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.
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
> 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
> NW-Mailing-List at nwhs.org
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