Transposition Brackets

[NW Mailing List]

The bracket was a line cross-over using a frame and four insulator 'wheels'
to cross over parallel signal lines.  Not up or down but side-to-side.
These are still seen on older signal systems, such as the Peavine, but
rarely now.  

The cross over works by, essentially, adding the electrical noise to the
signal and at the next cross over subtracting the same.  Thus, it is a
cancellation technique.

The frame was mounted to the cross arm on the pole.

Gary Rolih 
Cincinnati

 
-----Original Message-----
From: nw-mailing-list-bounces at nwhs.org
[mailto:nw-mailing-list-bounces at nwhs.org] On Behalf Of NW Mailing List
Sent: Sunday, July 29, 2007 4:19 PM
To: NW Mailing List
Subject: Re: Transposition Brackets

I remember seeing an article in the N&W Magazine (probably in the 1950's) 
about the introduction of transposition brackets so that communication lines

could be placed on signal poles in order to eliminate separate communication

pole lines.

Gordon Hamilton

----- Original Message ----- 
From: "NW Mailing List" <nw-mailing-list at nwhs.org>
To: <nw-mailing-list at nwhs.org>
Sent: Sunday, July 29, 2007 1:52 PM
Subject: Transposition Brackets



> In the days of the telegraph and telephone, both the ACL and the Norfolk

> Southern had transposition brackets on the cross-arms of lineside 

> telegraph

> and telephone lines.  If two wires stay parallel for a certain distance 

> they

> have a tendency  to induce each other's signal. To prevent this 

> possibility

> there are transposition brackets placed at strategic cross-arms. This

> bracket has one insulator located above the cross-arm, and another

> insulator positioned below the cross-arm to take the two wires 

> temporarily

> out of being parallel for a short distance, thus preventing line induction

> between the two lines.  Did the N&W use these devices?   Or more to the

> point,  are there any of them left on today's lineside cross-arms?  I know

> that they were used widely by AT&T and regional telephone companies.

> Bill Sellers

> Gainesville,Ga.

>

> ________________________________________

> NW-Mailing-List at nwhs.org

> To change your subscription go to

> http://list.nwhs.org/mailman/options/nw-mailing-list

> Browse the NW-Mailing-List archives at

> http://list.nwhs.org/pipermail/nw-mailing-list/

>

>

> -- 

> No virus found in this incoming message.

> Checked by AVG Free Edition.

> Version: 7.5.476 / Virus Database: 269.10.23/924 - Release Date: 7/28/2007



> 3:50 PM

>

> 


________________________________________
NW-Mailing-List at nwhs.org
To change your subscription go to
http://list.nwhs.org/mailman/options/nw-mailing-list
Browse the NW-Mailing-List archives at
http://list.nwhs.org/pipermail/nw-mailing-list/