Stuart0742 Posted November 28, 2009 Share Posted November 28, 2009 This topic started life as part of the Then & Now discussion topic, I have split off relevant posts to form a new topic Link to the previous post in the old topic The main building in these pictures is Steel City House, last refurbished 1995. The corner closest to the cameras was a bank (now the main entrance and reception) and the vault is still in the basement sitting on several feet of reinforced concrete. The old post office which was at the other end on what is now West St is now a large conference room. The Post Office end was also one of Sheffields main telephone exchanges when the system was 1st automated, taking over from the manual boards at the HPO in Fitzallan Sq. A state of the art telephone exchange building was built in the mid 1960's on Charter Row to replace the West St exchange, after which only the Post Office counter service remained. Link to comment Share on other sites More sharing options...
vox Posted November 28, 2009 Share Posted November 28, 2009 The Post Office end was also one of Sheffields main telephone exchanges when the system was 1st automated, taking over from the manual boards at the HPO in Fitzallan Sq. A state of the art telephone exchange building was built in the mid 1960's on Charter Row to replace the West St exchange, after which only the Post Office counter service remained. When it was first built, because it was "automatic" and because it had no windows, people rumoured that nobody worked in the new exchange building. I assume this was an exaggeration. Link to comment Share on other sites More sharing options...
DaveH Posted November 28, 2009 Share Posted November 28, 2009 When it was first built, because it was "automatic" and because it had no windows, people rumoured that nobody worked in the new exchange building. I assume this was an exaggeration. No, BT employed one man and a dog at the automatic exchange. The one man was Stuart0742 and the dog was there to stop him going near any of that automatic machinery and manually tampering with it lol Link to comment Share on other sites More sharing options...
Stuart0742 Posted November 28, 2009 Author Share Posted November 28, 2009 When it was first built, because it was "automatic" and because it had no windows, people rumoured that nobody worked in the new exchange building. I assume this was an exaggeration. Vox, I think you have made a common mistake of mixing up the buildings in the area, the building with no windows you are refering to (close to the roundabout) was/is a YEB/CEGB sub station, and would not be staffed. The Post Office/BT building is further towards the city centre opposite the rear of Atkinsons. During the time I worked there, even though the exchanges were automatic, due to the nature of the technology they were very labour intensive. These days with modern digital technology they probably have reached the way Dave describes it, a man and a dog, ie the man feeds the dog and the dog stops the man touching anything. Though I suspect nowadays they have realised that they can get rid of both and save even more money. As to how many people worked there its hard to say but a hell of a lot more were employed there. lol Link to comment Share on other sites More sharing options...
DaveH Posted November 28, 2009 Share Posted November 28, 2009 Vox, I think you have made a common mistake of mixing up the buildings in the area, the building with no windows you are refering to (close to the roundabout) was/is a YEB/CEGB sub station, and would not be staffed. The Post Office/BT building is further towards the city centre opposite the rear of Atkinsons. During the time I worked there, even though the exchanges were automatic, due to the nature of the technology they were very labour intensive. These days with modern digital technology they probably have reached the way Dave describes it, a man and a dog, ie the man feeds the dog and the dog stops the man touching anything. Though I suspect nowadays they have realised that they can get rid of both and save even more money. As to how many people worked there its hard to say but a hell of a lot more were employed there. I thought that was what BT had done to you (and the dog) around 1996 lol Link to comment Share on other sites More sharing options...
vox Posted November 28, 2009 Share Posted November 28, 2009 Vox, I think you have made a common mistake of mixing up the buildings in the area, the building with no windows you are refering to (close to the roundabout) was/is a YEB/CEGB sub station, and would not be staffed. The Post Office/BT building is further towards the city centre opposite the rear of Atkinsons. Learning all the time - Ta. lol Link to comment Share on other sites More sharing options...
Stuart0742 Posted November 28, 2009 Author Share Posted November 28, 2009 Learning all the time - Ta. I have even seen it in a book where somebody has mistaken that building Link to comment Share on other sites More sharing options...
DaveH Posted November 28, 2009 Share Posted November 28, 2009 Vox, I think you have made a common mistake of mixing up the buildings in the area, the building with no windows you are refering to (close to the roundabout) was/is a YEB/CEGB sub station, and would not be staffed. Yes but don't electricity sub stations usually make a continuous 50Hz buzzing noise, are painted mainly dark green, have loads of cables and insulating poles around them, have railings or high security fencing around them and have a big sign that says "DANGER! HIGH VOLTAGE" or "risk of death / electrocution" or something like that. If this one can pass itself off so easily as an ordinary building like a telephone exchange it must be a very different sort of electrical sub station. Link to comment Share on other sites More sharing options...
Stuart0742 Posted November 28, 2009 Author Share Posted November 28, 2009 Yes but don't electricity sub stations usually make a continuous 50Hz buzzing noise, are painted mainly dark green, have loads of cables and insulating poles around them, have railings or high security fencing around them and have a big sign that says "DANGER! HIGH VOLTAGE" or "risk of death / electrocution" or something like that. If this one can pass itself off so easily as an ordinary building like a telephone exchange it must be a very different sort of electrical sub station. I think due to its size it is "different" to the run of the mill local substation you find in your local street. I think it some sort of high voltage sub station, not sure really Link to comment Share on other sites More sharing options...
Stuart0742 Posted November 28, 2009 Author Share Posted November 28, 2009 I think due to its size it is "different" to the run of the mill local substation you find in your local street. I think it some sort of high voltage sub station, not sure really BT Exchange Charter Row Sub Station Moore St Both images courtesy of Google SV Link to comment Share on other sites More sharing options...
ukelele lady Posted November 28, 2009 Share Posted November 28, 2009 BT Exchange Charter Row Sub Station Moore St Both images courtesy of Google SV Is the Charter Row picture the Milton House and is it still used by BT? Link to comment Share on other sites More sharing options...
DaveH Posted November 28, 2009 Share Posted November 28, 2009 BT Exchange Charter Row Sub Station Moore St Both images courtesy of Google SV So if someone broke into the substation believing it to be an unoccupied telephone exchange they could be in for a bit of a SHOCK lol Link to comment Share on other sites More sharing options...
vox Posted November 28, 2009 Share Posted November 28, 2009 So if someone broke into the substation believing it to be an unoccupied telephone exchange they could be in for a bit of a SHOCK Some may say it would be their own volt but I amp got a clue so I'll shut up and go ohm. Wire you asking? I suppose it's the current topic that's generated your interest. Etc Ect lol Link to comment Share on other sites More sharing options...
hilldweller Posted November 28, 2009 Share Posted November 28, 2009 The Post Office end was also one of Sheffields main telephone exchanges when the system was 1st automated, taking over from the manual boards at the HPO in Fitzallan Sq. A state of the art telephone exchange building was built in the mid 1960's on Charter Row to replace the West St exchange, after which only the Post Office counter service remained. As a pupil of the Central Technical School over the road, I went to an exhibition of telephone equipment upstairs in this building in the early 1960's. Among the exhibits was a repeater for the trans-Atlantic phone line. In those days it used many thermionic valves with octal valve-bases but the wires which are normally cropped off on the end of the valve pins had been left on and soldered on to the valve bases to ensure continuity. All the interior of the repeater was gold plated to prevent corrosion. I was very impressed to be told that all the valve heaters in the entire chain across the ocean were connected in series and was fed from one end with several thousand volts like a huge set of fairey-lights. There must have been provision to automatically switch faulty valves out of the chain. A hell of a job to fetch the thing up from several miles down to change a valve. HD Link to comment Share on other sites More sharing options...
hilldweller Posted November 28, 2009 Share Posted November 28, 2009 So if someone broke into the substation believing it to be an unoccupied telephone exchange they could be in for a bit of a SHOCK To the best of my knowledge it's a main 275kV / 33kV substation like the ones at Norton, Neepsend, Pitsmoor and various other places around Sheffield which feed the National Grid into the city. Because it's right in the city it is in a building for aesthetic purposes but the building has to be huge to provide the necessary air clearances aound the high voltage switch-gear. The 275kV cables feeding it come over past the City Hall and have had to be re-routed in places because of the now postponed development taking place in the area. HD Link to comment Share on other sites More sharing options...
DaveH Posted November 29, 2009 Share Posted November 29, 2009 As a pupil of the Central Technical School over the road, I went to an exhibition of telephone equipment upstairs in this building in the early 1960's. Among the exhibits was a repeater for the trans-Atlantic phone line. In those days it used many thermionic valves with octal valve-bases but the wires which are normally cropped off on the end of the valve pins had been left on and soldered on to the valve bases to ensure continuity. All the interior of the repeater was gold plated to prevent corrosion. I was very impressed to be told that all the valve heaters in the entire chain across the ocean were connected in series and was fed from one end with several thousand volts like a huge set of fairey-lights. There must have been provision to automatically switch faulty valves out of the chain. A hell of a job to fetch the thing up from several miles down to change a valve. HD Impressive, but even by the early 1960's the days of valves were numbered. I wonder how they did switch faulty valves out of the chain? If they are series wired like Christmas tree lights doesn't someone have to go along and check every single one to find the faulty one (which is usually the last one that you check!! ). Also if they were series wired the failure of one valve would cut the current to all the others, - although they do seem to have overcome this in modern Christmas tree lighting sets. Ignoring the resistnce losses in the cable (which would be considerable) a standard octal base vave had a heater voltage of 6.3V (silly choice I know but all mains transformers for valve appliances had a 6.3V AC tap point). Now several thousand divided by 6.3 is a hell of a lot of valves. As you say hilldweller, very impressive technology for the time. Even being able to lay a cable across the Atlantic is itself an impressive achievement. Link to comment Share on other sites More sharing options...
DaveH Posted November 29, 2009 Share Posted November 29, 2009 Some may say it would be their own volt but I amp got a clue so I'll shut up and go ohm. Wire you asking? I suppose it's the current topic that's generated your interest. Etc Ect he he he he Nice one vox, - like it ;-) Link to comment Share on other sites More sharing options...
SteveHB Posted November 29, 2009 Share Posted November 29, 2009 It always reminds me of a castle Link to comment Share on other sites More sharing options...
DaveH Posted November 29, 2009 Share Posted November 29, 2009 It always reminds me of a castle Don't worry about the arrows, spears and boiling tar Steve, - its the 275,000 volts you need to watch out for ;-) Link to comment Share on other sites More sharing options...
hilldweller Posted November 29, 2009 Share Posted November 29, 2009 Impressive, but even by the early 1960's the days of valves were numbered. I wonder how they did switch faulty valves out of the chain? If they are series wired like Christmas tree lights doesn't someone have to go along and check every single one to find the faulty one (which is usually the last one that you check!! ). Also if they were series wired the failure of one valve would cut the current to all the others, - although they do seem to have overcome this in modern Christmas tree lighting sets. Ignoring the resistnce losses in the cable (which would be considerable) a standard octal base vave had a heater voltage of 6.3V (silly choice I know but all mains transformers for valve appliances had a 6.3V AC tap point). Now several thousand divided by 6.3 is a hell of a lot of valves. As you say hilldweller, very impressive technology for the time. Even being able to lay a cable across the Atlantic is itself an impressive achievement. When I was a technician then engineer at BSC Stocksbridge works, I remember that the voice frequency telephone tie-line to our sister plant at Tinsley Park had to have a repeater part way along the line and that would be only 15/20 miles away. If you needed a repeater every 20 miles then that's an awful number of repeaters (and valves) to cross the Atlantic. Perhaps one of our GPO/BT posters can enlighten us. I did know once why most modern valves had 6.3 v heaters but the reason is lost in the mists of time. I guess the repeater valves would be operated in a constant-current configeration and the exact voltage would not matter. Perhaps relays were arranged to switch out dud valves. Valve T.V.'s used constant- current series chains and the bigger valves for line output etc used higher voltage heaters with the entire chain operating at 0.3 amps. This chain was usually connected across the mains with a dropper resistor. The chassis of these T.V.'s was usually connected to one side of the mains making them potentially lethal if you didn't know what you were doing. The tube EHT supply of up to 25Kv (at low current) was also something to be avoided. HD Stop Press I've just found a website with details of a 1961 Atlantic cable. It used 182 repeaters, approx one every 23 miles, each contains 205 components. It was fed with 5.5kV from each end making 11kV in total !!! The line current was 389 mA. The cable had one big conducter with copper tapes to provide protection from undersea wildlife. If 6.3 volt heater valves were used then I calculate thats about 1750 valves in total, about 9.6 valves per repeater. HD Link to comment Share on other sites More sharing options...
DaveH Posted November 29, 2009 Share Posted November 29, 2009 Stop Press I've just found a website with details of a 1961 Atlantic cable. It used 182 repeaters, approx one every 23 miles, each contains 205 components. It was fed with 5.5kV from each end making 11kV in total !!! The line current was 389 mA. The cable had one big conducter with copper tapes to provide protection from undersea wildlife. If 6.3 volt heater valves were used then I calculate thats about 1750 valves in total, about 9.6 valves per repeater. HD Sounds quite impressive. Wonder how long it all worked before becoming unusable, or if by some good luck and good management and despite being toatally obsolete now, it is still working almost 50 years later. Link to comment Share on other sites More sharing options...
hilldweller Posted November 30, 2009 Share Posted November 30, 2009 quote [ I did know once why most modern valves had 6.3 v heaters but the reason is lost in the mists of time. ] I knew I knew ! Quote from 1943 edition of FOUNDATIONS OF WIRELESS FOURTH EDITION by M. G. SCROGGIE B.Sc A.M.I.E.E. "This curious voltage is to enable these valves to be used alternatively in cars, whose batteries average 6.3 volts when on charge". Link to comment Share on other sites More sharing options...
DaveH Posted November 30, 2009 Share Posted November 30, 2009 quote [ I did know once why most modern valves had 6.3 v heaters but the reason is lost in the mists of time. ] I knew I knew ! Quote from 1943 edition of FOUNDATIONS OF WIRELESS FOURTH EDITION by M. G. SCROGGIE B.Sc A.M.I.E.E. "This curious voltage is to enable these valves to be used alternatively in cars, whose batteries average 6.3 volts when on charge". This implies that most cars of the time had 6V electrics (which they probably did) rather than the 12V used today. Oh well, -I'll just switch on the old car wireless with its 3 valves with 6.3V heaters and tune in to the old BBC home service lol Link to comment Share on other sites More sharing options...
DaveH Posted November 30, 2009 Share Posted November 30, 2009 This implies that most cars of the time had 6V electrics (which they probably did) rather than the 12V used today. Oh well, -I'll just switch on the old car wireless with its 3 valves with 6.3V heaters and tune in to the old BBC home service Having said that I once owned a portable Marconiphone valve radio dating from around 1951. It was battery / mains Mains was lethal, - a metal cabinet and some of that old twisted rubber and cotton insulated flex terminating in a 2 pin (no earth) plug Battery wasn't much better. It required 3V for the valve heaters (a flat Ever Ready battery with screw terminals) and a large rectangular battery rated at 90V (yes, NINETY) with its own plug connector for the HT supply to the valves. The valves themselves were the miniaturised modern style of portable valve, they had low voltage heaters (3V, I think??) and the valve pins went straight through the glass envelope without a plastic base. Link to comment Share on other sites More sharing options...
hilldweller Posted December 1, 2009 Share Posted December 1, 2009 Having said that I once owned a portable Marconiphone valve radio dating from around 1951. It was battery / mains Mains was lethal, - a metal cabinet and some of that old twisted rubber and cotton insulated flex terminating in a 2 pin (no earth) plug Battery wasn't much better. It required 3V for the valve heaters (a flat Ever Ready battery with screw terminals) and a large rectangular battery rated at 90V (yes, NINETY) with its own plug connector for the HT supply to the valves. The valves themselves were the miniaturised modern style of portable valve, they had low voltage heaters (3V, I think??) and the valve pins went straight through the glass envelope without a plastic base. There were a number of such sets in the 1950's such as the Ever-Ready Sky Queen, They used a 90 volt HT battery and a 1.5 volt LT battery for the directly-heated valves which had a 1.4 volt filament (except the output pentode which had a center-tapped 1.4/2.8 volt filament normally connected for 1.4 volt). Perhaps some of them had the filaments connected in pairs running from 3 volts? The valve codes were something like DH** DF** & DL** and they had B7G all glass bases. I remember playing with and repairing them, the valves were subject to poor emission due to the tiny filament and the frequency-changer was always favorite if the set stopped working. I also remember the earlier 2 volt directly-heated valves such as the HL2 with a B4 base. And yet I've still got a full head of dark hair ! HD Link to comment Share on other sites More sharing options...
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