Halon 1301 is the gas that used to be used which was banned in the 90s. Most inert gas fire suppression systems use HFCs or Ketones now and have a ten minute hold time. They work by displacing the oxygen and reducing it to <10% which is not enough to support flame - or life.
In '86, I was in a data center that had expanded to take up 70% more space. During the expansion, emergency lighting hadn't been put up. During expansion, a 470 volt three-phase line had been put in, the insulation had been stripped off while they were pulling it through the conduit. As it heated up, gas or vapors from the melted insulation built up and the 1/4" thick conduit was ripped open with roughly an 8" hole and an explosion people on the first floor heard (computer room was in the basement).
One of the operators panicked, tripped over the anti static carpet, ripped the Fire Suppression box off the wall and pulled the Halon. He stumbled out the automatic sliding glass doors and hit the EPO leaving the data center completely dark with me about 120' from the door in pitch black.
I had walked those corridors between the drives hundreds of times, but, had difficulty finding the path. Time was running out, so, I stood on one of the minicomputers, moved one of the drop ceiling tiles and stuck my head into the return air plenum and the Halon went off. It was noisy, sort of a giant whoosh with a low rumble and a very odd smell.
I don't know how long I stood there, but, it wasn't more than a few minutes before a flashlight was shining on me with a Fireman in full gear.
After that, we had emergency lighting and oxygen tanks throughout and the Halon system was upgraded. When the tanks were refilled, they did the math and noticed that the amount of Halon we had wasn't enough for the expanded data center and probably wouldn't have extinguished a fire.
Most humorous moment - seeing firemen walk through the data center with axes in hand looking for fire.
In the 1980s we had the fire suppressant system in our server room upgraded and the installers test fired a cylinder of Co2. Unfortunately, someone hadn't fitted the discharge 'shower head' properly on the end of the outlet pipe - which for some reason had a 'j' bend in the end and so the head shot up into the false ceiling, followed by all the gas, which pressurised the void and caused the ceiling to explode into the data centre.
Imagine the scene - shredded ceiling tiles and years of dust and grime everywhere! It really looked like a bomb had gone off. Fortunately there was no-one in the room during the test and everything kept running, but the clean-up took quite some time.
15 minutes prior, I was working on the mux cabinet that would have put my back 18 inches from that conduit.
Good 'ole Racal Milgo equipment - where we had ~24* terminals on a 9600 baud line and we were happy to have that much bandwidth.
After that incident, there were a lot of changes to the data center, all safety related. It was a combination of an office building that was repurposed, a county government that was expanding very quickly, computer equipment that was taking more room and a government contractor under pressure to keep things running while the expansion was going on.
I don't believe the county government fined itself, but, things did change. It was the only building other than the courthouse in another city where we didn't run plenum rated cable. After the incident, all cable we ran was plenum rated.
It was the wild west back then. 143mb hard drives were the size of file cabinets, 67mb removable disks had 5 platters and weighed about 20 pounds. PCs were just starting to come into play, but, the mainframes and minicomputers took a lot of space. The tape library was easily 300 sq feet. When we needed more space, we asked the county, they would move whatever office group was adjacent to the computer room and the space would be expanded. There wasn't a lot of documentation at the time regarding best practices.
I never really felt that I was in danger, though, at 18, you sort of feel invincible anyhow. Had the computer room been built properly and not been converted office space, it wouldn't have had a drop ceiling and the outcome may have been different. Had the system been sized properly for the expanded room, perhaps things would have been different.
Edited: even though the mux we were using was a 32 channel mux, probably eight or more of the ports would have been 1200 baud for printers.
Ships engine rooms are required to have to separate CO2 release controls for exactly that reason. One releases the CO2 into a protected space and the other releases it into the protected space.
In '86, I was in a data center that had expanded to take up 70% more space. During the expansion, emergency lighting hadn't been put up. During expansion, a 470 volt three-phase line had been put in, the insulation had been stripped off while they were pulling it through the conduit. As it heated up, gas or vapors from the melted insulation built up and the 1/4" thick conduit was ripped open with roughly an 8" hole and an explosion people on the first floor heard (computer room was in the basement).
One of the operators panicked, tripped over the anti static carpet, ripped the Fire Suppression box off the wall and pulled the Halon. He stumbled out the automatic sliding glass doors and hit the EPO leaving the data center completely dark with me about 120' from the door in pitch black.
I had walked those corridors between the drives hundreds of times, but, had difficulty finding the path. Time was running out, so, I stood on one of the minicomputers, moved one of the drop ceiling tiles and stuck my head into the return air plenum and the Halon went off. It was noisy, sort of a giant whoosh with a low rumble and a very odd smell.
I don't know how long I stood there, but, it wasn't more than a few minutes before a flashlight was shining on me with a Fireman in full gear.
After that, we had emergency lighting and oxygen tanks throughout and the Halon system was upgraded. When the tanks were refilled, they did the math and noticed that the amount of Halon we had wasn't enough for the expanded data center and probably wouldn't have extinguished a fire.
Most humorous moment - seeing firemen walk through the data center with axes in hand looking for fire.