CPL history lesson

NW Mailing List nw-mailing-list at nwhs.org
Wed Jan 3 22:16:08 EST 2007

This is the reason that the PRR eventually converted their position
light signals at interlockings (known as "home" signals) to have red
lenses in the stop positions.

CG Tower

On 1/3/07, NW Mailing List <nw-mailing-list at nwhs.org> wrote:



> "Prior to being converted to color, didn't it seem kind of confusing for the

> untrained eye to distinguish a stop indication, a restricted indication and

> a proceed indication? Because you figure all you saw was 3 lights in 3

> different positions. How were engineer-trainees supposed to distinguish the

> indications?"


> Jerry,

> Your question isn't far fetched at all. Engineer C.H. Poage related to

> me that this could indeed be a problem in the fog at a distance. The example

> he recalled was rounding the curve at Port Republic going north and dropping

> down onto the flat at Lynnwood. After rounding the curve, the track is then

> straight for 2 1/2 miles and you can see the signals at both ends of

> Lynwood. There is a siding there so these are Home or Stop signals.

> Fog will tend to lay in this low lying area and obscuring the signals.

> So you can well see that if you are following a train and running on an

> approach signal, it could be hard to distinguish if the train ahead had

> cleared the block ahead or stopped in the block. Since ALL of the signals

> were yellow, you didn't know if the next one was Clear, Approach or Stop as

> all you could see was a big fuzzy yellow ball of light.

> Jimmy Lisle

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