I worked on these in 1964 as a Switchman. Brings back memories. For the Pacific Company of the Bell system. These things were very reliable. Some had been in service for 30 years and still worked well. Thanks for the video. Cheers.
I grew up in a city which had a Bell Long Lines facility. It was a large three story building. The middle floor was full of hundreds of frames of type 197 rotary selectors. The city size was about 50,000 so there were probably around 10,000 lines. The din of all the selectors was pretty amazing. The local Bell company gave an exceptionally rare public tour of the facility in 1968 and it is something I still remember well almost 57 years later. The building was not air conditioned on the lower floors and the tall windows would be open in the summer and the din of the selectors was clearly audible from the street. The facility was converted over to ESS in 1976 and the frames of selectors were pushed out the second story window down a chute into a dumpster. In subsequent years all the windows have been bricked up and the probability of another tour is likely close to zero given the current security atmosphere.
I learned about these in 1966 at the Army Signal School at Ft. Monmouth in New Jersey. It was a 19 week school and the instruction was superb. I went on to use this knowledge at Ft. Benning (now Ft. Moore), in Georgia. I ended my Army time in Germany, where the switching equipment was made by Siemens and I was no longer allowed to hold a screwdriver. But I can still tell you the 49 operations a line finder does to connect to the first selector and give you dial tone. Who knows what I could know if my brain wasn’t full of useless stuff like that.
I remember when phones were changed to rotary dials in our little town, ca. 1955. Previously, we had talked to an operator. My dad took me to see the exchange station. It was a one room brick building, no bigger than a modest living room. An attendant showed us how you could tell what number was being called by watching the contacts go up and down. Nominally, all the new numbers began with 425 ( "Garfield 5"), but you didn't need to dial that part.
I'm a controls electrician, loving this old relay logic gift the electrical engineers gave to us to advance everything away from picking up the phone and to have FIRST call an operator at a telephone switchboard... As more and more people were getting phones, ATT / BELL labs started engineering compact / far more complicated systems to handle the traffic. I find this video utterly fascinating...
When I started with Bell Canada in 1987 these were being phased out for digital switches. I miss the old days of the Central Office humming and clacking when in operation. Brings back some great memories.
Amazing early technology and only the first element in a number of mechanical decisions before the dialed subscriber's phone rang. The telephone system was the world's biggest analog computer before the digital world. Thanks for posting.
Step by step switches actually go a lot further back. They were in use in large metro areas in the 1910s. Strowger, an undertaker by trade, received a patent for a rudimentary rotary selector in the late 1800s. There were some really crackerjack engineers who figured SxS out. This film is about just one selector, never mind the topology of the switching fabric which tied hundreds or thousands of customers together.
So much was done with switching the polarity of tip and ring at different points during the connection to indicate different states; remarkable how they could get so much flexibility out of just two wires...
Started in TELCO career in a British type Strowger 10,000 line exchange in Dec 1972. Was witness to the chaos of a blown main fuse by somebody doing something stupid and all the selectors homing on power restoration and all the rack grasshopper fuses blowing. Was on fuse repair duty for 2 weeks afterwards.
I worked originally in a freight yard. My best move was transferring to Manchester telephone exchange. New job new life no nightshirts plus a very happy wife. She did not like being left alone for over 8 hours.
I remember screwing with the pulses and hook so you could get the exchange to enter into an endless ring loop and call your phone back. Used to do it on pay phones in lobbys and watch a bunch of people answer phones with nobody on the other end. 😂
Ah, remember when you had to actually dial a phone number? I was just a little tyke back then, but i remember that mysterious rotary phone hanging on the kitchen wall. In our next house, the phone had buttons instead. And we rented the phone from Ma Bell.
We purchased a $15 DialGizmo and have a Western Electric 500 on our "Gossip Table" running on a Spectrum VOIP service. At least a couple of times a month my teenagers will actually sit down and call their friends on it instead of from their iPhones. I love old tech and try to at least educate them on how things used to be. Cool when youth actually appreciates it!
I remember the Central Office building that handled 235 and 237, 3 cities, and my God, the noise The constant clicking a thousand times a minute. And the heat. All the windows were open in the summer but the temperature was over 130 degrees inside Just awful 😞
I'm assuming the rotary stepping was much faster than vertical. No mention about what happens if an idle trunk cant be found. Amazing enough how the dialing is done, but the real head-scratcher is how they cobbled this back into automated billing, because computer technology was quite limited back then.
Yeah, I was wondering about that. I was given some WWII remote control equipment that used a telephone rotary dial that controlled the channel selection in a remote receiver. It used the rotary stepper switch (which rotated until it found an open circuit, which in turn stopped the rotation.). I reriged it to control a remote antenna tuner. Watching this video made me think about since they were using rotary stepper switches in WWII, why would they use a vertical stepper switch? But I won't second guess the telephone engineers. 10 digit telephone circuitry is vastly more complicated than a 5 channel radio selector. But I sure learned a lot taking one apart and re engineering it. I had a friend who worked in one of the telephone switch offices in the seventies and eighties and I got to visit and watch and listen to the relay madness.....
Yeah, I'm an EE, and this is curious stuff, but to really get a grasp, I'd need to pause and rewind and really jump in hard. I'd be all day with this if I really needed to learn it.
Thanks!
@bambanguripno thanks so much, gifts like these help us preserve and post more endangered films!
I worked on these in 1964 as a Switchman. Brings back memories. For the Pacific Company of the Bell system. These things were very reliable. Some had been in service for 30 years and still worked well. Thanks for the video. Cheers.
I grew up in a city which had a Bell Long Lines facility. It was a large three story building. The middle floor was full of hundreds of frames of type 197 rotary selectors. The city size was about 50,000 so there were probably around 10,000 lines. The din of all the selectors was pretty amazing. The local Bell company gave an exceptionally rare public tour of the facility in 1968 and it is something I still remember well almost 57 years later. The building was not air conditioned on the lower floors and the tall windows would be open in the summer and the din of the selectors was clearly audible from the street.
The facility was converted over to ESS in 1976 and the frames of selectors were pushed out the second story window down a chute into a dumpster. In subsequent years all the windows have been bricked up and the probability of another tour is likely close to zero given the current security atmosphere.
Wow. Life was special. Reminds me of of getting a midair tour of the cockpit as a little kid.
I learned about these in 1966 at the Army Signal School at Ft. Monmouth in New Jersey. It was a 19 week school and the instruction was superb. I went on to use this knowledge at Ft. Benning (now Ft. Moore), in Georgia. I ended my Army time in Germany, where the switching equipment was made by Siemens and I was no longer allowed to hold a screwdriver. But I can still tell you the 49 operations a line finder does to connect to the first selector and give you dial tone. Who knows what I could know if my brain wasn’t full of useless stuff like that.
I remember when phones were changed to rotary dials in our little town, ca. 1955. Previously, we had talked to an operator. My dad took me to see the exchange station. It was a one room brick building, no bigger than a modest living room. An attendant showed us how you could tell what number was being called by watching the contacts go up and down. Nominally, all the new numbers began with 425 ( "Garfield 5"), but you didn't need to dial that part.
I hated rotary phones. Always got my finger stuck!
I'm a controls electrician, loving this old relay logic gift the electrical engineers gave to us to advance everything away from picking up the phone and to have FIRST call an operator at a telephone switchboard... As more and more people were getting phones, ATT / BELL labs started engineering compact / far more complicated systems to handle the traffic. I find this video utterly fascinating...
@@Steve-u2x6f Did you ever have to go to the hospital to get your finger moved out of it ? 🤣‼️
This is really cool!
When I started with Bell Canada in 1987 these were being phased out for digital switches. I miss the old days of the Central Office humming and clacking when in operation. Brings back some great memories.
Amazing early technology and only the first element in a number of mechanical decisions before the dialed subscriber's phone rang. The telephone system was the world's biggest analog computer before the digital world.
Thanks for posting.
You lost me at 'dial-tone' 😂😂 Actually, this is great stuff!
There were some mad scientists in the 50's and 60's with these switching systems, EM pinballs, analog computers !
Step by step switches actually go a lot further back. They were in use in large metro areas in the 1910s. Strowger, an undertaker by trade, received a patent for a rudimentary rotary selector in the late 1800s. There were some really crackerjack engineers who figured SxS out. This film is about just one selector, never mind the topology of the switching fabric which tied hundreds or thousands of customers together.
So much was done with switching the polarity of tip and ring at different points during the connection to indicate different states; remarkable how they could get so much flexibility out of just two wires...
Pinball machines made this thing look simple. Mad scientists for sure!
Started in TELCO career in a British type Strowger 10,000 line exchange in Dec 1972. Was witness to the chaos of a blown main fuse by somebody doing something stupid and all the selectors homing on power restoration and all the rack grasshopper fuses blowing. Was on fuse repair duty for 2 weeks afterwards.
I worked originally in a freight yard. My best move was transferring to Manchester telephone exchange. New job new life no nightshirts plus a very happy wife. She did not like being left alone for over 8 hours.
Incredible engineering.
Brought back some memories. Wow!
I remember screwing with the pulses and hook so you could get the exchange to enter into an endless ring loop and call your phone back. Used to do it on pay phones in lobbys and watch a bunch of people answer phones with nobody on the other end. 😂
Amazing technology!
Ah, remember when you had to actually dial a phone number? I was just a little tyke back then, but i remember that mysterious rotary phone hanging on the kitchen wall. In our next house, the phone had buttons instead. And we rented the phone from Ma Bell.
We purchased a $15 DialGizmo and have a Western Electric 500 on our "Gossip Table" running on a Spectrum VOIP service. At least a couple of times a month my teenagers will actually sit down and call their friends on it instead of from their iPhones. I love old tech and try to at least educate them on how things used to be. Cool when youth actually appreciates it!
Yep. See above (or below).
I remember going to the local phone company and watching these switches operate.
The film's opener says Part 3.🤔
And the narrator refers to previous parts at the beginning. I'm dying to know what happened before this one.
Very clever.
I remember the Central Office building that handled 235 and 237, 3 cities, and my God, the noise
The constant clicking a thousand times a minute. And the heat. All the windows were open in the summer but the temperature was over 130 degrees inside
Just awful 😞
It says Part 3 in the film, not Part 1.
Is any of this gonna be on Monday's test?
"Yep, Got a call out here. They think it's a bad double dog or virtical dog causing it so I'm gonna replace them."
I'm assuming the rotary stepping was much faster than vertical. No mention about what happens if an idle trunk cant be found. Amazing enough how the dialing is done, but the real head-scratcher is how they cobbled this back into automated billing, because computer technology was quite limited back then.
If an idle truck was not found you would get a 120 IPM "Fast Busy".
Yeah, I was wondering about that. I was given some WWII remote control equipment that used a telephone rotary dial that controlled the channel selection in a remote receiver. It used the rotary stepper switch (which rotated until it found an open circuit, which in turn stopped the rotation.). I reriged it to control a remote antenna tuner. Watching this video made me think about since they were using rotary stepper switches in WWII, why would they use a vertical stepper switch? But I won't second guess the telephone engineers. 10 digit telephone circuitry is vastly more complicated than a 5 channel radio selector. But I sure learned a lot taking one apart and re engineering it.
I had a friend who worked in one of the telephone switch offices in the seventies and eighties and I got to visit and watch and listen to the relay madness.....
Cool shit…💪🏻🤙🏻👍
I guarantee my father saw this when he was in Bell Telephone school in 1952.
comedian Brian Regan can now know what the big switch flipper is doing.
4:25 is this where "I double dog dare you" comes from🤔
I saw one step -by-step office the n operation. It was beautiful and noisy.
4:23 He double dog dared him...
I'm sure I've got it now.
And after this and a thousand more operations connect the call, then the system also automatically times the call and bills it.
I’m nostalgic for simplicity. But you can have it today if you really want it.
My job at 1980 use Siemens exchange....
Those switches stayed around a long time before they began upgrading to full digital switching.
If you didn't understand the system before you watched this then you certainly won't now. Is this something to do with D-Day?
Yeah, I'm an EE, and this is curious stuff, but to really get a grasp, I'd need to pause and rewind and really jump in hard. I'd be all day with this if I really needed to learn it.
Alright…enough already…no one ever remembered how this worked. You just replaced the phone or the relays at the central office. Sheez
回転した後に2番端子はビジーだから接地されていてDリレーが作動せずに再度回転して、3番端子はアイドルだから接地してなくてDリレーが作動してたのに、3番端子がいつの間にか接地しててBリレーが切れてもDリレーが保持されてるのは何故？
Some of these relays are slow-release.
@@SeekingTheLoveThatGodMeans7648BリレーとCリレーがスローリリースなのは理解しているつもりです。
Zzzzzzzzzzzzzz
Also known as Strowget Switching
*Strowger
*Strowger
And also as "peck and hunt".
@@robertmandell526 *Strowger