Diverging signals Re: Vera Jct
NW Mailing List
nw-mailing-list at nwhs.org
Wed Jun 25 09:06:59 EDT 2025
David,
Looks familiar, where is this? The lower rank of the signal contributes
to its aspect, indicating a siding. The siding's speed restriction could
be as low as that of the turnout by Rule 105, or even lower by Employee
Time Table. This is an example of variations and exceptions that I
hedged/weaseled about in my first reply.
Grant Carpenter
On 6/24/2025 5:39 PM, NW Mailing List wrote:
> I'd love to know what is causing that there, a trailing point spring
> switch, not having medium approach medium, .... Idk
>
> You can give clear in the nominal case like this. I only had 3 photos
> on hand.
>
> David Baker
>
> On Tue, Jun 24, 2025, 3:17 PM NW Mailing List
> <nw-mailing-list at nwhs.org> wrote:
>
> Jim,
>
> With apologies, I'll attempt a reply to your original post with
> some specifics.
>
> Diverging indications notify an engine crew of a speed restriction
> due to one or more turnouts ahead. By 1951, anyway, N&W Operating
> Rule 105 (b) simply stated that unless otherwise provided, speed
> is restricted to 25MPH for passenger trains and 15MPH for other
> trains or engines when using turnouts or crossovers. As Jimmy
> stated, exceptions were noted in ETTs and could vary a lot, for
> example, between the Radford and Pocahontas Divisions.
>
> So, diverging aspects are applied to signals in both directions
> "through" the turnout's slower/secondary route. BTW, the N&W's CPL
> version is not included in the earlier Rule 283 examples below.
> The three diverging indications are shown here, starting with the
> distant/advance signal indication Approach Diverging:
>
>
>
>
> This is an eastbound at Vera Jct. on the Cincinnati line
> approaching the turnout on the eastbound main from Columbus, shown
> in the lower-right corner. I can't recall specifics as to what
> other signals are here (bi-directional? both directions? etc.) in
> this time frame and with which aspects.
>
> So, what's with the term "medium" and the N&W?
>
> I don't know. I've asked around, and this came up here on the List
> several years ago. As of 1951, it appeared in two contexts within
> N&W signal rules:
>
> In the signal indication description of Rule 285 – Approach, the
> term "medium speed" appeared: "Proceed preparing to stop at next
> signal. Train exceeding medium speed must at once reduce to that
> speed." It appeared in the Operating Rules Definitions as half the
> max authorized speed, but not to exceed 30MPH.
>
> In the name of the three "diverging" indication rules, "medium"
> replaced "diverging," e.g., Diverging Clear became Medium Clear.
> However, the term "prescribed speed" was used in the rule
> descriptions per Rule 105 (b) above – not medium speed.
>
> Neither usage appeared to have much, if any, direct relevance, and
> the ambiguity seemed to be acknowledged later, because by the 1981
> Rule Book, both instances were deleted. "Medium" was changed back
> to "Diverging" for indication names, and the reference to "medium
> speed" was removed from the Approach Rule description and the term
> was removed from the Rules Definitions.
>
> Hope this helps, just my take; edits, thoughts and questions welcome.
>
> Grant Carpenter
>
> On 6/19/2025 7:55 AM, NW Mailing List wrote:
>> All signal fans,
>> I just found this definition/explanation for what a "diverging"
>> route can be interpreted to be and it covers the case at Vera:
>> One of these days I hope to understand to signal a railroad.
>> Jim Cochran
>>
>> On Wed, Jun 18, 2025 at 8:47 PM NW Mailing List
>> <nw-mailing-list at nwhs.org> wrote:
>>
>> The operating book rules calls out the AAR rules in my '51
>> and '45 rule book. That is speed signaling, although if you
>> look at the rules as written they do a bad job explaining
>> that. The only thing that usually drove medium speed was a
>> diverging route in a turnout.
>>
>> Is there another facing point turnout ahead?
>>
>> David Baker
>>
>> On Wed, Jun 18, 2025, 6:44 PM NW Mailing List
>> <nw-mailing-list at nwhs.org> wrote:
>>
>> Grant,
>> Thanks for the reply and great seeing you at the con as
>> well. Your answer caused me to dig more deeply into the
>> history of N&W aspects/indications and in particular the
>> horizontal arm over vertical arm aspect that has most
>> recently been referred to as "diverging clear". Please
>> refer to the attached pages from N&W rule books as
>> reference for what follows.
>>
>> In 1910 it was called "slower speed route clear" when
>> used in conjunction with one high speed route and
>> diverging routes. Seems clear this was speed signaling.
>>
>> In 1915 it was "proceed under control, being prepared to
>> stop".
>>
>> In 1930 it was just "proceed". Does anyone have a copy
>> of the rules between 1915 and 1930? I'd like to know
>> what that one has to say.
>>
>> In 1945 it was " proceed through diverging route at
>> prescribed speed". This looks like route signaling.
>> Again if someone has intervening information, I'd
>> appreciate knowing about it.
>>
>> In 1951 it was " proceed through turnout route at
>> prescribed speed" which would seem to indicate route
>> signaling, but the aspect name is "medium clear" which
>> point toward speed signaling.
>>
>> In 1961 it was the same but showed the option of a
>> colorized aspect.
>>
>> As far as I know this was maintained until the end of the
>> N&W. The term through diverging or turnout route seems
>> to reinforce my questioning its use where one line
>> "joins" another. When I visited Tom Dressler many years
>> ago, he informed me that going "through" a turnout was to
>> take the diverging path while going "over" a turnout
>> meant staying on the non-diverging route. Both of these
>> would indicate a facing points movement and wouldn't seem
>> to be readily applicable to trailing points movements.
>>
>> The NORAC definition of this aspect is something like
>> proceed at medium speed until you train clears turnouts
>> or interlockings and then proceed at prescribed speed.
>> This would seem appropriate for such a situation as we
>> find at Vera, but I have not seen this kink of definition
>> in any reference for N&W signaling.
>>
>> Hope there may be more to the story and would welcome
>> input from anyone who has experience/knowledge of how N&W
>> signaling worked and the philosophy used by the system
>> designers.
>> Thanks,
>> Jim Cochran
>>
>> On Tue, Jun 17, 2025 at 7:47 PM NW Mailing List
>> <nw-mailing-list at nwhs.org> wrote:
>>
>> Jim,
>>
>> Generally. . .
>>
>> Route signaling is speed signaling by implication.
>>
>> So, diverging aspects can indicate a lower speed
>> through the diverging route of a turnout, compared to
>> the adjacent track speed, and regardless of direction.
>>
>> So, diverging aspects will be used when facing
>> points, and _may_ be used when trailing points.
>>
>> . . . mostly.
>>
>> Good to see you and All at the Convention.
>>
>> Grant Carpenter
>>
>> On 6/8/2025 10:31 AM, NW Mailing List wrote:
>>> Attached is a photo of Vera Jct. showing the signal
>>> facing Peavine traffic. Why would the "main stem"
>>> from Columbus have been considered a "diverging"
>>> route in this case? Perhaps it is in some way
>>> analogous to middle sidings being signaled for
>>> diverging aspects where they rejoin the main. I
>>> tend to think of diverging aspects being displayed
>>> to facing points movements where they are signaled
>>> to take a route that "diverges" from the one they
>>> are currently on. Of course there are no "joining"
>>> aspects, so did the term "diverging" cover the act
>>> of taking a route that your current route is
>>> joining? Any thoughts will be appreciated.
>>> Jim Cochran
>>
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