Tehachapi signalling thread - prototype

[kc9jts]

That 1988 rulebook is horribly out of date.  Here is a link to something much more accurate: http://signals.jovet.net/rules/UPRR%20Signal%20Rules.pdf

Yes, very much! Thanks!


So let me see if I understand the rule mappings:

R/R = Rule 245Q Stop
Y/R = Rule 245D Approach
FY/R = Rule 245B Approach Limited
R/Y = Rule 245K Diverging Approach
R/FY = Rule 245J Diverging Approach Limited
R/G = Rule 245G Diverging Clear
R/FR = Rule 245N Flashing Stop and Proceed (diverging?)
FR/R = Rule 245N Flashing Stop and Proceed
G/R = Rule 245A Clear
Y/Y = Rule 245C Approach Medium

(Based upon: http://www.railroadsignals.us/rulebooks/up88/index.htm)

Interesting that facing Walong does not show a G/R.  So a southbound will always take the diverging route (and go thru Tunnel 10).

Negative, southbounds can take either main 1 or main 2

What about the South Woodford?  I don't have a clear pic, but I would guess that the trailings are same as on Walong, and the facing aspects include the G/R?

Yes, South Woodford would be the same as Walong, albeit with a clear aspect on the facing signal as you surmised.

That G/R at SP350 could be for either the main or siding at South Woodford, right?

If you are referring to the trailing signals at SP350 then yes, you are correct.

Thanks again,
Ed

You bet

[Sokramiketes]

D-heads are soulless and searchlights have life and animation.  Don't do it!

[jagged ben]

There have been lots of changes in signal spacing and what aspects they can display.  Likewise, the control points are designed so that if you are looking at the facing signal at either end of double track your diverging move would be to the right; as in if you go straight at SP351 (southbound) you would need to "diverge" onto the single main at SP354.  Same is true going the opposite direction: If heading north at SP354 the diverging move would be to the right and then it would be a straight move at SP351.  And of course the same would be true if the switch at SP351 was reversed instead.

The top heads would be for a yellow or red.  The facing signal at Walong and also Marcel can display a R/R, Y/R, FY/R, R/Y, R/FY, R/G, R/FR, FR/R.  The Stop or restricting aspects at the home signal would have a yellow approach signal at the next location, a Yellow approach aspect at the home signal would have a flashing yellow advance approach aspect at the next location, the Flashing yellow advance approach at the home signal would have a clear green at the next location (so the best aspect for a facing move going straight at either location is a flashing yellow.  Any diverging aspect at the home signal would have an approach diverging (yellow/yellow) at the next location.

Heading north from Walong both trailing signals can display R/R, FR/R, Y/R, FY/R, G/R, or Y/Y aspects (Y/Y denotes going in the hole at SP350 South Woodford).  UP typically follows a Y/Y aspect with an FY aspect, so keep that in mind.

Heading south from Marcel the signal on Main 2 can show R, FR, Y, FY, and G aspects.  The signal on Main 1 is considered an end of double track so it has a red marker light on the top head with R/R, R/FR, R/Y, R/FY, and R/G aspects with a yellow/yellow aspect at the next signal down.

There is a set of intermediates in between the control points, for a move "diverging" onto the single main a Y/Y aspect will be shown, otherwise a stop aspect or approach aspect will be shown.

Clear as mud?

Maybe this will help:  If you are a northbound at the approach signal for SP354 and are clear to SP348 (North Woodford) and let's assume main 2 through Walonger.
SP348 = R/R --> SP350 = Y/R --> SP351 = FY/R (over reverse switch)--> intermediate at 352.5 = Y/Y --> SP354 = FY/R --> intermediate at 355.6 = G.

Another scenario: heading southbound with Cable (SP358) at stop; taking main 1 through Walonger:
SP358 = R/R -->SP356 = R/Y (reverse switch) --> intermediate @ 355.6 = Y/Y --> SP354 = R/FY (Reverse switch) --> intermediate at 352.5 = Y/Y --> SP351 = FY/R --> SP350 = G/R

UP typically uses "Safetran" signal heads, so that is what you are looking for the dimensions of.

Nick

Hope this helps.

I'm confused.  (Not that I don't appreciate your posting this info!)   I think I would understand that the facing signals at north Walong or south Marcel wouldn't display a clear because of that red marker light at the end of double track, but where are the marker lights on the trailing signals?  There's a good view of the new trailing signals at north Walong at the 3:45 mark of this video. 

https://www.youtube.com/watch?time_continue=225&v=R-QYBybzQdk

On second thought ... I should delete this, I don't want to encourage Ed  to model D-heads either!   

[kc9jts]

I'm confused.  (Not that I don't appreciate your posting this info!)   I think I would understand that the facing signals at north Walong or south Marcel wouldn't display a clear because of that red marker light at the end of double track, but where are the marker lights on the trailing signals?  There's a good view of the new trailing signals at north Walong at the 3:45 mark of this video. 

https://www.youtube.com/watch?time_continue=225&v=R-QYBybzQdk

On second thought ... I should delete this, I don't want to encourage Ed  to model D-heads either!   

I get a message that an error occurred and it won't let me see the video?

[kc9jts]

I'm confused.  (Not that I don't appreciate your posting this info!)   I think I would understand that the facing signals at north Walong or south Marcel wouldn't display a clear because of that red marker light at the end of double track, but where are the marker lights on the trailing signals?  There's a good view of the new trailing signals at north Walong at the 3:45 mark of this video. 

https://www.youtube.com/watch?time_continue=225&v=R-QYBybzQdk

On second thought ... I should delete this, I don't want to encourage Ed  to model D-heads either!   

I get a message that an error occurred and it won't let me see the video?

Ok, I got it working.  There aren't any marker lights on the trailing signals at Walong; there is only a marker light at the trailing signal off of M1 at Marcel.  The facing signal doesn't have a "marker light" at either location, but it only has a 2-position head on the top of the mast as the best aspect a train could get is FY for a straight move.  Maybe the best way to describe it is that the facing signals at Walong and Marcel would look just like the trailing signals at Walong; but with the signal heads in the opposite order.

[svedblen]

This might work: https://www.youtube.com/watch?time_continue=225&v=R-QYBybzQdk

[ednadolski]

D-heads are soulless

Or perhaps, just misunderstood...?   

On second thought ... I should delete this, I don't want to encourage Ed  to model D-heads either!   

Too late, I had already seen it.    Anyways, as some have said, better to see the line being modernized and expanded rather than abandoned... 

Ed

[ednadolski]

southbounds can take either main 1 or main 2

Ok so then a southbound going onto main 2 (straight)  at CPSP351 would see Y/R (9.2.6 Approach) or FY/R (9.2.4 Advance Approach). 

What is the flash rate?  I'll have to modify my code to be able to display that.

Ed

[kc9jts]

Ok so then a southbound going onto main 2 (straight)  at CPSP351 would see Y/R (9.2.6 Approach) or FY/R (9.2.4 Advance Approach). 

What is the flash rate?  I'll have to modify my code to be able to display that.

Ed

If there are no other trains ahead it would be FY.  I want to say the flash rate is 50 flashes per minute. 

Nick

[jagged ben]

I just want to understand....

If a northbound is cleared through Woodford with no trains ahead, it could get at the least restrictive a flashing yellow at Marcel.  Are the signals ahead still green?  What would the aspect at north Walong (formely siding) be?

[kc9jts]

I just want to understand....

If a northbound is cleared through Woodford with no trains ahead, it could get at the least restrictive a flashing yellow at Marcel.  Are the signals ahead still green?  What would the aspect at north Walong (formely siding) be?

In the scenario you set up (assuming our northbound is staying on Main 2 at Marcel and "diverging" onto the single track at Woodford:
SP350 = G/R--> SP351 = G/R (reverse switch) -->Intermediate (Main 2) @ 352.5 = Y/Y --> SP354 (normal switch) = FY/R --> intermediate @ 355.5 = G --> any further signals would also be green (providing the dispatcher has the signals at control points cleared).

[jagged ben]

Old thread but something new to add...

http://www.railpictures.net/photo/682686/

Proof that there was once a triple-head signal at the west end of Woodford, to indicate if the short siding turnout was thrown.     (And this is Woodford.  Steve has been known to be imprecise on some details.  Compare this view (transformer bank lower right) and this one with the same electrical box on pole in background, which is blurred by engine exhaust in the first photo. )   

By 1989 the bottom head was gone (which is similar time frame to the disappearance of the third head at the east end of Woodford).  This signal mast has changed three times since 1986.  Not sure why the second double-head signal replaced the first one.  (Maybe it got lost in a derailment?)

[GaryHinshaw]

Timely reappearance, since I am back to wiring up signals on Tehachapi BC.  (Rereading this thread from the beginning was pretty bewildering though.)

Can someone tell me about approach lighting practices on the hill?  For specificity, I am only installing absolute signals at CTC control points and I'm using "searchlights in the modern era", meaning the signals are c. 2012, but the trains are c. 2019.    Aside from Kern Junction, the only two scenarios I have are crossovers and sidings, for example:



In the above example, where the red block is occupied, would all the signals in this view be on, or only the two facing the occupied block?  I believe it is the former (but I'm expecting the answer to be "it depends").  TIA

[jagged ben]

I believe it would have been the four signals facing 'inward', for both tracks.  That is, for any given control point, all the signals facing the same direction would light up if any track is occupied, even if only one of two main tracks (or main and siding) is occupied.

At the end of the SP era, signals facing sections without an occupied block didn't light up.  I believe the more current practice is a little more conservative, i.e. all signals in your view above would light up.  But I don't know if the pass was updated to this practice by 2012.

[GaryHinshaw]

Thanks jb, that makes sense.  If anyone has any knowledge that contemporary practice was/is different, please weigh in.  It's straightforward to change the logic.