Signals

THE SIGNAL BOX


Railway signalling discussion

Early NX panel question

British signalling of the past (UK, excepting Northern Ireland)

Re: Early NX panel question

Unread postby Dave J » Tue Nov 28, 2017 7:11 am

The truth and nothing but the truth.
User avatar
Dave J
Branch line box
Branch line box
 
Posts: 125
Joined: Thu Dec 13, 2007 5:33 pm
Location: Reading

Re: Early NX panel question

Unread postby Mike Hodgson » Tue Nov 28, 2017 7:14 am

The photo shows a combination of features which strike me as odd in terms of its ergonomics - and the physical size isn't obvious.

It has a flat work surface which appear suitable for use as an operator desk, to keep WTT, booking sheets etc on, and there are what appear to be two drawers, one on each side to keep small items or stationery in. Yet below these drawers at either side the cabinet does not look as though it has cupboard doors that you could keep things in. Whilst it looks like an office desk you would sit at, the whole thing is standing on a plinth which would stop you getting a chair close enough to work comfortably. Was it so large that you stood at it to work, or was the the top of this plinth simply set at floor level so you could get a chair in?
If so, were the plinth and/or side "cupboards" necessary as compartments for incoming cables and other electrical gubbins?

One the front of the desk portion there are a couple of things I can't identify - socket, switch, lock-switch perhaps.

Directly below the black thing on the panel in the operator footwell is a black box with trunking running up vertically. I had originally assumed the trunking was incoming power, but fittimg that on the outside of the cabient seems most unlikely. There is a simple wire thing around the box, obviously not a guard- is that a footswitch (depress to talk)?

The black thing in the middle of the other panel looks much larger - a speaker? Was it one-way communication only??
User avatar
Mike Hodgson
Double-manned box
Double-manned box
 
Posts: 2531
Joined: Fri Nov 9, 2007 5:30 pm
Location: N Herts

Re: Early NX panel question

Unread postby Mike Hodgson » Tue Nov 28, 2017 7:17 am

The second attac hment answers my question about the size - the signalman is obviously sitting at it.
User avatar
Mike Hodgson
Double-manned box
Double-manned box
 
Posts: 2531
Joined: Fri Nov 9, 2007 5:30 pm
Location: N Herts

Re: Early NX panel question

Unread postby John Webb » Tue Nov 28, 2017 10:07 am

Mike Hodgson wrote:.......
Directly below the black thing on the panel in the operator footwell is a black box with trunking running up vertically. I had originally assumed the trunking was incoming power, but fittimg that on the outside of the cabient seems most unlikely. There is a simple wire thing around the box, obviously not a guard- is that a footswitch (depress to talk)?

The black thing in the middle of the other panel looks much larger - a speaker? Was it one-way communication only??

Loudspeakers can be used in reverse as a microphone - not such good quality as a specifically designed microphone, but adequate for speech purposes - think of door intercoms, baby alarms etc. This would tie in with the fitting of a 'press to talk' foot switch as you suggest.
John Webb
(Member, St Albans Signalbox Trust)
User avatar
John Webb
Main line box
Main line box
 
Posts: 1873
Joined: Tue Jul 8, 2008 1:22 pm
Location: St Albans, Herts

Re: Early NX panel question

Unread postby JRB » Tue Nov 28, 2017 5:33 pm

GRS did a very comprehensive booklet about this installation. My copy is now in the SRS archive where it should be available for consultation.
Last edited by JRB on Thu Nov 30, 2017 8:43 pm, edited 1 time in total.
JRB
Double-manned box
Double-manned box
 
Posts: 3239
Joined: Sun Dec 9, 2007 10:12 pm
Location: GWR

Re: Early NX panel question

Unread postby kbarber » Wed Nov 29, 2017 8:58 am

John Webb wrote:
Mike Hodgson wrote:.......
Directly below the black thing on the panel in the operator footwell is a black box with trunking running up vertically. I had originally assumed the trunking was incoming power, but fittimg that on the outside of the cabient seems most unlikely. There is a simple wire thing around the box, obviously not a guard- is that a footswitch (depress to talk)?

The black thing in the middle of the other panel looks much larger - a speaker? Was it one-way communication only??

Loudspeakers can be used in reverse as a microphone - not such good quality as a specifically designed microphone, but adequate for speech purposes - think of door intercoms, baby alarms etc. This would tie in with the fitting of a 'press to talk' foot switch as you suggest.

Thinking about it, there was loudspeaker communication between Bow Junction and the supervisor at Thornton Fields Carriage Sidings. The loudspeaker/microphone was built in to the panel at Bow Junction and it was indeed dual purpose; as John Webb says, quality wasn't that brilliant but then it was never meant for hi-fi and it was perfectly adequate for its purpose.
User avatar
kbarber
Rest-day relief
Rest-day relief
 
Posts: 560
Joined: Tue Nov 13, 2007 7:12 pm
Location: London

Re: Early NX panel question

Unread postby Andrew Waugh » Wed Nov 29, 2017 10:57 pm

Andrew Waugh
Branch line box
Branch line box
 
Posts: 484
Joined: Wed Sep 17, 2008 1:34 am
Location: Melbourne Australia

Re: Early NX panel question

Unread postby Andrew Waugh » Wed Nov 29, 2017 11:07 pm

Mike Hodgson wrote:It has a flat work surface which appear suitable for use as an operator desk, to keep WTT, booking sheets etc on, and there are what appear to be two drawers, one on each side to keep small items or stationery in. Yet below these drawers at either side the cabinet does not look as though it has cupboard doors that you could keep things in. [...]
If so, were the plinth and/or side "cupboards" necessary as compartments for incoming cables and other electrical gubbins?


The second of the articles linked by DaveJ is about the NX interlockings themselves. In it is a photo of the rear of the Oaklands panel with the panels off.

The photo answers your question very clearly. The back and sides of the plinth are covered with a gazillion terminals to terminate the wiring from the relay room. They look like the standard terminals used for shelf relays etc.

So, no room for cupboards in the legs of the panel!
Andrew Waugh
Branch line box
Branch line box
 
Posts: 484
Joined: Wed Sep 17, 2008 1:34 am
Location: Melbourne Australia

Re: Early NX panel question

Unread postby Andrew Waugh » Wed Nov 29, 2017 11:14 pm

Photos of the operator sitting at the desk clearly show them wearing a headset, so the black thing in the middle is not a loudspeaker. It is, as I've said before, almost certainly a microphone.

The device in the footwell is almost certainly a footswitch to 'press to talk'. It's very similar to contemporary footswitches on US (and Australian) train despatching desks. A press to talk switch is necessary as otherwise the general noise in the box will be continuously transmitted to all other locations.
Andrew Waugh
Branch line box
Branch line box
 
Posts: 484
Joined: Wed Sep 17, 2008 1:34 am
Location: Melbourne Australia

Re: Early NX panel question

Unread postby Pete2320 » Thu Nov 30, 2017 4:07 pm

Mike Hodgson wrote:Thank you very much for that excellent and very detailed explanation Andrew. I am amazed that this was pre-war.

It does leave me wondering how a single light aperture could display red/white as LEDs were only invented in 1962. Two separate filament bulbs behind the bezel, one clear, one painted red? An electromechanically operated moving red filter, as found in traditional searchlight signals? I would have thought it much easier/cheaper just to fit two lamps side by side. We are acciustomed to track circuit indications being duplicated in case of filament failure, but I suppose an alternative would be lamp proving as provided for signal heads.

We are also used to seeing signal repeaters and fault alarms on NX diagrams, but I suppose aspect repetition is unnecessary if you rely on the signals working automatically in accordance with the route set up, and drivers can call in if there is a fault. Or perhaps there was a separate fault panel for technicians - S&T presumably had somebody on site all the time in view of the criticality of this panel to such a busy service.

Many, if not all Westinghouse panels of the 60s used this arrangement. Separate bulbs were provided, with coloured filters as required, and projected the light through a common hole via a prism arrangement. In fact if you looked carefully you could see that the light was from one side.
Pete
Pete2320
Main line box
Main line box
 
Posts: 2147
Joined: Wed Feb 20, 2008 10:50 pm
Location: Barton on Humber

Re: Early NX panel question

Unread postby Fast Line Floyd » Thu Nov 30, 2017 4:24 pm

Pete2320 wrote:
Mike Hodgson wrote:Thank you very much for that excellent and very detailed explanation Andrew. I am amazed that this was pre-war.

It does leave me wondering how a single light aperture could display red/white as LEDs were only invented in 1962. Two separate filament bulbs behind the bezel, one clear, one painted red? An electromechanically operated moving red filter, as found in traditional searchlight signals? I would have thought it much easier/cheaper just to fit two lamps side by side. We are acciustomed to track circuit indications being duplicated in case of filament failure, but I suppose an alternative would be lamp proving as provided for signal heads.

We are also used to seeing signal repeaters and fault alarms on NX diagrams, but I suppose aspect repetition is unnecessary if you rely on the signals working automatically in accordance with the route set up, and drivers can call in if there is a fault. Or perhaps there was a separate fault panel for technicians - S&T presumably had somebody on site all the time in view of the criticality of this panel to such a busy service.

Many, if not all Westinghouse panels of the 60s used this arrangement. Separate bulbs were provided, with coloured filters as required, and projected the light through a common hole via a prism arrangement. In fact if you looked carefully you could see that the light was from one side.

Indeed not just Westinghouse but AEI GRS and SGE panels as well.
Graham
User avatar
Fast Line Floyd
Main line box
Main line box
 
Posts: 1696
Joined: Tue May 26, 2009 11:42 am
Location: Raunds

Re: Early NX panel question

Unread postby JRB » Thu Nov 30, 2017 8:48 pm

That reminds me with a problem with some GRS equipment. We had the same design of 5A point machine made at Albany NY and at Manchester GB. The terminals looked similar, but ours were 0BA and theirs were a US thread. Wrong nuts &c. could be a problem.
JRB
Double-manned box
Double-manned box
 
Posts: 3239
Joined: Sun Dec 9, 2007 10:12 pm
Location: GWR

Previous

Return to Signalling - historical

Who is online

Users browsing this forum: Bing [Bot] and 10 guests