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Why did Amtrak choose position color lights?

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Posted by timz on Monday, May 23, 2016 12:22 PM

Retired Trainman
PRR used CPL in the East River and Hudson River tunnels

Color-light signals, you mean, not color position-light.

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Posted by daveklepper on Monday, May 23, 2016 12:41 AM

Not initially, if memory is correct.  Had front platform rides as a youngster on LIRR MP54s under the East River and  PRR MP54s under the Hudson, and I recall standard three-lens color-light signals during WWII, not position lights.  The reason given was that tunnel clearances would not permit the standard pure PRR position-light signals in the tunnels.  I recall being surprised and even shocked by the whistle at the first yellow just before entering the throat to Penn Station on my first front-plaform ride returning to Manhattan from the 1939 Worlds Fair, age 7-1/2.  There was the standard PRR automatic train stop and an approach to speed control, of course, and if the engineer had acknowledged the yellow well before passing the signal, the whistle would not have blown, I think.   If had not made a brake application right after the signal, automaic stop would have been effectuated automaticallly, with a full serice brake application.

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Posted by Retired Trainman on Saturday, May 21, 2016 3:57 PM
PRR used CPL in the East River and Hudson River tunnels
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Posted by k9wrangler on Monday, May 16, 2016 4:26 PM

Amtrak is not using color position lights along the Michigan line they are redoing for 110.  All new, extremely bright, LED lights with GRN/YELLOW/RED are in place at least as far East as Jackson, MI along the old NYC.  The old signals were searchlight style with internal color changes left from the New York Central/Penn Central/Conrail heritage of the line.

 

Karl Scribner

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Kentucky Southern Railway

RME
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Posted by RME on Sunday, May 15, 2016 4:46 PM

I didn't mean to imply LIRR used the red lights, but rather that it was N&W that I recalled using color in "PRR style" position lights to add the reinforcement of color to the stop indication.  Subsequent posts established that PRR had the same approach for a few years in the '50s... but certainly that didn't get applied 'everywhere'.

I cannot recall anything but pale yellow in any position light in the New York area the whole time I was there -- including many places on the Island.

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Posted by aegrotatio on Friday, May 13, 2016 12:52 PM

RME

The Amtrak CPLs don't have (or need) a center light, and it was N&W (not LIRR) that had some PRR-style position lights that used color (red) to emphasize a 'stop' aspect.

 

I never said LIRR had color lights, just that they are happy with the old PRR position lights.

 

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Posted by timz on Tuesday, May 10, 2016 4:28 PM

Position-lights around the Newark NJ station were still traditional PRR monochome (no red) in 2008 at least. Most (maybe all) the PRR position-lights between NY and Washington were monochrome until 1990 or so. (Including the ones at some/all the new 1980s interlockings-- Menlo and Iselin at least. Phil too?)

How about LIRR-- does it still have lots of monochrome position-lights?

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Posted by Buslist on Tuesday, May 10, 2016 10:28 AM

Electroliner 1935

PRR's CPL's as noted above were all yellow in the fifties when I started in the Signal and Communications Dept. By the early 60's the two lens's in the stop indication 3 and 9 oclock positions were being changed to red and the center lamps were being rewired to be dark for the stop indication. All the other lenses stayed yellow. Did the PRR CPL's ever have green lens's in the 6 & 12 oclock positions for a clear indication? I don't think they did. B&O had red, yellow and green lenses on the main head and white lenses on the auxiliary heads. 

 

It's my understanding that sometime in the 50s the ICC declared that all absolute signals display a red aspect when displaying a stop indication. Of course the 3 horizontal yellow light aspect of PRR's PL signals didn't meet that criteria. The problem was solved by changing the lenses in the 3 and 9 o'clock positions and extinguishing the center light as described above.

 

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Posted by oltmannd on Tuesday, May 10, 2016 8:42 AM

timz

That would surprise me too. Did the 1967 N&W rulebook include color position-light aspects?

PRR started trying red-for-stop position-lights around 1955, but I'm guessing no PRR position-lights were full color until Amtrak started converting them between NY and Washington-- around 1990?

 

My recollection is that Conrail standardized on red for stop at home signals pretty early on.  

-Don (Random stuff, mostly about trains - what else? http://blerfblog.blogspot.com/

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Posted by BaltACD on Saturday, May 7, 2016 1:40 PM

RME
BaltACD

Only some of them did -- I think a relatively small number of 'some'.  (Where are remaining CPLs with this aspect?)

For those who are wondering, the lunar white aspect was 45 degrees left, in the two positions normally unoccupied in a CPL main head.

Remember also that lunar white was an essential part of a NONrestricting aspect on B&O, as the center upper marker had to be 'on' for a green main aspect to be taken as authorizing any speed greater than slow.

B&O had a number of non-signalled directional sidings on their double track territory.  The Lunar White (Restricting) indication was displayed at interlockings for entrance to those sidings.  Additionally, in non-signalled TTTO territory, the Lunar White indication was displayed as the Distant signal to interlocked railroad crossings at grade.  The Pilot Lights (the marker lights above/below and/or to either side of the Main Head were not lunar white - they were plain white.

As info - the B&O CPL's at Mexico and West Hump control points at Cumberland are being replaced this weekend.

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Posted by RME on Saturday, May 7, 2016 9:49 AM

BaltACD
The B&O main signal head also displayed Lunar White, when displaying a Restricting indication.

Only some of them did -- I think a relatively small number of 'some'.  (Where are remaining CPLs with this aspect?)

For those who are wondering, the lunar white aspect was 45 degrees left, in the two positions normally unoccupied in a CPL main head.

Remember also that lunar white was an essential part of a NONrestricting aspect on B&O, as the center upper marker had to be 'on' for a green main aspect to be taken as authorizing any speed greater than slow.

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Posted by BaltACD on Saturday, May 7, 2016 3:35 AM

Electroliner 1935

PRR's CPL's as noted above were all yellow in the fifties when I started in the Signal and Communications Dept. By the early 60's the two lens's in the stop indication 3 and 9 oclock positions were being changed to red and the center lamps were being rewired to be dark for the stop indication. All the other lenses stayed yellow. Did the PRR CPL's ever have green lens's in the 6 & 12 oclock positions for a clear indication? I don't think they did. B&O had red, yellow and green lenses on the main head and white lenses on the auxiliary heads. 

The B&O main signal head also displayed Lunar White, when displaying a Restricting indication.

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Posted by Electroliner 1935 on Friday, May 6, 2016 3:07 PM

PRR's CPL's as noted above were all yellow in the fifties when I started in the Signal and Communications Dept. By the early 60's the two lens's in the stop indication 3 and 9 oclock positions were being changed to red and the center lamps were being rewired to be dark for the stop indication. All the other lenses stayed yellow. Did the PRR CPL's ever have green lens's in the 6 & 12 oclock positions for a clear indication? I don't think they did. B&O had red, yellow and green lenses on the main head and white lenses on the auxiliary heads. 

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Posted by Deggesty on Friday, May 6, 2016 2:41 PM

Timz, I hav no idea; I have never seen an N&W rulebook. I do not doubt that when the N&W began using CPL signals that steps were taken to make sure that all concerned knew that these were to be observed equally as strigently as the position light signals were. I would say that a new rulebook was issued as soon as possible after, if not before, the CPL signals were installed.

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Posted by timz on Friday, May 6, 2016 2:12 PM

That would surprise me too. Did the 1967 N&W rulebook include color position-light aspects? (Turns out it did.)

PRR started trying red-for-stop position-lights around 1955, but I'm guessing no PRR position-lights were full color until Amtrak started converting them between NY and Washington-- around 1990?

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Posted by Deggesty on Thursday, May 5, 2016 1:13 PM

When I was in college in Bristol in the mid to late fifties, I saw only position light signals on the N&W there; I knew of the connection between the PRR and the N&W.

In December of 1959, I was surprised to see color position light signals on the N&W somewhere near Bluefield. 

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Posted by BaltACD on Thursday, May 5, 2016 1:03 PM

On the 'true' PRR position light signals all bulbs, in all positions were off white yellowish.  With their transitions through various ownerships at various locations over the years various light positions have been colorized.  Initially starting with the lights at the 3 & 9 o'clock positions being made Red.  With the N&W having been controlled by the PRR during the 20's & 30's the PRR signals were installed on the N&W.

The B&O also began installing their Color Position Light signals during the same period of time that the PRR was installing their Position Light signals.  With B&O control of the Alton during this period of time, CPL signals were installed on portions of the Alton.  B&O sold the Alton in approximately 1942 to the Mobile & Ohio which became the Gulf Mobile & Ohio.

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Posted by WhiteLeather on Thursday, May 5, 2016 12:27 PM

blue streak 1

Have no idea why PRR had just the position lights but was told by an N&W old head that it N&W had color blind Engineers ( firemen as well ? ) at one time so the standard was position lights.  Once medical requirements were changed as all engineers who were retired that division was converted to color position lights.  Anyone with more info or was that just idle talk ?

 

I recall reading somewhere that the position lights mimicked the semaphores previously used.  Not sure if this is any particular railroad or a generalization, but if true, does seem to make sense.

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Posted by blue streak 1 on Thursday, May 5, 2016 12:11 PM

Have no idea why PRR had just the position lights but was told by an N&W old head that it N&W had color blind Engineers ( firemen as well ? ) at one time so the standard was position lights.  Once medical requirements were changed as all engineers who were retired that division was converted to color position lights.  Anyone with more info or was that just idle talk ?

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Posted by zugmann on Thursday, May 5, 2016 11:56 AM

aegrotatio
The position color lights just look like they can be easily mistaken. Surely it's not because the center lamp would burn out sooner than all the others. LIRR seems to like them just fine the way they are.

Don't know how.  Color position lights are easier to decipher at further distances since you can go by color and position.  Many older PRR signals just give you an "approach ambiguous" blob of yellow light at a distance if they aren't clean or aimed properly. 

Source - I've ran under both many, many times.

It's been fun.  But it isn't much fun anymore.   Signing off for now. 


  

The opinions expressed here represent my own and not those of my employer, any other railroad, company, or person.t fun any

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Posted by CSSHEGEWISCH on Thursday, May 5, 2016 6:44 AM

PRR had hybrid position light signals on the Bernice Cutoff and other lines in the Chicago area.  Proceed and Approach aspects displayed three yellow lights and Stop displayed two red lights aligned horizontally.

The position light signals on the approaches to Chicago Union Station were replaced a few years ago.

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Posted by rcdrye on Thursday, May 5, 2016 6:13 AM

B&O style CPLs were aqlready in use in Washington Union Station, so the crews were familiar with them.  In one or the other of the Corridor Improvement Projects Amtrak surveyed operating employess and found a large preference for the CPL-style indication.  Amtrak's CPL aspects are similar to PRR's PL aspects. B&O signals rely on extra amber and lunar white lamps with a single CPL head to show different aspects.

Amtrak's Chicago Union station had (and may still have) PRR-style signals on both approaches.

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Posted by RME on Thursday, May 5, 2016 4:04 AM

aegrotatio
The position color lights just look like they can be easily mistaken. Surely it's not because the center lamp would burn out sooner than all the others. LIRR seems to like them just fine the way they are.

The Amtrak CPLs don't have (or need) a center light, and it was N&W (not LIRR) that had some PRR-style position lights that used color (red) to emphasize a 'stop' aspect.  One point might be that Amtrak converted to high-intensity light sources (LEDs) that are also more reliable, and went to color aspects that as on the B&O have 'two' redundant means of conveying an aspect - on high-speed trains this is useful.

Not arguing that any of your points about the functionality of the PRR lights are not right...

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Why did Amtrak choose position color lights?
Posted by aegrotatio on Wednesday, May 4, 2016 11:25 PM

Why did Amtrak choose position color lights?  The original position lights still used by the Long Island Rail Road, at least to my untrained eyes, provide an unmistakable view of the aspect, with fog resistant color and brightness, with a clear shape even if the center bulb is malfunctioning (as PRR intended).

The position color lights just look like they can be easily mistaken.  Surely it's not because the center lamp would burn out sooner than all the others.  LIRR seems to like them just fine the way they are.

 

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