Saturday, January 16, 2010

The Expansions - The New Prefixes

Omaha's growth and increased telecom usage sparked the equipment upgrades and addition of the following prefixes to existing COs between our timeline start in 1953 and our checkpoint of 1977.

  • Douglas:

    In the mid 1950s, a new #5 Crossbar system was installed at 19th. and Douglas, replacing much of the aging Panel installation, part of which was Ma Bell's first Panel roll-out, serving ATlantic and JAckson. The first new prefix was EXpress, originally serving as Ma Bell's own internal Centrex. EXpress (and later 344) served some of the very first IMTS (direct-dial) mobile phones.

    A recorded time service was launched out of the Douglas Crossbar with a listed number of TIme-8111. See further notes on 844 below.

    At the time of the Great Renumbering 348 was added to the 19th. St. #5 Crossbar, becoming Omaha's first prefix not to have descended from a legacy named exchange. There is some evidence that what became the 348 prefix was originally scheduled to be launched prior to the Great Renumbering (tentative name of BLackstone), but that various circumstances delayed the roll-out until September of 1960.

    At the same time, 347, serving Carter Lake, was added to the Crossbar, giving Carter Lake its own dedicated prefix. See separate article for more details on this.

    271 and 281 were an enigmatic pair of prefixes, and elicited hours upon hours of talk, experimentation, and speculation among telephone 'afficianados'. :) These served the Union Pacific Headquarters exclusively at the time. Whether the UP installation was Centrex or DID-PBX is really a question of semantics. It was basically an on-premesis Step installation driven by the #5 Crossbar at 19th. and Douglas.

    The only listed number on the 281 prefix was the main UP incoming number, 281-5822. All other listed numbers for UP were on 271. The two prefixes 271 and 281 were 'aliased' to each other and could be interchangably dialed. You could dial either prefix plus the last four digits. Consensus was that this was done to 'balance the load' somewhat, directing the calls to the main number over one set of trunks, and direct-dialed calls to various UP offices to another.

    221 was another Centrex-or-DID-PBX which served the Federal offices in Omaha. Again, a Step installation off of the #5 Crossbar.

    536 and 541 were set up on the #5 Crossbar to serve mainly 101 ESS Centrex-Cu customers, some of which were also served by 348. Original Centrex-CU customers out of these offices were Norwest Bank, Lutheran Hospital, UNMC, and Lozier Corporation, among others.

    Phone 'enthusiasts' were quick to note that of these new prefixes, access to 536 from many other Omaha offices was via the downtown Crossbar Tandem, and a distinctive burst of MF could often be heard when calls to 536 were placed.

    The big addition to the 19th. and Douglas office was a very significant #1 ESS, commissioned around 1970. This replaced the last of the Panel (345, 346) and added 422, 444, 449, and eventually 633, 636, 977, and 978, among countless others as the facilities were expanded..

    Ma Bell's internal Centrex was then converted to 422 on the ESS, and Centrex-CO for Eppley Airfield was added to 422 as well.

    The main customer on 444 was the Douglas County offices, including County Hospital, a Centrex-CO installation. 444 also served some IMTS mobile phone customers.

    The then-new St. Joseph hospital on north 30th. was the first major customer on 449, Centrex-CO.

    633, 636, 977, and 978 were added during an expansion in the late 1970s, mostly intended to serve large Centrex-CO customers. OPPD, originally a Centrex-CU customer on 536, eventually spilled over to 636 as well. InterNorth (nee' Northern Natural Gas) was the first major customer on 633, a Centrex-CO replacing the former #101 Centrex-CU on 348. Omaha Public Schools was the first major customer on 978. 977 was at first mainly used for pagers and some pre-cellular mobile phones.

    844 was hosted out of Douglas, used exclusively for the automated 'Time' service. 844-8111 was the published number, but anyone with any kind of curiosity knew that the time recording could be reached equally well by dialing 844 and any four random digits.

    No, I haven't forgotten about 894. Yes, at the turn of the 21st. Century, 894 is a general service prefix out of 156th. and Harrison. However, 894 began life as a somewhat red-headed-stepchild 'choke' prefix out of Douglas.

    Only two published numbers ever appeared on the orignal 894 prefix, one being a recorded weather announcement, sponsored by a radio station, and another a medical advice recording, sponsored by a local hospital.

    894 was originally hosted on the #5 crossbar, as an 'alias' for 344. You could dial either 344 or 894 plus the four digits and get the same number.

    However, when the #1 ESS came to life, shortly after the 894 prefix was moved to ESS and 'aliased' to 444.

    341, 342, 344, 347, 348, 536, and 541 remained on the #5 Crossbar well into the 1980s.

    So, at our 1977 checkpoint, we have the following out of Douglas Street:

    221, 271, 281, 341, 342, 344, 345, 346, 347, 348, 422, 444, 449, 536, 541, 633, 636, 844, 894, 977, and 978.

  • Izard:

    The Panel office serving 551 and 553 remained in service well into the 1970s, until a new #1 ESS replaced it. Along with 551 and 553, 554 and 559 were added to the new #1 ESS.

    556 and 558 remained on the #1 Crossbar into the 1980s.

    An interesting quirk was that while the Izard #1 ESS was being installed, what would become the 551 and 553 sections were temporarily accessible from several other Omaha offices via 531 and 533. Many phone 'afficianados' became 'acquainted' with the Izard ESS this way.

    'Bay 1, circuit 2, Centrex Direct Inward Dialing intercept.' :)

    1977 checkpoint prefixes were: 551, 553, 554, 556, 558, and 559.

  • Fowler:

    KEnwood was the last remaining Omaha office to have manual ('Numberrr Pleeze') service. KEnwood was added to the Fowler #1 Crossbar in about 1957, finally bringing dial service to all of Omaha. 457 was added as an expansion in the late 1960s.

    Prefixes as of the checkpoint: 451, 453, 455, and 457.

  • O Street:

    The only major expansion to the long-lived O Street #1 Crossbar was the addition of the 734 prefix around 1970. O street was the only one of Omaha's #1 Crossbar offices which was converted to MF signaling on the interoffice trunks. The others (Izard, Fowler) used revertive pulsing throughout their lives.

    The O Street #1 Crossbar lived on until around 1985.

    1979 prefixes: 731, 733, 734.

  • Bellevue:

    I admit. I don't really know too much about the Bellevue CO. The earliest I remember this CO was in the early 1970s, and it was a #5 Crossbar. It was a bit quirky in that it had a tone plant which gave a ringback tone which could best be described as a 'low rumble', with not very much in the way of tones or harmonics as were typical in the 'metropolitan' ringing machines which were common on Panel, #1, and #5 Crossbar offices, or the newer 'precise' tones.

    The nuances of the connections indicated that it was most definitely a #5 Crossbar.

    At the time of the Great Renumbering, the only prefix in Bellevue was 291. 292 and 293 were added in the early and late 1970s respectively as the community expanded.

    I'm not really sure if the 294 prefix, which served Offutt Air Force Base exclusively at the time, was actually hosted out of Bellevue, or out of Douglas. I've heard some 'in the know' people say one, and some say the other.

    Prefixes at the 1977 checkpoint: 291, 292, 293. Honorable mention: 294.

  • Council Bluffs:

    The area's first #1 ESS switch was installed in Council Bluffs ca. 1970, replacing the Step offices serving 322 and 323. An additional prefix, 328, was added at the time of the cut, and 325 followed several years after, giving the main Council Bluffs downtown CO a total of four prefixes at the time of our checkpoint.

    In 1971, toll-free direct seven-digit dialing was established between Council Bluffs and metropolitan Omaha.

    Along with metropolitan Council Bluffs, the Manawa CO, serving prefix 366, was added to the Omaha dialing area. The Manawa office was unique in that it used 'directorized' Step switches. This was a typical up-and-around Strowger-switch type office, but with a common-control 'Director' device added. The Director was between the linefinder and the first selector. The Director returned dial tone to the subscriber, received the dialed digits, and then drove the switches appropriately to set up either an intra-office or inter-office call. This also allowed true Touch-Tone service on this Step office, as opposed to a simple tone to pulse converter. The Manawa office was the only Director Step office in the Omaha area.

    Council Bluffs also had toll-free calling to a few nearby rural CDO's, all on the Iowa side, in Silver City/Mineola (526), Crescent (545), and Underwood (566), but these remained toll calls from Omaha (and Carter Lake, Iowa) until the 1980s.

    Prefixes as of the 1977 checkpoint: 322, 323, 325, 328 downtown CB and 366 in Manawa.
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