A signal Question for Ben et.al. (NW Mailing List)

[NW Mailing List]

Jimmy,
Now that the N&W guys have responded allow me to tell you what I think it is.  
This is obviously shot on formerly Southern territory though I cannot identify the exact spot of that last sequence with the signal. Southern has used a lot of GRS Trakode which because of the huge capacitors in the decoders would act just like this.  The fact that these are positive signals does not mean they are home signals.  These are back to back headblock automatic signals in non-CTC territory.  It's the capacitors that are necessary for the operation that cause this characteristic, and it's not really a problem.  Boilers and long hoods have nothing to do with it, at least on Southern.
Trakode was being eliminated in favor of electronic track circuits that do not have this characteristic.   With the advent of PTC approaching, I expect the last of the Trakode to be gone in the next couple years. 
 
John Marbury
Buford, GA
Working with NS/SOU signals for over 43 years. 







> Subject: A Signal Question for Ben et.al.



> Go to the 9min 50 sec spot on this video and watch as 611 passes a clear 

> signal.

> 

>   My question is this: Why does it take until the engine, tender, 

> canteen and approx 7-8 cars (10 sec.) for the signal to drop to STOP? 

> Have seen short delays in signal changes, but, never before anything 

> that took this long.

> 

> Jimmy Lisle 

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