Signal aspects

NW Modeling List nw-modeling-list at
Fri Jan 18 08:05:51 EST 2008

I presented the same question at work a while back and here's what they told me, and it makes sense.

A Diverging Approach is telling you to proceed through the turnout prepared to stop at the next signal. Basically, telling the train crew that the signal beyond that one is giving a Stop indication.

If that same signal beyond the Diverging Approach signal were to upgrade to an Approach or Clear, then the Diverging Approach would upgrade to a Diverging Clear, meaning they don't have to be prepared to stop at the next signal. You cannot give a Diverging Clear with a Stop signal beyond it. That would be a "False Proceed" signal, and is not good!

However, a Restricting is telling the train crew to proceed through the switch at restricted speed. Many times this is used if a train is going into a yard track. Quite often it means the train is leaving signalled territory, as it would on a branch line. You can't give a Clear or Approach on a signal if it is the last signal a crew will encounter, as both aspects are giving you an indication leading to another signal. A Restricting doesn't necessarially do this.

Ben Blevins

NW Modeling List <nw-modeling-list at> wrote:
What is the difference between "Restricting" and "Diverging
Approach"? I've got a good idea of "Diverging Approach", but what is

Ron Davis

At 03:50 PM 1/17/2008, you wrote:


> Here's a diagram of what the aspects are, both in position signal

> and CPL signal diagrams. Now, the aspects were changed around 1952

> and this change eliminated the horizontal aspects on the B arm of

> the signals, and the marker lights underneath a B or C arm if the

> signal was so equipped were also eliminated. This marker was

> replaced by a letter plate "S". This is something Uncle EdK

> explained to me a great many years ago.


> Now, the aspects as I have them named: They weren't known by a

> "name" so to speak in the Position Signal era as far as I know, but

> now the color aspects are named as I have them listed. The

> indications are quite lengthy, so I left them out. I hope this helps.


> Oh, and the number plates were removed in the 60's or

> 70's. These signals now have names as per the Southern practice.


> Ben Blevins


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