User talk:Kbrose

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Editor talk[edit]

Mulberry exchange[edit]

The Mulberry and Waverly exchanges cutover in Newark in 1915 (January 16 and June 12) were “panel” automatic exchanges as is clear from the book I quoted in the Panel switch article, although they were initially operated as “semimechanical” offices with the operator doing the dialling. Semiautomatic operation was selected for field trial since it “could be used for a large-scale trial of the essential elements of the (panel) system in a large city without the complication and ambiguities involved in simultaneously introducing dialling by the subscriber” (pages 581-582) This is because “large cities would ultimately require a seven-digit number .... some tests made in the early 1900s indicated that ... the short-term memory span of many people could not handle seven digits and many dialling errors due to memory lapse might occur” (page 577; a note says that the documentation for these tests is lost). Hence J. J. Carty favoured “partial automation” in his 1910 paper, with the A operator instead of the customer doing the dialling” (page 578). See "A History of Engineering and Science in the Bell System: The Early Years (1875-1925)" by M. D. Fagen (editor) & Bell Labs technical staff (1975)

Similarly in The Hague telephone network the first Rotary switch exchange (type 7A) from Bell Telephone Manufacturing Co of Antwerp was cutover on Jan 7, 1920; Scheveningen exchange with 3400 semi-automatic lines plus 600 more in October 1921; on July 1922 “1000 additional full automatic lines were made available” (c1925 paper by B. A. Turkhud in Electrical Communication Vol 4 No 4) These Rotary exchanges (type 7A then 7A1, 7A2) from BTM/Western Electric of Antwerp were installed in New Zealand from 1919, and I have worked in them. The rotary and panel system were developed together, with the Rotary system selected for Europe (it was proposed for London in the 1920s, although the BPO chose the Director telephone system). Hugo999 (talk) 11:22, 21 October 2016 (UTC)

Congratulations on your readings. The article already states the installation of the first panel-type switches, that is not in dispute. What is in dispute is the notion that this constituted "introduction in the Bell System". Introduction of machine switching in the Bell System as a policy is generally attributed to the year 1919, as before that time it was the official Bell strategy to employ manually switched exchanges only. The Newark installations were really case research in technology, much like the later trials, not a system-wide change in direction. In 1919, Bell decided on using step switches made by AE Co. I grant you that the previous prose of that statement was not particularly helpful, and I attempted a revision after reversing your change. Kbrose (talk) 12:01, 21 October 2016 (UTC)