Who operates switches and turnouts?

[baldeagle]

There's something that has puzzled me for a few days.

 

In the US and Canada, I'm aware that many freight lines are very long, and that they can be single track, requiring fairly long passing places.

 

I'm also aware that they are often in remote area's.

 

The crew keep in touch with their despatchers by radio, and, from the technical standpoint, it would presumably be VHF or UHF, and via a system of repeaters which may, or may not, be trackside, I assume.

 

As each of these passing loops are going to need a turnout at each end, I presume that these are not operated by a system as archaic as 50 miles of metal linkage rods/counterbalance weights.

 

So how are they operated?

 

Do the crews themselves manually operate them, under the despatchers instruction, or is there a telemetry and remote operating system which is also radio operated?

 

John

[Prof Klyzlr]

There's something that has puzzled me for a few days.

...

So how are they operated?

 

Do the crews themselves manually operate them, under the despatchers instruction, or is there a telemetry and remote operating system which is also radio operated?

 

John

 

 

Dear John,

 

The answer is "both".

 

- If we're talking "dark territory' with no signals or CTC, then sure, it's all about the brakeman having to hit the ground at the turnout, and throw the groundthrow "Caboose Industries" style (oldskool)

 

http://mw2.google.com/mw-panoramio/photos/medium/38134606.jpg

 

http://sptco.proboards.com/index.cgi?board=trackside&action=display&thread=287

 

http://www.flickr.com/photos/williamgrimes/2188511120/

 

or trigger a localise power turnout (newskool)

 

http://www.vossloh-usa.com/cms/en_1/rail_infrastructure/signal_switch_control_systems/patented_fas_pas/patented_fas_pas.html

 

(and yes, in both cases, he's up for a long walk back to the loco after closing the turnout behind his train...)

 

- If however we _are_ talking about CTC territory, particularly recent era with telemetry and suchlike, then a guy staring at a computer screen in Utah can peck a few strokes at a keyboard, and a mainline/passing turnout somewhere in Nebraska, equipped with a solar-cell-powered motor, will kick over to the pass in prep for the approaching grain train...

 

http://www.rrtools.com/trackAccessories/SolarOperatedSwitchStand.asp

 

- and of course, in some instances, it makes sense to have a throw which is both powered _and_ manual

 

http://www.modelrailroadforums.com/forum/attachment.php?attachmentid=7752&d=1195497449

 

Hope this helps,

 

Happy Modelling,

Aim to Improve,

Prof Klyzlr

[Glorious NSE]

or trigger a localise power turnout (newskool)

 

http://www.vossloh-u...ed_fas_pas.html

 

(and yes, in both cases, he's up for a long walk back to the loco after closing the turnout behind his train...)

 

This is where the DCC handset throwing of points becomes prototypical!

 

I think there's different ways those local/radio controlled powered versions can be set up to reduce the long walk, either the train crew can dial up the switch again and return it to 'normal', or I think they can be set to 'normalise' automatically after the (local) track circuit clears...

 

(And the 'old skool' way of missing out the walk - assuming the line is quiet enough and the dispatcher is happy with it! - would be the train going past the siding, dropping off the conductor on the way past, then backing in from the far end!)

[dave1905]

The crew keep in touch with their despatchers by radio, and, from the technical standpoint, it would presumably be VHF or UHF, and via a system of repeaters which may, or may not, be trackside, I assume.

In previous days, miles of copper wire, in current days fiber optic or microwave networks.

As each of these passing loops are going to need a turnout at each end, I presume that these are not operated by a system as archaic as 50 miles of metal linkage rods/counterbalance weights.

mechanical interlockings are extremely rare anymore in any length.

 

Do the crews themselves manually operate them, under the despatchers instruction, or is there a telemetry and remote operating system which is also radio operated?

Sorta, yes and no, maybe.

 

For this discussion there are basically 4 types of territory, CTC, non CTC, tower interlockings and other.

 

There are also two types of switches, those at "control points" and others.

 

Control points are those places where somebody other than the crew handles the switches (and typically the signals too). Those switches are remote control or dual control switches. All others are hand operated (manually operated by the crew). Control points are in CTC or manual interlockings.

 

In CTC the dispatcher or control operator can remotely line the switches. The dispatcher or control operator can control them form locations hundreds or thousands of miles away. For example the UP and BNSF operate virtually their entire railroads from centralized offices. The communication is by copper wire, fiber optic, microwave and locally at a control point, radio. Dual control switches can be converted by the crew, with the dispatcher or control operator's permission, to a hand operted switch and operated by a train crew. SWitches not part f a control point in CTC are operated by hand, but may have a lock on them controled by the dispatcher or control operator.

 

At a manual interlockings with a tower, the interlocking operator operates the switchesby a mechanical linkage (rare) or by the same methods as in CTC, the only difference being the operator is located immediately adjacent to the interlocking. These are becoming fewer and farther between.

 

Everyplace else the crew operates the switches by hand.

 

The exception being certain large yards where a hump computer, yardmaster or operator may control switches, certain road territories where switches may be activated by the crew by radio control or locations where there is a switch tender who manually lines switches based on the direction of a dispatcher, control operator or yardmaster (usually an interlcoking or terminal).

[JWB]

Here's an example of a manual switchstand in CTC territory.

The silver device is the lock that allows the dispatcher to prevent the switch being moved. The low enclosure closest to the camera is the sensor that reports the position of the switch to the dispatcher, as I understand it (Dave H may be able to correct this). These parts at one time were made by Alexander. I'm not sure if Details West has equivalents.

[Glorious NSE]

DW does make equivalents.

[baldeagle]

Thank you to all who answered my question, I'm considerably wiser now.

 

Some very interesting pictures, and I particularly liked the rather wobbly lines on the Prof's photo's - definitely not a high speed track!

 

John