[comp.dcom.telecom] Some Comments on TWX, Telex and WU Time Service

larry@uunet.uu.net (Larry Lippman) (09/22/89)

In article <telecom-v09i0385m01@vector.dallas.tx.us> the TELECOM Moderator
writes:
> There were only minor differences between Telex and TWX. The biggest
> difference was that the former was always run by Western Union, while
> the latter was run by the Bell System for a number of years. TWX
> literally meant "<T>ype<W>riter e<X>change", and it was Bell's answer
> to competition from Western Union.

	The sequence of events as implied from the above is not correct.
AT&T TWX service PRECEDED Western Union Telex service by approximately
25 years.  More about this in a moment.

> There were 'three row' and 'four
> row' machines, meaning the number of keys on the keyboard and how they
> were laid out. The 'three row' machines were simply part of the
> regular phone network; that is, they could dial out and talk to
> another TWX also connected on regular phone lines.

	I would urge a bit of caution in identifying teletypewriters as
"three row" or "four row" devices; the preferred method should be 5-level
(Baudot) or 8-level (ASCII).  While the implication may be that 3-row
are 5-level Baudot devices, and that 4-row are 8-level ASCII devices, this
is not strictly true.  French and German 5-level Baudot teletypewriters
are 4-row devices, with some of these 4-row German machines made by
Siemens being common in the U.S.

	TWX service was started by AT&T in 1931 using 5-level (i.e., Baudot)
teletype machines.  TWX was totally manual service with the connection
established by an AT&T TWX "operator" until 1962 when dial switching was
installed.  Also, until this time only 60 wpm 5-level teletype apparatus
could be utilized on the TWX network.  Simultaneously with the introduction
of dial connection service, the TWX network was changed to 100 wpm
(110 baud) 8-level (ASCII) to take advantage of newer teletypewriter
apparatus, such as the Teletype Corp. Type 33 and Type 35.  For a short
period of time both 5-level and 8-level apparatus co-existed on the TWX
network using 5-level <--> 8-level translators, but the 5-level apparatus
was phased out by 1964.

	TWX switching was originally handled by regular WECO #5 crossbar
offices which had some separate line and trunk groups for TWX service.
The behavior of a dial-up TWX line is virtually identical to that of
a regular telephone line.  It was a voice-grade line which used a 103-type
data set.

	Most Telex service operating on leased lines utilize a totally
DC circuit (i.e., there was no modem) from the subscriber location to
the central office.  The DC circuit discipline is usually either neutral
or polar, depending upon service area and circuit length.  Once in the
central office, however, the DC circuit is often converted to 43-type
telegraph carrier.  Modems have been used with leased lines on Telex
service, but they are generally the exception rather than the rule.

	The "original" Western Union Telex system was installed in the
U.S. in 1957; it actually obtained world-wide access through the Canadian
Telex system which was installed in 1956.  All of the message switching
apparatus used in the original Western Union Telex system was manufactured
by a German vendor, Siemens-Halske, who has produced much of the Telex
station and message switching apparatus used elsewhere in the world.
Western Union later established its own direct Telex links to other
countries on a world-wide basis, and no longer routed messages through
the Canadian access point of Montreal.

	At some point in time - but I am not certain when or of the exact
details - Western Union split its operation into two separate companies:
"Western Union" (WU) for all domestic U.S. Telex, TWX and other services,
and "Western Union International" (WUI) for all communications and services
NOT domestic to the U.S.  I don't believe that the WU-WUI split was exactly
voluntary on their part; I believe there were some regulatory, legal and
financial legal issues involved.

	WUI has been owned by MCI for several years.  The relationship
between WU and WUI is somewhat unusual.  If you have WU Telex or TWX
service and send an *international* Telex, you must use an international
carrier such as WUI, RCA, ITT, etc.  You access the international carrier
through your WU terminal, and you may choose the international carrier
on a call by call basis.  So the point is, WU does business with WUI in
the sense that WUI may serve certain WU customers.  However, WUI also
drectly offers Telex service with terminals in the U.S., and to some extent
they compete with WU for basic service.

	Perhaps some telecom reader knows more about the WU and WUI split
and their relationship.

> Today, the Western Union network is but a skeleton of its former self.
> Now most of their messages are handled on dial up terminals connected
> to the public phone network. It has been estimated the TWX/Telex business
> is about fifty percent of what it was a decade ago, if that much.

	Well, that's no surprise.  Cost and improved, alternate transmission
methods such as FAX have substantially supplanted Telex and TWX service.
As an example of cost, in 1976 my organization first subscribed to TWX
service; we bought our own ASR-33 and paid for the monthly TWX service from
WU.  The basic monthly charge at that time (less usage, of course) was
around $ 30.00 per month, which *included* an additional mileage charge
because we were located outside the Buffalo, NY metropolitan area.  By 1985
our basic monthly charge was up to $ 135.00 and our traffic was way down
because of the use of FAX.  Since I wasn't too happy with WU anyways, I
told them to pound salt and we switched to RCA Global Communications for
straight international Telex service using a dedicated dial-up line (i.e.,
we installed a telephone line with a dedicated 300 baud terminal which
RCA calls when they have incoming traffic).  Our Telex traffic is now
99% international; we may have received one domestic message so far
this year.  Even international traffic is going FAX, and our Telex
traffic diminishes every year.  If this keeps up, we may well ax the
Telex service within the next five years.  However, our cable address
is easy to remember (RECOGNIZE NEWYORK, if you're curious :-) ), and we
get some international traffic on the Telex translated from our cable
address instead of from our actual Telex number.

> Then there was the Time Service, a neat thing which Western Union
> offered for over seventy years, until it was discontinued in the
> middle 1960's.  The Time Service provided an important function in the
> days before alternating current was commonly available. For example,
> Chicago didn't have AC electricity until about 1945. Prior to that we
> used DC, or direct current.

	You can't possibly mean 1945, can you?  1915, I can believe;
1945, I can't.

> The sub-master clocks in each building were in turn serviced by the
> master clock in town; usually this was the one in the telegraph
> office. Every hour on the half hour, the master clock in the telegraph
> office would throw current to the sub-masters, yanking them into synch
> as required. And as for the telegraph offices themselves, they were
> serviced twice a day by -- you guessed it -- the Naval Observatory
> Master clock in Our Nation's Capitol, by the same routine.

	The Pacific time zone of the U.S. was not serviced by the Naval
Observatory, but by a distributing clock located at the Mare Island
Navy Yard.

	Until the WU time service was discontinued, the "distributing"
clock at the Naval Observatory and at the Mare Island facility generated
synchronizing pulses for regional WU clocks.  The distributing clocks
sent pulses at two times per day: 1155 to 1200 hrs, and 2155 to 2200 hrs.
Pulses would be sent for five minutes right up to the hour itself.  No
pulse would be sent on the 29th second of each minute, and for the first
four minutes no pulses would be sent on the 55th through 59th second.  On
the 59th minute, and only on the 59th minute, no pulses would be sent on
the 50th through 59th second, with a single pulse at first second of the
hour.

	How's THAT for useless trivia? :-)

	Each day at approximately 1130 hours the distributing clocks
would be corrected based upon the Naval Observatory master clocks,
which were in turn corrected by astronomical observations.

	The overall accuracy of the WU clock system was a few tenths of
a second.  It was no better because of the various relay operate times,
and to a lesser extent because of electrical propagation delays since
electrical signals in long communication cables travel much slower than
the speed of light.

	Of course, all of the above time standard methods are now quite
obsolete and have long been replaced by the use of rubidium and cesium
"atomic" clocks.

> Western Union was a grand old company in its time.

	That's certainly true.  Unfortunately, as far as I know, the
financial future of WU is now rather cloudy.

<> Larry Lippman @ Recognition Research Corp. - Uniquex Corp. - Viatran Corp.
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[Moderator's Note: We got alternating current in the downtown area around
1915 or so. It was fully implemented in town by around 1925. I suppose we
are technically-oriented enough here that 'three-row' and 'four-row' could
have been replaced with other terms. But those were the terms WU used to
explain the machines to their customers. The WU Directory had a detailed
picture of each type keyboard (three or four row) and the subscriber was
supposed to select the one resembling his model, then read the instructions
associated. There was a section which explained how the one type was to
connect with the other type as well.

Regards clock service, did you know at one point, circa 1930-50, the FCC
required all radio stations to have a Western Union clock on the premises
for accurate time-keeping? And did you know that for about forty years,
the famous beep-tone heard on WGN (720 kc, Chicago) came from the clock
itself? The station ran a wire from the little red light bulb in the clock
to a little device which made the beep; and that was wired right into the
transmitter. For nostalgia purposes, they still give the beep every hour,
but it hasn't been from the clock for over twenty years!   PT]