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NO.2 Ocean Pioneer: Fatal Enclosed Space Entry After an Ineffective Gas-Freeing Operation, Strait of Hormuz 2025

🕑 5 min read words Safety • Incident

Vessel: NO.2 Ocean Pioneer, oil/chemical tanker, Republic of the Marshall Islands registry
Date & location: 25 August 2025, Strait of Hormuz, while transiting southbound from Jubail, Saudi Arabia toward Salalah, Oman
Outcome: Fatal enclosed space entry – the ship's chief officer collapsed and died inside a cargo tank roughly five minutes after entering it to inspect it following cleaning; the Master's own rescue attempt nearly created a second casualty
Human factors: Normalisation of Deviance · Tick-Box Safety Culture · Rescuer Self-Endangerment
Source: Republic of the Marshall Islands Maritime Administrator Marine Safety Investigation Report (published 29 July 2026)

9 decision points5 outcome paths~6 min read + Knowledge Checker

A Cleaning Plan That Didn't Match the Manual

NO.2 Ocean Pioneer had just discharged 17,393 MT of benzene at Jubail and was in ballast for Salalah, where she was fixed to load methanol. Before that cargo could go anywhere near the tanks, all 20 had to be washed, gas freed, and inspected. The company's own SMS pointed crews to a third-party tank cleaning guide specifying ambient seawater, then hot seawater at 70–80°C, then a fresh water rinse. The plan the chief officer actually wrote and the Master approved skipped the seawater washes entirely and substituted steaming plus a de-ionized water rinse instead. The investigation could not establish why. Nobody could explain the deviation afterward — not because anyone was hiding something, but because nobody had been tracking that a deviation had happened at all.

An Open Hatch That Quietly Defeated the Gas Freeing System

Eighteen tanks were gas freed overnight using a single fan feeding the system's high-velocity pressure/vacuum valves — valves designed to build tank pressure and expel vapour at 30 m/s once the dome hatch is closed. The crew left the dome hatches partially open “to help,” which felt intuitive and had likely been done before without consequence. It also meant the tanks never built the pressure the PV valves needed to function as designed. The fan ran for eleven to twelve hours — long enough, on paper, to change the atmosphere three to five times. In practice, the investigation concluded the gas freeing had only been partially effective, and that No. 3 Port cargo tank specifically was still likely oxygen deficient the next morning.

Thirty Minutes for a Job That Needed Three Hours

The chief officer tested the atmosphere in six cargo tanks alone, without a buddy, and recorded 20.9% oxygen and zero gas readings across all of them — a clean pass everywhere. The manufacturer's instructions for the benzene detector tubes on board required five pump strokes with two minutes between each, ten minutes per test, at three depths per tank. For six tanks, that's roughly three hours of testing. The chief officer's own paperwork recorded thirty minutes. The Enclosed Space Entry Permits he then issued and signed went unreviewed by the Master. Nobody entering those tanks that morning — including the chief officer himself — was wearing a personal gas detector, despite it being both a company requirement and written into the permits he'd just signed.

Five Minutes Alone in No. 3 Port

The chief officer had already been in and out of four other tanks without incident. Deck ratings who entered two of them afterward assumed it was safe because they'd watched him do it first — nobody wearing a gas detector, nobody carrying an escape breathing device. Just after 0850, he entered No. 3 Port cargo tank. Within five minutes, an ordinary seafarer and a deck cadet on standby at the tank dome heard a noise, looked down, and saw him lying motionless on the tank top.

A Master's Rescue That Nearly Became a Second Casualty

The alarm was raised correctly — nobody rushed in unprotected, crew instead gathered BA sets and a rescue harness, exactly as trained. Then the Master, who had left the bridge while the ship was transiting the Strait of Hormuz, arrived at the tank dome, put on a BA set, and went in himself. Finding the chief officer unconscious and breathing weakly, he took his own mask off and held it over the casualty's face, alternating it between the two of them until two able seafarers arrived with the harness. He later reported having had difficulty breathing while unmasked — a direct sign the tank's atmosphere was still dangerous, and a moment where the rescue itself was one bad breath away from a second fatality. He went back in a second time, wearing a fresh set, to fit an escape breathing device before the chief officer was finally hoisted out at 0920, roughly half an hour after he'd first gone down. CPR and an AED were used without success. He was declared deceased at 1040.

What the Company's Own Audits Found, Three Months Later

Follow-up audits in November and December 2025 — run by the recognized organisations that hold the company's Document of Compliance and the ship's Safety Management Certificate — turned up a pattern that went well beyond one morning's mistakes: a management review that hadn't happened in 2025 despite being required twice a year, an internal audit process crew described as a “tick-box exercise,” and crewmembers who told the company's own auditor they feared repercussions for reporting problems. The enclosed space rescue drills logged every two months turned out to rehearse the same one or two scenarios, with the same printed action list reused each time — the investigation concluded they were very likely pre-scripted exercises rather than genuine emergency rehearsals.

Recommended Actions

From RMI's Part 6 Recommendations, addressed to the company:

Revise cargo tank cleaning and gas freeing procedures so every plan includes the work schedule for the crew involved, the time genuinely required to test each tank's atmosphere at three levels per the detector manufacturer's instructions, and a written, Master-approved sign-off for any deviation from the approved plan — with the reason recorded, not just the fact of it.
Revise enclosed space rescue procedures to explicitly require testing the atmosphere before a rescue team enters — the company's procedures, as written, never addressed this.
Review and revise onboard training so every enclosed space drill is run as if it were a real emergency, not a repeat of the same pre-scripted scenario.
Review and revise the STOP CARD stop-work authority system and its training, incorporating RMI's Marine Safety Advisory 12-25 on how stop-work authority is meant to function in practice, not just on paper.
Run a genuine safety culture campaign across the fleet, addressing both the shore office and every ship, aimed specifically at the fear-of-repercussion and tick-box findings the company's own auditors identified.
Review the lessons from this investigation with every Master and management-level officer at their next on-signing briefing.

Human Element Analysis

Normalisation of deviance

The tank cleaning method drifted from the approved plan without anyone flagging it. The gas-freeing hatches were left open “to help,” quietly defeating the PV valve system's actual design. A thirty-minute atmosphere test stood in for a three-hour one. None of these were one person's dramatic shortcut — each one had likely worked before, which is exactly how a known gap becomes invisible practice.

Tick-box safety culture

Enclosed Space Entry Permits were signed off in full compliance — on paper — while the actual testing behind them physically couldn't have happened in the time recorded. The company's own December 2025 audit called its internal review process a “tick-box exercise” and found crew afraid to report problems. Paperwork said the risk was controlled. The risk wasn't controlled.

Rescuer self-endangerment

The Master's own procedures required him to stay outside and direct the rescue. Instead he went in twice, and in between removed his own breathing mask to share it with the casualty — a moment the investigation notes could easily have produced a second unconscious crewmember inside the same tank. Urgency and genuine care for a shipmate are understandable. They are also exactly how single-fatality enclosed space incidents become double fatalities.

Cross-Industry Parallels

Industry	Incident	The parallel
Chemical/Process	DuPont La Porte, Texas (2014)	A methyl mercaptan leak killed four workers at a DuPont plant — one of them a colleague who went in to help without the protection the situation required and became a second victim, the same pattern the Ocean Pioneer's Master narrowly avoided repeating.
Aerospace	Space Shuttle Columbia (2003)	A known foam-strike risk was tolerated across dozens of missions until it caused a fatal outcome — the textbook case of a deviation becoming normal practice, matching how Ocean Pioneer's cleaning procedure drifted from its approved plan without anyone treating that drift as a live risk.
Nuclear	Tokaimura criticality accident, Japan (1999)	Workers at a uranium processing plant followed an informal, unapproved shortcut instead of the documented procedure, triggering an uncontrolled nuclear reaction — the same gap between the procedure on paper and the procedure actually being followed that RMI's investigation found in Ocean Pioneer's tank cleaning plan.

Try the Decision Simulator

You're the chief officer with six cargo tanks to test and a cleaning schedule that's already running long. Do you take the three hours the manufacturer's instructions actually require, or do you trust the tanks that came back clear? Play through the real decision points and see which ending you land on.

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