pre-station closing crisis

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"we have to have a cryo crisis at the end of the season" says my boss on sunday afternoon after the dust settles on a close call with the liquid nitrogen plant, "it happens every year". of course, the usual ONE crisis at the end of the season wouldn't be enough for Christina. noooo, my season as the cryo tech, three things have to go terribly wrong within 48 hours of the close of station.

crisis 1:
"don't worry, no one was hurt, and the liquid nitrogen plant doesn't seem to have any permanent damage"
"excuse me?"
"yeah, a snowmobile crashed into it"
"WHAT?!!...when??"
such was the conversation sunday afternoon just as i was contemplating whether to take a nap, eat more cookies, or do some email. it may not sound strange except for one small detail...the liquid nitrogen plant is INDOORS. motorized vehicles should not be hitting it. it was like someone saying, "yeah, don't worry, nobody was hurt, but a motorcycle just crashed into your bathtub." it just doesn't happen. not to mention this liquid nitrogen plant is the sole source of this essential cryo item on station, and there would be little reason for me to be here without it, not to mention the telescopes couldn't function.

i rush out to the plant building and walk into a beehive of activity. one guy has a camera and is beaming the hugest smile, like he's thrilled something exciting has happened and he's definitely going to get it on film. an electrician is sprawled out on the floor attempting to fix the main power feed to the plant, which got ripped up, and another random guy is standing around still assessing damage. there's a huge dent across the one remaining panel on the plant, and it's sitting about a foot behind where it usually sits, knocked into other parts of the plant behind it. It looks like a car that just got in a bad fender bender.

Three hours later, with a little luck, the plant is actually running again. but, just ,like after you get in a car accident and the car still starts, you're constantly waiting for some unseen damage to surface, like your bumper to fall off, or some strange noise to start happening. luckily, the only permanent damage seems to be to the person's pride who neglected to take their hand off the snowmobile accelerator. there goes my one day off wasted fixing the plant and writing up the incident report.

crisis 2:
this crisis was more like a saga. it started the morning after crisis 1 when i went to turn on our cryo-cooler thingy that saves us a bunch of helium by keeping it so cold it doesn't boil off. without it, we run out of helium before the end of the season.

there is a compressor and a chiller to this thing. turning them on was supposed to take 5 minutes. i press the power button on the chiller. nothing. no tick, no lights, nothing. oh-KAY.....plugged in, check...breakers, check, every possible way of pressing the on button, check. alright, i'll try the compressor. nothing. oh-KAY....i radio for the electrician. he checks the panel and we do have power....which means my problem is worse than i hoped. chiller first...we tear off the housing and go poking around with the meter...power isn't making it out of the red box marked "DO NOT OPEN, HIGH VOLTAGE." we immediately open it. lucky we did, because the low voltage limiter inside is keeping our little guy from running. readjust it, and that's one down. compressor next..... i check the pressure gauges on it and find out that for some reason, and completely contrary to everything the manufacturer has said, the pressure is almost completely gone. this means a long sequence of using a helium cylinder to add helium after pulling a vacuum to be sure no impurities get in, etc.... all kinds of heavy crap and equipment has to be drug from other buildings in -40F across the snow to make this happen. when all is said and done, this 5 minute procedure has taken over a day. now we're ready to turn them on for real.

i'm next door when my boss does this. by the time i get there, enough glycol has spilled on the floor to cause our hazardous waste guy to have a heart attack. luckily we have backup and someone starts thinking smart and drains what remains out of the 7 gallon reservoir. this glycol stuff is slippery, so this whole clamoring to fix the leak happens in a mess of grown men in big boots slipping around like they're on ice skates. i just watched in amazement. fixing the leak took more time and energy that i barely had. but a few hours after the supposed end of my work day, it was finally done and i was going to head to the galley. i thought.

crisis 3:
what's that noise?.... i wonder to myself after i opened the vent on our new 27 ft long, 8 ft. high 4,800 gallon liquid helium tank. i *was* finally on my way to dinner. it's a hissing. ooh, and there's a little pop. and now louder hissing. grrrreat... it's 7pm, i've had an incredibly long day, and now this. probably just a little something that needs to be tightened. hmm, that's weird...the noise is coming from over there. that part shouldn't be leaking. that part is the main relief device for the tank, and is only supposed to go off in an extreme emergency when the inside pressure reaches it's uppermost limit. quick check of the pressure gauge....we're well below that limit. this is the part of the container that you generally just forget about....you never have to adjust it, open it, close it, etc. it's usually invisible to me in the jungle of plumbing. and now it's LEAKING. with this leak, not only will we not be able to regulate the pressure, we won't be able to monitor how much liquid is in the tank. not to mention it's audibly getting WORSE, and there's no way to valve it off without completely sealing in the boiling-off liquid that would be building pressure. a quick check of the manual reveals that this particular relief disk is something that's not to be mucked around with...it's extremely fragile..."installed only by professionals"...a fingerprint on the plate can cause it to fail...etc. that's echoed on the part itself, which is the ONE thing in all the plumbing that is sealed from being tampered with by wires holding the bolts from being turned.

one hour, two wrenches, and a wire cutter later, i have it completely disassembled.

i had no choice i guess...that's the south pole for you. 4 tries of tightening various little screws inside the device, carefully replacing it, re-tightening it in place, and holding my breath while i re-vent the dewar, it finally doesn't leak any more. and that was my night the day before station close.