Musing on the old telegraph network reminded me that it had an interesting evolution. Telegraphy was basically a messaging service, and therefore quite distinct from telephony which is so universally embraced by the public.
Initially, New Zealand operated a fixed-line telegraph service, employing mostly men to send messages via morse code. Small private links were established at first, slowly forming a network that covered much of the South Island and linked into Wellington with the commissioning of a Cook Strait telegraph cable in 1866.
Progress was slower in the North Island owing to dense bush cover, land disputes and rough terrain. A telegraph cable to Australia was commissioned in the late 1870s, not long after a link between Wellington and Auckland had finally been established. The network slowly expanded into the regions during the 1870s and 1880s.
Even as late as World War II, it seems that much of the telegraph traffic was sent by morse code, but via multiplexed circuits. The first telegraph machines were introduced in the 1920s but they still worked alongside morse until the early 1960s.
The Telex service, which offered users of teleprinters the ability to dial other customer’s machines, was commissioned in 1964. The service used step-by-step switching specially adapted from the telephone exchanges to switch the 80 volt telegraph circuits. By the 1970s, from memory, there were telex exchanges at Auckland, Wellington, Christchurch and Dunedin. Subscribers had 4 or 5 digit telex numbers. Telegraph systems allowed customers in the regions to receive a telex connection via a long-line connection to one of the city exchanges.
Inward international calls were automatically switched at Auckland, but outgoing international calls required the intervention of an operator in order to manage billing. Making an international telex call involved calling the international telex operator at INTELEX and typing in the call requirements. The international circuit would be established, right through to the remote answerback being triggered before the operator exited the circuit with a GA+ (Go Ahead). On call completion, the intelex operator called back with a message detailing billed minutes etc. As far as I know, all outward international calls were made on the “price required” basis, which involved a follow-up call with billing charges.
It was early in the 1980s that the step-by-step telex exchanges were replaced with a stored programme controlled (SPC) exchange located in Wellington. However, by this time, telex growth was minimal, with the 300 bps Datex service offering an enhanced service. This was the beginning of packet switching, and the days of Telex were numbered.