Branch signaling continued
NW Mailing List
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Tue Nov 12 09:07:15 EST 2013
slow down there.
go back that to that figure 5 signal in question. It precedes the turnout and its signal by one block.
Should it be a simple one head signal? Or is there a purpose for having that signal as is?
we're all here to learn
----- Original Message -----
From: NW Mailing List
To: NW Mailing List
Sent: Tuesday, November 12, 2013 2:54 AM
Subject: Re: Branch signaling continued
Let me see if I can drill this concept into your head. Block signals ARE NOT switch indicators! Let me say that one more time...BLOCK SIGNALS ARE NOT SWITCH INDICATORS!!! Therefore, forget the switch points, we are running on SIGNAL INDICATION!!!
Here in Roanoke, you will find that the Forwarding Yard Ladder, The Empty Side Ladder and the Motive Power Ladder all have switch indicators. Their only purpose is to indicate which way a switch is aligned. They offer absolutely ZERO, NIL, ZILCH, NOTHING in the way of block protection! They also DO NOT protect you if the switch points are gapped or lined incorrectly. Why? Because you are working at restricted speed.
Out on the road (and some places through yards), you have block protection signals. These signals control your movement. In order to comply with these signals, one must know the definition of the signal aspects (If I am not very much mistaken, the N&WHS Commissary sells a book showing signal aspects and their definition). I suggest you learn the definitions.
You mention a second head.
For example, what is the difference between an "Approach" and an "Advance Approach" aspect?
The "Approach", by definition, requires you to "Be prepared to stop at the next signal. If exceeding medium speed, immediately take action to reduce to that speed". That means you need to slow down. Even though the next signal may not be a "Stop", you still need to be prepared to stop. You can go a long way and take up a lot of time running on "Approach" signals. OR...
The "Advance Approach", by definition, allows you to, "Proceed prepared to stop at the second signal". It does not require you to reduce speed (Although, in most cases there is a short distance block involved and the need to reduce speed may be warranted.)
Do you understand the difference?
Using this example, on your own, apply this to the difference between the "Approach" and "Approach Diverging" signal aspects. Now tell me why the second head is useful?
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