"We're one TWA tick away from an H&S refresher course with a free lunch.
Huh. There's no such thing as a free lunch.
"Simon, Steven – a word?" the Boss burbles warmly. "What's up?" the PFY answers warily. "Nothing - just having an interesting conversation with a bloke from an outfit that deals with infrastructure obsolescence, code debt and I.T. asset leveraging." "Ah yes, I thought I felt a disturbance in the force," the PFY nods. "Come …
For a colour monitor, don't forget the shadow mask.
For early generation monochrome monitors, there used to be an offset bias on the beam deflector so that the beam did not strike the phosphor at right angles, but at an angle that would aim the beam away from someone sitting directly in front of the monitor.
Electrons from an electron gun in a CRT are relatively low energy, and can easily be stopped by the metalised inside coating of the glass, and the glass itself. And the energy was not high enough to generate X or gamma rays.
"there used to be an offset bias on the beam deflector so that the beam did not strike the phosphor at right angles, but at an angle that would aim the beam away from someone sitting directly in front of the monitor.
"Electrons from an electron gun in a CRT are relatively low energy, and can easily be stopped by the metalised inside coating of the glass, and the glass itself. And the energy was not high enough to generate X or gamma rays."
IKR? They really made it quite the hassle, modifying those things so that they were actually dangerous! Took bloody forever.
I worked in a research lab in the early 80's. In the lab round the corner they were developing a high definition projection TV. It was quite powerful and apparently gave off sufficient Xrays for them to wear a lead apron whilst working on it with the covers off. They told me that was the least of their worries. If the raster scan collapsed and the cutout didn't work the electron beam focused on one point of the 3 six inch projection tubes would melt the glass and cause it to implode. And that was one of the safer labs: there were a bunch on the ground floor that played with some really scary stuff that would have been great for the BOFH.
Back in the 1970s I was an apprentice TV engineer for Rediffusion. Once, I forget to connect up the wires to the vertical scan coils after fitting a new B/W CRT. So, upon turning the set on it took less than a couple of seconds to burn a permanent horizontal line across the brand new phosphor! Somewhat chastened, I had to remove the newly buggered CRT and fit yet another one. At least I only did it once!
Health & Safety people please look away now! One of the other engineers there told me a story of when he was an apprentice (probably back in the 60s). One day, not long after he'd started, someone announced that it was time to break up some old CRTs. Everyone grabbed a CRT and he did likewise, following them outside where they lined up facing a brick wall. All the others started swinging the tubes to chuck at the wall and, on a count of three, they all let go. Of course, they'd deliberately omitted to tell him to run like the clappers in the opposite direction as soon as he let go! When those buggers implode they do tend to shower glass everywhere! Obviously, he survived to tell the tale!
It was in the early 80's I was on a team working on a ship simulator that used three sets of CRT projectors for the display.
At one stage during testing all the displays were showing a black sea and white sky. One of the CRT display tubes cracked. From that point on water cooling was added....
"Does anyone still have a halon system?"
That is the beauty of it, the sales droids only have to believe that they do, letting off a CO2 extinguisher through the air vent would probably do the trick and be much cheaper. BOFH/PFY sell the idea of what the cloud of gas will be and then deliver a sub-standard product.
Let me walk down to our server room and see if the warning signs on the doors are still there (doors that exit to a 3-story atrium as long as a railway platform). Of course, I know nothing of the actual systems inside, but the warning is enough. If a BOFH lurks inside, I wish not to disturb it.
(At least I know it's on the ground floor, with no windows except to the atrium, and those don't open. No risk of tragic falls here. There are other hazards far worse, though, and if I mention them the BOFH will know, so I'll be a good luser and be quiet now.)
Uhm, sprinklers and Halon/Inergen/etc systems don't fill the same purpose.
Gas extinguishing systems are typically triggered by sniffing the outgoing air for tiny amounts of combustion byproducts. This catches really tiny fires really early, but if you have a fire that's big enough or recurring (or fuelled by an oxidiser in case of oxygen-depleting systems) they are useless as they will go empty.
Sprinklers are triggered by the sprinkler head physically heating up to the point of a wax plug melting or a glass bar breaking due to expanding liquid inside it (in addition to the system being pressurised by a fire alarm going off in higher-end systems). This catches big fires before they turn into huge fires.
Sprinklers are there to stop the entire building from burning down with people inside it - most of your servers will probably be toast before they even go off, and when they do they will obviously break the rest. They protect the building itself and the people in it.
Gas discharge systems are there to stop a small fire in some gear from taking out anything else - they won't save you from a fire that actually threatens the rest of the building. They protect the equipment but not the building or people.
You'll even see both fitted in quite a few installations.
Also, where does this pathological fear of Halon discharges come from? Halon by itself is fairly non-toxic. I wouldn't recommend picking up a habit huffing it - or doing the classic Halon sales demo of standing in a both as it's discharged inside it - but a single exposure isn't gonna hurt you.
At most being around when a large system is discharged might cause damage to your hearing, or being hit by a flying object.
The reason it's no longer used much is because it's a potent ozone depletor, not that it's a hazard to people.
CO2 systems - still widely used, though not in computer settings - are much more dangerous to people.
The warnings for these basically say "when the klaxon sounds, get out or you WILL die".
I talk to people who have the Halon Fear all the time. Its more likely to make a brown spot on your pants when the crushing noise of the gas comes out the discharge ports/heads. It's always great to see the new guys heart rate go up when working in a room protection by one of these systems.
The C02 systems work by displacing the O2 in the room your comment on the much more dangerous could not be any more correct, i hope people understand that aspect.
Depends on the Halon gas in question. The normal one BCF is only mildly toxic. Our military however liked to use Methyl Bromide because it was a more effective flame suppressor. Whilst it was almost exclusively used in aircraft this didn't stop some nut job for specifying it in a computer installation. If you got a lung full your chances of surviving for more than a day are slim, and if you do you will probably never be well again.
I was so shocked by the mention of MeBr as an actual fire suppressant - I have only encountered it as a pesticide and reagent - that I had to look it up. Apparently, the user-friendly Halons were developed specifically to replace MeBr because of its' toxicity.
Maybe the military finds it handy that their fire suppression system can also be used for chemical warfare? MeBr is a damn alkylating agent. Right up there with mustard gas, although in addition to being a non-specific alkylator sulfur mustard also attacks some specific protein targets in the skin.
And yeah, a lot of modern fire suppression systems simply lower the O2 to the level above killing people but below sustaining fire. Others (like Novec) work like Halon - by breaking the reaction cycle of the fire - but without the ozone depletion. There's also HiFog which is basically a very fine water mist. It's fine enough to be safe for equipment, but UPS batteries tend to get really pissed off at the sudden drop in temperature.
Some other fun trivia is that both the noise from the gas discharge and the actual fire alarm sirens can be really, really bad for mechanical disks. To the point of killing enough disks to take out entire RAID arrays in atleast one case I know of.
Most of the Halon scares are about accidental (or not-so-accidental...) discharges, not actual fires.
And if things really are burning, you are unlikely to be worse off from the Halon byproducts than what the combustion would have resulted in otherwise.
Hydrogen halide production isn't something that only occurs in a fire in the presence of Halon, you know*. Not to mention the others - I'm no expert on the toxicology of combustion gases, but carbon monoxide certainly comes to mind.
* Halon produces HF while many burning plastics would be mostly HCl. HF is more toxic (spill the liquid on you and the acid burns aren't your big problem - it gets absorbed into the bloodstream and poisons you... really does a job on bones as well unlike most acids), but HCl is the stronger acid. I'd think direct lung/airway damage would be relevant long before systemic toxicity when inhaling the thing?
Did a site risk assessment a couple of decades back in SA. The old mainframe machine room was being used for the ops/dev cube farm with an intact and active Halon system still in place; service inspection tickets three years out of date!
The "new" server room had no fire protection except for extinguishers (same for rest of building) but they had placed the servers underneath the air-con cassettes which had no drip trays.
To cap it all the whole lot was on the floor above the unsecured car park with no sprinkler system. Did I mention they had placed the power supply substation in the car park as it was shaded?
There's also the off-the-shelf, supposedly easy for ordinary users to implement, comprehensive systems for " business continuity" and similar data managing activities, sold as affordable, that turn out to take an expert (theirs or someone trained by them at exorbitant cost) to collate and enter the information because it's so complicated to navigate, then someone else to train users to use the, supposedly accessible, data when it's in there, after they haven't been able to make head nor tail of it.because it's so f***ing incomprehensible, with multiple overlapping levels of apparently identical data, idiosyncratic and non-standard icons that look pretty and bold, but give no indication of what they do - or a misleading one like a big silvery spanner to mean "save", and meaningless labels. Presumably designed purely to impress suits who think it looks simple because they have no idea how it actually should work or how it would fit in a real workplace. (Been there, suffered that).
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