dark territory

[pat390]

I am a little confused about how trains are dispatched in dark territory, is CTC not possible with the lack of signals or do trains have to hand off through multiple dispatchers? Also the lack of signals seems somewhat unsafe, are stretches of dark territory only a few miles long?

thanks,

Pat

[edbenton]

Dark territory is dispatched by track warrents. Any oppsing traffic is not allowed to move until the train you are supposed to meet at that time passes you. It is not the most efficent way to move traffic but it works.

[chad thomas]

In dark territory there are a couple methods of dispaching. First off though I should clairify that for each area of track there is one dispatcher. How big an area of track depends on traffic density. A dispacher on a secondary main might cover several hundred miles of track and may dispach more then one territory at a time (an example would be back in SP days on the weekends the Syskyou line and Modoc line would be handles by one person). On the other hand at a busy junction on a multiple track main line a dispacher might only work a few miles of line.

The most common method is Track Warrant Controll (TWC). In TWC territory warrants are given out to the trains and track workers allowing them to operate or work on a section of track. A maintainer might get a warrent to work on a section of track. Or a train might get a warrant to move from point A to point B. Point B typically being the point where the next meet will occour. The track warrant form is a standard form and has a series of "X boxes" next to certain instructions (I don't know where a sample is on the net, someone else might). Track warrents are preffered for there flexability as they allow for many situations. Note that just because a territory is TWC controlled does not nessasarily mean it's dark territory. It could be used with an Automatic Block Signal overlay, which is an additional saftey system to prevent collisions.

The second most common method is Direct Traffic Controll (DTC). DTC is similar to TWC but for simplicity in DTC the track segments (usually between sideings) are pre defined and given a name. Instead of giveing milepost limits for authority like with TWC. The dispacher will give out block limits (procede from the Alpha block to the Beta block). Although DTC is simpler, it is also a little less flexable.

Then on lightly used branchlines where there is little chance for two trains to need to be on that line, there is Absolute Block Register (ABR). With ABR there is a register box that has to be signed when a train enters that branch, and released (signed off) by the same person when that train leaves that branch.

And then there are Yard Limits. In yard limits (which may apply on branches & industrial areas) all trains move at restricted speed able to stop short of any men or equiptment on the track. That is also limited to 1/2 your line of sight and 20mph, depending on the specific railroad.

[Anonymous]

To add to Chad's description:

*ALL* "methods of operation are defined by a block, that is, a section of track with fixed limits. The *only* difference between CTC (and similarly interlockings) and the other common methods of operation (TWC, DTC, manual block, etc.) is whether the authority to occupy a block is granted by a signal indication or by an oral or written authority. The *only* significant difference between TWC and DTC is that the block in TWC has temporary limits chosen and designated by the dispatcher whereas the block in DTC has permanent limits. There are "floating block" methods extant in laboratory settings (the train carries the block with it) that may eventually replace the fixed block methods, if the technology can be implemented at a reasonable cost.

There is nothing intrinsically unsafe about operation in dark territory: a train crew can exceed its authority in CTC limits just as easily as it can in dark territory, in the former case by disregarding a signal indication and in the latter by disregarding the oral or written instruction on the TWC or DTC form. In my experience I much prefer DTC as the block limits are always the same, and as the train crew and dispatcher have to keep their head in the game much more than in CTC. Better yet was timetable and train-order operation. The flexibility of CTC has devolved to a crutch allowing undisciplined operation and ad hoc scheduling at every level of the railway operation, especially at the top where this technology facilitates impulsive operating policies that are born fresh every morning in reaction to the fad du jour or the squeakiest customer wheel.

Dark territory exceeds signaled territory in total mileage, though most dark territory is light-density branch line and tertiary main-line trackage. The major advantage of CTC is it offers a significant capacity increase over TWC or DTC.

Chad, a couple of notes:
1. ABS doesn't necessarily prevent collisions -- it only advises of track conditions ahead.
2. It's not accurate to say TWC is preferred. It happens to be more common in the Western U.S. but not in the Eastern U.S. The flexibility of TWC is largely theoretical, in my opinion, and at the expense of significant safety, also in my opinion.

S. Hadid

[chad thomas]

1435mm, Thanks again for your input. To clairify, I did not mean to say TWC is prefered, rather that TWC is prefered for it's flexability vs DTD being prefered for it's simplicity. I also prefer DTD and miss the old block authority that SP used.

[tree68]

Most of this has already been covered - here's my take:

The CSX line through my area is dark. Block stations abound, with locations usually governed by sidings - both passing and stub (places where a job might clear the main and still do work). Traffic in my locale is usually a pair of northbounds, a pair of southbounds, and a couple of locals that might go just about anywhere.

CSX uses DTC here, issuing "EC-1's" (more or less equivalent to the NORAC Form D, which was used here until recently). Permission is given between block stations, dependent on how much clear track is available. If there are no opposing trains, and none ahead, a given train may get clearance for almost the entire line. On the other hand, meeting trains will be cleared only to a certain block (usually with a "take siding") until their meet is complete.

In the case of following trains, the leading train will report clear of each block station (in effect giving the block back to the dispatcher), at which time the DS will give the following train the block.

If there is no other traffic, the DS may give a local the main "in both directions" so they can do their work and not have to call for a second EC-1 to return.

The block stations can be as close as a couple of miles (around yards and passing sidings) to as far as 10 miles or more.

You can do a search on the NORAC Form D - plenty of copies on the web.

[edblysard]

This link will show you a typical track warrant...

http://www.railroadcontrols.com/gcor/warrant.html#14.0

Chad left out RTC, radio traffic control...basically used on roads that run at restricted speed, we keep constant contact with each job (train) and the dispatcher.
On small roads, or switching and terminal roads where each train does a specific job such as yard switching, or working a set of industries in a defined group, say, the candy factory and the paper mill, we all know what each other is doing, and approximately where each others train are...so when we get close, we contact each other via radio...and if a job(train) leaves its normal work area, he will contact anyone out ahead of him, and anyone he expects to be following him to advise them of such.

I switch a yard job; work the main lead in our major yard.
I "own" that lead, the crossovers, and the other main into the yard, out to a particular point.
No one is allowed to enter my part of the yard, or depart the yard, unless they contact the yardmaster, and then me, to ask permission.

Same applies to train working industries...they own the track out to certain points, no one is allowed to enter or pass those points without that jobs Forman’s permission.
These control point may be actual milepost, or landmarks, such as a street crossing or a bridge, and all of the points far exceed the length of any of our trains, for safety reason.

With TWC, it works pretty much the same, except the instructions are written, instead of verbal, and can have a time limit.
When you are issued a track warrant, you own that section of track between those points until your warrant expires, or you request an extension.
If you are a road freight just passing across a system, your warrant will include the direction you will travel, the time you have to do so, the points or milepost you must stay within, and any special instructions, such as taking a siding at a specific point and allowing a train to overtake you, or move past you in the opposite direction.
You may only travel in the direction the warrant specifies, and only between the points stated.

If you are a local switch job, your warrant will give you control points you may work within, with no limit on direction, and will specify the amount of time you have to work.
If the work will exceed the time limit of the warrant, the conductor has to ask for a new warrant.
If the work is done prior to the warrant expiring, the conductor will release the warrant to the dispatcher, and request a new one allowing the train to proceed to another point on the system.

Because each train is issued a warrant to occupy a given section of track, and at times it is necessary for trains to occupy the same portion of track, say opposing traffic or a faster train overtaking a slower one, control points in TWC are often close together.
Overlapping authority to occupy a given section of track can be given to two or more trains, with specific instructions on where, and how far, and what direction you may move.

TWC is often used in conjunction with CTC system to facilitate local and regional roads movement onto and off of CTC controlled main lines, one of the reasons that warrants must be read back to the control operator correctly word for word.
The other reason is so there is no confusion as to what limits the warrant grants to a particular train.
You get three tries, and then you’re out!

Because CTC uses interlocking signals, the aspect / indication of the signals give instructions to train crews, and the turnouts are controlled by the CTC operator, it is possible for a CTC operator to run a train across their entire system on signal indication without ever speaking a word to that trains crew.

For the "official" version of the rules used in CTC, TWC, DTC and RTC, follow this link to the GCOR, General Code of Operating Rules.
It starts with rule 10.0...scroll down to get the rest of the rules...

http://www.railroadcontrols.com/gcor/ctc.html#10.0

Ed

[kenneo]

I have worked all of these forms of dispatching, both as a dispatcher and a conductor. I much prefer timetable and train order for "light traffic" lines and CTC for "main line" and "heavy traffic" lines. For several years I worked one interlocking within a series of CTC interlockings with DTC on one line and CTC on another, yard limits on a third.

DTC is the easiest to use, and by the way it is constructed, the most dificult to violate. TWC is closest to train orders, but in this flexability lies its greatest failings - a lap can be dispatched and only the dispatcher had a record. If he didn't discover the error, oops .

Train orders have an overlapping protection built in. The dispatcher has a copy, the train authorized has a copy, any trains that will be interacted with will have a copy, and each operator (Telegrapher) copying will have a copy. In adition, each operator will repeat the order back to the dispatcher who will need to underline each word as it is repeated. That gives at least three chances to catch an error, and even more when other operators and trains are included.

Signals, can, actually create problems. In any non-CTC territory, the placement of the block signals can cause an oncomming train to flag red blocks espicially when a meet is to be held and the train holding the main is there first.

[Anonymous]

QUOTE: Train orders have an overlapping protection built in. The dispatcher has a copy, the train authorized has a copy, any trains that will be interacted with will have a copy, and each operator (Telegrapher) copying will have a copy. In adition, each operator will repeat the order back to the dispatcher who will need to underline each word as it is repeated. That gives at least three chances to catch an error, and even more when other operators and trains are included.

Assuming the train order is prepared correctly.

There have been instances of train orders being incorrectly issued (in conflict with other trains) by the Controller, and only being detected by other train crew listening in on open radio. Use of telephone would have reduced awareness amonst the crews operating trains, as they would not have heard the conflicting order being issued.

[kenneo]

mt14l ---- Look back at what I wrote. The train order is down in writing and at least three others have a copy and also a copy of all of the other train orders for any other train that will affect them. The very purpose of this is so that any and all concerned can read the instructions, and if something is wrong, get it fixed prior to something bad happening.

My personal opinion, to me at least, is vindicated by the rash of collisions in TWC territory after the operators were removed and "radio" dispatching was introduced. The checks and balances inherent in train orders disappeared. TWC does not have these protections, and DTC does have most. The way DTC is set up it is difficult to set up a lap.

[pat390]

thanks guys, that answered my questions more than i had hoped for


Pat

[MP173]

Pat:

The CFE thru town uses track warrents. You can hear the NS dispatcher and the train crew receiving or cancelling the warrents.

NS is CTC, but they use a lot of 23-A's....dont know what they are, but I hear the term. For example today there is a 91K work train dumping ties at Sprgborro and Nickel and no to S. Wanatah. There is also some sort of crew behind them, so they issue a 23-A so the crew can be behind the train. Pretty fascinating.

A question for the operating guys here.

I often hear a MOW worker or dispatcher refer to "blocks are in place". This is usually with the "23-A". Does the dispatcher actually enter the 23-A into the computer and the signals then protect the area? I will hear the MOW crew then "give it back". I assume the dispatcher then removes the 23A from teh computer? is that correct?

So, if the 23A is in place, does the actual hardware and software NOT allow any signal indications at the control points to display anything other than stop? Is that the failsafe? The software? I cannot imagine a dispatcher having to "remember" where the protection was issued.

ed


ed

[CrazyDiamond]

QUOTE: Originally posted by 1435mm

The flexibility of CTC has devolved to a crutch allowing undisciplined operation and ad hoc scheduling at every level of the railway operation, especially at the top where this technology facilitates impulsive operating policies that are born fresh every morning in reaction to the fad du jour or the squeakiest customer wheel.

Even if CTC/ABS were not available, even if everything were 100% dark, this decay in operational behavior would still happen. It's happening to many companies in every industry. Just be thankful when got a little 'light' to help you along more safely! [:)]

.....but if you need someone from the RR to blame for this 'decay' then you might want to look at Charles Minot, Superintendent, Eric Railroad as the one you who started it! [;)][:D]

[zardoz]

The thing I did not like about dark territory is the lack of signaled protection against misaligned switches (consider that head-on recently that caused the hazmat deaths of 9 people) or broken rails, or other equipment on the tracks.

Sure, it's cheaper to operate a track as "dark" but the risks are much higher also.

[edblysard]

Blocking devices are or can be as simple as a lock on a switch or removing the control handle from a power switch, or cutting out a signal, or forcing one to show red or a stop indication.
The form 23A would be notification to the dispatcher or control operator that the device has been applied, basicly locking out that switch and protecting a portion of the track, say a siding.
Giving it back, or releasing the form 23A is just that, releasing the protection and removing the device from the switch or signal.

Telling a following train about the form 23A is notification to that crew that a track is protected.

I would assume that the control operator would have either a manual device to lock out that switch or signal on his control board, or a computer program that would reconize it and "lock" that part of his system.

Ed

[Anonymous]

I work in train planning in the UK and we don't have anything remotely like TWC and dispatchers. Everything is ridgidly time tabled and the signalling regulators and regional controle only step in when something goes wrong. Now i aquired a copy of Trains from 1985 which had an article about Time Table and train order running on the Katy. I dont understand how a dispatcher plans his meets and i did not understand the references to the schedule? The dispatcher had a train sheet in front of him but it did not say if it was a train graph that the dispatcher filled in as they ordered trains so he could see what sections were occupied or if it was a table that the dispatcher filled in likelly passing times. The author also said a schedule had authorety for 12 hours or some thing and on the day one train was running on another trains schedule. In Britain a train leaves point A at such a time, passes c, d, e, f and g at a specific time and terminated at h at a specific time. I just could not follow the system as to how orders are determined.

[tree68]

Something I've been hearing on CSX lately has been "Authority Numbers." They are given to MOW crews instead of an EC-1. One of the dispatchers had to explain it over the air to someone one day when they first started it, with regards to what limits they could give, etc. All but emergency maintenance must apparently be scheduled, which appears to be where the "authority number" comes from.

Since many times the MOW crew is doing work that technically takes the track out of service, but actually still is capable of handling trains, I can only guess that it has to do with the interaction with the EC-1's and the "authorities", and the DS not being able to allow a train through an block that has a standing EC-1 (as used to be given out for MOW).

As for switches, the DS now gives out permission to operate specific mainline switches, and gets a report of time open and restored, aw well as assurance from the crew that both the engineer and conductor have signed the "Switch Awareness Form."

Townsend - while trains on the line in my area have planned "call times," and I can often count on seeing a certain train at about a certain time, there is nothing resembling a schedule. In fact, the two 'regular' northbounds originate out of Selkirk (Albany) and Dewitt (Syracuse). That means that by the time the Selkirk train hits Syracuse, it's already got several hours behind it, running with the traffic on the Chicago line. I've encountered numerous times when the train symbol indicates that it's actually yesterday's train...

Depending on how each of the four does getting out, it's likely that they will encounter a meet an any of the half dozen suitable sidings on the line. Sometimes you can tell the DS is playing a bit of a chess game, making sure that the trains will fit on sidings (sometimes they don't), and that a crew that's running short on the law will be someplace besides out on the main if they run out of time. The through trains also often have work to do at a couple of intermediate yards, too. Everything conspires against having a specific schedule...

[geomodelrailroader]

let me give you an example. I am an Idaho railfan all the tracks in Idaho are PTC controlled and use CTC and ABS the only exception is the Butte Subdivision north of Idaho Falls. This section is single track and is dark territory there are signals on the line but you must get a track warrant in Pocatello before moving a train north of Idaho Falls. South Bounds are the exception since they deliver their cars to Pocatello Yard and use ABS.

[petitnj]

Are you ready for this. Another rule book, USOR, uses a mandatory directive called the Track Authority. It is very similar to the Track Warrant, but slightly different. It works the same as TWC. You get a TA to occupy the main track.  Two trains can have a Track Authority for the same track as noted on the authority. The trains must contact each other and coordinate their movements. If a work party is also on the track they get a Track Authority as well and the Employee in Charge coordinates all the other EIC's and trains on the track. It is complex but actually works well when the trains dispatch each other. I can bring a train right up to the nearest milepost while my train takes the siding. When we are locked in the siding, the other train can proceed. The dispatcher is not the middle man here and things get done efficiently . 

As you can see "dark territory" is covered by a number of different control methods. All main line track is covered by one of these methods. Often there are heavily used main lines that have CTC and TWC alternating along the route and you can hear trains getting their warrants as they go. 

Either GCOR (General Code of Operating Rules) or USOR (U.S. Operating Rules -- ironically used by the Canadian National RR) is used as the basis for operation. Those are modified by Bulletin Orders,  Operating Bulletins, Special Instructions, Time Tables and other documents for train operation.  With these many layers of instruction, operation is very complex but an explanation sounds much harder than actual operation.  

[SD70Dude]

petitnj

Are you ready for this. Another rule book, USOR, uses a mandatory directive called the Track Authority. It is very similar to the Track Warrant, but slightly different. It works the same as TWC. You get a TA to occupy the main track.  Two trains can have a Track Authority for the same track as noted on the authority. The trains must contact each other and coordinate their movements. If a work party is also on the track they get a Track Authority as well and the Employee in Charge coordinates all the other EIC's and trains on the track. It is complex but actually works well when the trains dispatch each other. I can bring a train right up to the nearest milepost while my train takes the siding. When we are locked in the siding, the other train can proceed. The dispatcher is not the middle man here and things get done efficiently . 

That is pretty much how it works in Canada too, except for some terminology differences.

The is only one rulebook north of the border, the Canadian Rail Operating Rules (CROR).  Dark territory main track is governed by the Occupancy Control System (OCS, not to be confused with On-Company Service) and trains operate with OCS clearances issued by the Dispatcher, who is called a Rail Traffic Controller (RTC) here.

[mudchicken]

geomodelrailroader

let me give you an example. I am an Idaho railfan all the tracks in Idaho are PTC controlled and use CTC and ABS the only exception is the Butte Subdivision north of Idaho Falls. This section is single track and is dark territory there are signals on the line but you must get a track warrant in Pocatello before moving a train north of Idaho Falls. South Bounds are the exception since they deliver their cars to Pocatello Yard and use ABS.

 

Rethink your statement. (EIRR)