Mar 15, 2008
My first job when I left home in 1946 was as a technician (technically called a “junior mechanician”) in an automatic telephone exchange at Kelburn in Wellington. The exchange was a sort of Iron Age version of a computer. It occupied all the top floor of a substantial brick building on Upland Road, and it consisted of several hundred metres of shafting, both horizontal and vertical driving a ten foot high array of wheels and “sequence switches” that served to connect you (usually) to the number you had dialled. The shafting was driven by a series of electric motors which ground on, day and night whether anyone was ringing up or not. It must have cost the earth in wasted electricity. Today, with transistors and computer chips, the whole thing is contained in a box not much bigger than an ordinary office desk, and the only moving part is a fan to keep it cool.
Our exchange, a Western Electric 7A, had been built in America about 1915, and was really worn out, but what with the war and the depression there was no question of replacing it, so with traditional Kiwi ingenuity we kept it running with spare parts and tricks. I don’t know whether I can explain how it worked, but I’ll try.
When you lift the receiver of your phone, it closes a switch which tells the exchange that you would like to make a call. The exchange then goes into a mechanised panic, asking itself “Who in particular, wants to make a call?” After all it can’t handle calls from everyone at once. In fact it goes into total shock, and goes off the air if more than about 10% of subscribers want to ring up simultaneously, (as when there is a power cut, or a bad earthquake or a bomb or some such civil disaster.) So it activates a magnet that pulls a disc down onto one of these eternally revolving wheels, and the disc carries little copper contacts around a semicylinder of other contacts one of which is connected to the end of the wire from your phone. When it finds this one, it switches off the magnet, and sets up several circuits one of which transmits the “humming sound” to tell you can start dialling. Of course a bit of dirt on the contact, or a bit of slip between the wheel and the disc fouls up the whole process, so in fact there are a dozen or so such wheels that go searching for you, which improves your chance of success. Dialling the number you want follows a similar but somewhat more complicated process, but finally with a bit of luck you get connected to the number you dialled.
Technicians are employed to routinely clean the contacts with a piece of cheese cloth wetted with some carbon tetrachloride, but slip between the wheel and the disc is another matter. Originally, Western Electric had imprinted a network of grooves on both wheel and disc, but by the end of the First World War these had worn smooth and shiny, and slipping was becoming common. This is where kiwi ingenuity came in. Someone invented a sort of varnish made of shellac and oil and methylated spirits, which, when painted onto the wheels would give them a grip on the discs until the varnish wore off, (after about a week). The technicians would then clean off the old varnish with meths, and repaint each wheel, (there are thousands of them) after immobilising the magnet with a tooth pick until the varnish dried The process was known as “doping drives”. As you can imagine it was very tedious. If you want to see the blood drain from an erstwhile technician’s face, just mention “doping drives”. There were three of us junior mechanicians at Kelburn, and for two weeks out of three we would be on “routine”, which was mainly doping drives or cleaning contacts. By the end of the second week you were just about away with the fairies.
One of the other juniors was a bright young fellow from Lower Hutt called Bowden. He was one of a pair of identical twins. The other one worked in the main Wellington exchange in Stout Street near the Railway Station, and I think our one had only been assigned to us because the bosses at Stout Street couldn’t distinguish one from the other, and imagined they could solve the problem by separating them. Of course the twins were aware of this, and occasionally we would get the unsmiley one at Kelburn, when they had decided to swap places just for a joke. Later they transferred both of them to Stout Street, and tried, equally unsuccessfully, to keep them on different shifts.
The other junior was a big lumpish lad from Ashburton called Fat Cook. (People still had nick names in those days.). He had been employed to assist the linesmen at Ashburton during the “snow break” of 1945, when all the telephone lines in the district had been brought down by the weight of snow built up on them, and he spoke, when he did speak, of almost nothing else. He had lost his pliers during the snow break, and since they were government property he had to put in a lost property report on the matter. The form asked him to explain where and when and how he had lost them, among other details. Being a humourless lad, he wrote that if he knew where he had lost them, he would go and get them. Head Office, being also humourless, thought he was being smart arsed, and transferred him to Wellington so he ended up with us. Almost the only other thing I remember about him was that he had a peculiarly sensitive upper lip, which, each time he drank his tea, would curl back on its approach to the hot liquid, even before it had actually made contact. It was as if it had a sensory system of its very own.
Most of the ground floor at the exchange was taken up with a vast array of large glass batteries, which could be used to operate the exchange if there was a power cut. From time to time they would be run down and recharged with a big electric motor driving a generator, to keep them in optimum condition. During one such occasion Fat Cook, ever helpful, pulled the main switch before the charging process was quite finished, causing the batteries to turn the generator into a motor which then tried to use the motor as a generator. The system couldn’t stand it, and blew the main fuse, putting the whole exchange off the air for about half an hour, until the senior technician could repair things. I think Cook took up some other form of employment after that, probably selling fish or something to which he was better suited.