By the way........
Safety in the Telephone Business
Our New Zealand correspondent, Geoff Jull writes about the old days in New Zealand Telecom
The very interesting article by Bob Estreich in the January newsletter on the subject of working conditions experienced by telephone workers in the early days prompts me to mention some quite dangerous practices that telephone technicians were involved with in times past.
My career in New Zealand telephone exchanges started in the mid 1940s, a time when working conditions and subsequent hazards were not of too much concern to the “powers-that-be” of those times.
Following a brief introduction to rural and country manual exchanges, I was shifted to new installations and extensions on the then current Western Electric Rotary Systems which were rapidly taking over the larger manual exchanges.
At the time, most cable supplied for new systems was cotton covered with the individual wires being enameled. The introduction of plastic covered cable did not reach us until later so the very dangerous practice of dipping the prepared cables into a container of boiling wax was used to seal the cotton coverings. Often the “wax-pot”, as it was called, needed to be moved from the floor where it had been plugged into the mains power, to a position high on overhead cable racking, often 3 to 4 metres above floor level.
The approved method of testing the wax temperature with a thermometer was often ignored and the usual method was to direct a “judicious spit” into the boiling wax. If that produced a suitable and often violent “mini volcanic eruption”, the wax was hot enough!
I only saw one very serious accident where the person lifting the boiling wax pot up to a mate on the overhead racking, missed a step on the ladder and unfortunately, as he was wearing shorts, suffered very serious burns to his legs. To make matters worse, a well meaning person tried to dissolve the wax on his legs with kerosine. This only made worse the damage to his skin.
Much of the cable supplied in those times, and especially cable used for switchboard wiring, was impregnated with arsenic powder to deter carpet beetles and other vermin which were attracted to waxed cotton. Unfortunately, it wasn’t until some staff showed signs of arsenic poisoning that suitable warnings and procedures were introduced.
To maintain the friction drives of the Western Electric Rotary selectors, where a flexible disc was pulled in by a powerful electric solenoid to the permanently rotating solid discs on the shafting, the drive surfaces were first cleaned then treated with a mixture of powdered shellac and methylated spirits. When dry, this mixture provided a very strong drive for the selectors. The volatility of methylated spirits was often the cause of localised flare-ups when working on live equipment at the voltage of 50V D.C.
I saw one instance of a technician cleaning the commutator of a 50 volt shaft driving motor while it was running despite warnings of the danger. The resulting flare-up was quite spectacular but disastrous to the equipment concerned and to the technician’s promotional chances.
At a later date Carbon tetra-chloride was trialled as a cleaning agent then later trichlorethylene was used. Despite the reduced fire risks of these new and potent chemicals, staff began to suffer skin problems and other disorders. Needless to say staff soon realised that these were the chemicals used by the dry-cleaning trade and quite large quantities mysteriously disappeared from stocks.
Maintenance of the large open top lead acid exchange batteries was part of staff duties and, in retrospect, the lack of safety clothing and safety aids was pathetic. Normal safety gear provided was a large rubber apron which partially protected one’s front , a pair of “one-size-fits-all” rubber boots and celluloid eye goggles. Duties such as mixing acid for new installations, topping up cells with distilled water and descaling the battery plates for incipient short circuits invariably played havoc with clothing and by the end of the day a cotton shirt could be worthless.
50 volt distribution from the battery rooms used lead covered cables and I remember causing a temporary exchange shut-down when tightening a brass nut where the cable terminated on the row of cells. Somehow the 8 inch Crescent spanner I was using made contact with the earthed sheath of the main power cable and what we called “a mass migration of electrons” occurred almost welding the spanner to the lead sheath. Needless to say, I was duly reprimanded and had to vigorously dispute a claim for the value of the 8 inch spanner, probably equal to a week’s pay.
Where these heavy duty 50 volt copper bus bars or cabling passed through a wall the opening had to be filled with bags of asbestos, tightly packed around the conductors. It wasn’t until later years that we realised these bags contained asbestos.
Until electric soldering irons became easier to obtain, many installations were wired up using soldering “bolts” heated up over a gas ring in a back room and carried into the switch room. No wonder poor soldering connections were a source of later fault conditions.
Hearing loss from exposure to very noisy mechanical switching plus using a head set with probes to test for battery (on or off condition) must have contributed to hearing loss for many staff.
One of the two remaining Western Electric Rotary exchange working models known to be in existence can be seen at the Auckland Museum of Technology (MOTAT) plus working exhibits of other switching technologies. The large Western Electric Rotary model can only be shown when we are in attendance, currently one day a week and on special events days. ATCS members visiting Auckland can contact a MOTAT member for a special visit to the Museum.
(our New Zealand Correspondent)
Things were not a lot different this side of the Tasman in the “early days”. We didn’t have Western Electric Rotary but we did have ringers, open batteries and tools that melted when dropped across the 50 volt bus bars. Add that to the day the entire roof blew off the exchange at North Ryde during a storm in 1975 and you have”Workcover nightmares”.
By the way........