North American semaphore signals

[Marmight]

I always thought that North American semaphore signals were placed on the opposite side of the track to UK signals and that they faced the same way. In other words the coloured side faced oncoming traffic and the white side with black line faced the rear of the signal. I’ve seen a few pics recently where the coloured side seems to be opposite to oncoming trains, ie, the white side is facing the train. Does this mean that this set up is for either way traffic on the same track? I’ve got a lovely semaphore that I want to put on the layout, but I want it to be correct. Any help would be grateful.

Cheers,

Martin

Edited November 22, 2021 by Marmight

[mdvle]

My knowledge of signals is close to zero.

 

But I would guess it would the same rule everywhere - you want the coloured side facing the relevant train so it would be most visible.

 

And generally you should be correct that the signal is on the right side of the track - engineers (aka drivers) on North American trains are on the right side of the cab.

 

 

Edited November 23, 2021 by mdvle

[dave1905]

Correct, the convention is that the colored side faces the oncoming train and they are generally (but not always) placed to the right.

 

By the way, in the majority of US rule books, the signal shown above cannot display a "Stop" signal.  The most restrictive it can display is "stop and proceed", the number plate makes it a stop and proceed signal, a train would stop at the signal and then proceed at restricted speed, prepared to stop short of train, engine, obstruction or switch not properly lined, looking out for broken rails.  Generally they are intermediate signals, that is signals between sidings.

Edited November 23, 2021 by dave1905

[Marmight]

Thanks Dave. Just curious as to why there are three aspects to the signal. My UK mindset would have though it would have been red = stop, amber= caution and green = proceed. Mind you, the American signal code seems to change for every road that operates. Must be a nightmare for engineers. 
cheers

Martin

[uax6]

Pedant mode <on>

Signals here in the UK do not display Amber aspects. They display Yellow aspects. Road traffic signals display Ambers....

 

Pedant mode <off>

 

Andy G

 

 

[dave1905]

4 hours ago, Marmight said:

Thanks Dave. Just curious as to why there are three aspects to the signal. My UK mindset would have though it would have been red = stop, amber= caution and green = proceed. Mind you, the American signal code seems to change for every road that operates. Must be a nightmare for engineers. 
cheers

Martin

 

Red - Stop and proceed - Stop and proceed at restricted speed 

Yellow - Approach - Reduce speed immediately to 30 mph and be prepared to stop at the next signal

Green - Clear - Proceed

 

This is normally an intermediate signal, so there are no switches or rail crossings or derails involved.  It's just a signal alongside the track.  It doesn't give authority to operate on that track, something else does (train order, schedule, track warrant, CTC signal, etc.)  All it's doing is relaying track conditions, is something happening in the two intermediate blocks ahead of it.  On a real railroad, it can be red for any number of reasons.  There could be a train (which would require a failure on the part of another train or the dispatcher), it could be a car rolled out of a track, it could be a switch open on the main, it could be a broken rail, it could be a "bond" wire connecting the individual rails broken, it could be there was freezing rain and the ice broke a signal wire on the pole line, it could be the wind was really strong and caused the wires on the pole line to wrap around each other, or even somebody has stolen or cut a signal wire on the pole line. 

 

Yes, individual railroads had their own take on signals, but then engineers were hired on one railroad and tended to operate on that railroad their entire career.  When you pass the same signals every day for a 30 year career, it's not too confusing.  Modelers tend to look at a bunch of sources (often not even one for the railroad they are modeling) and get confused.  There are also signals for higher speed operations that some railroads didn't use because frankly they didn't operate at those speeds.  As mergers happened railroads had to absorb the signal systems of the railroads they acquired, so the signal rules became more complex.  However, from the standpoint of the crews, if their territory only used 10 aspects before the merger, they will only use 10 of the now 20 aspects after the merger.

The complexity comes when crews run over new territories (change working areas) or get trackage rights over other railroads.  But they have to get qualified on those territories before they can run on them.  That entails making several student trips (or in the modern world, runs in a simulator) over the new territory.

Edited November 24, 2021 by dave1905

[Marmight]

Dave, thank you! Brilliant explanation of how they work. What would normally be written on the plate? 
 

Cheers

 

Martin

[Marmight]

6 hours ago, uax6 said:

Pedant mode <on>

Signals here in the UK do not display Amber aspects. They display Yellow aspects. Road traffic signals display Ambers....

 

Pedant mode <off>

 

Andy G

 

 

Hmm,

Smug mode <on>
 

maybe it’s a good job I’m talking about American Signals then!

 

Smug mode <off>
 

 

[dave1905]

9 hours ago, Marmight said:

What would normally be written on the plate? 

 The signal number, typically a 4 digit number, the first three being the milepost and the last the signal number. 

 

Here is a picture of an SP semaphore signal.  It would be near milepost 507. 

Picture from :  Railroad Signals (USA): Explained, Meaning, Examples (american-rails.com)

 

Edited November 25, 2021 by dave1905

[russ p]

There were some US type three position semaphores in this country installed by the GCR near Scunthorpe I believe.  Not sure when they were abolished 

[Marmight]

12 hours ago, dave1905 said:

 The signal number, typically a 4 digit number, the first three being the milepost and the last the signal number. 

 

Here is a picture of an SP semaphore signal.  It would be near milepost 507. 

Picture from :  Railroad Signals (USA): Explained, Meaning, Examples (american-rails.com)

 

Brilliant once again. 
Thanks Dave.

[Marmight]

8 hours ago, russ p said:

There were some US type three position semaphores in this country installed by the GCR near Scunthorpe I believe.  Not sure when they were abolished 

That’s very interesting Russ. Just goes to show there really is a prototype for everything.

Cheers

 

Martin

[Regularity]

9 minutes ago, Marmight said:

That’s very interesting Russ. Just goes to show there really is a prototype for everything.

They were used to combine distant and home signals into one arm, like a 3-aspect colour light signal (which the glasses in front of the lamp would display): stop (horizontal), caution (45 degrees) and clear (vertical). As 45 degrees or so was used elsewhere to indicate clear, this could get confusing.

The example above is related to train orders, etc, so not the same use, but similar looking.

[roythebus1]

I think various LT lines used 3 position semaphores in the early days.