TELECOM Digest OnLine - Sorted: Re: Buyouts of AT&T, MCI Sign of Long Distance's Demise

Re: Buyouts of AT&T, MCI Sign of Long Distance's Demise
Thu, 24 Feb 2005 20:18:47 EST

In a message date24 Feb 2005 07:41:49 -0800, (Lisa
Hancock) writes:

> The high capacity of fibre optic is really no big deal when looking at
> long distance over the long haul. In the beginning, it was one very
> thick wire barely carrying one call at a time. Longer calls required
> setup of trunks connecting one town to the next as well as the
> appropriate amplification (too much wouldn't work -- it had to be just
> right). In the 1930s every long distance call needed considerable
> workup by operators consulting routing charts, and engineers tinkering
> with routing and amplification and transmission.

Then, as now, most long distance calls were to nearby points to which
the operator had direct trunks or on high-traffic routes to which
operators also had direct access. If they needed routing information
beyond that it was on the keyshelf (which had the great majority of
the remaining routes shown) or on the keyshelf bulletin which had
hundreds or thousands more routing instructions, well designed for
very quick access.

The percentage of calls which had to go to Rate & Route was only a
very small percentage.

> But they discovered carrier signals and some automation so that a
> physical circuit could handle more calls and spread the cost. Setup
> time was reduced saving money too.

Carrier systems, and before that phantom circuits, were in general use
well before the 1930s. In the 1950s, living in Oklahoma City, I found
a Bell Labs Record or Bell System Technical Journal article describing
"The Fourth Transcontinental," which was built in 1935.

It was of special interest since the fourth "transcontinental" started
in Oklahoma City and extended to the West Coast. From the East Coast
to Oklahoma City by 1935 the toll network was so dense and of adequate
capacity that there was no construction needed east of Oklahoma City.

The article went into detail as to what building it started from in
Oklahoma City, the considerations in routing the cables out of the
building and down what streets, and eventually to the actual
originating carrier system on SW 89th Street, with a photo of that

A new carrier system, I believe designated L carrier, was used on the
open wire pairs from that building to the next repeater, the next, and
so forth to the West Coast.

Carrier systems were designated alphabetically, and while some never
saw any use, L is pretty far down the alphabet to consider carrier
systems as being developed in the 1930s.

Wes Leatherock

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