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

[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.

[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.

[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]

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.

[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]

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

[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!

[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

[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

[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]

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.

[Anonymous]

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

[Anonymous]

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

OS

[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.

[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.