Control points, controlled signals and intermediate signals

[NW Mailing List]

For the engineer, the signal indicates the speed to 
operate...really...period.
For us anaylizing everything it can clue/tell more about track 
conditions, turnout settings and such.

A line such as the South Shore Line, electric running betwen South Bend 
and Chicago, practically the whole line is "intermediate" signals, 
automatic block signals, for turnouts.
They used train orders forever to govern movements, because of the 
signals the orders were limited in instruction and use but they used radios.

They only recently centralized the system changing to new signals and 
the now have full dispatcher control over the entire line. I don't know 
if turnouts have been dispatcher controlled
yet, freight runs usually the crew runs out and manuall turns a turnout, 
or it has spring switches.

A distant signal gives advance indication to the track condition ahead 
(signal condition..speed to run) and often has 2 or 3 heads, or may have 
a sign such as "D" that designates its a distant signal. It may or may 
not be dispatcher controlled, depends on  the railroad or conditions if 
the dispatcher needs to throw that signal red for whatever reason.

The other point I think about is after any train passes these signals 
its thrown red, block occupied. Technically you could have a series of 
distant signals that would display appropriately like the immediate 
distant signal is protected. (multiple blocks of 2 head signals capable 
of displaying distant aspects).

Theres so many ways to look at signals its like art...

-Lynn-






On 8/20/2013 12:00 PM, nw-mailing-list-request at nwhs.org wrote:

> Subject:

> Re: Control points, controlled signals and intermediate signals

> From:

> NW Mailing List <nw-mailing-list at nwhs.org>

> Date:

> 8/20/2013 4:43 AM

>

> To:

> NW Mailing List <nw-mailing-list at nwhs.org>

>

>

> On 8/19/2013 7:55 PM, NW Mailing List wrote:

>> Nathan,

>>     All of the signals between Sampson and Lynnwood, just like those 

>> between Calera and Glasgow et. al., are intermediate signals. They 

>> are not controlled by the dispatcher, only by the signal aspect ahead.

>>

>> Jimmy

> Excuse me, that should read/"*just like those between Solitude and 

> Glasgow et. al., are intermediate signals.*"/ Sorry if I confused 

> anyone there.

>

> Jim & Lynn,

>     Signals are not nearly as hard to understand as you are trying to 

> make them. It is just a simple progression from one to another. You 

> run on a Clear (at prescribed speed) until you get an Approach 

> (prepared to stop at the next signal. If exceeding medium speed 

> imediately reduce to that speed), then you get a Restricting (proceed 

> at restricted speed [a speed that will permit stopping short of a 

> train, engine or obstruction, watching out for a broken rail and not 

> to exceed 15 mph]). You run on a Clear (prescribed speed) until you 

> get an Approach Diverging (prepare to take diverging route beyond next 

> signal) , then you get a Diverging Approach (proceed through turnout 

> or turnouts at prescribed speed preparing to stop at next signal), 

> then you get a Stop (STOP). You run on a Clear (prescribed speed) 

> until you get an  Advance Approach (prepare to stop after second 

> signal), then you get an Approach (prepare to stop at next signal...), 

> then you get a stop (STOP).

>     Then you grab your grip, swing down off of the engine, wipe the 

> sweat off of your brow and say "That wasn't so hard, was it?"

>

> Jimmy Lisle


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