He Named My Offshore Corrosion Discovery After Himself — Then the HSE Investigator Asked Him to Identify the Alloy in the Failed Weld
The electrochemical sweep interface displayed the final data points in real time, plotting a series of logarithmic values that defined the thermodynamic boundary of the metal junction.
Adjusting the copper contact clips on the working electrode, Dr. Fatou Dieng checked the cell connection. A faint smell of electrochemically generated chlorine and damp salt lingered around the glass beaker, a constant reminder of the aggressive chemical environments she simulated daily.
On the high-resolution monitor, the logging software plotted the polarization curves for the carbon steel and duplex stainless steel galvanic couple.
The red curve traced the anodic dissolution of the carbon steel anode. The blue curve represented the cathodic reduction occurring on the duplex stainless steel. Replicated from the platform’s splice zone specification, the electrolyte—synthetic North Sea seawater at 10°C with 8 ppm dissolved oxygen—filled the temperature-controlled cell, kept at a constant baseline by the external chiller unit.
At the intersection of the two curves, the mixed potential of the system settled. This crossing point dictated the steady-state potential and the galvanic current density the couple would adopt in actual seawater.
She read the intersection coordinates from the data table: mixed potential at −728 mV versus the saturated calomel electrode, galvanic current density at 87.4 µA/cm².
Inputting these values into the Faraday’s Law spreadsheet on her workstation, Fatou calculated the corrosion rate.
The metal loss at the carbon steel anode was 3.8 mm/year.
No sound came from the workspace except the quiet, rhythmic hum of the potentiostat’s cooling fan.
Across the lab, Moussa logged the electrode impedance measurements from the previous test run. The twenty-seven-year-old lab analyst had spent eight months preparing metal samples, his fingertips calloused from polishing steel with silicon carbide papers down to a 1200-grit finish.
“Moussa,” Fatou said, pointing to the screen. “Come here.”
Leaving his logbook, the assistant walked over to the workstation, wiping his hands on a heavy cotton towel.
She pointed to the screen—the two curves, the intersection, the mixed potential.
“The red curve is the anodic dissolution of the carbon steel,” she said. “As we sweep the potential in the positive direction, the carbon steel oxidizes faster. The blue curve is the cathodic reduction on the duplex stainless steel. Where they cross—that is the mixed potential. The current at the intersection is the galvanic current flowing from the carbon steel to the duplex SS. That current corrodes the carbon steel.”
Moussa leaned closer, tracking the grid lines.
He said: “87.4 µA/cm².”
“At 87.4 µA/cm²,” she said, “the carbon steel at the connection geometry loses material at 3.8 millimetres per year.”
She let him sit with that, the heavy silence of the lab pressing against the hum of the chiller.
“The design assumption for corrosion allowance at this connection,” she said, “is 0.95 millimetres per year.”
He looked at the screen.
He looked at the curves.
He looked at the intersection again.
“Four times,” he said.
“Four times the design assumption,” she said. “The connection has an 8-millimetre wall thickness. At 3.8 mm/year, through-wall perforation occurs in approximately 25 months under current cathodic protection conditions. The cathodic protection system is designed for the NORSOK 0.95 mm/year corrosion allowance. It is not designed for this.”
Taking the printed Evans diagram from the plotter tray, she laid it on the wooden lab bench. A green smear of dried salt from the electrolyte cell stained the lower margin of the heavy-stock paper. With a blue biro, she circled the mixed potential intersection, pressing hard enough to dent the page.
She wrote “3.8 mm/yr at anode” below the circle, with a sharp, definitive arrow pointing to the intersection.
She stood back from the desk.
She crossed the lab to the board wall—the section of corkboard she had kept clear for analysis outputs that needed to stay visible, free of the daily clutter of requisitions.
She pinned the print at eye level, in the upper left quadrant, exactly in the position she used for foundational teaching references.
The red anodic curve.
The blue cathodic curve.
The intersection circled in blue biro.
“3.8 mm/yr at anode” in her handwriting.
She stepped back.
She said to Moussa: “When you run a new galvanic couple, this is the baseline you check against before running your own intersection.”
He said: “Yes.”
ICorr-SA-FD-7718 was etched into the session header of the dataset she had just closed, a permanent digital watermark of her technical jurisdiction.
She read the HSE submission on a Thursday afternoon, sitting alone at her desk while the rain beat against the heavy thermal glass of the laboratory window.
The document was titled “Eriksson Corrosion Risk Assessment — materials integrity assessment prepared under Chief Materials Engineer P. Eriksson.”
She found her name buried deep in the acknowledgements section, a footnote to her own discovery.
“Electrochemical analysis support: Dr. Fatou Dieng, ICorr-SA-FD-7718.”
She read that line twice, the cursor blinking impassively at the end of the sentence.
She looked up at the lab wall.
The polarization curve print.
The blue circle.
“3.8 mm/yr.”
She opened the ICorr registration record on her computer, the official database loading slowly over the secure network.
ICorr-SA-FD-7718.
SeniorAssocICorr.
Dr. Fatou Dieng.
She closed it, her hand steady on the mouse.
She looked at the HSE submission on her screen.
She looked at “electrochemical analysis support.”
She went back to the Evans diagram dataset, the raw voltage and current arrays demanding her focus.
Three weeks earlier, she had reported the 3.8 mm/year finding to Eriksson in his office, the smell of his expensive espresso machine masking the metallic tang she was so used to breathing.
She had the printed Evans diagram—before she had pinned it to the lab wall, before the blue biro circle had formalized the crisis.
She had placed it flat on his immaculate desk.
“The galvanic couple at connection C-4,” she said. “Carbon steel structural member to duplex stainless steel node. No insulating flange. The mixed potential analysis shows a galvanic current of 87.4 µA/cm². Corrosion rate at the carbon steel anode: 3.8 millimetres per year.”
Eriksson leaned over the diagram, adjusting his silver-rimmed glasses.
He was fifty-seven.
He had been Chief Materials Engineer for fifteen years.
He had read hundreds of corrosion assessments, treating them as administrative hurdles rather than physical inevitabilities.
“The design assumption was 0.95,” he said.
“Yes,” she said. “The NORSOK M-001 table gives 0.95 for carbon steel in seawater under freely corroding conditions. That table does not account for galvanic acceleration from a large-area cathode. Connection C-4 is directly welded to duplex SS—no isolation. The duplex drives accelerated anodic dissolution at the carbon steel.”
He looked at the print for a long moment, the quiet hum of the air conditioning filling the space between them.
He said: “3.8 mm/year. This is exactly the kind of proactive integrity intelligence that protects the asset.”
She said: “The connection requires a cathodic protection upgrade or materials redesign within 18 months. The analysis is certified under ICorr-SA-FD-7718.”
He said: “Good work, Fatou.”
He picked up the Evans diagram print from his desk, his thumb smudging the very edge of the graph.
He held it.
He looked at the intersection she had mapped, circled it in his mind, and set it back down.
She left his office.
She went back to the lab, where the air tasted of salt and chlorine.
She pinned the print to the wall.
She noted, without typing it into any official database: “protects the asset.”
The asset.
The analysis protected it.
She went back to the dataset.
The quarterly operational readiness briefing was held in the Alpha-9 command center, a heavy-doored control room overlooking the bleak, iron-gray swell of the North Sea.
Outside, rain lashed against the reinforced perspex windows.
Inside, thirty senior platform managers, integrity inspectors, and regulatory coordinators sat around a vast modular table, the air thick with the smell of instant coffee and wet woolen coats.
Eriksson commanded the floor during the afternoon session, stepping confidently into the harsh glare of the overhead projector.
He had titled his presentation “Galvanic Corrosion Risk Management at CS/Duplex SS Connections: A Gamma-7 Case Study.”
His slide 7 was her Evans diagram.
The red anodic curve, stark against the white background.
The blue cathodic curve.
The mixed potential intersection.
Her blue biro circle—magnified to three feet across on the projection screen, its slightly uneven, hand-drawn edges unmistakable.
Her handwriting: “3.8 mm/yr at anode.”
He swept a laser pointer across the intersection.
“Our corrosion assessment methodology identified a galvanic current density at the carbon steel and duplex stainless steel interface that produces a corrosion rate of 3.8 millimetres per year,” he announced, his voice projecting easily over the hum of the ventilation system. “That is four times the design assumption of 0.95 millimetres per year under standard NORSOK allowances.”
He said “our corrosion assessment methodology” with smooth, practiced authority.
He did not mention the Evans diagram setup parameters.
He did not explain the polarization sweep procedure.
He did not cite ICorr.
He did not mention ICorr-SA-FD-7718.
He did not speak the name Dr. Fatou Dieng.
Near the back of the room, Dr. Thomas Keller—the company’s HSE Regulatory Coordinator—watched the laser pointer trace the curves.
He had been the one who circulated the original Eriksson Corrosion Risk Assessment internally to the platform operators after the HSE submission was formally filed.
He had titled his distribution email: “Eriksson galvanic analysis — platform integrity reference.”
He had never looked at who else was listed deep in the technical appendices of the assessment.
He had never looked at “electrochemical analysis support.”
He had looked only at “Chief Materials Engineer P. Eriksson” printed in bold at the top of the cover page.
Watching the projection screen now, taking in the granular detail of the anodic dissolution curve, Keller thought: Eriksson really knows his galvanic analysis.
Three months after the Aberdeen briefing, Dr. Ingrid Bakke’s contact arrived.
The email breached Fatou’s professional inbox at 08:41 on a Tuesday morning, flagged with a stark red priority banner.
Subject: “HSE Formal Investigation — North Sea Platform Corrosion Integrity — ICorr Registration Required.”
She opened it, the glow of the monitor casting a pale light over her desk.
“Dr. Dieng — I am the HSE Materials Investigation Lead for a formal investigation into through-wall corrosion perforation identified at connection C-4, Platform Gamma-7, North Sea block 211/18. NDT inspection at C-4 has confirmed a 4mm-diameter through-wall channel in the carbon steel wall at the exact predicted location of elevated galvanic corrosion.
The investigation requires: one, the original galvanic coupling polarization curve analysis in full; two, documentation of the ICorr Senior Associate registration under which the analysis was certified; three, confirmation of your availability to provide expert technical evidence at the investigation hearing. ICorr-SA-FD-7718 is identified on the analysis documentation as the certifying registration. Please confirm your availability by close of business Friday.”
She read “ICorr Senior Associate registration.”
She read “ICorr-SA-FD-7718.”
She read “through-wall channel in the carbon steel wall at the predicted location,” the words carrying the immense, undeniable weight of physics proving itself true.
She set the mouse aside, feeling the sudden, cold adrenaline spike in her chest.
She stood up from her desk, the legs of her chair scraping loudly against the linoleum.
She walked to the lab wall.
The polarization curve print was exactly where it had always been—upper left quadrant, pinned at eye level.
The red curve.
The blue curve.
The blue biro circle.
“3.8 mm/yr at anode.”
She carefully unpinned the heavy-stock sheet, her thumbs brushing the margins where the dried salt of the electrolyte had long ago crystallized. She verified that the intersection coordinates at the center of the blue biro circle remained perfectly legible, unchanged by time or corporate erasure. Satisfied, she held the print in her hands for a long moment, feeling its physical reality, before placing it flat on her desk.
She returned to her keyboard.
She did not call Eriksson to warn him.
She opened a direct reply to Dr. Bakke.
She confirmed her identity and confirmed that ICorr-SA-FD-7718 was her active registration.
She confirmed her availability to travel for the formal investigation hearing.
She wrote: “I will prepare the full analysis documentation including the raw polarization sweep data, electrode conditions, galvanic current density calculations, and the Faraday’s Law derivation.”
She hit send, the email vanishing into the external network.
She began the documentation package immediately.
The raw electrochemical sweep data from the Platform Gamma-7 analysis session—two files, 214 and 187 kilobytes respectively, the anodic sweep and the cathodic sweep, each irrevocably timestamped with the laboratory session date.
The electrode conditions log: synthetic North Sea seawater, 10°C, 8 ppm dissolved oxygen, electrode geometry replicating connection C-4’s as-installed dimensions.
The mixed potential derivation—the curve superimposition, the intersection coordinates, the corrosion current density reading.
The Faraday’s Law calculation—the atomic weight of iron, the carbon steel density, the current density to corrosion rate conversion.
The ICorr-SA-FD-7718 certificate—the Senior Associate designation, the scope of practice document, the registration expiry date.
The analysis report as originally drafted—with her name proudly on the cover page and ICorr-SA-FD-7718 boldly printed in the certification block.
The meticulous assembly took four unbroken hours.
She dispatched the encrypted package to Dr. Bakke at 13:22.
Then, she turned back to her active workstation—a different metal pair, a different subsea platform, a different current density problem waiting to be solved.
That same Tuesday afternoon, deep in the administrative wing of the Aberdeen office, Eriksson received the HSE investigation notification.
It had bypassed normal channels, arriving via the company’s registered legal address and forwarded directly to his desk by the regulatory administration team. The attached note was brief and terrifying: “HSE formal investigation — Platform Gamma-7 C-4 through-wall — your response required.”
He read the notification, his mouth going suddenly dry.
He understood instantly what the “through-wall finding” meant—connection C-4, the galvanic analysis, the 3.8 mm/year prediction manifesting as a catastrophic physical failure.
He picked up the phone, his hand trembling slightly, and demanded the integrity team in his office.
Their assessment came back within ninety agonizing minutes.
“The HSE investigation demands the physical presence of the ICorr Senior Associate,” the lead integrity counsel said, standing stiffly across Eriksson’s desk. “That is Dr. Dieng. ICorr-SA-FD-7718 is her specific registration. Your CEng MEng is a general management designation, not an ICorr registration. You cannot be examined as the ICorr Senior Associate on Evans diagram polarization curve methodology or galvanic current density calculations because you did not run those analyses.”
Eriksson swallowed hard, the reality of the regulatory trap closing around him. “Has Dr. Dieng been contacted?”
“She responded to the HSE this morning,” the counsel replied, his tone devoid of sympathy.
“She confirmed her registration and transmitted the full analysis documentation package.”
“She did not contact the company for permission before responding.”
Eriksson leaned back in his leather chair, the fight draining out of him.
He said nothing.
He stared at the HSE notification printed on his desk.
He looked at the project reference line, the very title he had claimed: “Eriksson Corrosion Risk Assessment.”
He sat alone in his darkened office until half past eight that evening, the glow of his monitor illuminating his exhausted face.
The executive building had emptied out after six.
The platform integrity team had gone home.
The regulatory administration team had gone home, leaving him to the quiet hum of the empty floor.
His executive assistant had left a single, terrifying printout perfectly centered on his desk: the HSE formal notification, with two specific paragraphs highlighted in stark, fluorescent yellow.
The first highlighted paragraph defined the severe scope of the through-wall failure investigation.
The second defined the strict requirement for the ICorr Senior Associate’s physical testimony.
He had read them both four times, rubbing his eyes until they ached.
He had been Chief Materials Engineer for fifteen years, ascending through the ranks by managing budgets, delegating technical risk, and commanding the room.
He had submitted eleven HSE structural integrity assessments across the company’s vast offshore portfolio.
Every single one had gone out under his name, carrying the weight of his CEng MEng title.
That was simply how the bureaucracy functioned—the company’s designated HSE correspondent submits the consolidated assessment, and the correspondent’s name goes on the cover sheet.
He was the correspondent.
He had understood that structural reality clearly for fifteen years, leveraging it to build his career, but he had never looked at it closely enough to see the gaping technical vulnerability that was now lying exposed in front of him.
He could explain the financial concept of corrosion allowance to a boardroom of investors.
He could quote the NORSOK M-001 tables from memory.
He could comfortably explain cathodic protection design at a high level—the theoretical current output requirements, the rough anode sizing, the generalized attenuation curves.
He had read enough technical corrosion assessments to speak fluently about material degradation in the administrative context of inspection scheduling and operational budget allocation.
But he could not explain Evans diagram polarization curve methodology.
If the HSE investigation examiner looked him in the eye and asked: *Dr. Eriksson, how exactly did you derive the mixed potential intersection coordinates for this specific couple?*
He would have absolutely no answer.
If they asked: *What is the precise mathematical relationship between the galvanic current density at this intersection and the Faraday’s Law corrosion rate you claimed?*
He would have no answer.
If they asked: *Why is 87.4 µA/cm² the empirically correct reading at the intersection, and how exactly is that critical number read from these superimposed logarithmic curves?*
He had no answer.
He cannot defend Evans diagram polarization curve analysis he did not conduct, and the sickening realization of his own technical inadequacy settled into his stomach like lead.
ICorr-SA-FD-7718 was stamped across the raw analysis documentation.
ICorr-SA-FD-7718 was Dr. Fatou Dieng’s personal, hard-earned registration.
His management-track CEng MEng was not ICorr.
He was not a practicing marine corrosion electrochemist.
He was just a materials manager with fifteen years of administrative platform integrity oversight, caught claiming the genius of someone else’s grueling laboratory work.
He looked down at the HSE submission printout on his desk, his vision blurring slightly.
“Eriksson Corrosion Risk Assessment.”
His name, bold and commanding, at the top.
Her name, minimized and easily overlooked, buried in the administrative acknowledgements.
“Electrochemical analysis support: Dr. Fatou Dieng, ICorr-SA-FD-7718.”
He had not physically typed those words.
The regulatory administration team had formatted the final submission from his generalized executive brief.
He had merely reviewed the formatting and signed the bottom line.
He had read “Eriksson Corrosion Risk Assessment” and comfortably understood it as the company’s collective submission—the integrity programme’s administrative product—rather than a fraudulent statement about who had actually built the complex galvanic coupling model.
He had been terribly wrong to understand it that way.
He had not known he was understanding it wrongly until this very evening, sitting alone in the dark.
The specific moment of his failure was a Tuesday afternoon in March, nineteen months ago.
He had been sitting exactly here, at this desk, sipping a fresh espresso.
He had held the Evans diagram print in his hand—she had just placed it firmly on his desk, the blue biro circle stark against the white paper.
She had said, looking him in the eye: “The connection requires a cathodic protection upgrade or materials redesign within 18 months.”
He had said: “This is exactly the kind of proactive integrity intelligence that protects the asset.”
He had been looking blindly at the diagram.
He had been seeing the phrase “4× corrosion rate” without grasping the physical reality of the metal eating itself alive under the freezing ocean.
He had been calculating—without using a spreadsheet—what it would cost the department to upgrade the cathodic protection at C-4 versus what it would cost in downtime if the connection eventually failed.
He had understood “protects the asset” purely as an operational budget observation.
He had not understood, in that critical moment, that identifying 4× galvanic corrosion at a specific offshore node—a brilliant, precise finding that, if acted on immediately, would definitively prevent catastrophic through-wall failure—was not merely “programme output.”
He had not understood that the finding was the actual, grueling work of science.
He had never bothered to examine whether “the execution was the invention.”
He had never stopped to examine whether the Evans diagram analysis was the automated output of his administrative infrastructure programme, or the brilliant, singular product of her elite professional expertise.
He had simply nodded and said, “Good work, Fatou.”
He had handed the print back to her, dismissing her from his office.
She had left, taking her brilliance with her.
He had received the 18-month emergency recommendation in the final analysis report.
He had filed it away, scheduling it as a standard priority inspection at the next routine cycle—twenty-four comfortable months away.
He had not escalated it to an emergency diving intervention.
He had administratively downgraded “requires within 18 months” to a mere recommendation.
He had contextualized it within a matrix of competing inspection priorities, neutralizing the threat on paper.
The massive through-wall perforation at C-4 had ruptured the system exactly nineteen months after her analysis, flooding the connection.
He picked up his desk phone, his hand heavy.
He opened the digital HSE submission amendment portal on his secondary screen.
He typed her name, the keystrokes echoing loudly in the empty office.
“Analysis by Dr. Fatou Dieng, SeniorAssocICorr, ICorr-SA-FD-7718.”
He was beginning to understand that there had been a specific, fleeting moment when he could have looked at this reality directly, acknowledged her brilliance, and done the right thing.
That he had been holding the profound evidence of her expertise—the Evans diagram—right in his hand when that moment arrived.
That he had stolen her credit with a dismissive “good work, Fatou” instead.
Down in the quiet, chemical-scented isolation of the corrosion lab, the polarization curve print rested flat on Fatou’s desk.
She had not pinned it back up since pulling it down to verify the coordinates.
She sat illuminated by the harsh glare of her computer monitors, compiling the final encrypted entries for the HSE documentation package.
The print sat beside her keyboard.
The blue circle faced upward, an undeniable marker of the truth.
“3.8 mm/yr” remained stark in her handwriting, an anchor of reality in a sea of corporate erasure.
The HSE investigation hearing was held in a windowless, concrete-walled emergency response bunker beneath the HSE’s Aberdeen field office on a brutal Thursday morning.
The air in the room was dense, thick with the smell of ozone from the overworked server racks and the tension of an impending disaster analysis.
Six chairs lined one side of a battered steel table for the investigation panel.
Two chairs sat exposed on the opposite side for the technical witnesses.
The investigation panel sat with rigid posture: Dr. Ingrid Bakke as lead investigator, flanked by two veteran HSE Materials Inspection Officers, and a silent investigation clerk hammering away at a stenographer’s keyboard.
Eriksson took a seat in the row of cramped observer chairs pushed against the damp concrete wall.
He cleared his throat, his voice lacking its usual boardroom resonance as the session officially opened. “Dr. Dieng is the ICorr-registered corrosion electrochemist who built the galvanic coupling model. The Evans diagram methodology questions are strictly for her.”
He sat down heavily.
He did not speak another word for the duration of the hearing.
Fatou sat entirely composed at the witness table, the harsh fluorescent lights casting sharp shadows across her face.
She had brought the polarization curve print—carefully rolled into the battered cardboard tube she used for transporting large-format technical data.
She unrolled it now, the heavy paper fighting to curl back on itself, and placed it flat on the steel table, weighting the corners with two dense documentation folders.
Beside the print, she placed the through-wall corrosion inspection photograph extracted directly from the HSE’s own emergency inspection report.
It was the NDT diving team’s terrifying close-up of connection C-4—a jagged, 4mm-diameter through-wall channel visible in stark cross-section, displaying the unmistakable, spongy morphology of rapid anodic dissolution rather than simple mechanical damage.
The Evans diagram.
The inspection photograph.
Side by side on the cold steel.
Dr. Bakke leaned forward, her eyes darting between the predictive curve and the catastrophic reality.
She asked Fatou to formally confirm for the audio-recorded investigation record the precise ICorr registration under which the platform analysis was legally certified.
Fatou kept her voice steady, entirely devoid of the nervous deferral common in corporate hearings. She stated that her certification was that of an ICorr Senior Associate, registration number ICorr-SA-FD-7718.
She detailed the stringent requirements of the Institute of Corrosion Senior Associate designation, emphasizing the demonstrated competence required in electrochemical corrosion measurement, corrosion rate assessment, and advanced cathodic protection design. She pointed directly to the signed analysis report on the table, noting that this specific registration number was stamped on every single page of the polarization curve dataset.
Dr. Bakke wrote furiously in her notebook.
The investigation clerk’s keystrokes echoed like quiet gunfire.
Dr. Bakke then requested a granular explanation of exactly how the 3.8 mm/year corrosion rate prediction was derived from the Evans diagram sitting between them.
Fatou traced the curves with her index finger, detailing the complex graphical method for determining the galvanic corrosion rate. She explained the necessity of running a separate anodic polarization sweep for the highly active metal—carbon steel—and a complementary cathodic sweep for the noble metal—duplex stainless steel. She specified the exact electrolyte conditions: synthetic North Sea seawater at 10°C, highly saturated with 8 ppm dissolved oxygen.
She tapped the intersection of the curves, where the superimposed plots of potential versus current density collided to determine the mixed potential the galvanic couple would unavoidably adopt in the brutal offshore environment.
She pointed to the blue biro circle on the print, the ink indented deeply into the paper.
“The intersection coordinates show the mixed potential at −728 mV versus the saturated calomel electrode, yielding a massive corresponding galvanic current density of 87.4 µA/cm²,” Fatou stated, her gaze locking with the lead inspector. “When converted mathematically using Faraday’s Law and the exact density of carbon steel, this current density yields an unavoidable material loss rate of 3.8 mm/year at the carbon steel anode.”
The first HSE Inspection Officer, a grizzled engineer with a scarred jawline, asked why the standard design allowance of 0.95 mm/year, derived from the NORSOK M-001 table, was insufficient for this specific connection geometry.
Fatou met his gaze without blinking, explaining that the NORSOK M-001 table blindly assumes a freely corroding steel member isolated in open seawater and fundamentally ignores galvanic acceleration.
When carbon steel is welded directly to duplex stainless steel without a heavy-duty insulating flange, the duplex SS acts as a massive cathodic area, aggressively driving the accelerated dissolution of the carbon steel anode. The Evans diagram was the only empirically valid methodology to analyze this couple.
The second HSE Inspection Officer pushed his glasses up his nose, asking for the technical basis behind her 18-month emergency intervention window recommendation.
Fatou gestured to the inspection photo. “The carbon steel wall thickness at connection C-4 is exactly 8 millimetres. At a highly accelerated corrosion rate of 3.8 mm/year, total through-wall perforation is mathematically guaranteed in approximately 25 months under baseline conditions.
I specified 18 months as the absolute maximum intervention window to provide a critical safety margin, because fluctuating seawater temperatures and surging oxygen levels during winter operational windows actively increase the cathodic current, pushing the corrosion rate even higher than 3.8 mm/year.”
The bunker fell dead silent, the only sound the hum of the ventilation fans.
Dr. Bakke tapped her pen against the table, noting that the through-wall perforation was physically discovered at 19 months. She asked if the connection between the prediction and the observed catastrophic outcome fell within the acceptable range of analytical uncertainty.
Fatou nodded once, a sharp, definitive motion. She confirmed that the prediction of 25 months under baseline conditions and the actual failure at 19 months under aggressive winter operational variations was entirely consistent, falling perfectly within the analytical uncertainty of the Evans diagram methodology.
Dr. Bakke wrote for a long, agonizing minute.
She looked at the Evans diagram print, the elegant logic of the curves.
She looked at the horrific through-wall inspection photograph.
She looked at the faded blue biro circle.
She looked back at the perforation photograph.
“Dr. Dieng,” the lead investigator finally said, her voice dropping an octave in profound respect. “Your ICorr registration and your Evans diagram galvanic coupling analysis are the absolute technical foundation of this investigation’s findings.”
The investigation record that the clerk was diligently building solidified into permanent regulatory history in that moment: *ICorr Senior Associate: Dr. Fatou Dieng, ICorr-SA-FD-7718. Evans diagram galvanic coupling analysis. Predicted corrosion rate: 3.8 mm/year at carbon steel anode. 4× design assumption.
Through-wall perforation confirmed at predicted location. 18-month intervention window explicitly stated in original analysis report. Perforation discovered at 19 months.*
There were three other HSE Inspection Officers in the cramped room acting as silent observers.
The first—a woman in her late forties who had spent twelve grueling years inspecting freezing North Sea platforms—stared intently at the Evans diagram print on the steel table. She had reviewed thousands of generic corrosion assessments.
She had never seen a single one predict a catastrophic through-wall location with such terrifying precision. She looked at the blue biro circle, then at the inspection photograph, then back at the print. She underlined a massive, heavily inked note in her journal.
The second observer—a male inspector in his early fifties—had actually reviewed the “Eriksson Corrosion Risk Assessment” when it had been filed with the HSE eighteen months ago. He had mentally flagged “Eriksson” as the Competent Person in charge.
He was now watching Dr. Fatou Dieng effortlessly dismantle technical questions he knew with absolute certainty Eriksson could not have even comprehended. He remained completely silent, deliberately copying the ICorr-SA-FD-7718 number from the investigation record printout into his personal file.
Thomas Keller, the company’s HSE Regulatory Coordinator, sat sweating in the observer row right beside Eriksson. He was the man who had blindly forwarded the “Eriksson galvanic analysis” to the offshore platform operators.
He watched Dr. Dieng explain the complex mechanics of the Evans diagram to the transfixed investigation panel, feeling the immense weight of his own administrative negligence. He refused to look at Eriksson.
After Dr. Bakke officially closed the formal hearing, Eriksson did not linger in the bunker.
He walked out into the freezing, rain-slicked car park, his shoulders hunched against the biting wind.
He did not wait for Fatou.
He called her mobile that evening, sitting in the dark cab of his SUV.
“The investigation outcome is satisfactory,” he managed, his voice hollow. “Your analysis was the sole technical basis.”
Fatou listened to the silence on the line, the sound of traffic bleeding through the connection.
“I have already filed the HSE submission amendment,” Eriksson continued, the words tasting like ash. “The permanent regulatory record has been formally amended to show your name and ICorr-SA-FD-7718 as the certifying engineer, going forward.
I am also implementing an immediate company protocol requiring the ICorr-registered corrosion engineer to hold named authorship on all HSE submissions involving galvanic coupling analysis.”
“The Evans diagram methodology was complete,” Fatou replied, her tone perfectly flat.
“Yes.”
A long, suffocating moment of silence stretched across the cellular network.
“Good work, Fatou,” he whispered.
“Yes,” she said, and ended the call.
In her hotel room, she rolled the polarization curve print carefully back upon itself.
She slid it securely into the cardboard tube, securing the plastic end cap.
She opened her laptop, the screen illuminating her face in the dark room, and pulled up the dataset for her next project.
That was the second, and final, time he had ever said “good work.”
Six quiet weeks after the investigation hearing, Fatou was back in her element, the steady, rhythmic hum of the corrosion lab a comforting baseline beneath the morning traffic outside.
It was a completely new project—a brutal manganese steel and titanium alloy galvanic couple extracted from a deep-water subsea umbilical system, representing a vastly different metal pair, a profoundly different offshore environment, and a highly complex electrolyte temperature question.
Across the room, Moussa stood focused at the electrochemical analysis station, methodically preparing the expensive titanium electrode—meticulously degreasing the surface, measuring the precise exposed area with a digital caliper, and securely connecting the fine potentiostat leads.
The battered cardboard tube rested quietly on the wooden bench near the door, exactly where she had left it the exhausted morning she had returned from Aberdeen.
She had not unpinned the print since the intense hours of the investigation hearing.
The heavy corkboard wall had remained starkly bare for six entire weeks.
She reached for the tube, popped the plastic cap, and carefully slid the heavy-stock paper out. She unrolled the old carbon steel and duplex stainless steel polarization curve print, the paper resisting her slightly before flattening out.
Before she permanently pinned it back to the corkboard as a foundational teaching reference, she ran her finger along the axes scale, feeling the slight indentations of her own pen pressure.
Before initiating the loading sequence for the massive new subsea dataset, she utilized the old print as a vital calibration reference—systematically verifying that the new Evans diagram axes were scaled consistently with her established baseline, ensuring that the critical potential range and complex current density range were configured appropriately for the unforgiving metal pair and freezing electrolyte she was about to interrogate.
The mixed potential for the new subsea couple would inevitably land at an entirely different, unpredictable position.
The catastrophic corrosion current density would be different.
But the beautiful, immutable logic of the intersection would remain exactly the same.
The red curve rising.
The blue curve descending.
The violent crossing point: the exact, unforgiving galvanic current the system would inevitably settle into under the ocean’s immense pressure.
The final HSE investigation record had been officially filed deep in the permanent regulatory archive.
*ICorr Senior Associate: Dr. Fatou Dieng, ICorr-SA-FD-7718. Evans diagram galvanic coupling analysis. Predicted corrosion rate 3.8 mm/year at carbon steel anode. 4× design assumption. Through-wall perforation confirmed at predicted location. 18-month intervention window explicitly stated in original analysis. Perforation discovered at 19 months.*
That specific record was now permanent, immortalized in the institutional memory.
Moussa paused his precise electrode preparation, glancing over his shoulder. “ICorr-SA-FD-7718 is in the final HSE record.”
She adjusted the corner of the heavy paper against the corkboard. “Yes.”
He nodded toward the wall. “The blue circle.”
She pressed the metal pin deep into the cork. “The blue circle is in the HSE record.”
He looked at the worn print on the wall, a quiet smile touching his eyes, before returning his absolute focus to the titanium electrode preparation.
The offshore integrity technical bulletin had been rapidly distributed to thirty-four distinct North Sea operators three frantic weeks after Eriksson’s Aberdeen conference—a crisp, three-page executive summary detailing the terrifying 4× galvanic corrosion finding at the carbon steel and duplex SS connection, outlining the polarization curve methodology, and issuing the severe inspection scheduling recommendation.
The bold cover of the bulletin still read: *Technical Bulletin OIG-BULL-2024-CR-047 — Galvanic Corrosion Risk at CS/Duplex SS Connections — Eriksson Corrosion Assessment.*
She kept the bulletin reference number securely in her files: OIG-BULL-2024-CR-047.
Thirty-four independent offshore operators had received it.
Not recalled.
It remained quietly filed away in their sprawling engineering archives, a testament to a stolen discovery.
The formal HSE submission amendment was actively registered in the HSE’s digital regulatory system: *Analysis by Dr. Fatou Dieng, SeniorAssocICorr, ICorr-SA-FD-7718.*
But the original, flawed submission was also permanently locked in the HSE’s regulatory system: *Eriksson Corrosion Risk Assessment.*
Both documents existed simultaneously as permanent, unalterable records of corporate reality.
The severe company protocol had arrived via a mass email attachment the turbulent week following the investigation hearing: *Protocol INT-MAT-2024-12: ICorr-Registered Corrosion Engineer Named Authorship Mandate for HSE Galvanic Corrosion Analysis Submissions.*
She had read the administrative mandate.
She had dragged it quietly into her company correspondence folder.
The massive new project brief had arrived directly from Eriksson on a quiet Friday afternoon.
Subject: *Galvanic Coupling Assessment — Subsea Umbilical — Manganese Steel/Titanium.*
The first line of the brief read: *ICorr lead: Dr. Fatou Dieng, ICorr-SA-FD-7718.*
She had opened the heavily encrypted file without hesitation.
She had immediately begun constructing the theoretical Evans diagram framework for the new, highly reactive metal pair.
Over at the electrode station, Moussa had the raw titanium surface perfectly prepared, the metal gleaming dully under the harsh fluorescent lights.
He checked the connection leads. “Ready for the first anodic sweep.”
She loaded the complex potentiostat parameters for the new, high-stakes run.
She meticulously set the slow scan rate.
She dialed in the broad potential range.
She stared intensely at the stark, blank Evans diagram axes displayed on the high-resolution screen—the empty digital space where the two curves would violently appear when the potentiostat sweep initiated.
She looked away from the monitor, her eyes drawn across the quiet lab to the print on the wall.
She looked at the faded blue biro circle.
The exhaustive manganese steel and titanium analysis would consume three grueling weeks of continuous laboratory work.
The manganese steel working electrodes had been painstakingly cut from a heavily weathered sample of the actual subsea umbilical steel—bearing the exact same metallurgical heat number as the failing installed system.
The opposing titanium electrodes had been precisely machined from grade 2 titanium, the specific commercial-purity grade explicitly mandated for the heavy-duty umbilical’s protective titanium sheaths.
Both metallic samples were laboriously polished to a mirror-like 1200-grit finish.
Both were firmly mounted in the dense resin-embedding compound that rigidly standardized the exposed cross-sectional area to exactly 1.0 cm².
The testing electrolyte was pure synthetic seawater, hyper-chilled to the umbilical’s brutal operational depth temperature: 4°C.
At that freezing 4°C, the dissolved oxygen concentration skyrocketed to 11.4 ppm—significantly higher than standard surface conditions.
Higher dissolved oxygen concentration meant a far more aggressive, unforgiving cathodic environment.
That increased aggression would violently shift the cathodic curve across the graph.
The mixed potential intersection would inevitably move.
She would need to know exactly where that crucial intersection moved before she could safely make the high-stakes corrosion rate prediction that would dictate the survival of the umbilical.
She was not guessing.
She was running the raw electrochemical curves.
The critical first sweep session was firmly scheduled for the following morning, right as the lab opened.
Moussa had absolutely everything prepared to a flawless standard.
He had meticulously logged the bare electrode masses using the micro-analytical balance before mounting—establishing the vital pre-exposure reference weight for each individual electrode.
He had flawlessly prepared the cold electrolyte—balancing the exact NaCl concentration, dialing in the precise pH adjustment, and stabilizing the complex temperature-controlled cell.
He had systematically labeled the awaiting data files: *MnSteel-Ti-4C-umbilical-session01-anodic.csv* and *MnSteel-Ti-4C-umbilical-session01-cathodic.csv*.
He was exceptionally thorough.
He had been exceptionally thorough since the very beginning of his tenure in her lab.
She looked back at the faded Evans diagram print pinned securely to the wall.
The red curve.
The blue curve.
The blue circle.
She thought, with a profound, quiet clarity: the massive corrosion current surging at the mixed potential out in the freezing ocean doesn’t know whose name is typed on the HSE submission cover page.
It was exactly 87.4 µA/cm².
It had always been exactly 87.4 µA/cm².
The catastrophic through-wall perforation tearing through connection C-4 confirmed unequivocally that it had been 87.4 µA/cm²—or even higher—from the very first day the heavy connection was welded into place over the churning water.
The raw metal had known the devastating truth long before the administrative submission was ever filed.
The metal had known the truth long before the Evans diagram was even run in her lab.
The brutal galvanic current had been flowing the entire time, silently eating away the steel in the dark, freezing seawater, settling perfectly at −728 mV versus the saturated calomel electrode.
ICorr-SA-FD-7718.
She looked at the blank, waiting axes on her glowing screen—the open, expectant space for tomorrow’s undiscovered curves.
She pinned it back. She looked at the blue circle.
