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RE: (erielack) Signal question - East Lincoln Park

Gordon,

> A few more details about East Lincoln Park that might be 
> useful.  I don't want to appear picky, but the term "aspect" 
> applies to the appearance of the entire signal as seen from 
> an approaching train.  The collection of lamps or lenses in 
> one sheet metal background is still termed an "arm," dating 
> from semaphore signal days.  So I think we are discussing the 
> bottom lamp of the top arm of the eastward signal from 
> Lincoln Park siding having been blanked with sheet metal.  
> The lamp would have been removed because it was no longer 
> used in any of the aspects displayed by the signal.  The hole 
> in the background would be blanked to prevent sunlight or 
> other light from passing through the target and giving a 
> false indication.

Thanks for this wonderful description. Yes, I realize that "aspect" is
incorrect, but I didn't know what the correct term was. Thanks for
educating me on this! I agree with Bill Burt's comments that "arm" is
certainly archaic and outdated!

When the Boonton Line was single tracked, a vast majority of the signals
became ABS and had the lower lamp on the upper arm (using the correct
terminology now!) filled in with a metal plate.


 
> The best indication that the siding signal could display in 
> 1975 was "Clear Medium," Red over Green, because the 
> diverging route (even though it was trailing through the 
> switch) was limited to Medium Speed.  So the top arm always 
> displayed a red lamp.  By itself, with no lamps lit in the 
> bottom arm, it indicated "Stop."  When the bottom arm 
> displayed a green lamp, the indication was "Clear Medium," 
> Red over Green, and when the bottom arm displayed yellow, the 
> indication was "Restricting," Red over Yellow.

This is helpful for signalling - so only the bottom two lamps are
variable, and I can just keep the top lamp on consistently.


 
> The eastward signal governing the route from the main track 
> retained the two lamps in each arm because it displayed 
> aspects for a normal speed route.  The single Red (top arm) 
> aspect indicated "Stop." Red (top arm) over Yellow (bottom 
> arm) indicated "Restricting." Single yellow (top
> arm) indicated "Approach."  Yellow (top arm) over Green 
> (bottom arm) indicated "Approach Medium," and single Green 
> (bottom arm) indicated "Clear," unless . . (see below).
> 
> I don't recall the indications of the eastward signal at 
> Mountain View.  
> The curve itself from the Boonton Branch to the Greenwood 
> Lake Branch was limited in the time table to 30 mph.  I don't 
> remember if the best indication on the eastward home signal 
> was "Medium Clear" or "Clear;" 
> that is, if EL covered the speed restriction simply in the 
> time table, or if it was also enforced by the signal indication.


That would be useful information to me, too, if anyone has it?



 
> Good signal practice calls for the latter.  If that was the 
> case, and if the eastward signals at East Lincoln Park 
> governed the approach to Mountain View, then the best 
> indication on the main track signal at East Lincoln Park 
> could have been "Approach Medium," Yellow over Green, and on 
> the siding signal, "Medium Approach," Red over Flashing Yellow.  
> Also, in that case, the bottom arm of the siding signal would 
> have needed only a single yellow lamp because there was no 
> green in any of the aspects.

As stated before by Bill Sheppard, the best indication for eastbounds
off the siding at East Lincoln Park was clear medium (Red-over-Green) -
does that mean the westbound interlocking signal at Mountain View simply
gave a "Clear" indication? Since that was a signal on the Erie side, it
was a tri-head searchlight - I assume it would have shown Red-Red-Green?


 
> When I (as a Track Department guy) expressed my displeasure 
> over that to our signal supervisor, he told me that they used 
> light-out relays to protect against that.  But of course a 
> relay doesn't protect against a physical obstruction 
> obscuring the lamp.  I always considered that a violation of 
> the fail-safe principle.

Good point! But would a bird be able to build a nest that quickly? ;)

Thanks again for a LOT of good information!

	- Paul

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