Branch signaling continued

[NW Mailing List]

Yes there is a purpose to have that signal with two heads. Some times 
the second head may not be used , when? well for instance in figure 5 
the home signal is at STOP therefore this signal would display APPROACH 
for the blue train. NOW move the purple train away from the home signal 
like in figure 4 then you would get the APPROACH DIVERGING. You would 
get the Approach in figure 5 due to the fact the signal offers Block 
Protection and an Approach Signal is more Restrictive then an Approach 
Diverging. Here is a little more on the difference in the aspects (I 
pulled the rule book out for this so I could exactly quote the rules):

RULE 282-APPROACH DIVERGING:
     Proceed preparing to take diverging route beyond next signal at 
authorized speed.
^With this you are NOT stopping at the home signal, but continuing on 
via a diverging route

RULE 285-APPROACH:
     Proceed preparing to stop at next signal. Train or engine exceeding 
Medium Speed must at once reduce to that speed.
^With this you ARE STOPPING at the next signal. IT DOES NOT matter if 
you are taking a Diverging route at the next signal or not, because you 
ARE STOPPING. Therefore you will be well below what the prescribed speed 
for the diverging route would be. This is because under typical 
circumstances you with be stopped before getting the signal for the 
diverging route. If the signal comes in for the diverging route before 
you get there, you should still be below the prescribed speed as you 
should be damn near stopped when you get within sight of the signal.

Does this help in understanding the situation at hand?

Nathan

Nathan Simmons
trainman51 at gmail.com
http://www.t-51.org
KI4MSK

On 11/12/2013 09:07, NW Mailing List wrote:

> 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

> cheers.

> -Lynn-

>

>     ----- Original Message -----

>     *From:* NW Mailing List <mailto:nw-mailing-list at nwhs.org>

>     *To:* NW Mailing List <mailto:nw-mailing-list at nwhs.org>

>     *Sent:* Tuesday, November 12, 2013 2:54 AM

>     *Subject:* Re: Branch signaling continued

>

>     Lynn,

>         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?

>

>     Jimmy Lisle

>

>

>

>

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