Author Topic: Tehachapi signalling thread - prototype  (Read 9456 times)

0 Members and 2 Guests are viewing this topic.

ChrisKLAS

  • Crew
  • *
  • Posts: 112
  • Respect: +36
Re: Tehachapi signalling thread - prototype
« Reply #15 on: April 29, 2016, 06:27:32 PM »
0
That certainly wouldn't have been an impediment to some of the weird stuff I ran across. Right up there on the "weird" scale were the SA pot signals in and around the engine service area at Taylor Yard. They had blue and orange roundels. Never used on UP to my knowledge, but I'm certainly going to use the idea on my layout, if only for the WTF? factor.

Those sound like mechanical blue flags.

One of the most endearing aspects of the SP from the standpoint of both an enthusiast and modeler, at least to me, is how those guys seemed to just cobble things that they needed together on whatever shoestring budget they had to work with. There were signals all over Tehachapi (like the one below, which is perhaps my favorite) that you could look at and just imagine some frustrated signal foreman saying "okay, we need a three-headed dwarf here, go see what you can find in that pile over there to make one." The line back then had so much more character than it does now.


jagged ben

  • Crew
  • *
  • Posts: 2293
  • Respect: +178
Re: Tehachapi signalling thread - prototype
« Reply #16 on: April 29, 2016, 07:26:37 PM »
0
One of the most endearing aspects of the SP from the standpoint of both an enthusiast and modeler, at least to me, is how those guys seemed to just cobble things that they needed together on whatever shoestring budget they had to work with.

Sounds just like how we make our N-scale signals for the club layout.   :D

Quote
There were signals all over Tehachapi (like the one below, which is perhaps my favorite) that you could look at and just imagine some frustrated signal foreman saying "okay, we need a three-headed dwarf here, go see what you can find in that pile over there to make one." The line back then had so much more character than it does now.

Okay, since you posted that photo, next question...

Why is there a three headed dwarf there and do you know what aspects it shows for what situations?

jagged ben

  • Crew
  • *
  • Posts: 2293
  • Respect: +178
Re: Tehachapi signalling thread - prototype
« Reply #17 on: April 29, 2016, 07:33:48 PM »
0
Also, whoever can answer this...

Did the dwarves and 'short pole' signals at the ends of sidings typically display only red and green, or did any of them display yellow and under what circumstances?  Did any of them display yellow and not green?   

Did green on these low signals basically mean the same as yellow because they were slow signals?   I always thought that this sort of thing did not apply to SP 'route signalling' but all the recent new info in these Tehachapi threads is making me rethink.

ChrisKLAS

  • Crew
  • *
  • Posts: 112
  • Respect: +36
Re: Tehachapi signalling thread - prototype
« Reply #18 on: April 29, 2016, 07:43:44 PM »
0
Why is there a three headed dwarf there and do you know what aspects it shows for what situations?

No clue. I've often wondered that myself. There was another three headed-dwarf (pictured below) coming off the old siding at Summit Switch, but that one makes some sense because the next signal is the crossovers at Tehachapi so if you were heading out, crossing over to main 2, then being crossed back over to main 1 at Tehachapi, that signal needed the ability to show you a Diverging Approach Diverging (red over yellow over yellow) aspect. That scenario doesn't apply to the signal at the Bealville crossover, so maybe someone else can shed some light.

BTW, I got an answer on Trainorders re: the Approach Diverging aspect change and posted it in the thread, but it fell off as the last post on the last page. Just wanna make sure you didn't miss it.  :trollface:


kc9jts

  • Crew
  • *
  • Posts: 133
  • Gender: Male
  • Respect: +14
    • my blog of miscellaneous info:
Re: Tehachapi signalling thread - prototype
« Reply #19 on: April 29, 2016, 08:09:15 PM »
0
No clue. I've often wondered that myself. There was another three headed-dwarf (pictured below) coming off the old siding at Summit Switch, but that one makes some sense because the next signal is the crossovers at Tehachapi so if you were heading out, crossing over to main 2, then being crossed back over to main 1 at Tehachapi, that signal needed the ability to show you a Diverging Approach Diverging (red over yellow over yellow) aspect. That scenario doesn't apply to the signal at the Bealville crossover, so maybe someone else can shed some light.

BTW, I got an answer on Trainorders re: the Approach Diverging aspect change and posted it in the thread, but it fell off as the last post on the last page. Just wanna make sure you didn't miss it.  :trollface:



I will have to look on Monday when I am back in the office. Just guessing though the one at Bealville probably had a lunar on that bottom head for a following move.  Guessing the same would be true for Summit.

kc9jts

  • Crew
  • *
  • Posts: 133
  • Gender: Male
  • Respect: +14
    • my blog of miscellaneous info:
Re: Tehachapi signalling thread - prototype
« Reply #20 on: April 29, 2016, 08:16:01 PM »
0
Also, whoever can answer this...

Did the dwarves and 'short pole' signals at the ends of sidings typically display only red and green, or did any of them display yellow and under what circumstances?  Did any of them display yellow and not green?   

Did green on these low signals basically mean the same as yellow because they were slow signals?   I always thought that this sort of thing did not apply to SP 'route signalling' but all the recent new info in these Tehachapi threads is making me rethink.

The low or dwarf signals would essentially have the same aspect as the "tall" signals.  As the SP was route signaled there really weren't any "slow" aspects per se; a clear signal was a clear signal regardless of the mast height.  There "may" have been one or two locations that only had a yellow and not green but I would have to research it.  As previously discussed though north Walong did only have red and green aspects for northbound trains.

C855B

  • Crew
  • *
  • Posts: 7625
  • Respect: +839
Re: Tehachapi signalling thread - prototype
« Reply #21 on: April 30, 2016, 04:08:39 AM »
0
Those sound like mechanical blue flags.

One of the most endearing aspects of the SP from the standpoint of both an enthusiast and modeler, at least to me, is how those guys seemed to just cobble things that they needed together on whatever shoestring budget they had to work with. There were signals all over Tehachapi (like the one below, which is perhaps my favorite) that you could look at and just imagine some frustrated signal foreman saying "okay, we need a three-headed dwarf here, go see what you can find in that pile over there to make one." The line back then had so much more character than it does now.



Yes, mechanical blue flag. But it seemed odd that SP would spend the bucks on full SA signals - about 20-25 of them - to do this when just a plain heavy duty blue light (like an airport taxiway marker) would do the same job.

This three-headed dwarf was at Bealville, yes? I have a friend who was a DS over Tehachapi for several years. I should ask 'im.
...mike

http://www.gibboncozadandwestern.com

We don't make mistakes, we have happy accidents. We just don't tell anybody. -Bob Ross

jagged ben

  • Crew
  • *
  • Posts: 2293
  • Respect: +178
Re: Tehachapi signalling thread - prototype
« Reply #22 on: May 01, 2016, 12:15:24 PM »
0
The low or dwarf signals would essentially have the same aspect as the "tall" signals.  As the SP was route signaled there really weren't any "slow" aspects per se; a clear signal was a clear signal regardless of the mast height.  There "may" have been one or two locations that only had a yellow and not green but I would have to research it.  As previously discussed though north Walong did only have red and green aspects for northbound trains.

Thanks.

About north Walong...  So putting this together with your other post, the reason for no yellow was because this was the 'double-blocked' red.   When you look at how short the distance is between north walong and 3507, that double blocked red makes some sense.  In fact it's remarkable that 3507 is half the distance from Walong than it is from Woodford.   And before Woodford was lengthened in 1975, it would have been about 3 times the distance!   Which brings me back to another question...

Anybody know if there used to be another set of intermediates closer to Woodford?   In this photo from before the siding was lengthened there isn't a lower head on 3507 northbound.   (Compare to link from post #1.)    Perilous as it may be to apply logic to SP signal history, my supposition is that there may have been another set that was the mirror image of these.   (Or in other words, like the signals between Rowen and Cliff, or Bealville and Caliente.)   When they lengthened Woodford, it would have no longer made sense to have two sets, but the approach signal at 3507 would have needed the lower head added.     It would also make sense if they put in the double-block red at north Walong about this time.    Too speculative?   Anybody ever see another set of signals?  (Mike?)



ednadolski

  • Crew
  • *
  • Posts: 2935
  • Respect: +331
Re: Tehachapi signalling thread - prototype
« Reply #23 on: May 01, 2016, 12:45:32 PM »
0
I haven't had time to read thru all this thread (or similar discussions in other threads) in detail, so I apologize in advance if this has already been answered.

Looking at this pic of South Woodford ca. 2004-2005, shouldn't there be another signal head visible, for a southbound train on the siding?   I think UP has one there now, but I am wondering why SP might not have had it there in that timeframe.

TIA,
Ed

C855B

  • Crew
  • *
  • Posts: 7625
  • Respect: +839
Re: Tehachapi signalling thread - prototype
« Reply #24 on: May 01, 2016, 01:11:11 PM »
0
After four decades, detailed memory is pretty hazy, guys... but I'm pretty sure there were signals between the old east Woodford switch and 3507, the eastbound an advance signal with a lower head without a target, also a fixed green. Thinking back (but unable to have seen both simultaneously, obviously), the lower head was likely a repeater of 3508. This signal was just about where Woodford-Tehachapi Road veers south away from the tracks.
...mike

http://www.gibboncozadandwestern.com

We don't make mistakes, we have happy accidents. We just don't tell anybody. -Bob Ross

jagged ben

  • Crew
  • *
  • Posts: 2293
  • Respect: +178
Re: Tehachapi signalling thread - prototype
« Reply #25 on: May 01, 2016, 10:26:21 PM »
0
I haven't had time to read thru all this thread (or similar discussions in other threads) in detail, so I apologize in advance if this has already been answered.

Looking at this pic of South Woodford ca. 2004-2005, shouldn't there be another signal head visible, for a southbound train on the siding?   I think UP has one there now, but I am wondering why SP might not have had it there in that timeframe.

TIA,
Ed

Ed I meant to mention this in your build thread.  It was a dwarf and it's circled in this cropped edit.

[ Guests cannot view attachments ]


jagged ben

  • Crew
  • *
  • Posts: 2293
  • Respect: +178
Re: Tehachapi signalling thread - prototype
« Reply #26 on: May 01, 2016, 10:45:59 PM »
0
After four decades, detailed memory is pretty hazy, guys... but I'm pretty sure there were signals between the old east Woodford switch and 3507, the eastbound an advance signal with a lower head without a target, also a fixed green. Thinking back (but unable to have seen both simultaneously, obviously), the lower head was likely a repeater of 3508. This signal was just about where Woodford-Tehachapi Road veers south away from the tracks.

Interesting!    So, you're saying the signals were about where the siding ends now?  (i.e. just north of the bridge).    That would certainly put them pretty symmetrical with the ones closer to Walong. 

C855B

  • Crew
  • *
  • Posts: 7625
  • Respect: +839
Re: Tehachapi signalling thread - prototype
« Reply #27 on: May 01, 2016, 11:25:31 PM »
0
Yep, that's about right.
...mike

http://www.gibboncozadandwestern.com

We don't make mistakes, we have happy accidents. We just don't tell anybody. -Bob Ross

ChrisKLAS

  • Crew
  • *
  • Posts: 112
  • Respect: +36
Re: Tehachapi signalling thread - prototype
« Reply #28 on: May 02, 2016, 01:04:11 AM »
0
Anybody know if there used to be another set of intermediates closer to Woodford?   In this photo from before the siding was lengthened there isn't a lower head on 3507 northbound.   (Compare to link from post #1.)    Perilous as it may be to apply logic to SP signal history, my supposition is that there may have been another set that was the mirror image of these.   (Or in other words, like the signals between Rowen and Cliff, or Bealville and Caliente.)   When they lengthened Woodford, it would have no longer made sense to have two sets, but the approach signal at 3507 would have needed the lower head added.     It would also make sense if they put in the double-block red at north Walong about this time.    Too speculative?   Anybody ever see another set of signals?  (Mike?)

That seems entirely plausible. The absence of a lower head on the 3507 westbound signal in the photo you linked certainly suggests there was another pair of intermediates further down the mountain. The only place I know of on the hill where there was a single head signal protecting the block prior to a 2-headed signal capable of displaying a diverging aspect was on the signal bridge at 326.9 before it was lost to the great flood of 83. A westbound train running on main 1 to be crossed over at Sandcut would have seen a straight approach here.



Interestingly enough, even when the new signals were put in place after the flood, the replacement mast signal still featured only a single head. Perhaps westbound movements on main 1 in this area of bi-directional CTC were so infrequent (given that the main obvious purpose of the CTC here was to allow eastbounds to run up main 2 around other eastbound traffic picking up helpers at the now-removed helper pocket) that it wasn't considered cost-effective?


GaryHinshaw

  • Global Moderator
  • Crew
  • *
  • Posts: 5413
  • Respect: +559
Re: Tehachapi signalling thread - prototype
« Reply #29 on: May 02, 2016, 01:06:06 AM »
0
Ed I meant to mention this in your build thread.  It was a dwarf and it's circled in this cropped edit.

Yes, I do believe that is a dwarf as well.  It was replaced with a full searchlight some time around 2005-6:

http://www.railpictures.net/viewphoto.php?id=139275&nseq=308
http://www.railpictures.net/viewphoto.php?id=239101&nseq=212

and of course, with a Darth Vader more recently:

http://www.railpictures.net/viewphoto.php?id=538999&nseq=23