Yellow Over Yellow vs. Yellow Over Green -- A Safety Issue

[K. P. Harrier]

Union Pacific seems to often use a yellow over yellow signal to indicate a diverging route at the next signal beyond, irregardless of the turnout speed, with the exception of 40 M.P.H. turnouts. Since it is conceivable that a disoriented, tired crew could disastrously mistake a 25 M.P.H. turnout for a 60 M.P.H. one, it strikes me as being more prudent if a yellow over green indication was used in advance of 60 M.P.H. turnouts, and an advance yellow over yellow be limited to 30 M.P.H. or less turnouts. For 40 M.P.H. turnouts -- like on the Central Corridor -- a flashing yellow in advance is standard on UP, and conforms to safe logic.

[CSSHEGEWISCH]

Railroaders are expected to know the subdivision over which they operate: sidings, turnouts, location of signals, etc. I would need to see UP's operating rules to know what a given signal aspect denotes before commenting on this situation.

[Anonymous]

An employee timetable with turnout speeds listed is no longer sufficient?

OS

[Anonymous]

Besides, "yellow over green" is the aspect for "Advance Approach"-proceed prepared to pass the next signal not exceeding 40mph.

[Anonymous]

Not sure about down there, but up here the CTC will always tell you how fast you can go.

If you have a red/yellow/red then that's a medium to stop, so you know you are going to take the siding, and the speed limit on the siding is going to be medium speed (no faster than 30MPH.)

Then once you're in the siding you'll get a dwarf that'll usually be green/red which would be a medium to clear which would mean medium out of the siding, then you can go track speed.

If you are crossing over between two main tracks, then the signal will tell you how fast you can cross over.

You'll get a red/flashing green/red for a limited speed (45MPH or less) to clear signal, meaning 45 MPH or less over the crossovers, then you can go track speed.

Or you may get a red/green/red which would mean medium speed to clear, meaning the cross overs are good for 30 MPH then track speed once you are clear.

Things are easy up here.

[K. P. Harrier]

QUOTE: Originally posted by O.S.

An employee timetable with turnout speeds listed is no longer sufficient?

OS

OS:

The scenario was a “disoriented, tired crew.” Every once and a while a railroad loses crews because of sleep deprivation that led to a head-on. I believe the concept in the original post would enhance crew safety on UP. Crews know thoroughly their job … but weird things happen. That is why derails came into existence, and which UP now uses in Montclair, CA.

Best wishes.

K.P.

[Anonymous]

True. There's more than one way to improve safety. You could also make sure crews are given good call times so they are fully rested before they go on duty. If the crew is that fatigued and disoriented, I'm depressed and dismayed, because they're an accident waiting to happen. Adding some extra signal indications isn't going to erase more than a few percentage points of that risk.

I mean, do you have an agenda here? Do you have a participation in this other than disinterested observer? This whole thread seems to be dancing around something left unsaid. If you feel UP has signal indications that are misleading or unsafe, that's one thing.

OS

[jeffhergert]

QUOTE: Originally posted by K. P. Harrier

Union Pacific seems to often use a yellow over yellow signal to indicate a diverging route at the next signal beyond, irregardless of the turnout speed, with the exception of 40 M.P.H. turnouts. Since it is conceivable that a disoriented, tired crew could disastrously mistake a 25 M.P.H. turnout for a 60 M.P.H. one, it strikes me as being more prudent if a yellow over green indication was used in advance of 60 M.P.H. turnouts, and an advance yellow over yellow be limited to 30 M.P.H. or less turnouts. For 40 M.P.H. turnouts -- like on the Central Corridor -- a flashing yellow in advance is standard on UP, and conforms to safe logic.

Most places I run 30MPH turnouts have a yellow over yellow in advance. 40MPH turnouts have a flashing yellow in advance. We now have a few 50MPH crossovers and they have a yellow over green which is now "Approach Clear 50" proceed prepared to pass next signal at 50MPH in advance. The one 60MPH turnout we encounter has a yellow over flashing green, "Approach Clear 60" in advance.
This seems to be the standard the UP uses at new installations. You may still find old setups from the former railroad. Example, we have a yellow over green that by bulletin is still a advance approach because of local conditions. This is a former CNW installation and if it is ever upgraded would be changed to the new standards.
Jeff

[K. P. Harrier]

OS:

You bring up a super significant point with “good call times” in your 15 Feb 2005 15:15:40 post above. Personally, I believe if the railroads put their minds to it, they could greatly improve the work environment for employees, and many lives could be saved. As has happened so often before, the Government may eventually have to get involved and force the issue.

The subject topic is NOT part of a secret agenda. The relatively new operating practices over Beaumont Hill in California outright baffle me. That is what inspired this topic. I am baffled because slowing a train down to 40 M.P.H. (with a flashing yellow signal) four miles from a crossover designed for 60 M.P.H. seems illogical.

With a 60 M.P.H. crossover, I am inclined to believe that the four mile away signal should be green, the two mile away signal should be yellow over green, and the crossover signal red over green. Now that is logical!

[Anonymous]

Im a driver here in the U.k.Over here signals are solely used to keep a safe space between train's.It seem's too complicated to have different colour combination's relating to junction speed."Route knowledge" over here dictates what speed the junction is.When i started with this company i got 21 week's to learn all the track including diversion route's between Manchester and London.Signal's,speed's,junction speed's,staton's and so on.Keep the signal's simple and give the crew's learning time for the junction speed's.Yes, at some juntion's over here we do have yellow over yellow flashing,but that only proves that the route is set to diverge away.You still have to know the speed of the cross over.All the best from the U.K

[kenneo]

We are talking about 2 types of signaling systems here. All systems started out being "occupancy" signals which simply keep trains apart. In such a case, with CTC type of track control, the top head showed track occupancy ahead and each head below represented a dirverging route, and that signal also was an occupancy signal. Just a couple of examples --- red over red = switch is lined for the diverging route, complete stop and do not advance; red over yellow = switch ahead at next signal is lined for the diverging route and the signal after that is set to red.

As trains got longer and also sometimes faster, the length of the control blocks to maintain proper separation became simply too long to permit decent train operations, so a different type of signalling was needed. This type, now comming into universal use in the US and Canada, is called "speed" signaling. The signals still do convey an occupancy indication and switch position/route indication information, but superimposed over that is speed indication. Speed signaling can be done with either single head or multiple head signals, but as indicated in several messages above, the signals now specify the maximum speed of your train so that a train can be kept under control as it approaches switches or other trains that may be ahead. This system permits, among other things, train speed nearly twice that of occupancy signaling for a given block length. Train movements are much more fluid.

[Anonymous]

QUOTE: Originally posted by virgintrainsdriver

Im a driver here in the U.k.Over here signals are solely used to keep a safe space between train's.It seem's too complicated to have different colour combination's relating to junction speed."Route knowledge" over here dictates what speed the junction is.When i started with this company i got 21 week's to learn all the track including diversion route's between Manchester and London.Signal's,speed's,junction speed's,staton's and so on.Keep the signal's simple and give the crew's learning time for the junction speed's.Yes, at some juntion's over here we do have yellow over yellow flashing,but that only proves that the route is set to diverge away.You still have to know the speed of the cross over.All the best from the U.K

Seems that it's easier to me just to memorize the CTC light combinations and then be governed by signal indication, I know there are speed limits on all the different cross-overs, but the signal indication always tells you how fast you can go over them, no memorizing required, even though you memorize them after a while anyway......

I know I would have a hell of a time remembering all the different speed limits as a new hire, but I suppose 21 weeks would be sufficient time to do so.

[arbfbe]

Disoriented as in fog so thick you cannot even see the ties in front of you, snow so heavy the wipers that have not had their rubber blades replaced in over 5 years cannot keep the windows clean or rain so heavy the water is level to the top as well as not being fully rested.

BN in Nebraska gave you a flashing yellow before you left double track on the diverging route, a nice reminder at 0230. When they double tracked in Washington they just left signals clear all the way if you were lined out, 60 mph to 35 mph with no reminder in inclement conditions. The reason, you are supposed to know your track locations, from a suit in from the home office.........

Alan

[Anonymous]

As i have'nt seen your signalling system i cant really comment, but it sound's like you can tell what speed the junction is from the signal's? Good idea ...but i personally think lots of different speeds and signal combination's could be distracting especially if there is another train not far in front too.

[Anonymous]

QUOTE: Originally posted by virgintrainsdriver

As i have'nt seen your signalling system i cant really comment, but it sound's like you can tell what speed the junction is from the signal's? Good idea ...but i personally think lots of different speeds and signal combination's could be distracting especially if there is another train not far in front too.

In CTC territory the signals tell you what speed to travel at, the most permissive signal "Clear" allows you to run at track speed, all other signals have speed limits attached to them.

Slow Speed = 15MPH
Medium Speed= 30MPH
Limited Speed = 45 MPH

Here's a link to all the Canadian signals:
http://www.tc.gc.ca/railway/Rules/CRORprint.htm#RULE

The signals aren't really distracting, they are telling us what we can do, and that's pretty much what we're getting paid for.

[CrazyDiamond]

I'm new to railroading, and was never employed in the industry. I am a telecommunications engineer.

However that said, I have done a lot of reading on signaling, and am a signaling fan one could say.

I for one believe in using signaling to control speed versus using it to control only block occupuncy. However I find it very confusing (hard to remember) all thos combinations of red/yellow/red, or red/flashing green/red for example. It appears that this new speed signaling was the result of one thing, a given head can display only one color at a time. I think it would be more easy to remember signaling from a 3-lamp signal head, that can display any combination of red, yellow and green. To me this would help reduce the number of signaling rules for someone to remember.

For exmaple:
Green only = Track speed.
Green & Yellow = 45 MPH
Yellow only = 35 MPH
Yellow & Red = 20 MPH
Red only = Stop

A second head could be used to display information at a track switch.
Green = Main Route
Yellow = Diverging Route
Red = No Route

So a Yellow & Red / Yellow = 20MPH onto the diverging route. Then some short distance afterwards, the next signal could be a single head signal and display the next speed assigment:

Green & Yellow = 45MPH.

A variation of this would not be to assign actually MPH, but to assign % of track speed. So for a given area track speed could be 60MPH, and the signaled percentages would determine actual speed.

Please take this with a grain of salt, because as I said I was never employed in the railroad industry.....just a telecom guy that is becoming a fan of signaling and model railroading.

Ps, the nick name 'signals' that I am a Pink Floyd fan!

[kenneo]

CrazyDiamond --- your idea is a good one but has a really serious drawback. And were it not for this drawback, I think a system similar to yours would be in operation now because of the cost of multiple signal heads.

That drawback is -- (Rule) if a signal is dark (no lit) it must be considered as the most restricting indication that this signal could display. In other words, stop right now, flag the train and call the dispatcher for instructions.

Now, if we were to use your system and one of those lights were burnt out, the crew would never know it unless the signal was "dark" (no light of any color). Bazoooooom, there goes your train right by the signal and into an accident.

So, for safety, only one color can be displayed for each head at any one time. That way, if you have a burned out bulb, you will know it and not go zinging right on by.

[CrazyDiamond]

That is easy to overcome. A automatic lamp changer can be used, just like they are now in numerous applications, including signaling, and airport and navigation aids.....and if that were not enough, then a dual lamp module or those new LED lamps (that contain dozens of LEDs) would work.

[jeffhergert]

The present setup works just fine, thank you.
Jeff

[CrazyDiamond]

Don't worry Jeff......North America won't up and change any time soon.

[Anonymous]

Everybody tries to arbitrarily apply signal aspects and indications from other roads to this situation when they are as useless as trying to fit Ford rods in a GM product. Most of the indications listed here are bogus......slow, med, etc. speed......crap! I have a current UP SSI in front of me. The double yellow's indication states:Proceed prepared to advance on the diverging route at next signal at prescribed speed thru turnout. Name: Approach Diverging. Yellow Green: Proceed. Speed passing next signal must not exceed 50. Name: Approach clear 50. In all of these scenarios posed by the resident non railroaders, nobody differentiates an absolute from intermediate signal (big difference when it is red). The bottom line is KNOW YOUR TERRITORY. As I have said before, Eastern RRs and Western RRs signaling aspects and indications share very little in common. If somebody comes on here asking what a Red/Flashing yellow means on the NS, I wouldn't jump up and say, "oh that means Diverging approach medium," because that is what its name is on my RR. If you are gonna deliver info you should be accurate about it.

[Anonymous]

i work for 1 railroad with 3 different classes of signals. chessie, seaboard, and now conrail signals. There are places that the signals don't just tell us to go or stop or slow down to cross over they space us out and in some places they are still set up for when there were cross overs back in the wooden wheel days . The "railroad' honestly has no clue what to do about the signal systems because some of them are seriously messed up and it takes a pileup or the fra to catch it. Crews young and old work over the same territory and see the same signals time and time again, untill one day they see a different signal that they don't understand since they have never passed before. Is it because they are tired or stupid or is it because its on a small piece of railroad that is left from 3 mergers and the signals are backwards from all 500-1000 miles of railroad that they are qualified on . Maybe if it was just dark we wouldn't have the troubles but now the fra is really putting the hurt on the dark territory. I know maybe they get a guy like at the airport with the flashlights with the cones directing traffic. Naaa. Almost everywhere on csx has to call signals on the radio, but we don't have to on our local divisions BUT the conductor must keep a log and write them down. some conductors ask for the speed if they don't have a speedometer i like to lie and tell i'm speeding and see if they right it down lol bottom line WE have to care about our safety the railroad doesn't

[CrazyDiamond]

Jeff wrote: "The present setup works just fine, thank you."

Gee Jeff I was thinking, it the present setup did work fine this thread (and all the comments about costs, knowing your routes versus, using 'simple' signaling versus complex signaling, etc,) would not exist. :-)

[Anonymous]

The current signaling system IS simple....when you run on different RRs trackage is when it gets a little confusing. That said, all of the signal changes/deviations are well published and made available to us via Div. General order, or the foreign RR's own instructions and timetables are made available to us. If a signal is moved, it is listed on our GTBs as a Form C or a TCM or it is stated in a General Notice or General Order. The information is there. We get paid to stay in the know. Crazydiamond...........are you a rail?

[CrazyDiamond]

Hi ironken,

No I am not 'a rail'. I am simply an observer who has done lots of reading about signaling all over the world. I posted an 'idea' in the previous page, and I'm sure this idea has been previously considered and defeated for various reasons. Other than that my comments on this site will really be limited simply because I don't know enough to comment. I do find the various signaling systems interesting and the "yea and nea" debates are also great to read. Someday when I build a model railroad, I hope to incorporate a lot of what ye tell me in here.

[Anonymous]

Diamond, its really not that bad. As Chief stated, it gets a little hairy where mergers meet. I can't say for sure how other lines work, but, on our RR as I said, the signals are defined in writing and made readily available. Also as Chief said, it is up to the crews to keep themselves safe. The info is there, we just have to apply it. By no means am I pro company. I just believe that we have to take responsibility to interpret these things. If these issues didn't exist, there would be no need for a 2 man crew or even a 1 man crew. Job insurance!

[CrazyDiamond]

I will say this too.....I believe having one universal (North America wide) signal system, that communicates great amounts of information to the engineers should be, in my mind (with zero expereince in the real rail world) much better then a simple signal system that depends on engineers knowing their track. Besides look at it from a career perspective.....if you know you can leave your job in the Southern US (for example) and take up that job that you always wanted in the Northern US, or up here in Canada, and can immediatly be a vauled employeed because you do not need to relearn the signals, I would think that be a good thing. Does a solid robust signal system not bring better and consistent information to the engineer behind the snowed up window?

It like me deciding to drive to the USA and visit all that your great country has to offer.....but....what if your traffic lights were differents, and your signage were different. I'd be in a crash no time at all.

Remember, K.P. started this thread by presenting us with a scenario of signals displaying something he feels would cause confusion, at the risk of leading to a dangerous situation. One of the key fuctions of signals are to help prevent a dangerous situation. The fact that there is confusion, and the numerous opinions in this thread prove it, leads me to think improvements can be made.

[CrazyDiamond]

You're right ironken, it is up to all of ye to read and apply. Anyway, I am gonna stand back and 'observe'....I may have intruded to much in this important discussion already.

Best wishes everyone!

C.D.

[Anonymous]

who's intruding?

[CrazyDiamond]

QUOTE: Originally posted by kenneo

CrazyDiamond --- your idea is a good one but has a really serious drawback. And were it not for this drawback, I think a system similar to yours would be in operation now because of the cost of multiple signal heads.

That drawback is -- (Rule) if a signal is dark (no lit) it must be considered as the most restricting indication that this signal could display. In other words, stop right now, flag the train and call the dispatcher for instructions.

Now, if we were to use your system and one of those lights were burnt out, the crew would never know it unless the signal was "dark" (no light of any color). Bazoooooom, there goes your train right by the signal and into an accident.

So, for safety, only one color can be displayed for each head at any one time. That way, if you have a burned out bulb, you will know it and not go zinging right on by.

This doesn't seem to be an issue over in the UK:
http://www.railway-technical.com/sig-uktypes.html#4-Aspect-Operating