I presume that on most railroads today, any trackside signal is automatically displayed in the lead locomotive as well. Still, I was wondering what an engineer would do when confronted with the following situations:
At midnight, two head signal at trackside, only one lamp lit.
In this case, with the aspect reproduced in the cab, I presume the engineer would only have to report the unlit lamp and proceed according to the aspect shown in his cab.
At midnight, two head signal at trackside, no lamps lit.
Does the engineer act on the cab signal alone?
Aspects different as shown trackside and in cab.
Here I would guess the engineer would throttle down to the lowest speed indicated by either aspect, including a full stop if one of the aspects indicated such.
How common are the above scenarios, and what do the operating rules call for in such situations?
I believe that when a signal fails, the engineer must assume it’s showing the most restrictive aspect. I’m not sure if that’s still the case with cab singals still working though.
Certainly makes sense. A malfunctioning signal could be more than just a burned out lamp.
There are signal problems on the Northeast Corridor several times a year. I do know all traffic on all tracks then comes to a grinding halt. Trains are then allowed to proceed only at the slowest possible speed, ostensibly operating on “visual flight rules only,” prepared to come to a full stop when any obstruction is seen. Sometimes I am on one of those trains.
I do not write from any inside knowledge or authority, just an outside observer or sometimes an unwitting and involuntary participant.
I was just wondering if movements on freight-only lines might be handled differently.
If a signal is improperly displayed, or a signal, flag, or sign is absent from the place it is usually shown, regard the signal as showing the most restrictive indication it can give. However, if a semaphore arm is visible, it will govern.
Promptly report improperly displayed signals or absent fixed signals, flags, or signs to the train dispatcher.
In NORAC country, if the locomotive is equipped with cab signals, the cab signal rules…
The presumption that most locomotives have cab signals is erroneous. Most do not. Anyway, you’ve been given the correct answer. Regard the signal as displaying its most restriuctive aspect. That doesn’t always mean “stop.” For example, it may be a signal with a number plate, and its most restrictive indication is “proceed at restricted speed.”
Very few routes across the country are equipped with cab signals.
On the former CNW East-west main line, cab signals are part of an Automatic Train Control system. GCOR (Rule 17.6) says that the cab signal indications will not supersede fixed signal indications.
However, if the cab signal changes to more favorable within the block, speed may be increased after the train has traveled its own length (also in Rule 17.6).
On the other hand, the cab signal will often remain clear when the fixed signal shows a Diverging Clear aspect (and also for the Approach Diverging in the preceding block). There, the fixed signals would govern.
I would have thought most have cab signals. Is it that those that pull passengers are required to have cab signals? If so, by whose directive?
If there is no number plate, what would be the correct procedure for the engineer to follow? Radio the dispatcher, give the location, and then follow whatever verbal instruction is given? Mile markers, too, seem to be a thing of the past.
If most locomotives do not have cab signals, do all of them have radios?
I do recall that in decades past, in the era before cab radios, call boxes were positioned along the line. If a train was disabled, a crew member, probably the conductor, had to walk to the nearest call box to advise dispatch. I don’t see call boxes anywhere these days, on Class I main lines or short lines. I presume two-way cab radios have now become the norm.
Non-cab signal territory is more common then cab signal territory.
Lead qualified locomotives, must be equipped with an operating radio, and head of train device capable of two way telemetry.
This is not necessarity a non-conforming signal. NORAC rules contain aspects for Clear, Approach and Stop Signal that have the top target lit, and any lower targets dark.
Rule 242 Imperfectly Displayed Signals
Imperfectly displayed signals must be reported to the Dispatcher as soon as possible. Imperfectly displayed signal must be regarded as the most restrictive indication that can be given by that signal. The following exception apply:
If only one indication is possible, this indication will govern. IE, the only possible signal with a high green is Clear.
If more then one indication is possible, and it can be determined that all possible indications are more favorable than Stop and Proceed, trains may proceed as though a Restricting Signal were displayed.
Rule 242 Absent Signals
If a fixed singal is absent from the place where it is usually shown, movement must be governed by the most restrictive indication that can be given by that signal. This absence must be reported to the Dispatcher immediately.
Rule 552 Conformity between Cab Signals and Fixed Signals a. Cab Signal does not comform to fixed signal:
The more restrictive signal indication will govern movement. The Engineer must notify the dispatcher as
On your two head example it would depend on which head is dark. Some indications allow a bottom head to be dark. It depends on the railroad.
Both heads or the wrong one dark would be regarded as the most restrictive indication it can give. In territory where there are both cab signals and wayside signals, the most restrictive indication between the two governs. An example would be if you have a restricting cab signal indication and you go past a clear wayside signal and the cab signal doesn’t clear up, you are still governed by the cab signal, the more restrictive of the two.
If the cab signal changes to a more restrictive indication between wayside signals, you comply with the new cab signal indication. A while back I was coming into Omaha in UP cab signal territory where the cab signal aspect went from a clear to an approach between signals. I knew the next signal was an absolute but I couldn’t yet see it on my side. I started a brake application and asked the conductor if he could see it. He couldn’t either. When it came into view, the top head was dark. It had burned out. Newer signal systems have this burn out protection. If a signal burns out, the system acts as if the signal went to red and sets the preceding signal to approach.
As Ed said, however stop train with good train handleing for me that is a full service reduction of the brake pipe, notify the dispatcher and get permission to proceed in the prescribed direction at restricted speed untill the leading wheels get by the next governing signal.
Wait for answer. Stay calm, It wont be long before the system notices your lack of progress. When it does, that signal had better be really broken.
It is my understanding that both the Fireman and Engineer must agree to the upcoming signal indication. If neither can agree there is a problem. I dont even know if this applied outside of steam at all these days.
Cab Signalling is useful when the track speed is so high that the engineer needs to understand the signal for stop with enough space and time to do something about it.
I would guess speed isn’t the only consideration. I’ve noticed some freight trains on the ex-LV to be so long they exceed a mile in length. Without question, they occupy more than one block. (I can see the next signal go red before the last car passes the signal at which I am near.) If all of those cars are loaded, which is most likely the case e/b, those trains would need lots of room to stop even if travelling at Approach Slow due to momentum alone.
The length of a train has nothing to do w/ signal aspect. If the train is 2 or three signal blocks long the signal protecting each block will show red until the last car of the train leaves that block.
As for stopping at dark signal, as stated above you regard the signal as its most restrictive aspect. In Spokane the BNSF line from Hillyard is unsignalled until it reaches Napa St Interlocking. At Mission Blvd there is an aproach signal for the interlocking that normally displays yellow and doesn’t indicate track occupancey. If that signal’s dark it can be passed at track speed prepared to stop short of next signal
At certain signals we know if we are going to crossover from one main to the other at the next Control Point when we go past an Advance Approach. If the cab signal stays Clear, we will be crossing over. If the cab signal goes to Restricting, we are either catching up to a train ahead or we are being held at the Control Point.