U.S. signaling questions?

[JWB]

Here's where it gets interesting. In the Los Angeles area, we had a bad head-on between a commuter train and a UP freight in 2008, because the engineer, alone in the cab, was (as best anyone can determine) sending text messages to a boyfriend on his cell phone and missed a red CTC signal.

 

You wouldn't believe the rail employees who started posting on the discussion boards about how stressful their jobs were now, what with people trying to keep tabs on them all the time, putting cameras in loco cabs, giving them all these darn unnecessary drug tests, putting those dang red flags up to see if they'd notice and stop the train -- after all, you flunk one of those, and you'd better consider flipping burgers for your new career.

 

Due to the head-on, the union came up with a bright idea: put a second engineer in the cabs! Boy, that was so stressful that a few weeks later, a train with TWO engineers in the cab overran a CTC stop signal and sideswiped the opposing train. You wouldn't believe the stress those guys must have been under.

 

CTC, it would appear, is in fact very, very, very, very stressful.

[F-UnitMad]

A critical thing to understand is that on single track ABS signals do not convey authority on the main track. That is, the signals by themselves do not allow the train to operate on the main track. They tell the train how to proceed...

I think that must be a key difference from UK signalling, although the second part is true of UK signals too.

[The Stationmaster]

Thanks for replies to my query - have ordered the Kalmbach book.

 

Phil,

You might also find this site useful http://www.railway-technical.com/US-sig.shtml There used to be an excellent site on the web dealing with US signalling but alas I've lost the link, I'll try to delve around for it sometime. This one used to be quite good altho' I've not looked at it for ages

http://www.lundsten.dk/us_signaling/index.html while this site used to have some excellent links http://broadway.pennsyrr.com/Rail/Signal/

[PhilH]

Thanks Mike.

[PhilH]

Very impressed! I ordered the Kalmbach book from a place in Massachusetts via Amazon Marketplace on the 28th May. It was waiting on my doormat when I got in from work today, absolutely mint as well. I don't think you can beat that for service - just love internet shopping!

 

It's going to be a useful book too, thanks again for the heads up.

[urbancohort]

In the early days of the pioneering transcontinental railway (particularly ATSF, 1870-1900ish,) what sort of signals were used please? Semaphores?

 

Thanks

 

Graham

[signalmaintainer]

In the early days of the pioneering transcontinental railway (particularly ATSF, 1870-1900ish,) what sort of signals were used please? Semaphores?

 

Thanks

 

Graham

 

Sure, a nice easy one, like a 100 mph fastball !

 

In the 1870s to 1900s west of the Mississippi, train orders and hence train-order signals predominated, and these were semaphores types.

 

Block signaling in the US had its origins in the 1870s: here's a link -- http://mysite.du.edu...ailhom.htm#hist. Interlockings came in around the same time. But both occurred in the East before the technology migrated westward.

 

As for early Santa Fe signaling, that's a bit out of my reckoning. However, the Santa Fe Railway Historical & Modeling Society may be a source of help.

[Talltim]

At a slight tangent, in the UK, drivers must have route knowledge, especially where the signals are before they are allowed to drive on their own. Is this the case in the US? If not how would an engineer know if the power to a signal had failed in the dark if they didn't know it was supposed to be there?

(I ask this because I had a conversation ages ago about specific traction (loco type not electric) knowledge in the US, and was told that it wasn't considered a prerequisite (on Guilford anyway) and route knowledge is similar)

[signalmaintainer]

Specific locomotives, not really. Route knowledge, at least in a nominal sense, yes, but not to the extent that it trumps seniority when bidding on a job.

[dave1905]

At a slight tangent, in the UK, drivers must have route knowledge, especially where the signals are before they are allowed to drive on their own. Is this the case in the US? If not how would an engineer know if the power to a signal had failed in the dark if they didn't know it was supposed to be there?

 

Route knowledge to that extent is not required on most US railroads.

 

One difference is that US roads have headlights so they can see the signal mast.

 

The ATSF used semaphores (upper quadrant) initially and replaced them with color light.

[F-UnitMad]

(I ask this because I had a conversation ages ago about specific traction (loco type not electric) knowledge in the US, and was told that it wasn't considered a prerequisite (on Guilford anyway) and route knowledge is similar)

I think I read in "The Little Jewel" by Wallace Abbey - that especially once the Soo Line was an all-EMD Road, many train crews didn't know the specific model of loco they were on, beyond it being an F, GP or SD. They just knew them by the loco number.

[rodshaw]

What's the US equivalent of shunt signals? In particular, would a small switching layout like mine, notionally based in the north east US in the 80s, need any kind of signalling on it?

 

Here's a shot of the entire layout - the track at rear right comes from a fiddle yard, all the rest are dead ends:

 

 

Thanks.

[dave1905]

Since we don't use the term "shunt signals" I'm not reall sure what they are. "Shunt" or "shunting" in the US means either switching cars or shorting the track circuits to activate signals.

 

The most you would have are switch targets which indicate whether the switch is lined for or against you move. They could be just metal blades, or lanterns (kerosene or electric) either high or low stand. They convey no permission or authority.

[Grovenor]

Since we don't use the term "shunt signals" I'm not really sure what they are.

Essentially what we call shunt signals you would call "low speed signals", ie meaning that you may proceed slowly prepared to stop short of an obstruction, interlocked turnouts will be correctly lined but the track may not be clear, usually I think the bottom arm on a 3 arm signal.

Regards

Keith

[signalmaintainer]

In particular, would a small switching layout like mine, notionally based in the north east US in the 80s, need any kind of signalling on it?

 

No wayside signals are needed at all, although switch targets would be appropriate to convey whether a switch is lined for a straight-through or diverging route.

 

Switch targets move 90 degrees as the switch is lined by hand from one route to the other.

[BR60103]

Rod: are you modelling a "one engine in steam" type of branch? That would be done with no signals at all.

[rodshaw]

No wayside signals are needed at all, although switch targets would be appropriate to convey whether a switch is lined for a straight-through or diverging route.

 

Switch targets move 90 degrees as the switch is lined by hand from one route to the other.

 

Ok, thanks.

 

Rod: are you modelling a "one engine in steam" type of branch? That would be done with no signals at all.

 

Yes, never more than one engine, coming from the fiddle yard (interchange yard?) to switch the industries.

[dave1905]

 

Yes, never more than one engine, coming from the fiddle yard (interchange yard?) to switch the industries.

 

In American practice it wouldn't really matter whether its one engine or a dozen engines, there still wouldn't be any signals.

[dave1905]

I think the difference is that switching areas are almost never interlocked. There is no tower that controls the switches in an industrial area. All the switches are "hand operated" switches, the switch crews line the switches for their movement. All of the movements are made under rule 105 which is essentially restricted speed (prepared to stop short of (list of things) not exceeding 20 mph (or some other low speed).

 

The only place there would be signals would be a siding or yard in CTC where a train could clear there might be restricting, slow or low speed into the yard and dwarf signals leaving the siding or yard. But that is not the situation here.

[Grovenor]

I think the difference is that switching areas are almost never interlocked.

Same here, the shunt signals are normally for entry or exit from Yard to main, or for moving around interlockings at passenger stations.

Some very busy major goods depots had a measure of internal signalling but the great majority of yards just relied on hand levers and hand signals.

Regards

Keith

[signalmaintainer]

Rod, food for thought. There are cases (I've seen this with the Union Pacific in Portland, Oregon, and my company, BNSF, in Renton, Washington) where a train is coming from yard/industrial trackage and will enter Centralized Traffic Control (CTC) territory. A distant signal, either fixed or active, is used to indicate to the engineer the indication of the CTC home signal at the junction.

 

So, there might be a rationale for a fixed distant signal at the entrance to your staging yard, assuming that your switching district is connecting to a mainline within a half mile or so.

[highpeak]

Since we don't use the term "shunt signals" I'm not reall sure what they are. "Shunt" or "shunting" in the US means either switching cars or shorting the track circuits to activate signals.

 

The most you would have are switch targets which indicate whether the switch is lined for or against you move. They could be just metal blades, or lanterns (kerosene or electric) either high or low stand. They convey no permission or authority.

Here's a low switch stand on the Maine Central at Brunswick in the late 70s.

And here's a high one with lanterns at Rigby yard on the Portland Terminal.

More modern ones would be a bit more ergonomic.

[dave1905]

Rod, food for thought. There are cases (I've seen this with the Union Pacific in Portland, Oregon, and my company, BNSF, in Renton, Washington) where a train is coming from yard/industrial trackage and will enter Centralized Traffic Control (CTC) territory. A distant signal, either fixed or active, is used to indicate to the engineer the indication of the CTC home signal at the junction.

 

So, there might be a rationale for a fixed distant signal at the entrance to your staging yard, assuming that your switching district is connecting to a mainline within a half mile or so.

 

An approach signal would be used where the speed on the track would be better than restricted. If a train is at restricted speed then it has to be moving prepared to stop short of a stop signal already. In many cases the approach signal will be set to only indicate approach, it will always be yellow, never red or green. I have even seen fixed signals that were a "semaphore" , a yellow blade at a 45 degr angle attached to a sign post.

 

In the case of a single stub ended switching area 1/2 half mile from the main track, I doubt that the speed would be better than restricted.

 

Where the branch enters the main there would be a signal or dwarf to enter the main track.

[signalmaintainer]

An approach signal would be used where the speed on the track would be better than restricted. If a train is at restricted speed then it has to be moving prepared to stop short of a stop signal already. In many cases the approach signal will be set to only indicate approach, it will always be yellow, never red or green. I have even seen fixed signals that were a "semaphore" , a yellow blade at a 45 degr angle attached to a sign post.

 

In the case of a single stub ended switching area 1/2 half mile from the main track, I doubt that the speed would be better than restricted.

 

Where the branch enters the main there would be a signal or dwarf to enter the main track.

And I should have clarified, the branch line in Renton has a fixed single-aspect yellow colorlight on 10 mph track leading to a CTC junction. I know that's different that what you described, Dave, but the distant signal is still extant and 10 mph is the maximum speed.

 

And as Dave pointed out, distant signals of any type, like in Britain, can never, ever be red. An active distant can display yellow or green. Just depends whether the home signal is red, yellow or green. And I seem to recall there being on the Stampede Pass one that gave a flashing yellow aspect for diverging approach medium indication.

 

Dave, somewhere in California, in the San Joaquin Valley on the old Santa Fe, there's a line with at least one or two of the type of "poor man's" distant signal you describe. Last I heard they were still in service. I believe the maintainer still had bungalows with old code generating relays. A real antique at work.

[298]

Whilst on the subject of signalling, does anyone know how this was used...?

 

 

I'll post an answer in 24 hours time if no-one's got it...