Yellow signal doesn't change, what's up?

[Willy2]

Usually when a train passes a green or yellow signal, the signal changes to red until another train is ready to pass or until the first train has gone far enough for a yellow and not a red.

But recently, a couple of times on single track, I've seen a train pass a yellow approach with caution signal, but the signal never turns red, it just stays yellow.
How come?

Willy

[Willy2]

The signal is by itself, it's a search light signal, and it does have a number plate.

[Hugh Jampton]

There used to be one like that near where I grew up. It was in unsignalled teritory, but protected a signal that protected a diamond, The yellow signal was a braking distance from the absolute that protected the diamond, and trains passing it had to slow down, preparing to stop at the diamond. Once they saw that the signal at the diamond was green they sped up again

[Anonymous]

I rememebr back in the day-

The power company was having electrical problems and there voltage dropped to 52 Volts for about 20 minutes in select areas

fired all electrical motors, Sump pumps, and oddly enough, A lot of RR signals were affected-

The signals wouldn't change from the colour they were preceeding the diminished voltage-

never could figure out-

some just short- some got jammed-

and the power company was out big bucks.

[Anonymous]

I do know that the Falls City Sub has alot. Alot of times there will be signals that will stay green or yellow all the time even when no train is even around.
BNSFrailfan.

[locomutt]

QUOTE: Originally posted by M.W. Hemphill

Hugh, that's exactly what I described above. Here, it's called a distant signal.

Hugh,
I have to agree with Mark.
Sometimes certain signals don't change.[:)]
It does mean be pepared to STOP!

[mudchicken]

Distant Signal / Fixed Approach...Mark has it. There are all kinds of variations on the theme, especially in Willy's neighborhood. Curious to see where and to see what significance the numberplate means (CTC/ABS/TWC DARK)....Then there is the fun & games with HWD's and railroads that did not believe in revolving/ strobe lights...

[Willy2]

Maybe I should have pointed this out earlier, (I thought that most if not all subdivisions have similar signals. I may be wrong.) This signal was on the Union Pacific down between Springfield and Branson, Missouri. Not sure of the subdivision. We were riding a scenic railroad, that's how I know of all these signals.

Another question: There were lots of signals on a 20 mile stretch of track, but only a few were operating, the rest were turned away from the tracks and shut off. Was there once a need for more signals, or something else? Thanks for the answers about the yellow signal. I just couldn't figure out why it wouldn't change!

Willy

[Big_Boy_4005]

There is a signal near here on the ex C&NW tracks that is always yellow but does turn red when there is a train in the area. The signal is located at the top of a steep down grade, and at the bottom of the hill is a junction for a short branch. Just beyond the junction is a swing bridge. There is no green, so trains can't just go charging down the hill.

[mudchicken]

We know where Willy's been. How was the ride? Make any sidetrips?

Will ask the M&NA General Roadmaster (Ray the Road Warrior, drives everywhere!) your question when I see him in Reno in a few weeks.

[CShaveRR]

The signal system as a whole has been de-activated (turning the signal heads away from the track is the standard treatment for inactive signals, be they deactivated or not yet cut in).

But I don't buy the part about your yellow signal that didn't change as meaning nothing. I suspect that it was retained as a distant signal, or possibly as a slide-fence signal. What was a "block" away from that signal? I suspect that it was not a sideways-turned signal...more likely a crossing, junction, or slide fence.

[Willy2]

A block away from the signal there were two tunnels and after the tunnels an operating signal. The operating signal was green and turned red after the engine passed it, like it was supposed to do.

The ride was fun, we went 20 miles down the line and then came back. A coal train went by the depot before we departed so that was nice. There's not a whole lot to see, just lots of trees, and an abandoned town. At the end of the tour we stopped on a very high bridge for a few minutes and then headed back to Branson. The train also almost hit a deer. We were nearing a tunnel and a deer was running ahead of the train, luckily for the deer, it did not get trapped in the tunnel. It's a nice trip and lasts for 2 hours. The train is complete with 2 dome cars, a cafe car, and several other cars with lots of seating.

We didn't make any sidetrips because there was just too much to do in Branson. Thanks to everyone for the answers to my questions!

Willy

[Big_Boy_4005]

Hey Mark, It's the UP's Altoona Sub. I could probably get closer to the signal to see the plate, but it's about a quarter mile from the grade crossing, and I'm usually going 50 MPH. I have a book that describes the line though. The bridge is at MP 18.6, the junction is at MP 18.4, so I'm guessing that the signal is around 18.0 give or take a tenth. Next time I fly by there I'll look at the shed that houses the stuff for the crossing signal, there's a MP number on it too. By the way, you did an article on this section of track back in August 2002, entitled "Up Hill Both Ways" about the Omaha's steam helpers of the St Croix River valley.

I'm anxious to see the Triple Crown service come through here, but I have plans this evening. Maybe I can get some photos of tomorrow's eastbound. This line has been so dead except for the local service to the power plant and Andersen Windows that use the switch at the junction to run up into the town of Bayport.

What are you looking at to find this info? Special book, or is it public info, just not well known?

[Nora]

QUOTE: Originally posted by M.W. Hemphill


Another possibility is that those that still remain active are now slide-fence protection, giving either a yellow to indicate that the circuit is live, or a red if the fence is tripped -- but not block protection.

Well, then, what the heck's a slide-fence?

[BaltACD]

QUOTE: Originally posted by Nora
[
Well, then, what the heck's a slide-fence?

Slide fences are devices that are wired into the signal system and are used in territories where rock slides, mud slides or avalanches are a relatively common occurence. The debris slides into the fence and triggers it's detector mechanism which turns the signals to restrictive indications thus either stopping trains or indicating that trains should operate at Restricted Speed (A speed that permits stopping within one half the range of vision, not to exceed 15 MPH). On some CTC machines there will be an indication displayed that the slide fence has tripped, on other territories the slide fence tripping will activate a track occupancy indication on the machine. In Dark (DTC or Track Warrent Territory without signals) trains crews must report the observance of the Slide Signal to the Train Dispatcher so the appropriate personnel can be dispatched to remedy the situation.

[kenneo]

On the CTC machines at Eugene (before they moved the Dispatchers Office) there was a separate light for each slide fence, high water detector, collision detector, etc., on the hill between Oakridge and Cascade Summit. Most tunnels and rock and snow sheds had detectors, also.

Marks description of how these devices work is accurate. Yet, on the Oregon Division, we had quite a few fences, particularly around Roberts Mountain, that had mercury switches because the hillslides would not slide in a normal manner, but slip slowly. These fences had both types of detectors. So, if the ground got water soaked, for example, and started to move down hill, the post with the mercury switch on it would start to tip and that would complete the circuit and set the signal. This added warning was needed because you often could stop a track blocking slide if you could drain the slope quickly. The regular slide fence would not activate until you had a track blocking slide in motion. Of course, when a deer would run into the fence or kids try to climb it, off would go the detector.

Block signals having some sort of a detector attached to them always had a triangluar black plate with a reflective "P" which permitted a train to pass a red on that signal at restricted speed to the point(s) protected and then the crew would have to make an inspection to determine if they should advance or stay put.

It should be noted that a slide fence need not be located above the track. It can be on a down slope below the track if the roadbed whats to move in that direction.

[Big_Boy_4005]

As long as we are talking about slide fences, you don't have to be in the mountains to need them. Here in the upper midwest, along the bluffs of the rivers, the soft rock is prone to collapse. The railroad grade is basicly a carved ledge in many places as it climbs out of the valleys.

This isn't the greatest photo, but it was handy. I took this a couple of weeks ago while riding behind 261along the Mississippi south of St Paul.

[Anonymous]

It may have been a permissive block signal, which will not change, it would be a stop signal to a passenger train if it were to approach the signal, but it will permit a freight to enter under the same rules as a restrictive signal.

[railfan619]

the signal at 64th and mill road the old cnw tracks is always stuck on yellow only once or twice I've seen it red or green but other wise I've seen it yellow.

[Willy2]

... And I'm learning about more things than what I asked. Pretty good deal.

Willy

[kenneo]

Mark ------ I don't remember the number for sure, but it was about 50 different detectors between Dexter and Cascade Summit, but only about 1/2 dozen or so got their own special light on the panel. We had the USS "Ding-a-ling" machines with the track diagram and light bulbs, normal and reverse togle for switch machines and the same for direction and an actuator button. The type from the 1950's. The Hill between Eugene Yard and Crescent Lake had the old style as mentioned above, but between The Lake and DR (Dunsmuir) they had a semi-automatic computer aided machine that looked like the old machine, but would give you an indication of the signal the hoghead was seeing, auto-dispatch if you told it to along with other bells and whistles.

The Dectector Lights on the CTC panel were for those places where you really had to know what was wrong before you sent a train into the area. These were places that the crew would have to stop and check from the ground and make their own decision on proceeding. Places where you have a tunned open onto a high trestle and dive right into another tunnel (snow sheds and rock sheds qualify as tunnels in this post).

One of those type of places I vivedly remember from Christmas Week of 1964 and then again in the middle week of January 1965. We had just had about 15 feet of snow at The Lake and then a week of VERY warm and heavy rain (a Pinapple Express with a Chinook Wind), and that meant a LOT of water came down Salt Creek and the Willamette main stem. One of the bridges where the railroad hangs on the edge of the cap rocks washed out (Roaring Creek (the name is an understatement)) at its foundation but the bridge looked OK from a train. This is the one location I remember for sure that had its special light and it saved a freight from going out on the span and falling several hundred feet. The train was able to get out of the area 15 days later just ahead of another heavy snow dump and Chinook in mid January.

So, Mark, before you go and get all green with envy, remember that the SP NEVER spent money just to look good. Remember SP's "domes"? Raised floor coaches with a partially glazed roof and furnished like a Lounge Car - the advertising folks thought they could convince you that you had a real full length vista dome car. Then there were those of us who had ridden in the real ones on the MILW and GN. Like I said........

[kenneo]

So we're off topic. Not the first time!

I was not griping about the SP's spending habits. They made sure they got their monies worth. All those lights on the locomotives were not there for the train fans. They reduced grade crossing accidents and insurance costs (court costs, too) in an amount greater than their cost new and fixing costs.

Dave is correct about the 3/4's atrium feel, but a dome they were not. And UP's domes (ACF) were superior to Budd's. I rode the MILW and GN when they had their original full length domes, and all of the cars had lounge seating on the upper level and the bar itself was on the lower level along with "the trains offices" for the Pullman Conductor, the Train Conductor and the on-board crew manager (they had a name, but I can't remember it right now). When the tour people took out the tables and such and put in those 55 coach seats, yes, you felt like you were in a ditch.

Your mention of Noisy Creek is the same weather event I was talking about. We actually had three trains stalled up there and the crews were fed by chopper for a few days until they could be gotten out. The train in Datri's article took a bit longer to get out than the one I was refering to. This one would have take the engine crew down with it but I was using it for illustrative purposes.

I agree with your comments about the Moffett. My favorite steam locomotive is their "Old Maud" modification into a 2-6-6-0. My best man at my marriage gave me a painting e did of one going into the hole - head man has the gate lined and is signalling the hogger to bring her inside.

I had a sign on my desk as an Agent -- "Here, we do everything with almost nothing - doing it with nothing will take until tomorrow."

[Anonymous]

Alot of the UP's Signals do that too.