• Dark Signals

  • General discussion about railroad operations, related facilities, maps, and other resources.
General discussion about railroad operations, related facilities, maps, and other resources.

Moderator: Robert Paniagua

I will try one last time. The dudes picture DOES back up, exactly what I said, though. If there are three signals, in a row, numbered 1, 2 and three, and they are approach lit, 1 would be lit, for a train headed towards three. As soon as the loco crossed over the I J, at 1, it would then light 2, which might be as far away as 10 miles, or as close as several hundred yards. As the train approached 2 (and saw it's indication) it would cross the I J at 2, as it headed towards 3. When the I J is crossed, 3 would then light up. This goes on, as long as there are signals in the approach lit territory, and the train is moving. Signal 1 prepares you for what you might see, at 2. 2 prepares you for 3, and so on. As stated already, a "dark" or absent signal must be interpreted as the most restrictive indication, that signal is capable of indicating. If you are running 60MPH, on a clear indication, and you round a curve and find a dark, or missing signal, you must stop, as soon as possible, consistant with proper train handling techniques. You don't need to see multiple signals at once, to understand what's in store for you, at the next signal. A clear will lead you to a clear, approach, or variation of approach. You won't get a restricting, or stop, from a clear signal, unless something has gone very wrong, or the "weed weasels" are about :wink: An approach will most likely lead to a restricting, stop, or possibly another variation of the approach. (if you are following another train, you might see a clear, but you should never expect it. Be prepared to stop) You don't need to light every signal on the line, for a train dozens, or hundreds of miles away. No opposing traffic? No reason to light opposing signals, until the block is occupied. (by you) It's really all very simple. Regards :-D

As the train exited the tunnel, and passed the signal, it then lit up, as it was now in the block, where the signal would need to be seen from. The "system" doesn't care which direction you are moving in, only that the block(s) are occupied. Sometimes "Home" signals, or Interlocking signals, stay lit regardless. Sometimes they don't. Depends on the location, and signal system in use. Regards :-D

  by conrail_engineer
G-A is exactly correct. On most systems' wirings...ONLY the signals ON THE OCCUPIED BLOCK are lit. In other words, a train is entirely on one block...all the signals, both directions, on that block will be lit. In the past and preceeding blocks, the signals will be dark, unless standing equipment or a ground fault shunt the track on that block.

So, a person standing by a signal mast FACING an approaching train will see a dark signal UNTIL that train passes onto the block circuit. From a railfan standpoint it may seem unsafe to persons around. But from a railroaders' perspective TRESSPASSING is unsafe :wink:

There are exceptions to this. Common on some parts of CSX are signal systems where the wayside signals are ALWAYS lit. Also, not so common, are signals that are lit up one block advanced and behind.

It really is not unsafe, even though I know many railroaders are suspicious. We trust the signals to tell us whether the block ahead is occupied. Why wouldn't we trust the signals to tell us OUR OWN block is occupied, by lighting up?

As to the other: Switches are NEVER lined by hand except by authority and direction of the dispatcher. Train crews do NOT have the authority to route their own trains this way.

  by CROR410
G-A, thanks for your explainations, it actually cleared a misunderstanding I had.