In the middle of no-where in particular,in southwest Minnesota: I saw a sign on a rail line that said “S one mile. Check authority”. What, exactly are they being asked to check, and from whom?
Presumably this bit of track is dark territory, and S is a point that track warrants are issued to. The sign instructs the crew to check the authority of their track warrant to see if it extends beyond S or just to there, in which case they must stop & ask the dispatcher for a new one.
“S” being a point on the map, verses a switch location? If it did mean switch location, is the word “switch” usually written out on a railway sign?
You weren’t a mile or so away from a railroad crossing, were you?
Not knowing which railroad you were looking at and where, it’s hard to say–but that could be a warning sign for a crossing still protected by a stop sign.
A stop sign?? Are you pulling my leg?
http://www.trainweb.org/southwestshorts/images/ptragatethumb.jpg
No, Murphy, he isnt.
We use stop signs all the time, to protect railroad at grade crossings, and at some manual interlocking plants.
And just like the stop sign on the street where you live, it means stop, look, go.
Describe the sign in a little more detail, if you would.
Not much to describe, I’m afraid. White,perhaps 10"X12" whith plain, white lettering.
[(-D] I’m still mulling over the stop sign. If one of the lines is seldom used, do they just settle for a “yield” or “merge” sign?[;)]
Actually, some of these crossings were protected by gates. Said gates would have a normal position, and would be set against the route that had the least traffic. A sign like yours could be used in advance of that, too, I suspect.
Would the lesser train crew have to, I don’t know-*shut the gate after themselves, as in, put it back in the original position after passing through?
Yes, definitely.
Yes…they do.
See the photo in the link I posted above.
The Stop sign protects the PTRA main from the old SP cut across from their Clinton Sub.
The sign is normaly displayed against the SP…when they want to cross our main, they pull up, stop, look, and if no traffic, they swing the gates open locking them against the PTRA…when they are through servicing the small plant in the background, or if they are just crossing, they line the gates back against the SP main.
They was a manual interlocker about a mile west, (left) of this shot…it had a four way stop sign.
Just like on a public street, you pulled up, stopped, and if no opposing traffic, you flaged through.
It has been replaced by four red over lunar signal heads and a circut, which is a pain, it screws up every time it rains!
Is a manual interlock something like I saw in a book about local railroad history-the photo showed a switchman “winding the clock at the interlock”(?). This was at a diamond where CNW trains infrequently crossed a regularly used BN line.
IIRC, that’s a time delay - I can’t tell you exactly how it works, but I believe it forces a crew to wait for X minutes before they can throw a switch or some other action. A kitchen timer of sorts.
Yes and yes…
At our interlocker, if you do not get a lunar when you enter the circut, you have to stop short of the signal limits, and go to the interlocker control box, unlock it, and press a button.
This starts the timer circut, or clears the signal if nothing is in the circut.
If the circut does not clear, and remains red, you wait five minutes on the timer, which should reset the signals, but if no change, then you visualy check for opposing traffic, if none, proceed to flag throught the interlocker.
UP has a bad habit of stopping their locomotives just inside the circut, and tieing them down for crew changes, which of course, locks the opposing signal (ours)to red.
The old four way stop was better, you have over a mile sight line every way.
Stop, look and go…
An automatci interlocker has approach signals, is part of a ABS or CTC system, and works off of the track circuts.
You have to get premission from the dispatcher to flag through it.
On the CP main of the C&M Division at Bain Station Road there is a white diamond shaped sign next to track 1 measuring about 12" square showing only the letter “S”. No sign next to track 2. There is a facing-point switch approximately 1/4 mile from the sign that leads into a siding of about 1/2 mile in length. This is the only place on the CP that I have seen this sign. The CNW never used such an indicator. I have no idea what the sign is for.
As a guess, it indicates the switch is a spring switch.
Our road uses the diamond shaped white signs for just that purpose, to indicate to a crew the switch they are approaching is a spring switch, or a variable switch.
The switch itself is also marked, with the diamond on the switch stand proper too.
Which is what I was thinking Murphy’s sign might be…
Often, such switches are used as control points in CTC.
I often hear CSX here issue “EC-1’s” from “south end siding switch…”
That’s a possibility. I know the switches used there are electric-lock controlled, and the operating conditions are two-main tracks CTC. On the CNW we used a “SS” indication on the switch target for spring-switches. However, the sign is so close to the switch (about 1/4 mile) that it does not seem to provide sufficient stopping distances; perhaps it is just an ‘advisory’ type sign.
I would say it means, “station one mile.” The Milwaukee Road used a sign that actually said station one mile. The Rock Island used a white, diamond shaped sign with a black S. I think I’ve seen other RRs use some similiar warning in some of my employee time table collection. Look in the Special Instructions section of a railroad’s employee time table and it will list what signs the railroad uses and what it means.
Remember, a station isn’t a building. It’s a designated place listed in the time table. It may have a building, it might not. There may be a siding, or there may only be a sign with the station name. Since it is a designated point, it can be used for the limits of movement authorities, hence “Check Authority.” The next station may be the end of your limits. The authority this particular sign refers to is what ever type (TWC, DTC, etc) that particular railroad uses.
Jeff
No. A manual interlocking is one controlled by a human being. An automatic interlocking operates without human intervention. The human being that controls the manual interlocking can be located in a tower at the interlocking, 20 miles away running several interlockings (PRR and B&O had lots of these), and 2000 miles away in a dispatching office. Manual interlockings are essentially indistinguishable from CTC in practice, rules, and technology.
Another way of looking at it is that manual interlockings require a human being to decide who goes first. Automatic interlockings run on a first-come, first-serve basis. Automatic interlockings generally have a manual override in the field, which is what you observed in the photo you describe.
The basic d