[wacampbell]

On a CTC operated route. Does the dispatcher console, and signal logic, have visibility of switches out on the line leading to minor industrial spurs? I assume these switches would not be remote controlled by the CTC, and I also assume they would not have a sensor. And as such they would be invisible to the dispatcher and the CTC signal logic. What's the common practice in this situation?

[charland]

Hi Wayne,

If you are talking about an industrial siding beside a mainline sort of thing, the train crew would let the dispatcher know they are stopping to set a car off or lift one but these days if it's on CTC the switch would be wired into the CTC and when they opened it it would change the signals around it.

Industrial parks and spurs are a little different. Movements to and from the industrial sidings would be governed by CTC and a Dispatcher but not while on the industrial siding or spur. The local job in Dartmouth gets clearance from the Halifax Dispatcher to move along the mainline from Dartmouth Yard to Burnside Yard where he leaves the mainline. For hours he switches the Burnside industrial yard on his own without asking the Dispatcher anything until he wants to return to the Dartmouth Yard, then he needs to ask the Dispatcher fir clearance to occupy the main again.

Paul :-)

[atsf37l]

Most industrial sidings and spurs off the mainline in CTC territory would be locked, electronically. The crew would request access to the switch from the dispatcher and the dispatcher would flip the lock toggle to unlock which would set signals to red around that switch and allow the crew to manually line the switch. Once the crew is clear the switch would be thrown normal and locked again until they were ready to leave. :thumbup3:

[Genma Saotome]

I suspect in the old days the turnouts were not wired into the signal system, especially if the spur could not take the whole train. Think about it: The whole train is sitting on the main, the conductor instructs the crew to cutoff the first three cars, pull forward, throw the switch, and back the cars into the spur. With the bulk of the train sitting on the main why would that switch need to be wired into the signal circuit? The rule books would have been clear: crews were always required to return the switch to its original position.

What would make sense is eventually the switch would be locked/unlocked as Herb said, above, just to make sure the train crew returned the points to their correct location -- for thru traffic. The question is, I suppose, at what time did railroads feel the need for the extra expense? I'll ask around and see if anything turns up.

[wacampbell]

Thanks for the input and additional comments are welcome.

It seems to be flexible we'll need some configuration options for such switches - ie

- remote controllable - yes/no
- signalled - yes/no

I have heard the term 'unlocking the switch' . Is this something the ground crew does with the padlock. Or is this something that is done by remote control from the dispatcher?

[Genma Saotome]

wacampbell, on 09 October 2012 - 10:49 AM, said:

I have heard the term 'unlocking the switch' . Is this something the ground crew does with the padlock. Or is this something that is done by remote control from the dispatcher?

Both. You don't want members of the public throwing the switch on the main to excite an otherwise dull day. Locks might not be required on industrial switches off the main (this member of the public remembers throwing a switch on many a dull summer afternoon in my youth; they're heavy).

[inflammable]

On some lines, perhaps more modern, the electronic locks are also timers. You get permission from the dispatcher to operate the switch, and having received it, you unlock and trigger the timer.

The timer, in theory, gives enough time that should there be a train on the main, and it having already passed the nearest signal, it would arrive at the switch prior to you throwing it. If it hasn't passed when the switch is thrown, then the thrown switch will cause a stop or restricting signal, protecting any moving train from your movement.

There may be circuitry to allow the timer to skip to open if the main block is already restrictive (due to your train being on it), but if the main block is clear, the timer is applied.

Like what was mentioned in previous posts, why would you be operating a switch if your train isn't on the main? Some routes have rather short locals, and if the local crew is on a light engine, the engine could clear the main on just about any industrial siding. So if they ran out of their hours for whatever reason, they'd tie up the engine at any industry, and the taxi pick them up. When the next crew arrived, the main would need to be protected when they went to leave the siding.


James

[dajones]

Track circuits are usually setup so that the track appears occupied if an industrial siding switch is reversed (not aligned for the main). This provides some protection even when the is no electric lock.

Doug