the mathematics of station-keeping rewritten in real time by the failure of a single component.

The chamber tilted. Not dramatically — a degree, perhaps two, the incline so slight that a standing man would barely notice it, but Kwame noticed it because he was attuned to the chamber's orientation the way a pilot was attuned to the horizon, the body's vestibular system registering the deviation from level, the inner ear reporting that the floor was no longer horizontal, that the chamber was no longer at its normal attitude, that the vessel had moved.

Fraser's voice came through the intercom from the bell, the voice pitched up by the helium but steady, the steadiness a thing that Fraser had earned, a thing that was different from the steadiness he had lacked in the trunk, the steadiness of a man doing his job in a situation where the job mattered in the way that it had always theoretically mattered but had never, until this moment, actually mattered.

Surface, Fraser said. Bellman confirming. Both divers are returning to the bell. Mac is one hundred metres out, returning along his umbilical. Sean is forty metres out, returning along his. I am taking in slack on both umbilicals. Bell position is stable. Bell depth is 153 metres. Standing by for recovery.

Gary's voice: Copied, Fraser. DP is compensating. Vessel excursion is currently four metres from station. We are within the yellow alert limit. If excursion reaches eight metres, we go to red alert and initiate emergency bell recovery. Confirm you are prepared for emergency recovery.

Fraser said: Confirmed. Emergency recovery prepared. Bottom hatch can be sealed in fifteen seconds once both divers are inboard.

The numbers were in Kwame's head. He had memorised them years ago, the numbers that described the margins of the system, the distances that separated normal from abnormal from emergency from catastrophe. The yellow alert was at five metres — the vessel five metres from its intended position, the bell wire angled, the umbilicals under lateral tension. The red alert was at eight metres — the vessel eight metres off station, the bell wire at an angle that could cause the bell to swing, the umbilicals stressed beyond their design tolerance. Beyond red was the unthinkable — the vessel continuing to move, the bell wire reaching its limits, the snap, the bell free-falling or the wire dragging the bell sideways through the water, the divers on their umbilicals caught in the geometry of a system that was designed for stasis and that was now in motion.

Sarah Webb's voice came through the intercom, the voice of the Life Support Technician providing the atmospheric data that she provided every hour but that she was now providing because the situation required the confirmation that the chamber and the bell were atmospherically sound, that the life support systems were functioning, that the gas supply was intact, that the men were breathing.

Chamber and bell atmospheric parameters are nominal, Sarah said. PPO2 zero-point-four bar. CO2 zero-point-three per cent. Temperature twenty-nine degrees. Gas supply reserves are at full capacity. Emergency gas reserves confirmed available.

Kwame stood in the chamber and listened. Tomasz was standing beside him, the Polish diver's face calm, the calm of a man who had been in situations before and who understood that the situation was not yet a crisis, that the system was responding, that the procedures were being followed, that the margins still existed. Davy was on his bunk, sitting upright, his hands on his knees, the hands steady — the HPNS resolved, the tremor gone, the steadiness holding even now, even in the alarm, the body's accommodation with the depth tested and found sufficient.

Mac's voice from the sea floor: Bellman, I am at fifty metres from the bell. Returning along the umbilical. Speed is limited by the current. The current has increased — I am estimating zero-point-five knots from the south, consistent with the vessel excursion. Confirm.

Fraser said: Copied, Mac. Your umbilical is clear. Continue return to bell.

Sean's voice: Bellman, I am at the bottom hatch. Ready to enter the bell.

Fraser said: Copied, Sean. Enter the bell.

The intercom carried the sounds of Sean's entry — the clang of the helmet against the hatch rim, the scrape of the bailout bottle on the steel, the grunt of a man pulling himself up through the bottom hatch of a diving bell at 153 metres while the bell swayed on its wire, the sway imperceptible to the instruments but perceptible to the diver entering the hatch, the body registering the motion that the gauges could not display.

Sean was in. One diver recovered. One diver still on the sea floor.

Gary's voice: Vessel excursion is now six metres. Repeat, six metres. Approaching yellow alert limit. DP is compensating. Thruster three remains offline. Engineering reports the fault is in the thruster control module. Repair time estimated at twenty to thirty minutes. We are holding position on three thrusters.

Twenty to thirty minutes. Mac was fifty metres from the bell, swimming against a current that had increased because the vessel's movement had disturbed the water column, the thrusters pushing water that created current that pushed against the diver who was trying to reach the bell that was trying to remain stationary beneath a vessel that was trying to remain stationary above the work site, the system of stabilities disturbed, each element affecting every other element, the chain of consequences rippling from the failed thruster control module through the DP system through the vessel through the water through the bell through the umbilical to the diver on the sea floor, the man at the end of the chain, the man who experienced the consequences of every failure upstream.

Kwame could do nothing. This was the particular torment of the chamber during an emergency — the confinement not merely spatial but operational, the men in the chamber sealed behind the pressure, unable to assist, unable to act, unable to do anything except listen to the intercom and stand in the living chamber and wait for the information that would tell them whether the situation was resolving or escalating, whether the margins were holding or closing, whether their crewmates were safe or not.

He stood at the intercom panel. He pressed the transmit button. Gary, he said. Kwame here. What is the bell wire angle?

Gary said: Bell wire angle is three degrees to port. Within limits. If excursion reaches eight metres, the angle will increase to approximately five degrees, and we will initiate emergency bell recovery regardless of diver position.

Regardless of diver position. The phrase meant: if the vessel moved too far, the bell would be recovered whether Mac was inside it or not. The bell would be pulled from the water, the bottom hatch sealed, the bell brought to the surface, and Mac would be on the sea floor with his bailout bottle — ten minutes of gas — and the bell would be above him, ascending, the connection severed, the umbilical pulled from the water like a root pulled from the soil, the diver left at depth.

The scenario was in the procedures. The scenario was trained for. The scenario had contingencies — the standby bell, the second bell that could be deployed in an emergency, lowered from the vessel on a separate wire to recover a diver who had been left on the sea floor. The standby bell could be deployed in forty-five minutes. The bailout bottle lasted ten. The gap between the two numbers — thirty-five minutes — was the gap that the diving industry referred to as the intervention gap, the period during which a diver on the sea floor without a bell was breathing his last gas and waiting for the recovery that might arrive in time and might not.

The gap was survivable only because of the emergency procedures that every diver memorised. The diver would find his emergency gas supply — the bailout bottle, a small cylinder of heliox strapped to his harness. He would switch to the bailout. He would control his breathing — the long, slow breaths that extended the gas supply, the breathing discipline that was the last tool available to a man whose equipment had been reduced to the minimum. He would wait. He would wait on the sea floor in the dark and the cold, the hot water suit cooling, the body's heat draining into the three-degree water, the cold the second enemy after the gas, the cold closing in at the rate determined by the thermodynamics of a human body in a neoprene suit without circulation, the rate approximately one degree of core temperature per ten minutes, the mathematics of survival a countdown.

Mac did not need the bailout. Mac was swimming. Mac's voice came through the intercom with the steady cadence of a man who was working hard but was not panicking, the breathing audible between the words, the breathing the sound of effort rather than alarm.

Bellman, Mac said. I am at twenty metres. I can see the bell's lights. Continuing approach.

Fraser said: Copied, Mac. Your umbilical is clear. Bottom hatch is open. Sean is inboard.

Gary's voice: Vessel excursion is holding at six metres. DP is stable on three thrusters. Engineering reports progress on the thruster control module. Estimated repair time now fifteen to twenty minutes.

The numbers were improving. Six metres, holding. Fifteen to twenty minutes. The margins were not closing. The margins were holding, the system stabilising on three thrusters, the vessel finding its balance on the reduced power the way a man with an injured leg found his balance on the remaining leg, the gait altered, the stability reduced, but the position maintained.

Kwame stood at the intercom and waited. Tomasz stood beside him and waited. Davy sat on his bunk and waited. The chamber held them and they waited the way the bellman waited for the divers, the way the mother waited for the letter, the way the tree waited for the fruit — without the ability to act, without the power to affect the outcome, the waiting not passive but attentive, the attention the only contribution available to men who were sealed inside steel at fifteen atmospheres while their crewmates navigated a situation on the sea floor 153 metres below.

Mac's voice: Bellman, I am at the bottom hatch. Entering the bell.

Fraser said: Copied, Mac. Enter the bell.

The sounds came through the intercom — the clang, the scrape, the grunt, the sounds of a second diver pulling himself through the hatch of a bell that was swaying on its wire above a sea floor that he had just swum across in a current that was trying to push him away from the thing that was trying to hold him, the bell, the sphere, the small container of air and light and connection that was, for the diver on the sea floor, the difference between life and the absence of it.

Mac was in. Both divers recovered.

Fraser's voice: Surface, all divers are inboard. Sealing the bottom hatch.

The sound of the hatch closing — the heavy, mechanical sound of the steel disc rotating into the sealed position, the dogs engaging, the seal compressing, the bell becoming a closed system, the atmosphere inside preserved, the water outside excluded, the hatch the boundary between the bell and the ocean, the boundary sealed, the men inside.

Gary's voice: Copied, Fraser. Bottom hatch sealed. Initiating bell recovery. Bringing the bell up to the transfer chamber. All stations, the situation is stabilising. Vessel excursion is five metres and decreasing. DP is maintaining position on three thrusters. The bell is being recovered.

The bell ascended. Kwame could not see it but he could hear the lifting wire through the chamber's hull — the wire running through the sheave on the vessel's deck, the wire pulling the bell up through the water column, the bell rising from 153 metres at a rate faster than the normal ascent rate because the recovery was urgent and the vessel was still off station and the bell needed to be out of the water before the situation changed again, the bell rising through the dark water toward the grey water toward the vessel, the ascent a rescue, a retrieval, the system pulling its most vulnerable component out of the most dangerous position.

The bell arrived at the transfer chamber. The mating process — the bell clamped to the transfer chamber trunk, the pressures equalised, the hatch opened, the three men — Fraser, Mac, Sean — passing through the trunk into the transfer chamber and from there into the living chamber, the transit that was always routine now carrying the weight of relief, the crawl through the ninety-centimetre tube a passage from the emergency back to the ordinary, the trunk delivering the men from the bell to the chamber the way the birth canal delivered the child from the womb to the world.

Mac came through last. He stood in the living chamber and he was breathing hard, the breathing of a man who had swum one hundred metres against a current at 153 metres depth, the exertion written in his face, the redness of effort beneath the flush of the hot water suit, the sweat on his forehead. He sat at the table. He put his hands on the surface. The hands were steady.

The vessel's thruster was repaired at 17:23 — thirty-six minutes after the alarm. The DP system resumed full operation. The vessel returned to its station. The bell wire angle returned to zero. The excursion returned to within two metres. The system returned to normal.

Gary came on the intercom. He delivered the debrief — the facts, the timeline, the sequence of events, the actions taken, the outcome. The debrief was the industry's way of converting an experience into a record, an event into a procedure, a crisis into a lesson. The debrief took twenty minutes. The men in the chamber listened. The men asked questions. The questions were practical — what failed, why it failed, what was done, what would be done to prevent it from happening again.

Nobody asked the other question, the question that was not practical and that did not belong in the debrief. Nobody asked: what would have happened if Mac had not made it back. Nobody asked about the thirty-five-minute gap, the gap between the bailout and the standby bell, the gap that Mac would have occupied alone on the sea floor in the dark while the cold closed in and the gas diminished and the mathematics of survival counted down.

Nobody asked because everybody knew. The gap was the thing they carried. The gap was the margin that they worked inside. The gap was the space between the system's promise and the system's limit, the space in which the diver's life depended not on the equipment or the procedures or the engineering but on the things that could not be engineered — the luck, the current, the timing, the body's willingness to swim one hundred metres against the current fast enough.

Kwame did not write in his notebook that night. He lay in his bunk and he looked at the chamber ceiling and he thought about Mac swimming in the dark, swimming against the current, swimming toward the bell, the bell swaying on its wire above him, the bell's lights visible in the murk, the lights the only lights, the bell the only destination, the umbilical the only guide, the man swimming through the margin between the system's design and the sea's indifference, the man swimming through the gap.

He thought about the gap in his own life — the thirty-five minutes between the bailout and the standby bell, the gap between the money he sent and the presence he did not provide, the gap between the letter and the visit, the gap between the uncle in the photograph and the uncle at the kitchen table, the gap that was survivable only if the recovery arrived in time.

The chamber hummed. The pressure held. Mac slept in his bunk, three metres away, the breathing steady, the man recovered, the diver returned, the gap closed for today.

For today. The gap was always closing and never closed. The gap was the condition. The gap was the industry. The gap was the sea.

The vessel held its station. The thrusters hummed. The bell sat on its handling frame, empty, cleaned, checked, ready for the morning run, the bell waiting the way it always waited — patient, orange, spherical, the container that would descend again tomorrow into the dark water and hold the men while they worked in the gap between the system's promise and the sea's indifference, the bell the last connection, the bell the thing between them and the depth, the bell the only home at the bottom.