What does the red, green, yellow light along a track mean, I know it is a signal for the engineers but forwhat

Question

Now that they started a coummuter rail service in our area they had to install signals along the tracks where only freight trains would run before. It is one light that changes colors: yellow, red, green.

Answer 1

Train tracks are set up in "blocks" - like a mile or so; depends on the area, etc.

Green is nobody in the NEXT block.

Yellow is train in the NEXT block that's (typically) going in the same direction.

Red is train is IN the SAME or NEXT block -- S T O P!!

A train can not pass a red signal, and can leave block it's in when the signal turns yellow, but will maintain a slower speed.

Answer 2

JUST LIKE HOW WE DRIVE OFF SIGNALS OFF THE STREET. WE MOVE TRAINS THE SAME WAY. A DISPATCHER WILL LIGHT THE SIGNALS UP FOR US AND THAT WILL LET US KNOW WHERE WE MIGHT BE GOING. THE ONLY DIFFERENCE IS THAT THERE ARE A LOT MORE SIGNALS THAT WE RUN OFF OF.

Answer 3

Green means the track is clear red means there's a train coming I'm not sure about yellow, maybe it means it's in the process of switching.

Answer 4

It's for traffic control, like the highways, but it works a little differently because trains are so darn hard to stop.

So they cut the railroad into "blocks" a mile or two long.  At the entry to each "block" is a signal, and it says whether the blocks ahead contain a train.  

"Red" means there's a train in the immediate block following.  You better ALREADY be going slow when you come up on this one, or you'll skid right into the train that's in the block.   How do you know!?

Enter Yellow.  This says the immediate block ahead is clear, but the next signal is most likely red, i.e. the next block most likely contains a train.  You better set some brakes!

Now, some of the more studly railroads also have Flashing Yellow.  That means the next signal might be yellow.  

And as you can guess, Green means it's all clear ahead.

Watching the masters at work is amazing.  I've sat out on the Conrail mainline through northern Ohio and watched the parade,   freight after 100 car freight tear by westbound at 60 mph.  A train knocks the west signal to red... we look east and there's another freight coming up fast.  West signal flips to yellow as the next freight tears by us. 9000 tons, 60 mph straight at a yellow signal.  Closer, closer... will that signal turn green?  Closer... BLAM! It turns green, and the train knocks it red.  You can bet the freight crew was watching it even closer than we were.

Every once in awhile a freight gets caught and gets to the signal before it turns green. But not often. Those guys are good.

Some railroads use different indications (ways of showing the signal.  For instance, many railroads use 2 signals, a yellow over a greeen, to indicate flashing yellow. A rare few still  use mechanical semaphores, http://www.semaphores.com/ verticlal is like green, diagonal is lile yellow, horizontal like red.  And some use position-lights, where there are 2-3 lights vertical, diagonal or horizontal like semaphores.

Answer 5

It's not quite as simple as traffic signals and there are slight variations form one RR to another. Basically green means go of course. Yellow means be prepared to stop before the NEXT signal. Red usually means stop but in some cases it means proceed at a restricted speed looking out for obstacles.

Answer 6

Signaling rules vary between railroads somewhat, BUT... most rail signals are base on BLOCKS of track.

The signals are as a road SHOULD be... Green means the block is clear and you can go, Yellow means proceed at reduced speed, and Red means STOP.

I've used these links when working on building my Model Railroad:

http://www.trainweb.org/signals/

http://www.lundsten.dk/us_signaling/inde...

Answer 7

Hoghead has it down. I'm a railroad conductor, and it's people like him I like to work with. Very thorough, and knows the common signals and the uncommon ones just as well. (Hoghead is a slang for engineer)

Answer 8

its the same thing for trains as it is for streets....red=stop green=go and yellow=slow

they have to follow traffic laws as well....they have to slow down when they come into a residential area and sometimes have to stop...they won't know unless they have signal like we do...it takes a train waaay longer to stop than it takes a car...so they have to know miles ahead of time that they have to stop.

Answer 9

If you come along and see a signal that's red and it has a number plate on it, that is an intermediate signal & means restricting, restricted proceed, or stop and proceed (different railroads call it differenlty but it means the same thing), when a train comes to this kind of signal it doesn't have to stop but it has to proceed at a restricted speed (between 15 mph-30 mph) because the block you're entering is occupied by another train that is hopefully going the same direction as you..lol!

If you see a signal that displays red and has no number plate, that is called a home signal and that means STOP! If you run past it, the dispatcher will see it on his computer and you will be relieved of your duties (fired). Major rule violation right there

A yellow signal, means you can proceed at reduced speed preparing to stop short of the next signal. Most crews acknowledge this signal as approach. Example "NS 227 has an approach signal at milepost 56.2 north out"

A green (clear signal), of course means proceed at authorized track speed. Now even though that signal is green, it doesn't mean the next one is, on the railroad you have to think miles ahead and not just think about what is right out in front of you. Most railroads do not acknowledge a clear over the radio, they only acknowledge anything restrictive but Norfolk Southern does, they have to acknowledge every signal they come upon.

Some railroad lines do not have signals so they have to use what is called Track Warrants or Track Authorities. Dispatcher calls them out over the radio, and the crew copies it down on a form and repeats it back over the radio. They give a train permission to proceed from one point to another, and gives them info on things such as other trains they will meet and speed restrictions along the way. Once a train gets to a point and it hasn't received any more warrants then it CANNOT proceed until it receives another. Also, dispatchers cannot "see" the train on their computer like they can on a line that is signaled, so trains every so often have to report to the dispatcher their location so the dispatcher can issue a following movement a warrant up to the point where the train notified it's rear end was last at. Confusing? Thought so..lol

Also, Hoghead mentioned many more signal aspects. Restricing, Stop, Approach, and Clear are only the basics. Past those, the signals become increasingly harder to memorize, so often some have to study up on their signals! Like me!..lol

Answer 10

Green  =  proceed

Flashing Green  =  reduce to 60 MPH

Flashing Yellow  =  reduce to 40 mph

Yellow  =  Immediately reduce to 40 mph and be prepared to stop short of the next signal

Yellow Over Yellow  =  Prepare to advance on diverging route not exceeding the speed thru the turnout

Red Over Green  =  Proceed on diverging route



Red Over Yellow  =  Proceed on diverging route prepared to stop short of the next signal

Red Over Lunar  =  Proceed on diverging route at restricted speed (A speed that will permit stopping within one half the range of vision, short of train, railroad car, engine, derail or switch not properly lined or other obstruction and looking out for broken rail, not exceeding 20 mph)

Red Block Signal  =  Stop and proceed at restricted speed

Red Controlled Signal  =  Stop  (Controlled signals are found in CTC and Interlocking Limits.  As their name implies, a train dispatcher can 'control' which aspect (color) a signal will display.  When displaying a red aspect, the train dispatcher's  permission to pass the signal must be obtained before proceeding).

Blue  =  Men working

Sometimes signals are wired with some sort of a protective device, such as a high wide detector, slide fence, high water, collision detector, etc.  These are identified with a triangular plate baring the letter "P".  In these instances, an inspection of the protective device must be made from the ground before proceeding.

Sometimes, there may be two or more diverging routes involved.  Here, one may find a red over red over yellow, or green, or so on, often with multiple tracks side by side, with these signals mounted on a signal bridge over the tracks.  It can be quite confusing until one is familiar with the territory.