[rdamurphy]

Just to clarify a couple of points... On the Union Pacific, they've eliminated STOP & PROCEED and use RESTRICTING. Notice that's not RESTRICTED. What this means is on a previously Red permissive signal where you had to come to a complete stop, and then you could proceed, you can now pass the signal at RESTRICTING speed, usually 10 mph, prepared to stop within half the sight distance.

Reasoning is financial, and not safety. Ask any UP engineer if you want to get a long drawn out tirade about it, LOL! The reason is:

Train A is in Block 1, and has a CLEAR signal to pass another train. Train B is in Block 2 behind, and normally, it would have to stop, even though Train A is accelerating out of the block. By keeping to 10 mph through the block, it saves time, saves fuel, and saves freight damage from not stopping the train, and by the time it reaches the next signal, it will also likely have an Approach or a Clear, and can accelerate.

The problem arises when Train A has a STOP. Now you have two trains following each other in the same block, and the rear one not having any idea what the front one is doing, and having to be prepared to stop at any time. And trains don't have brake lights.

As far as different aspects, STOP will almost always be Red over Red or Red over Dark. Never a single Red, like the permissive. If it's not all red, it's not red at all.

Robert

[Jovet]

rdamurphy, on 01 February 2013 - 07:17 AM, said:

As far as different aspects, STOP will almost always be Red over Red or Red over Dark. Never a single Red, like the permissive.

Errrr, that's not true, Robert. A single Red for Stop is very common in the United States, especially in this day and age, and especially on route-signaled railroads (BNSF, UP). There are many railroads that practice a more-than-lone-Red-for-Stop philosophy, but it's far from universal. On the other hand, permissives may be Red over Red over Red for Stop and Proceed or Restricted Proceed or whichever applies. CSX comes to mind, where a permissive signal may need to show Approach Slow (Yellow over Red over Green) and thus it will require three signal heads.

[rdamurphy]

OOOPS, you're right. A single Red can be STOP. But if it's modified, by a plate or additional light, such as the Lunar in your example, it becomes "less than" STOP.

However, the rule of thumb still applies. "If it isn't all red, it isn't red at all."

A red with a Gradient Plate is Restricting, a red with a number plate is Stop & Proceed, two reds and a non-red is less restricting. Even in your CSX example, the double reds are modified by a plate or a third head. There's a good example out West, also, a Yellow over Yellow Diverging Approach will display red over red when it's indicating Restricting, but again, it has the number plate to modify it.

It's actually a good thing that MSTS included the plates, since in real life, they're actually equivalent to a signal head. Some D&RGW signals actually have a dummy signal head to modify the indication. They don't even have lenses.

Robert