UP West Colton Yard signaling

[Mr_Sven]

I've a question about signaling at the UP West Colton Yard LA, especially, the east end at S Pepper Ave.
In some YT videos mostly the night shots there are some signals in the tracks, and I wanted to know the meaning.
The blue light is maybe the “Man at work” sign, and also yellow or red, it’s a bit difficult to determine the exact color in the videos.

[C855B]

Can you supply a link or two to the YT video which shows this?

Many decades ago I lived near West Colton, and have a good handle on yard ops there. I don't recall the signals specifically - they might be new since then - but I have an educated supposition of what they are for.

[Mr_Sven]

Here is a video,

at minute 13:40 you see yellow lights in the track, not the turnout signals. At the moment I don't find the video with the blue signal, but it is at the same place.

[C855B]

Thanks!

OK. With some certainty, those are signals for the trim crews and hostlers, controlled by the hump tower.

Red = actively being humped or worked from the other end. Do not enter.
Yellow = OK to trim or couple departing power.
Blue = personnel working cut with manual operations, such as connecting air hoses. Do not enter; blue flag rules apply.

Like I said, it's been a long while since I was there. Correction is welcome!

[Mr_Sven]

Ok, cool tank you for the explanation.

[Mr_Sven]

Can I ask you another signaling question? It's not about the yard in direct, it is more about the yard exit/entry, the loop and the northbound rail.
I try to understand the signaling aspects, I've a drawing which I can share.

[C855B]

Sure, go ahead. But even with a drawing I'm going have a lot less certainty, as it has been 45 years since spending any amount of time there. Aspects/routings I might have known then may not be the case today, especially given the new-to-me grade separation at Colton.

[Mr_Sven]

Ok, here is a picture of the track, in the meanwhile they added some more turnouts.


1, 2 and 3 are ok and they are clear for me.
4 is also ok, all for the main track and enter the yard with "restricting".
6, the same for my opinion, from loop track to main and yard,
5 is the signal what confuses me, the signal from the northbound rail

[jagged ben]

After looking at some pictures of the spot ... are you sure that 5 isn't the same as 4 and 6?

For all of those tracks the upper three light signal would indicate an aspect for continuing on the main line and red-over-red-flashing would indicate entering the yard.   (Most likely, I'm making some reasonable assumptions.)  If I'm correctly understanding that they all face compass east (i.e. they're for compass west-bound trains). 

[Mr_Sven]

I've looked at the videos, in the linked video around minute 6:06 you can see the signals from the back.

Money shot at minute 49:

[Mr_Sven]

Hm, seems to be a complex question.

My idea is: the northern main joins the east-west main, so the northern main ends and diverges on the east-west main. So I assume there is no continue on main because it ends here.

[Mr_Sven]

I studied now some documents and rule books.
Following I will describe the signals, If I’m wrong on anything, please correct me.

• Signal 1
  • Continuing on main track
    clear; approach clear; approach …..
  • Entering the Loop
    Only possible via diverging approach (9.2.11) because we have to assume signal 6 is red due to blocked turnout or yard entrance via restricting (9.2.13).
• Signal 2.
  • Exit loop via all single head rules.
• Signal 3.
  • Exit yard onto main, diverging route or into the loop.
• Signal 4.
  • Continue on main, or enter yard via restricting (9.2.13).
• Signal 5.
  • Continue on main
    Only possible via diverging rules due to speed limitations of turnouts and the downhill gradient in the curve from north to west.
  • Enter yard via restricting (9.2.13).
• Signal 6.
  • Continue on main
    It could be clear, because loop entrance is only possible via diverging approach (9.2.11) so the train is at limited speed and prepared to stop. As the train is in the loop and short enough and the turnouts get switched the signal can be flipped to clear. The train is slow enough that if it accelerates, the train is out of the loop until it may reach critical speeds for the turnouts. Other single head rules also possible.
  • Enter yard via restricting (9.2.13).

Regards