Several seconds--maybe a minute or more--are required for sirens or horns to notify persons near a generator that it is getting ready to autostart. No way it could start in 1/3 sec. Wes Leatherock snipped-for-privacy@aol.com snipped-for-privacy@yahoo.com
The 125kW generator we used to power the I.T. infastructure (Server room and entire I.T. space) would spin up withing 10 seconds. No sirens, no horns. Just a brief flash as the overhead lights went to generator power.
The server room itself had an APC Symmetra to keep power up while the generator spun up.
Times have certainly changed: when I was on working Toll Test, on the night shift at Back Bay in 1973, the turbine came on every Wednesday night, just like clockwork, and no alarms or horns or other warnings were ever sounded. The turbine was in the area next to the Toll frame and testboards, separated by only a standard set of double-doors, and the unit at Back Bay was rated for 500KW.
After the first couple of times, when I and my teammate went home with our ears ringing, we would call the night forman and tell him we were retreating to another floor: we'd do what work we could at the MDF, but we refused to work with the generator running next to us, and our boss never said anything about it.
Bill Horne (Filter QRM from my address for direct replies.)
They were too cheap to buy ear protection?
I worked for a non-telco employer in Florida. Our tester required a vacuum pump which they placed right next to the tester instead of the machine room to save on installation costs. It was LOUD. We demanded our safety department come out. It was the nurse who came out and said she measured the volume level and it was within OSHA guidelines. We all brought in our own hearing protection paid for with our own money and were told we were forbidden from wearing it because it would imply the volume levels were dangerous when they weren't. IIRC it was merely 1 or 2 dB away from requiring hearing protection.
I ended up having a dumb terminal (remember those?) installed in my office and only worked in the lab when absolutely necessary.
John
That's a more complicated question than you'd think: New England Telephone was never big on that, and I never figured out why. As a pilot, I had access to noise-cancelling neadsets and to ordinary ear protectors, both considered essential for pilots, but I didn't use them on the job because there was a very pronounced "everyone or noone" attitude among we union men. Not even the power room techs, who worked on the generators for hours at a time, had hearing protection provided to them.
Bill Horne (Filter QRM from my address for direct replies.)
I know (knew....RIP) a couple of switching techs. who lost 50% or more of their hearing from working in the common equipment room of #5 Crossbar. I'm surprised their TEETH didn't fall out !! It was pretty obvious that hearing protection was needed in there but in the early days whatever was provided was apparently not good enough.
***** Moderator's Note *****In N.E.T., there wasn't any protection provided, and the techs just accepted hearing damage as a part of the job. I'd bet that a sociologist would have a field day, figuring out the corporate gestalt that made workers believe that they were destined to loose their hearing at a young age.
My cow-orker and I were the first wave of a new age: the time when workers realized that corporations didn't always have the workers' best interests at heart.
Bill Horne Temporary Moderator P.S. If you think #5 was bad, you should have heard the Panel office: the schreech of metal clutches combined with the ordure of burnt Brylcreem would ruin two of your senses at the same time. ;-)
A lot of deaf employees now.
In 1967 I was interviewed for the job, and was brought into a Step SATT room, talk about noise. When ever I went into the power room or satt room, I put sound blocking sets on. The old Step offices were bad on their own: in time I guess we got used to it, no hearing problems now.
Years ago I had wax removed from my ears and went to work, that day I stayed in the Frame room.
I believe hearing protection, or other occupation safety, wasn't as big an issue back in 1973 as it would be later, in many industries. In many areas (noise, fumes, radiation, etc.) the allowable hazard exposure was lowered over time as delayed problems to situations was recognized.
For instance, pre-war subway trains were quite noisy but trainmen didn't have any ear protection in the 1970s.
Today workers like cops and medical personnel wear gloves to reduce risk of infection exposure when not that long ago they didn't; yet they dealt with infectious people all the time. Back then they washed their hands afterward and thought that was sufficient.
Also, in industrialized workshops sometimes there was a macho attitude among the workers in that they're "tough enough to take it" and they didn't want to wear safety gear (some of which was uncomfortable).
AT&T's TL and TM short-haul microwave systems used klystrons, the voltages for which were generated by DC-DC converters operating at
2 kHz. In a lab room or in a repeater hut with several runing, there was a loud 2 kHz hum. Two Labs engineers I worked with each ended up with a hole in their auditory frequency response at 2 khz, perfect hearing above and below 2 khz.On Sun, 17 May 2009 00:02:05 -0400, Richard wrote: .........
If I recall my lessons on physiology correctly, the physical structure of the human ear that converts sound vibrations into nerve impulses is a long length that is sensitive to frequencies from low to high, so if one section of that is essentially "worn out" then you lose sensitivity to the frequency range detected by that area.
I know someone who works in a dentist's office where there is a constant whirl from the air compressor. She says she will lose hearing as a result, "just part of the job".
Many young chemists told me their life expectancy will be reduced five years as a result of their working in chemistry.
All statements were made "as a matter of course"; no sense of regret. It surprised me people were so blase about occupational hazards.
During WW II, many of the scientists of the Manhatten Engineering District were well aware of the dangers of radiation (they knew of the deaths of the radium clock-dial painters), yet they ignored mandated medical tests or even rudimentary safety precautions of time. Two scientists died nasty deaths as a result of accidents that happened _after the war ended_ (so they was no sense of urgency anymore).
It's hard to know the long term effects since everyone smoked back then, ate very high-fat diets, and industrial air and water pollution was much more prevelent than today. The stuff dumped into the air and water in 1950 by American industry would be incomprehensible by today's standards; there were very few laws back then. (Sadly, today some foreign countries do the same thing.)
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