Cab signals are supposed to conform to the wayside signal after passing it. If it doesn't (some specific exceptions due to some forms of cab signal that are railroad specific) for two consecutive blocks, the cab signals are defective. I think all the rule books that I have, collected and issued to me, have a rule similar to that.
Here's what the first sentence of Rule 551 ( Penn Central 1972 Rules for Conducting Transportation) reads. "The Cab Signal system is interconnected with the fixed signal system so that the Cab Signals will conform with the fixed signal indication within 8 seconds after the engine passes fixed signal governing the entrance of the engine or train into the block in the direction for which the track and engine are equipped and will be governed as follows:" It goes on for 9 items, a thru i.
One night a few years ago, we were mid-block. The next signal was a two headed absolute at a controlled crossover. We were running on clear a cab signal and wayside when the cab signal went to an approach, skipping the advance approach aspect/indication. This was unusual. "Dead" or de-energized track results in a Restricting aspect/indication. It isn't unusual to have short, momentary spots of dead track. I immediately asked the conductor if he could see the next signal. I couldn't because of a bridge structure and vegetation. He couldn't either so I immediately started slowing down to be prepared to stop at the next signal. When it came into view, the top head was dark. Either the green or yellow bulb had burned out and the "burn out" protection circuitry changed the block condition. We stopped, contacted the dispatcher and reported the dark signal head. Then he flagged us by it.
Jeff
PS. DP units can occasionally pick up a stray signal when the cab signal is left cut-in. There are instructions to make sure the cab signal is cut-out on DP engines.
DSO17We must be talking about two different things.
How they work on today's locos is unknown to me. Even though the cabsignals were taken out, we still had problems at times with a cab signaled loco picking up a stray signal and putting the train into penalty.
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BRAKIEI'm confused. After we passed that approach signal the cab indication went from approach to a absolute stop at Mounds and the engineer stopped at the required distance from the red block at Mounds.
We must be talking about two different things. The only PRR cab signals I ever saw had four aspects - Clear, Approach Medium, Approach, and Restricting. There was no Stop aspect.
I'm confused.
After we passed that approach signal the cab indication went from approach to a absolute stop at Mounds and the engineer stopped at the required distance from the red block at Mounds.
Larry
Conductor.
Summerset Ry.
"Stay Alert, Don't get hurt Safety First!"
BRAKIEHere's a example..We went through a clear signal and the cab indicator went from clear to approach and the next signal displayed that approach indication.
Here in the east, the cab signal displayed the condition of the block you were in. If the cab signal dropped from clear to approach while you were in a block you would expect to find the next wayside at stop and proceed if it was an automatic signal or something "worse" than approach if it was an interlocking signal or a distant signal for an interlocking.
If a cab signal changed to a more favorable indication in a block (say from approach to clear) you could take the more favorable indication after the train had run its length from the point where the cab signal went up.
DSO17In the 1960's and 1970's east of Harrisburg the PRR cab signals displayed the condition of the block you were in. The way side signals displayed the condition of the block ahead.
Interesting because we already passed our last signal and knew what the signal was for the block we was occupying.
Are you talking about the next block signal?
Here's a example..We went through a clear signal and the cab indicator went from clear to approach and the next signal displayed that approach indication.
BRAKIE jeffhergert The difference between a wayside signal and a cab signal is this. The wayside signal indicates the condition of the block you are about to enter. The cab signal indicates the condition of the block you are already in. Jeff,Did that change over the years? On the PRR and C&O we knew what the next signal was before we reached it. From the horror stories about peeking tommies watching every move to ensure the ever changing rules was being followed I'm surprise you got by stopping to close to the signal bridge.
jeffhergert The difference between a wayside signal and a cab signal is this. The wayside signal indicates the condition of the block you are about to enter. The cab signal indicates the condition of the block you are already in.
Jeff,Did that change over the years? On the PRR and C&O we knew what the next signal was before we reached it.
From the horror stories about peeking tommies watching every move to ensure the ever changing rules was being followed I'm surprise you got by stopping to close to the signal bridge.
In the 1960's and 1970's east of Harrisburg the PRR cab signals displayed the condition of the block you were in. The way side signals displayed the condition of the block ahead.
jeffhergertThe difference between a wayside signal and a cab signal is this. The wayside signal indicates the condition of the block you are about to enter. The cab signal indicates the condition of the block you are already in.
BRAKIE 7j43k Which does get me to wonder/ask, at what point, approaching a signal, does it become impossible to see the indication. With a semaphore, you can actually look backwards. But with lights, I wonder how close you can get to "being alongside", and still read the indication. This could have some implications for his comment and siding length. Ed,Every locomotive cab I rode in had signal indication box located on the engineer's side plus we would acknowledge the signal indication by saying the following: Engineer:Proceed or whatever the signal indication was. Head brakeman or fireman would repeat: Proceed or whatever the signal indication was.
7j43k Which does get me to wonder/ask, at what point, approaching a signal, does it become impossible to see the indication. With a semaphore, you can actually look backwards. But with lights, I wonder how close you can get to "being alongside", and still read the indication. This could have some implications for his comment and siding length.
Ed,Every locomotive cab I rode in had signal indication box located on the engineer's side plus we would acknowledge the signal indication by saying the following:
Engineer:Proceed or whatever the signal indication was.
Head brakeman or fireman would repeat: Proceed or whatever the signal indication was.
Not all engines are equipped with cab signals. Almost all the engines I ride in have them, but then I also work in cab signal/automatic train control territory. Leaders in such territory (there are limited exceptions) have to have them. The difference between a wayside signal and a cab signal is this. The wayside signal indicates the condition of the block you are about to enter. The cab signal indicates the condition of the block you are already in.
I think all rule books (at least "modern" ones) have a rule requiring stopping a set distance from a signal or clearance point at meeting or waiting points. (Ours is 400 feet) However, most include the passage, "when train length permits" or words to that effect. Meaning if the siding is 5000 ft and your train is 4800 ft, you don't have to stop 400 ft back and then pull up.
I once was stopped close enough to a signal bridge where, because of sunlight on the color aspect signal head, I couldn't tell the aspect of the signal from the cab. (The dispatcher needed us to try to clear a switch behind us to let MOW equipment clear up.) I went to the back of the unit, but still couldn't tell for certain which aspect was displayed. I ended up asking the dispatcher to flag (give us verbal authority to pass the signal) us by the signal. He said his board showed us lined, but gave the verbal authority past it.
cx500If he is so close to the signal that the angle is too great to see the indication, but still stopped before the insulated joint, the solution is simple.
Not so simple because he is in violation of passing a restricting signal (in this case a absolute stop) even if he didn't trip the detector..
There are operating and safety rules that must be obeyed.
cx500 If he is so close to the signal that the angle is too great to see the indication, but still stopped before the insulated joint, the solution is simple. The conductor can get down on the ground, or perhaps into the second unit, and watch for it to change. Doesn't have to happen right away; wait until the train he's meeting has passed and the switch relined.
If he is so close to the signal that the angle is too great to see the indication, but still stopped before the insulated joint, the solution is simple. The conductor can get down on the ground, or perhaps into the second unit, and watch for it to change. Doesn't have to happen right away; wait until the train he's meeting has passed and the switch relined.
The CGW had rules as to how far from a signal a train had to stop. I would assume most other railroads did as well.
7j43kI was thinking more of when the engineer is creeping up on the signal. Seems to me if he goes too far and then stops, he can't see when it goes green.
Ed,If he does he's fired or if he is lucky gets a unpaid vacation or like Dave said gets decertified.
On today's railroads he's removed from service and fired.
Thanks Dave,
Very interesting comments.
For some reason, this topic reminds me of a video I've seen, taken forward from a locomotive cab. In the distance, a siding with a train comes into view. As "we" get closer, you can see the other train slowly coming forward. More and more. And then we hit it. I've wondered "Why?". Here's a possibility.
Ed
7j43kWhich does get me to wonder/ask, at what point, approaching a signal, does it become impossible to see the indication. With a semaphore, you can actually look backwards. But with lights, I wonder how close you can get to "being alongside", and still read the indication. This could have some implications for his comment and siding length.
Remember the signals are driven by track circuits, which are tripped by the wheels on the track. If you pull up where the engineer is even with the signal, 99.999% of the time that puts at least one axle PAST the signal which automatically trips the signal to drop to red. In studies of why engineers were being decertified for passing a stop signal without authority, we found that a major cause was engineers trying to "stop on a dime" and the slack or the ability of the train to brake didn't cooperate.
Most engineers stop several car lengths back from the signal just in case the slack runs in it won't shove them past the signal. Several engineers that have pulled up too close have been fired when the slack runs in (or out) and shoves them forward.
You also have to realize that train length is an approximation, a train can be longer if the slack is stretched or shorter if the slack is bunched. Having worked in a dispatch office, any dispatcher who puts a 7000 ft train in a 7001 ft siding is asking for trouble. Most dispatchers allow a couple hundered feet extra, plus if you have to cut a crossing that makes the train anywhere from 400-600 ft longer.
Dave H. Painted side goes up. My website : wnbranch.com
BigDaddy 7j43k Which does get me to wonder/ask, at what point, approaching a signal, does it become impossible to see the indication. The signal has to be visible in time for the train to stop.
7j43k Which does get me to wonder/ask, at what point, approaching a signal, does it become impossible to see the indication.
The signal has to be visible in time for the train to stop.
I was thinking more of when the engineer is creeping up on the signal. Seems to me if he goes too far and then stops, he can't see when it goes green.
I was wondering how far "too far" is.
Seems to me signals don't shine sideways all that well, over to the guy parked right next to one.
And I'm leaving out cab indications, 'cause in the olden days they weren't that common.
7j43kWhich does get me to wonder/ask, at what point, approaching a signal, does it become impossible to see the indication.
The signal has to be visible in time for the train to stop. Line of sight from the cab to the signal is not the critical distance, unless the engineer is not paying attention as in the 1987 Amtrak Chase MD wreck.
Henry
COB Potomac & Northern
Shenandoah Valley
I would think that "siding length" would be the length of track measured between the points where the distance between the rails of the two tracks starts to lessen in anticipation of the siding rejoining the main.
And, following Brakie's point, that distance could be lessened by shortening the siding length to the distance between siding signals, if there are any.
Which does get me to wonder/ask, at what point, approaching a signal, does it become impossible to see the indication. With a semaphore, you can actually look backwards. But with lights, I wonder how close you can get to "being alongside", and still read the indication. This could have some implications for his comment and siding length.
BRAKIE Signal to signal from my experience since you can not pass a stop signal to the normal fouling point which and IMHO why to close for a meet.
Signal to signal from my experience since you can not pass a stop signal to the normal fouling point which and IMHO why to close for a meet.
That makes sense to me, if the siding has a signal.
kingcoal Clearance point including signals, if applicable, is UP practice.
Clearance point including signals, if applicable, is UP practice.
That's what I figured. It seems like the most logical answer. I've wondered about this for some time; I finally got around to asking!
Thanks!
When a siding is measured in feet (as opposed to the number of cars), where is it measured from? Is it measured from the switch point(s) or the clearance/fouling points?