I commend you for finally doing some research. You didn’t get it quite right though: what you found is not “rule 291 for a stop signal.” If you thought about it, you’d realize that doesn’t make sense: why would one signal have two meanings? How would the railroad operators know which meaning applied in a given case?
The appearance of a railroad signal is called its aspect. The meaning of the signal is called its indication. For historical reasons, each indication corresponds to a numbered rule. Simply put, the list of signals is found in a document called a “rule book.” Rule 291 is the indication numbered 291 in the rule book. The indication is, “stop, then proceed.” Rule #292 is just plain “stop.” There is a different aspect for the two rules; they are NOT interchangeable. When the novel states that they obeyed a signal to STOP, we know that it wasn’t a signal to STOP, THEN PROCEED, because if it were, they’d already be proceeding.
I never said that, so you’re still not reading carefully. I said that in any given situation, ONE AND ONLY ONE signal will present the aspect with the STOP indication. That signal may or may not be protecting a switch, but the signal with the STOP indication is the last one before whatever it is you’re stopping for. Other signals may or may not be present before the one with the STOP indication. Those signals will NOT present a STOP indication. They may indicate “stop, then proceed,” or “be prepared to stop,” or “proceed, half speed,” or even “all clear.” But they will not indicate STOP; only one signal will indicate STOP.
This would all be clear if you realized that railways use block signaling. To prevent collisions, the network of rails is divided into blocks, and (in its basic form) only one train is allowed to occupy a block at one time. A STOP signal serves primarily to exclude a train from an occupied block (and occasionally other safety purposes). It serves no purpose to put another STOP signal further up the line, because trains are required to stop at the first STOP signal, and therefore will never see the next signal. You might think it prudent to “put another STOP signal further up the line, in case they missed the first one,” but that’s not how things were done. To signal a train to stop, ONE signal is set to the aspect indicating STOP. If that signal is visible from far enough back to permit the train to stop, there are usually no other signals. Otherwise–for example, on a curve–that signal will be protected by other signals, and those signals will be set to “prepare to stop,” or “proceed medium speed,” or “proceed slowly,” or “stop then proceed,” as the case may be, to ensure the train is able to stop when it reaches the STOP signal.
If you value objective thought, then you won’t cherry-pick facts to try and bolster a foregone conclusion. You’ll actually find out the correct facts, whether or not they agree with your original position. Taking that to heart will make you a better Objectivist.
–Len.