What was the reason for New Zealand's reversed numbering on rotary dials?

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unspecified

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#171168 8-Apr-2015 20:09

Does anyone here know the reason for reversed numbering on New Zealand's rotary telephone dials? I heard somewhere that it was to avoid a patent, but I've found no-one to confirm that. Supposedly on the first automatic exchange (Oamaru) but this doesn't match with any other histories of phones in New Zealand.

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#1279267 8-Apr-2015 20:17

There's a recent thread on Public Address on this very subject. Apparently:

The old dial phones would signal the number that was dialled to the exchange by pulsing the line. As the dial wound back to its rest position it would break the circuit repeatedly, at ten pulses a second. In NZ, the mapping was reversed so that the numbers printed on the dial would be in the correct order. (In other countries, the numbers on the dial would read 9,8,7 ...). One intersting impact of this reversal was the emergency services number : 999 in the UK 911 in the US and 111 here. This was necessary as if we had used 999, it would have corresponded to three lots of one pulse, which could occur due to wind blowing the overhead lines together.

Gilco2

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#1279269 8-Apr-2015 20:20

never thought of ours being reversed. Just looked up google and I would say others are reversed as we count left to right and that is how our dial was. Looking on google the others are right to left which is reversed way of counting for us

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unspecified

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#1279272 8-Apr-2015 20:26

Um, well, then of all the countries in the world* we are the only one that numbers correctly.

Does anyone know why?

All the others have 'one' as one decadic pulse, (the shortest turn of the dial) whereas our dials have the number 'nine' producing one decadic pulse.

I saw the clumsy Hard News article and it was actually that which prompted me to finally ask why. The question has been bugging me for decades.

[*] All the other countries except Sweden where they put 'zero' in the one-pulse position.

freitasm

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#1279277 8-Apr-2015 20:41

The PA blog post is about "tapping" (the term the author used)... The first time I saw a rotary Type D was in New Zealand. The sequence that is logical and natural (and used in most countries) would be starting with 1 as the first hole followed 2 3 4 5 6 7 8 9 0. When you "dial" a number and release it each this sequence would produce an interruption on the line corresponding to the number. The Type D was an anachronism as it required the interruptions to be subtracted from 10 (as the author explains about using the phone when the rotary dial was locked) so more complicated mechanism - and obviously not the same in use on phones sourced from other countries, so no patent issues.

A good overview on why 111 (just the inverse of Britain's 999 seeing both send 999 to the exchange) in the Wikipedia entry here.

No references but the reason I was given for the difference in New Zealand is, as above, a patent issue.

roobarb

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#1279280 8-Apr-2015 20:50

unspecified: Um, well, then of all the countries in the world* we are the only one that numbers correctly.

Surprising to see that NZ differed from Australia. I hope that frequency signalling was used for international dialling.

If you understand how a step-by-step Strowger system works then one pulse=1, two pulses=2 make a lot on sense. In the step-by-step system the pulses and delays were crucial for the switches to step to the required level. The mechanical dial on the phone is governed to return to normal at a fixed rate so the pulses are of the correct timing.

Numbering correctly is all in the eye of the beholder, which is correct out of a numeric calculator or a digital telephone pad?

DarthKermit

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#1279283 8-Apr-2015 21:08

And here I was thinking it had to do with the Coriolis effect.

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unspecified

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#1279286 8-Apr-2015 21:09

Yes, CCITT No. 5 signalling was used on international lines when I worked for the NZPO (as was) except for some stop-gap lines installed shortly before NZ moved to the fancy new crossbar exchanges that allowed customer dialling.

The extra lines were 'borrowed' Sydney operator circuits and were indeed decadic (No. 2 signalling, if I remember, using interruptions to a (filtered) carrier tone in place of the loop-disconnect of copper lines.

New Zealand operators had to use push-button decadic keypads showing two sets of number labels -- one for the Australian lines, one for the national circuits.

And had to try to remember which numbering system they were using.

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shk292

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#1279288 8-Apr-2015 21:12

I heard (ages ago) that it was to stop cheap imported phones being used on the NZ phone network, because NZ Post Office had "exclusive rights" to deliver telephony services and equipment in this geographic region. NZ's isolated position and different standards allowed the incumbent to heavily overcharge their captive customers.
There were some third-party suppliers who made dial overlays to allow the use of grey import phones in NZ, but these were subjected to legal action by NZ Post to ban their sale.
NZ Post's successful monopoly of telephony in NZ continues to this day, making them the model for similar anti-competitive legal challenges by other companies seeking to preserve their legacy position

gzt

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#1279333 8-Apr-2015 21:52

I did some work experience in a telephone exchange in the 80's and asked this exact question of the senior engineer.

He said there was absolutely no reason whatsoever for the decision. At the time of the changeover to rotary dial he said the chief engineer just picked that as the convention and nobody could understand why and there was no technical reason at all - with emphasis!

If the rotary dial decision was made during the import control era it could have been just giving someone a job printing new dials in NZ or some related reason - this last bit is pure speculation on my part.

unspecified

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#1279361 8-Apr-2015 22:42

I've read the suggestion about it being protectionism -- but the original decision would have been made in the 20s, before anyone even thought of unofficial imports of telephone apparatus, when imports were quite strictly controlled, and a government department was megalomaniacal in its control.

And the other suggestion -- that somehow New Zealand re-thought the dial labels to match arithmetic order -- seems odd, too. The very first automatic exchanges would have been imported complete (indeed, they still are) with no obvious special reason to re-invent the wheel. And in matching one order (0-1-2-3... on the dial labels) the re-labeling broke the functional match with the 1:1 click per digit that existed in 0-9-8-7... .

No other country in the world seemed to need to do either of these.

It's completely perplexing to me. Patent avoidance (and by a government department, too!) seems likely, but... why did no other country try it, and whose patent -- bearing in mind that equipment was imported directly from the manufacturer? Could it have been caused by an overseas manufacturer who manufactured to avoid a patent?

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#1279382 9-Apr-2015 01:33

I was not aware the decision was made that early. The import substitution program (and associated controls) did not start until the 40's. Starting in the 20's rules out import substitution as a reason. The earlier suggestion that it was purely a commercial decision now seems more plausible.

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#1279479 9-Apr-2015 09:17

I had "heard" that when the first exchange went in, there was a wiring error, and was connected / wired back to front. By the time the error was discovered, quite a few phones had already gone in, and would have been quite a major to reverse.

This was relayed to me in the early 80's when I was working for Plessey in Mt Eden, by a crusty old grey-beard of indeterminate age, who may have been around in those days when the phones first went in.

Or he could have been pulling my leg, but sounded plausible anyways

ubergeeknz

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#1279482 9-Apr-2015 09:27

I have heard it was an error in reading the specifications for the telephone, but "the chief engineer said so" is equally (if not more) plausible. I suspect we will never know for sure.

PolicyGuy

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#1279550 9-Apr-2015 11:42

I too heard that this was a simple straightforward non-tarriff trade barrier, to protect the jobs at the Plessey(?) factory in Porirua(??) that made the special for New Zealand phone handsets.
The underlying idea NZ market was small enough that it wasn't worth another manufacturer setting up to make different phones.
And of course any potential competitor would have had to get an import license to bring in devices for which there was an established local manufacturer - very difficult unless you had powerful political friends.

All changed with the Douglas / Prebble / Lange government in the 1980s, thank goodness

nzkiwis

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#1743718 19-Mar-2017 09:39

The first 7A Rotary automatic machine switching system registers were designed to work with the reverse numbered 7001 dial. In 1913 NZ Govt., ordered some 13 of these exchanges, the first being installed at Masterton in 1919, after WWI, Orders placed for more 7A Rotary exchanges were designed to work with the standard numbered 7002 dial, for example Christchurch, St Albans and Dunedin. Strowger exchanges installed were equipped with the standard numbered ATE dial. So for a number of years NZ had both standard and reverse number dials. When a decision was made to standardise on just one, for economic reasons, there being more of one type than the other, the reverse numbered dial won the day. WE or more to the point the BTMC of Antwerp, used the reverse numbered dial because logically it suited the technical designing of the 7A Rotary. To allow a standard dial to work with the 7A Rotary register a modification had to be undertaken to ensure correct digital pairing and selector level selection. Was the any Patent issues regarding their choice of dial, NO there was not

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