My father was a technician in our local telephone exchange. As a young child I used to love standing in the selector room watching and listening to rows and rows of mechanical selectors like this at work. What a cacophany!
Same here, my Dad was an "IR" guy (Installer/Repair), and he would take me to see the "switching rooms" (his term). Like you, I was fascinated to see all the mechanics happening as people were making phone calls. It was truly a cacophony!
Western Electric technology has always been of interest to me. When I was a kid in the 1960s our school principal arranged a "field trip" for the students to see the workings of our local Bell (New Jersey Bell). It was fascinating and I became a lifelong fan of the Bell System and Western Electric. The quality and longevity of Western Electric products is amazing (and were made in the USA). I am still using a 1968 Western Electric 10 button Touch Tone and it works perfectly.
Western Electric was not the inventor or designer of the S X S switch, it was Automatic Electric Company, of Chicago, IL. The original switch was the Strowger Switch later manufactured by WE under license.
@darrellw82, this is connecting the numbers that would be dialed using a rotary phone. For this video, I used a modern computer to simulate calls (it generated the dial pulses that would normally be created by a rotary dial). But, there are several rotary phones connected to it that can be used to call one another.
This is fascinating! I'm building an electronic rotary dial exchange that attempts to mimic the operational theory of an old exchange, if not the actual electromechanics. github.com/diggydude/php-pbx
This is old technology. The oldest switch in the video was built in the 1940's and the newest was built in the early 1970's. Switches like these were replaced by ESS or Electronic Switching Systems and those were later replaced by digital switches. Today the only noise you hear in most telephone central offices is from the fans that keep the equipment cool.
I remember touring a GTE Central Office in West Covina, CA as a kid in the 70's, our elementary school took a field trip, and I remember so well the sound of all these switches doing their thing, it was LOUD! :D
I worked for GTE AE in the 70's and remember working on a central ofice in Victorville, CA, wow, what a small world! I am now 73 and just remembered reading your coment.
My father worked in our local telephone exchange. I sometimes used to viist him at work aftrer school in the early 70s and spend ages mesmerised by the selectors.
@HappyDiscoDeath For the portion of the video that has multiple calls being processed at once, I'm using the open source PBX Asterisk to generate the calls. When it's a single call, it's just a plain old rotary telephone.
So when the connection maker i.e. the machine is making the connection, is it opening or closing the loop of the connection i.e. data followed by voice or voice followed by data?
Great! How did you get it to behave like that? Are you using a routine tester? I notice that at 0:48 the vertical wiper rotates, is that normal on US strowger is is it simply that it is trapped by the wiper cords? On UK strowger the vertical wiper is double sided and remains in contact as the shaft rotates.
The Line Group has a built in test function that sends each Line Finder to the top level and last position. The vertical wiper is designed to rotate off of it's contacts when the switch rotates. It's only used to find the level requesting service. I know that this is standard behavior for Western Electric switches. I'm not that familiar with others.
Yes, a line finder would normally hunt for a vacant pair and stop. If one could not find one from the first layer it would go up one and try again, 1000 attempts, before dropping out, So it should be a click, than ten clicks, drop and two clicks, and ten clicks, etc. Several companies produced a unit that gave most of the features of an ESS office to a step office. This was done by placing the line finder under electronic control. In that case you would have heard a faster buzz only.
Nice video. Any chance you may know if there's schematic & maintenance info for these online somewhere? I've seen some with only a few relays, some with a bunch. Likewise I hear a lot about linefinders connecting to vacant lines, etc... but never seen a schematic of how these are hooked up in a CO in practice.... I could really enjoy having a garage wall covered in those things "just because." ;) But yeah, asterisk is sooo nice in so many ways.
Kristy, there's a show from the early 90's called the secret life of machines, and the Secret life of the telephone episode shows an.exchange in rural England that was still running these, but they might have been on the way out. So maybe 30s to the 90's?
Atom, whow, 2005! That's *late* for something like this to still be used! But then how are you really *sure* about that, all over the world? How would you have gotten that information so certainly?
so Strowger switches are basically a multi deck rotary switch with stepper motors to move the spoke up and down each deck of the switch and also to rotate the spoke on each deck through each contact position.? Interesting! thinking of some fascinating electronics projects I could do, if I could get my hands on one of these :)
i used to fix all that gear. if you think that is noisy imagine a main exchange with about an acre of floor space loaded with thousands of them all going at once. it sounded like distant thunder along with the close noise you hear now. also worked on pre 2000 type, SE 50, line finder and 2000 type .later on crossbar and various type of PABX s . mainly fault finding and maintenance.. loved it did it for 25 years .the hardest fault i ever came across was on a silly little C type PABX .took me months but it was there for years. . .
Erik yes in sydney. i worked in most of exchanges in sutherland shire plus hurstville and in the newtown main exch. finally worked at haymarket, city south and pitt st. worked on all type of gear step.strouger 2000 type se50 and then crossbar.
Paul Richardson wow I'd love to know more. What years was this between? Back in 93 I tried to get more info and parts to build (or try to build) my own little sxs set up from the pymble exchange. They cut their sxs off in winter 92. The people were really helpful but I never ended up getting anything as I was just a school boy back then. Always wanted the 44 ringer. I bought a small ringer off eBay years ago and still have it. Do you think the suburban exchanges still have all this stuff in them? They don't look as though they've been touched since then
Erik i was at newtown when the step shut down . not exactly sure but i thnk about 92 or 93. i know a texh who was there much longer than me. i will ask him and get back to u. way back i worked on linefinder and keith equip. plus linefinder pabx's i did just about the lot. i even had a trt in the shed after it was about to be theown out.
Why is it that the step selectors promptly drop out? A call placed should select another and another. And, although I do agree that electromechanical switches have charm, the Asterisk switch can handle hundreds of calls in the time that the stepper can handle 2 digits and in the same space.
They were not usually this noisy. Where they are running one after another in the video, all the equipment in the next stage of the exchange is busy. By the 1980s they were only for low volume customers. It took me a week to do the maintenance on suite of these. By the time I had finished, the wipers on the first ones were showing signs of wear. Some of the selectors were date coded 1942! The 2000 series selectors were much more durable.
NOT That NOISY ?? I've never heard of one not being loud as it shows or more. Most times there are floor models and rows of them (Corpus Christi, Tx. Central Office for one) and all running a mile a minute and so loud ear plugs had to be worn. If not the ringing would stop about as long as standing in front row of any concert.. Not that noisy? Have you ever be in communications long cause I've be doing it for 32 and step switches are all loud.
Western Electric was not the original manufacturer of the Strowger step-by-step. That would be the Automatic Electric Co. Actually, when the Strowger system was first employed by the Bell System, all of their step switches were made by AE but with a WE nameplate.
Right on, I worked for AE in the 70's in Northlake, IL, started with S X S engineering of central office then on to the N. 1 EAX, and others, left AE in 77 to ITT, then NORTEL and so on until my final retirement at Lucent, a real wild ride!
depending on the type of switch , eg .group selector or final selector the three levels of banks are used for a and b leg of outlet , also a second a and b leg outlet .Then the c wire for upper or lower outlets .that is six contact points 2 per bank. There are variations of this depending on the type of manufacturer.
the last ones came out in the 90's from the rural areas last to see funds of course, in 1989 New York still used them and also Florida. It may have been in the 2000's for some companies, year after year replacing them. Back them new stuff like today cost way more than years ti follow.
@westernelectric ...and just think, all the ESS equipment has to be in Air Conditioned rooms whereas before the old mechanical switching did not require it. You wonder why it cost's so much to operate this equipment these days?
I remember watching these...some of the switches we had were very old but they just kept working. Nothing wrong with them they just wanted to replace them with new stuff and eliminate jobs.
Don't forget the drudgery of routine maintenance on these somewhat unreliable electro-mechanical beasts - the regular schedule of cleaning the banks of contacts being one nasty task. As an ex UK "Post Office Telephones" engineer, I remember being lumbered with that dreary task during my training period! 'Orrible, squire!
they only added the tone cause everyone would not think it was working and leave it off hook. So someone came up with the idea to beep when left off hook to long, another came up with a tone. short and sweet that's how the tone came about and the busy signal too.It was an analog signal before it became a digital tone also.
Dandy Don, what are the capitals on "air conditioned" supposed to be for? And then "cost's"? Where's my errant-apostrophe eraser when I need it? Anyway, Don, if it supposedly costs (without an apostrophe) more to run the modern systems, then why did they install it in the first place? Probably because it takes a lot less manpower and labor time to maintain them, right? So then are you sure that just because today's equipment might need air conditioning, it actually costs more to keep running? Why wouldn't it cost *less* to keep running, hence the reason it was invented in the first place?
My father was a technician in our local telephone exchange. As a young child I used to love standing in the selector room watching and listening to rows and rows of mechanical selectors like this at work. What a cacophany!
Same here, my Dad was an "IR" guy (Installer/Repair), and he would take me to see the "switching rooms" (his term). Like you, I was fascinated to see all the mechanics happening as people were making phone calls. It was truly a cacophony!
Western Electric technology has always been of interest to me. When I was a kid in the 1960s our school principal arranged a "field trip" for the students to see the workings of our local Bell (New Jersey Bell). It was fascinating and I became a lifelong fan of the Bell System and Western Electric. The quality and longevity of Western Electric products is amazing (and were made in the USA). I am still using a 1968 Western Electric 10 button Touch Tone and it works perfectly.
Western Electric was not the inventor or designer of the S X S switch, it was Automatic Electric Company, of Chicago, IL. The original switch was the Strowger Switch later manufactured by WE under license.
@darrellw82, this is connecting the numbers that would be dialed using a rotary phone. For this video, I used a modern computer to simulate calls (it generated the dial pulses that would normally be created by a rotary dial). But, there are several rotary phones connected to it that can be used to call one another.
This is fascinating! I'm building an electronic rotary dial exchange that attempts to mimic the operational theory of an old exchange, if not the actual electromechanics. github.com/diggydude/php-pbx
This is old technology. The oldest switch in the video was built in the 1940's and the newest was built in the early 1970's. Switches like these were replaced by ESS or Electronic Switching Systems and those were later replaced by digital switches. Today the only noise you hear in most telephone central offices is from the fans that keep the equipment cool.
I remember touring a GTE Central Office in West Covina, CA as a kid in the 70's, our elementary school took a field trip, and I remember so well the sound of all these switches doing their thing, it was LOUD! :D
Michael Cook me too!
+Michael Cook Merced Elementary class of 1973. Been there, done that.
I worked for GTE AE in the 70's and remember working on a central ofice in Victorville, CA, wow, what a small world! I am now 73 and just remembered reading your coment.
What is the stepper @0:48 ~ 1:43 used for? Was it used to determine the horizontal step of the line finder?
You have no idea the panic one experienced when walking into one of these offices and it was silent. You knew you had a major problem on your hands.
In 1966 I was final inspection on this switch leaving the Automatic Electric plant in Northlake, Illinois
My father worked in our local telephone exchange. I sometimes used to viist him at work aftrer school in the early 70s and spend ages mesmerised by the selectors.
@HappyDiscoDeath For the portion of the video that has multiple calls being processed at once, I'm using the open source PBX Asterisk to generate the calls. When it's a single call, it's just a plain old rotary telephone.
Reminds me of the phone system in the original Black Christmas
why were there 3 paddles? do they each connect to 3 different switches in case one is busy? or was one for the ringer, one for dial and one for voice?
Are these connecting actual calls or connecting the numbers that someone would being using like in a rotary phone?
So when the connection maker i.e. the machine is making the connection, is it opening or closing the loop of the connection i.e. data followed by voice or voice followed by data?
Great! How did you get it to behave like that? Are you using a routine tester?
I notice that at 0:48 the vertical wiper rotates, is that normal on US strowger is is it simply that it is trapped by the wiper cords? On UK strowger the vertical wiper is double sided and remains in contact as the shaft rotates.
@westernelectric what software do you use to generate the pulses?
The Line Group has a built in test function that sends each Line Finder to the top level and last position.
The vertical wiper is designed to rotate off of it's contacts when the switch rotates. It's only used to find the level requesting service. I know that this is standard behavior for Western Electric switches. I'm not that familiar with others.
Yes, a line finder would normally hunt for a vacant pair and stop.
If one could not find one from the first layer it would go up one and try again, 1000 attempts, before dropping out,
So it should be a click, than ten clicks, drop and two clicks, and ten clicks, etc.
Several companies produced a unit that gave most of the features of an ESS office to a step office.
This was done by placing the line finder under electronic control.
In that case you would have heard a faster buzz only.
Nice video. Any chance you may know if there's schematic & maintenance info for these online somewhere? I've seen some with only a few relays, some with a bunch. Likewise I hear a lot about linefinders connecting to vacant lines, etc... but never seen a schematic of how these are hooked up in a CO in practice....
I could really enjoy having a garage wall covered in those things "just because." ;) But yeah, asterisk is sooo nice in so many ways.
Kristy, there's a show from the early 90's called the secret life of machines, and the Secret life of the telephone episode shows an.exchange in rural England that was still running these, but they might have been on the way out. So maybe 30s to the 90's?
ben ,the last step by step was switched off in australia at newtown about 1989 . was there. .the silence was deafening.
Awesome, thanks Paul. I can't imagine how loud it would have been with a whole room of them going would be!!!
I know there was a step switch in Naunt,Qubec that was the last one to be switched off in North America in 2002.
Paul Richardson no it wasn't. No way. Pymble 1992, Drummoyne 1992, kings grove 1993 (44, 81, 50)
Atom, whow, 2005! That's *late* for something like this to still be used! But then how are you really *sure* about that, all over the world? How would you have gotten that information so certainly?
so Strowger switches are basically a multi deck rotary switch with stepper motors to move the spoke up and down each deck of the switch and also to rotate the spoke on each deck through each contact position.?
Interesting! thinking of some fascinating electronics projects I could do, if I could get my hands on one of these :)
i used to fix all that gear. if you think that is noisy imagine a main exchange with about an acre of floor space loaded with thousands of them all going at once. it sounded like distant thunder along with the close noise you hear now. also worked on pre 2000 type, SE 50, line finder and 2000 type .later on crossbar and various type of PABX s . mainly fault finding and maintenance.. loved it did it for 25 years .the hardest fault i ever came across was on a silly little C type PABX .took me months but it was there for years. .
.
Paul Richardson which exchange? You're in Sydney aren't you?
Erik yes in sydney. i worked in most of exchanges in sutherland shire plus hurstville and in the newtown main exch. finally worked at haymarket, city south and pitt st. worked on all type of gear step.strouger 2000 type se50 and then crossbar.
Paul Richardson wow I'd love to know more. What years was this between? Back in 93 I tried to get more info and parts to build (or try to build) my own little sxs set up from the pymble exchange. They cut their sxs off in winter 92. The people were really helpful but I never ended up getting anything as I was just a school boy back then. Always wanted the 44 ringer. I bought a small ringer off eBay years ago and still have it. Do you think the suburban exchanges still have all this stuff in them? They don't look as though they've been touched since then
Erik i was at newtown when the step shut down . not exactly sure but i thnk about 92 or 93. i know a texh who was there much longer than me. i will ask him and get back to u. way back i worked on linefinder and keith equip. plus linefinder pabx's i did just about the lot. i even had a trt in the shed after it was about to be theown out.
i dont think the gear is there anymore i know newtown old building has been sold and now a med. centre.
Why is it that the step selectors promptly drop out?
A call placed should select another and another.
And, although I do agree that electromechanical switches have charm, the Asterisk switch can handle hundreds of calls in the time that the stepper can handle 2 digits and in the same space.
They were not usually this noisy. Where they are running one after another in the video, all the equipment in the next stage of the exchange is busy. By the 1980s they were only for low volume customers. It took me a week to do the maintenance on suite of these. By the time I had finished, the wipers on the first ones were showing signs of wear. Some of the selectors were date coded 1942! The 2000 series selectors were much more durable.
As a military trained central office repairmen ours where not even stepping relays as these, just regular relay banks in the 1960s...
+Andrew White The most boring thing was bank cleaning.
Barry Jones ...
You mean. .. cleaning each contact individually....?
NOT That NOISY ?? I've never heard of one not being loud as it shows or more. Most times there are floor models and rows of them (Corpus Christi, Tx. Central Office for one) and all running a mile a minute and so loud ear plugs had to be worn. If not the ringing would stop about as long as standing in front row of any concert.. Not that noisy? Have you ever be in communications long cause I've be doing it for 32 and step switches are all loud.
That's why Microwaves for me at least their quiet. ..
Western Electric was not the original manufacturer of the Strowger step-by-step. That would be the Automatic Electric Co. Actually, when the Strowger system was first employed by the Bell System, all of their step switches were made by AE but with a WE nameplate.
Right on, I worked for AE in the 70's in Northlake, IL, started with S X S engineering of central office then on to the N. 1 EAX, and others, left AE in 77 to ITT, then NORTEL and so on until my final retirement at Lucent, a real wild ride!
I remember watching these as a kid🤗
Why are there three banks of contacts per rotor?
depending on the type of switch , eg .group selector or final selector the three levels of banks are used for a and b leg of outlet , also a second a and b leg outlet .Then the c wire for upper or lower outlets .that is six contact points 2 per bank. There are variations of this depending on the type of manufacturer.
Why are they resetting before the connection?
after it's dailed the number it's made the connection to the two lines and ringing them both.
How does the connection work? Like when it resets how is the connection "passed on" for the call?
in what year/decade would this switchline have been used?
the last ones came out in the 90's from the rural areas last to see funds of course, in 1989 New York still used them and also Florida. It may have been in the 2000's for some companies, year after year replacing them. Back them new stuff like today cost way more than years ti follow.
These machines are really beautiful to look at
Most modern systems just show blinking lights!!
@westernelectric ...and just think, all the ESS equipment has to be in Air Conditioned rooms whereas before the old mechanical switching did not require it. You wonder why it cost's so much to operate this equipment these days?
That was fascinating. Thanks for posting.
is this sort of technology still in use?
yes
only one of those would operate at a time, and connect you to a first selector, so that noise would only happen once per call.
Last one was shut down in Poland in 2005.
maybe this device cannot destructed by EMP, as they only run in electric-mechanical instrument.
I remember that hum from prankycallz's phonetapes. (old network sounds)
I remember watching these...some of the switches we had were very old but they just kept working. Nothing wrong with them they just wanted to replace them with new stuff and eliminate jobs.
Don't forget the drudgery of routine maintenance on these somewhat unreliable electro-mechanical beasts - the regular schedule of cleaning the banks of contacts being one nasty task. As an ex UK "Post Office Telephones" engineer, I remember being lumbered with that dreary task during my training period! 'Orrible, squire!
Thanks a lot for posting this!
That is funny, using an asterisk box to create dial pulses to work an old step switch.
they only added the tone cause everyone would not think it was working and leave it off hook. So someone came up with the idea to beep when left off hook to long, another came up with a tone. short and sweet that's how the tone came about and the busy signal too.It was an analog signal before it became a digital tone also.
昔は、このスイッチを見て逆探知していた
凄い技術力 ロータリースイッチが
縦にも動く、 ロストテクノロジーになる前に、再現して欲しい
STROWGER DE BEST !
Dandy Don, what are the capitals on "air conditioned" supposed to be for?
And then "cost's"? Where's my errant-apostrophe eraser when I need it?
Anyway, Don, if it supposedly costs (without an apostrophe) more to run the modern systems, then why did they install it in the first place? Probably because it takes a lot less manpower and labor time to maintain them, right? So then are you sure that just because today's equipment might need air conditioning, it actually costs more to keep running? Why wouldn't it cost *less* to keep running, hence the reason it was invented in the first place?
super film strowger ok
very interesting
Jesus what a racket....
This is what I use as a sleep aid.
***** Hahah~ lol...erm...I'm not sure what to say to that other than what I have already.
Yes and the British type 2000 switch made even more racket.
Oh my god that is even more annoying than a dot matrix printer
All "0"'s
lol i want one
very interesting