[GreenKeys] OT: Teletypes, Telephone & Railroads

[pdwills at cedarknolltelephone.com]

Most railroads had very extensive communications networks
with trunk facilities that could handle all manner of AC and
DC communications.  My experience was mostly with ex-PRR
facilities which were built to AT&T toll grade standards
using Western Electric equipment and cable.

The trunk circuits were usually phantoms with three voice
paths and four telegraph/teletype paths.  Later, the DC
paths were used for dial signalling and the teletype was
moved over to FSK carrier units.

There was a set of regenerative repeaters in the Pittsburgh
station that I am still kicking myself over not grabbing
when I had a chance!

Someone asked about the nature of the Teletype traffic the
PRR sent but I only remember the CT-220 reports (passenger
train consists) of the early Amtrak era (1977-1978).  The
service went between New York and Washington and it was the
last vestige of the PRR TTY network.

A lot of business traffic must have gone by Teletype since
they had full Teletype message facilities in the major
cities.  There was at least one Teletype switchboard in
Philadelphia.

There were a lot of local loops for special functions such
as distributing information within a large station or
sending consist information to a hump tower.  Hopefully,
there are those on this list who would know more about the
subject.

PDW

----- Original Message Follows -----
From: John Hensley <w5jv at hotmail.com>
To: <greenkeys at mailman.qth.net>
Subject: [GreenKeys] OT: Teletypes, Telephone & Railroads
Date: Thu, 16 Apr 2009 17:14:48 +0000

> Maybe its a two thing: two wires, two rails ... i.e. what
> can you do over two wires or two rails ... I know that for
> years private offices had their ASR's running off a
> telephone modem of sorts as did Telegram Offices.  I
> suppose the railroads did the same (use existing telephone
> lines).   ... semaphore is two flags ...  the first
> telegram delivery vehicle was on two feet until the
> bicycle was needed (two wheels) ... morse and baudit both
> pattern their language after two components (one short,
> one long) ... and there were, by the way, two signal lamps
> hanging in the Boston tower alerting locals that the
> British were detected on the sea route ... 
> 
> >>>http://dvice.com/archives/2009/03/astonishing_mos.php
> 
>