signal use

NW Mailing List nw-mailing-list at nwhs.org
Mon Apr 1 21:04:30 EDT 2024


Interesting. Nice job of finding a picture showing a train doing something I said normally shouldn’t happen (southward on the northward track past that dwarf). I assume this was from the Conrail era since an EL unit is trailing the PC leader.

I’m assuming IMG_7858 is 1967 given it mentions NYC and PRR while IMG_7856 is 1974 as it mentions PC. The way I read it for, TC is not by Colsan but by that brace that extends from Worthington to Bayside on IMG_7858. I take it to mean that TC was already in service then. Although I realized after my last note that there was no reason that with a plan for TC (and frankly, CTC is just a bunch of remote controlled interlocking all controlled from the same place and some additional display of occupancy between interlocking on the model board) that they could have put the model board in, cutover Colsan to Chatfield (already TC) and added remote control of Carrothers long before the rest was changed to dispatcher control (but that would have meant remote control of Carrothers interlocking while still having a manual block operator at Carrothers which sounds bizarre).

DT is Double Track. Now thanks to my exposure to western roads (they do things differently than eastern roads), these days to me Double Track is two tracks each with a current of traffic (rule 251 in most rule books except GCOR) while “two tracks” means a CTC system (rule 261) and tracks signaled for both directions. But terminology evolved so I think they mean the same thing - just different years.

Regarding the interlocking diagrams, the notes on the later one tell us ownership has been split. The left half says “Maintained by N&W 100%” and “Remote Control from Portsmouth 6-1-66" while the right have says “Maintained and Oper. by PRR 100%” and “Remote Control from Tiffin installed 6-1-66.” I assume the dashed line indicates where control and ownership changed.

There’s a couple of oddities in that interlocking. First is the westward home signal on #1 track where it appears the upper and lower heads were operated by separate levers (16L for the upper head, 14L for the lower head). Also, one pair of signals is on what is normally a switch lever (signal levers are normally the even numbered ones and switch levers are the odd numbered ones). But we have 7L/7R as signals while I don’t see lever 6 being used. Both of those suggest there may have been more to this interlocking at some point in the past.

-- 
Larry Stone
lstone19 at stonejongleux.com





> On Apr 1, 2024, at 4:22 PM, CG Tower <s141asheville at gmail.com> wrote:
> 
> Larry, et. al.:
> 
> Did some digging, the earliest N&W TT I have from the Scioto Division is 1967, both it and the 1969 edition have the line as "ABS/DT" with the aforementioned "TC" (Traffic Control) at Colsan. I must admit I am not familiar with the "DT" designation in the N&W timetable of that era, thoughts? 
> 
> By 1974, the entire line was now listed at Traffic Control (which I think I got my date from).
> 
> Also in that mix of images is the PC Lake Region TT from 1969.
> 
> Also attached is a PRR interlocking diagram of the original configuration of Carrothers, circa 1957 with the tower present.  Both lines of course are still PRR at this point. Note the intermediate signals: MP...25.7/25.8 east of the diamond, and 28.7/28.8 west of the diamond. Also by this time, the Toledo Branch had been effectively downgraded by PRR with the line cut between Toledo Junction and Tiro, Ohio. This tells me that the PRR actually is responsible for the connection and said interlocking seen below. The PC merger found better routes to Toledo (via the former NYC) so the line was left to wither away. Conrail removed signals from the Carrothers Branch in 1984, moving the line to manual block rules. The line and the N&W trackage rights were abandoned on Oct 1, 1985.
> <IMG_7859.jpg>
> Picture credit: Jim Roberts,  from the book: Pennsylvania Railroad Lines West, Vol. 3, Hipes/Oroszi, Copyright 2016, White River Productions
> 
> 
> <carrothers.gif>
> 
> PRR Interlocking Diagram
> 
> 
> <IMG_7856.jpg><IMG_7857.jpg><IMG_7858.jpg>
> 
> I love this stuff...
> 
> Eric formerly of the Columbus District
> 
> On Mon, Apr 1, 2024 at 6:25 PM NW Mailing List <nw-mailing-list at nwhs.org> wrote:
> Eric, thank for that interlocking diagram.
> 
> To add some more, I also have a 1965 Sandusky District ETT (our chief clerk at Sandusky was a pack rat who never threw anything away without permission and I guess nobody gave him permission since there was ton of them in a closet in 1980). At that time, the Sandusky District still used the PRR rule book. Signal rules for the Sandusky District were Manual Block Fields (Columbus) to Colsan (Bucyrus - so named because it’s where the Ft. Wayne main line crossed the COLumbus-SANdusky line), CTC (rule 261) Colsan to Chatfield, double-track ABS Chatfield to Carrothers, and Manual Block Carrothers to Bayside (Sandusky). So it would appear that the PRR though the line to Toledo rated ABS but the rest of the Sandusky District didn’t. By 1980, the entire Sandusky District would be TC (CTC) except for five miles of eastward track well east of Colsan.
> 
> Back to my 1980 Conrail ETT and Eric’s interlocking diagram, the ETT in addition to Carrothers (shown as on the N&W), there was North Carrothers, different from the N&W’s North Carrothers, which I suspect is the interlocking on the diagram from Eric betweens signal 8L and 2R. Unfortunately, the CR ETT does not show the distance between their North Carrothers and Carrothers (the former shown as a distance from Mansfield and the latter as a distance from Columbus) but it’s shown as 6.2 miles from Bloomvville and my measuring on Google Earth puts Bloomville 6.2 miles away. Oddly, CR did not show a speed between their North Carrothers and Carrothers nor did N&W show a speed for the diverging routes at Carrothers. 
> 
> So back to the question I raised which it appears a move from westward N&W to northward Conrail could at best get Diverging Approach. I’m going to speculate and suggest that N&W’s signal system did not talk to Conrail’s so the signal logic had no idea what was displayed around the curve at 8L and therefore couldn’t display anything better than Diverging Approach. I’ll also speculate that originally it was all one interlocking given it's all on one diagram that just calls it Carrothers but after the sale of the Sandusky line, it was split into an N&W portion and a PRR portion and by 1966 (per the notes on the diagram), both remotely controlled*. That signal systems don’t talk between different railroads is seen other places. As late as 1981, moves between the Sandusky District and the ex-NKP at Bellevue (including trains out of Bellevue headed to Columbus) could get no better than Restricting. I’ll also note that it appears the eastward track had a full bottom head for westward moves but it probably needed to display both Diverging Approach (for a move to the Conrail northward track) as well as Restricting for a move to the Conrail southward track.
> 
> And back to why a diverging signal for the converging move off the Conrail Carrothers Branch. I would not be surprised if that signal was installed pre-1964 by PRR, it would be correct for PRR’s signal rules, and N&W saw no reason to replace a signal that didn’t govern N&W trains and worked.
> 
> Looking at it today from Google Earth, Carrothers is gone as an interlocking (doesn’t even look like there are even any signals there) and North Carrothers (N&W) seems to be gone without a trace (North Carrothers on the N&W was the end of two tracks after which it was single track with passing sidings between there and Bellevue - today, two tracks all the way from Chatfield to Bellevue).
> 
> * Eric, you speculated that TC came to the Sandusky District in the early 70s. Yet the diagram says Carrothers was remote controlled from Portsmouth (where the dispatcher was) as of 6/1/66 which makes me think that may have been the TC installation. I strongly suspect N&W wanted to get rid of the PRR manual block as quickly as they could.
> 
> -- 
> Larry Stone
> lstone19 at stonejongleux.com
> 
> 
> 
> 
> 
> > On Apr 1, 2024, at 10:45 AM, NW Mailing List <nw-mailing-list at nwhs.org> wrote:
> > 
> > Larry, et al.:
> > 
> > I've attached an interlocking diagram of Carrothers circa 1967 that will likely confuse the situation even more! :). I'll need to dig around and find out when the N&W completed the upgrades to the Sandusky District to make it TC/CTC. I'd say sometime in the early 1970's.
> > 
> >  <Screenshot 2024-04-01 at 13.42.04.png>
> > 
> > 
> > Eric formerly of the Columbus District.
> > 
> > On Mon, Apr 1, 2024 at 1:24 PM NW Mailing List <nw-mailing-list at nwhs.org> wrote:
> > Well now we’re in to what was my N&W territory (Asst. Trainmaster in Sandusky). I didn’t pay too much attention to down there.
> > 
> > Thoughts: while N&W did route signalling, PRR/PC/CR did speed signaling. And that signal is governing a train coming off PRR/PC/CR (after PRR sold the Sandusky line to N&W, they retained trackage rights between Colsan (Bucyrus) and Carrothers for trains to/from Toledo) so would it be displaying an N&W Diverging Clear/Approach or a PRR/PC/CR Medium Clear/Approach?. If the latter, it’s correct.  
> > 
> > As for the dwarf, the Toledo line west of Carrothers was double-track ABS (current of traffic signaled only for that direction). Every track needs a signal at an interlocking but why spend the money on a high signal for a move that should normally never happen (southward (the Carrothers Branch as it was officially called was north/south) train on the northward track). But looking at the N&W westbound signals from behind, it looks like Diverging Approach was the best you could get from the N&W “westbound” (it was TC (CTC) territory) track to the Carrothers branch northward track (there’s no vertical possible on the lower head). From a 1980 CR ETT I have, the Toledo line went to single track (Rule 261 TCS (CTC)) six miles north of Carrothers. It’s possible there were no intermediate signals in between so that might be a Diverging Approach with a Medium Clear/Approach at the next signal six miles ahead.
> > 
> > -- 
> > Larry Stone
> > lstone19 at stonejongleux.com
> > 
> > 
> > 
> > 
> > 
> > > On Apr 1, 2024, at 5:50 AM, NW Mailing List <nw-mailing-list at nwhs.org> wrote:
> > > 
> > > That is Carrothers, Ohio. One time junction of the N&W Sandusky District and the PRR/PC/CR Toledo Line.
> > > 
> > > As far as the dwarf signal goes, what kind of comment do you want?  While I cannot be certain, it appears the dwarf could show "Stop", "Restricting" and "Slow Clear".
> > > 
> > > Excellent photo looking the other way showing a CR train leaving their line head of an N&W man:
> > > 
> > >  https://flic.kr/p/QYjfsz
> > > 
> > > Eric
> > > 
> > >> On Apr 1, 2024, at 07:13, NW Mailing List <nw-mailing-list at nwhs.org> wrote:
> > >> 
> > >> Just came across this interesting signal installation showing use of diverging only aspects where branch enters main.  Anyone care to comment on the dwarf?
> > >> Jim Cochran
> > >> <signal plant.jpg>
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