Worst Accident of 2006: Liquid Nitrogen + Staircase

December 26th, 2006

As discussed in an earlier comments thread, this award was never intended to tag the accident with the most tragic outcome. If that were the case, we would have picked the explosion of ethene that destroyed a French research lab in March, killing a professor that wasn’t even working on the botched experiment. Instead, we’ll use this award to (dis)honor the most avoidable or bone-headed accident of the year. Correspondingly, the Chemmy for the Worst Accident of 2006 goes to:

The undergraduate student at Berkeley who tried to move a 400-lb.
dewar of liquid nitrogen down a flight of stairs

As chronicled on another blog:

Condensed matter labs such as ours receive frequent deliveries of liquid nitrogen in one- or two-hundred liter dewars. Unfortunately, most of the Berkeley cond-mat labs are in Birge Hall, which has no loading dock, so that the LN2 dewars arrive on the first floor of neighboring LeConte where they must be wheeled over to their destination by some low-seniority student. Since the Berkeley campus is on a hill, the loading dock at the back of the building is one floor higher than the other entrances to LeConte and all the entrances to Birge. One can push the dewar around the outside of LeConte, but a shorter route is to take the elevator down one floor and go out the side door.

Yesterday the LeConte elevator was out of order, which for most of us would have meant taking the long way around. However, one undergrad, tasked with transporting a full 230L dewar, simply decided to take the stairs.

At about 80% the density of water, 230 liters of liquid nitrogen weighs about 400 pounds, not counting the additional weight of the steel vessel containing it. When rolled onto the stairs, the dewar promptly tipped over and plummeted downward on its side, knocking deep gouges in the marble steps and dragging along the unfortunate student, who inexplicably held on as his cargo began to tumble. Miraculously both student and dewar arrived at the landing without rupturing…

The nameless student is lucky that his Chemmy wasn’t awarded posthumously; the outcome could have been a lot worse. As for the people who agreed to go back into the staircase to right the tipped dewar, I don’t know whether they deserve an award for bravery or stupidity. It’s safe to say that I would have left the vicinity as quickly as possible.

On a related note, anyone with a tale of an unsecured gas cylinder becoming a torpedo should share it in the comments. I’ve heard plenty of stories, both in real life and on the Internet, but it’d be nice to see some legitimate evidence. For instance, this story has several hallmarks of an urban legend: no source, no specific subject, and no photographs. My instincts say that there are a few safety officers out there who enjoy writing ghastly reports of fictional accidents.

Next post: Citizen of the Year (for service to the chemistry community)

Previous Comments

  1. Uncle Al Says:
    December 26th, 2006 at 1:32 pm The kid held on for dear life. Had he let go he would have been excoriated for committing an act of consummate stupidity. Riding the bomb down makes him a VICTIM! and therefore deserving of praise and compensation.Chemistry is an apprenticeship. Ruined projects come under beginners’ bad luck. Damaging the Master’s tools is not acceptable.The highest amplitude wowser I know of was attempting a C-13 Magic Angle NMR spectrum of glassy graphite. Don’t whiz up a conductor in a strong magnetic field.
  2. Wolfie Says:
    December 27th, 2006 at 10:40 pm I’m keeping my comment for the worst arrogance upright.
  3. Bruce Hamilton Says:
    December 31st, 2006 at 2:41 am According to Wikipedia, the Mythbusters team in epidsode 63 ( 18 Oct 2006 ) demonstrated that a compressed air cylinder rocketed through a cinder block wall once the cylinder valve was severed. They also reported that they had accounts of similar events. I also recall some photos of similar cylinder incident damage shown at a British Oxygen gas cylinder safety seminar many year ago.http://en.wikipedia.org/wiki/MythBusters_(season_4)#Episode_63_.E2.80.94_.22Air_Cylinder_Rocket.22
  4. Hap Says:
    January 4th, 2007 at 6:41 pm Derek Lowe’s blog has pictures and discussion on a Texas A+M LN2 incident a year or so ago. In that case, the release valves on a rolling LN2 cylinder were in some way disabled (two separate times) so that instead of being released, pressure buildup caused the inner cylinder and the outer cylinder to meet and the top to blow out. The damage was substantial (through two floors, damage to equipment, massive flooding, etc.) but no one was hurt because the incident occurred in the early morning.The lesson would seem to be: amateur repair crew + large cylinder of liquid that wants to be gas = bad.
  5. bink Says:
    January 5th, 2007 at 12:06 pm Bruce is right. I remember seeing that Mythbusters episode. They basically laid a cylinder filled with compressed air on its side, then rigged a makeshift gas cylinder “guillotine” to break off the head and nozzle. It went through a cinder block wall as Bruce mentioned, and dented the wall a few feet behind it pretty well too.


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