July 23, 2010

メキシコ湾原油流出事故で技師証言「現場はBSOD放置で警報もオンになってなかった」:Oil Rig Alarm Disabled Before Blast

“They did not want people woke up at 3 a.m. from false alarms,” Michael Williams, the chief electronics technician aboard the Transocean's Deepwater Horizon, testified today that its safety alarm had been switched to a 'bypass mode' and the alarm did not sound during the emergency.

From NYTimes;

On Friday, Mr. Williams added several new details about the equipment on the vessel, testifying that another Transocean official turned a critical system for removing dangerous gas from the drilling shack to “bypass mode.” When he questioned that decision, Mr. Williams said, he was reprimanded.

“No, the damn thing’s been in bypass for five years,” he recalled being told by Mark Hay, the subsea supervisor. “Why’d you even mess with it?”

He recalled that Mr. Hay added: “The entire fleet runs them in ‘bypass.’ ”

Problems existed from the beginning of drilling the well, Mr. Williams said. For months, the computer system had been locking up, producing what the crew deemed the “blue screen of death.”

“It would just turn blue,” he said. “You’d have no data coming through.”
From WSJ;
Other documents reviewed by The Wall Street Journal show that the Deepwater Horizon had equipment problems long before the disaster, and that employees of both Transocean and BP raised concerns about maintenance aboard the rig.

Another example of critical system failure was emergency power. The rig was equipped with backup generators that are meant to kick on within seconds of a blackout, powering the rig's thrusters, firefighting systems, and other key equipment.

In testimony earlier this week, Transocean employee Stephen Bertone, the rig's chief engineer, described standing on the bridge the night of the disaster, desperately waiting for the emergency power to kick on.

When it didn't, Mr. Bertone, Mr. Williams and another worker rushed toward the room that housed the standby generator. Mr. Bertone pulled the lever to restart the power. Nothing happened. He tried again, and again, with no success.

"I said that's it," Mr. Bertone told investigators. The three men ran back to the bridge. "I hollered out, 'That's it. Abandon ship. Let's go," Mr. Bertone said.



なんでも掘削現場から危険ガスを除く大事なシステムも、「夜中の3amに誤った警報で起こされたんじゃたまらない」ので別の社員が「バイパス・モード」にしたそうだ。ウィリアムズ氏がその理由を尋ねると、海中現場責任者Mark Hay氏に「こんなもん5年も前からずっとバイパスで使ってるのだ。何故おまえはわざわざ動かすのだ?」、「この艦は全部"バイパス”で動かしてるのだ」と怒鳴られたという。

現場は掘削開始当初から問題続きで、コンピュータシステムはうんともすんとも言わず、ブルー・スクリーン(blue screen of death:BSOD)状態。「青くなったきり、データがひとつも入ってこなかった」(ウィリアムズ氏)。交換用のハードウェアも発注したが、それが届く前に事故が起こった。命からがら助かった氏は現在会社を相手取って数百万ドルの賠償を求める訴訟を起こしている。

木曜の公聴会ではトランスオーシャン社員Shane Roshtoさん(22歳)を事故で亡くした妻Natalieさんも証言、故障を沢山抱えながら掘削を続けるプレッシャーに悩んでいたと語った。「夫は第1日目から、これは地獄の井戸だと感じていました。母なる自然がここは掘るなと嫌がってると、言ってました」。(以上、NYTimesより)

もうひとつのクリティカルなエラーは緊急時の電力供給だ。停電の際は数秒以内に掘削現場のバックアップ用発電機が発動し、スラスタや消火システムなどキーとなる機材が動かせるはずだったが…。これについては今週はじめ、トランスオーシャン社員で掘削設備チーフエンジニアを務めるスティーヴン・ベルトーネ(Stephen Bertone)氏は、事故当夜、緊急用電源がオンになるのを必死の思いで待ちながらブリッジに立ち尽くしていた時の状況を語っている。



[NYTimes, WSJ]


Yoshinori_K said...


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