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signals: siding vs run-around

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  • Member since
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Posted by dehusman on Thursday, April 26, 2018 10:35 PM

BRAKIE
Today there is no manned towers,no OSing GPS and computerized DS'ing is used. CSX closed F Tower at Fostoria five(?) years ago and those are hot diamonds and connectors. In dark territory the DS better know where his trains is.

I spent 2/3 of my railroad career in dispatch offices.  The dispatcher doesn't need to know EXACTLY where the train is at all times.  He needs to know where the train was authorized and that the train is in its authority.  Even in CTC the train dispatcher doesn't know EXACTLY where the trains are, he just knows they are in a block which could be miles long.  He doesn't need to know it the train 1000 feet west of mp 201 or 2000 ft west of mp 201. 

The person that needs to know EXACTLY where the train is is the engineer (and conductor).

Dispatch offices do NOT use GPS to dispatch trains.  Primarily because not all trains are equipped with transponding GPS locators, and the GPS signals are not shared real time between railroads.  A UP engine on the NS doesn't share its GPS info with the NS and an NS engine on the UP doesn't share its info with the NS.  They are working on that, but it wasn't in place a couple years ago.  In some cases the GPS only reports at intervals, like every 15 minutes, which is not good enough for dispatching.  Plus the commercial GPS is only good to plus or minus 15-20 ft.  Since tracks can be on 13 ft centers, commercial GPS isn't accurate enough to tell which track a train is on, that is kinda important for dispatching.  Dispatch systems do NOT use GPS for dispatching.  PTC uses GPS to locate trains on the railroad, but that is a different thing.  That is the engine locating itself on the railroad, it is one way communication, the same as your auto GPS telling you where your car is on the road.  For that measure, plus or minus 15-20 ft is good enough.

Dave H. Painted side goes up. My website : wnbranch.com

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Posted by dehusman on Thursday, April 26, 2018 10:40 PM

ATLANTIC CENTRAL
So that is the question, did the crew report the switch as lined to the main? If they did, it falls on them.

Crews are required to report that they have restored all main track switches to normal position by federal law, an emergency order was issued following a previous accident and it became a rule/law.

I have heard of several incidents where a train reported they restored the switches and had not. Lots of reasons, they thought another crew member did it, they intended to and got distracted, they thought they had, but hadn't.

Dave H. Painted side goes up. My website : wnbranch.com

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Posted by Anonymous on Friday, April 27, 2018 6:49 PM

gregc

thanks

one aspect of the hobby is to better understand the how real railroads work.   I know some modelers truly try to model real railroads in contrast to building a model railroad.

as i add signals to my model railroad, they've made me wonder about how real railroads use them.   In my case, i'd like the signals to be helpful as well.   So as you've helped me understand, i realize what i'd like to do is not prototypical and I'm fine with that.

what i'd like to do is make the signal indicate "stop" if the turnout is aligned to an occupied track at a siding (station/depot).   This would be helpful to me when I operate my model RR.

i appreciate all the explanations.  I wouldn't be surprised if over time i see the weaknesses of what I've done and can better appreciate prototypical operation.

 

Greg,

There is a lot of really good information that can be had from OPSIG (NMRA membership encouraged, but not required).  They have a quarterly publication that can be had digitally.   

Also you might wish to pick up one of Brian Solomon's Railroad Signaling books (I think he has written two now).

Another good reasource is 19 East Copy Three (from OPSIG, I dont know if they have any copies left edit: I just checked, they dont, but several online retailers have it).  A review can be found here: http://www.opsig.org/doff/DOpages/19EastReview.pdf

19 East Copy Three explains TT & TO operation very well.  

OPSIG also has a book called A Compendium of Model Railroad Operations.

Another good resource is Rights of Trains by Peter Josserand.  This book contains the Standard Code of Operating Rules, Adopted March, 1949.  It provides the stardard code, operating rules, block signal rules, interlocking rules, individual carrier changes to the rules, and a very useful question and answer section and much more.   Its a little light on photographs (just has some figures).  

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Posted by gregc on Friday, April 27, 2018 7:10 PM

thanks for the book recommendation

i've read the Soloman books, but they are just about signals.   The books on operations sound more interesting.

greg - Philadelphia & Reading / Reading

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Posted by Anonymous on Friday, April 27, 2018 7:54 PM

gregc

thanks for the book recommendation

i've read the Soloman books, but they are just about signals.   The books on operations sound more interesting.

 

Also for a very detailed explaination of model railroad signalling, Bruce Chubb did a 13? part article in RMC last year (or the year before).  Its extensive in its discussion of signaling.

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Posted by dehusman on Saturday, April 28, 2018 11:54 AM

gregc
i've read the Soloman books, but they are just about signals. The books on operations sound more interesting.

For the books on operations, it helps to have a rule book handy.  They are all pretty dry.  Josserand assumes the reader has a familiarity with the rules.  They also tend to say what the rules mean, but not necessarily how to use them.  The OpSig books and articles are the more along those lines, being intended for modelers.  Stuff by Steve King is very good.

Also be prepared to find that there is a lot of model stuff that is not covered because the prototype didn't do that.  For example, the dispatcher authorizing a runaround in ABS or dark TT&TO or signals set up to facilitate switching moves.  Or even installing signals on a line that has only two stations.

Dave H. Painted side goes up. My website : wnbranch.com

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Posted by faraway on Saturday, April 28, 2018 3:44 PM

I have read all the long thread but I do still not understand how a train gets out of a siding or double connected lead again.

Let's assume only one direction with the ABS blocks 1 to 10. Four trains enter that string of blocks. Train A goes into a siding in block 8, realignes the switches and starts some switching. After some time is the switing done and train A wants toget back on the main.

Train B is fast and has passed block 8 while train A did switching. Train C and D are slow and travel in block 4 and 6.

Who knows train C is at block 6 and train A may throw the switch and reoccupy block 8? The train crew has no indication. The dispatcher has no "electric" information of the location of trains C and D. 

Will train A ask for permission, the dispatcher ask C and D via radio and grant or deny permission based on the verbal location report?

Reinhard

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Posted by jeffhergert on Saturday, April 28, 2018 6:23 PM

faraway

I have read all the long thread but I do still not understand how a train gets out of a siding or double connected lead again.

Let's assume only one direction with the ABS blocks 1 to 10. Four trains enter that string of blocks. Train A goes into a siding in block 8, realignes the switches and starts some switching. After some time is the switing done and train A wants toget back on the main.

Train B is fast and has passed block 8 while train A did switching. Train C and D are slow and travel in block 4 and 6.

Who knows train C is at block 6 and train A may throw the switch and reoccupy block 8? The train crew has no indication. The dispatcher has no "electric" information of the location of trains C and D. 

Will train A ask for permission, the dispatcher ask C and D via radio and grant or deny permission based on the verbal location report?

 

Assuming single track ABS and the train in the siding has authority to proceed and any following trains aren't superior to this train.  That is, there are no approaching trains that the train would have to meet, nor is there any following trains that train would have to allow to pass before entering the main track. 

A crewmember goes to the main track switch and opens it.  The crewmember stays at the switch and the train waits 5 minutes before leaving the siding and entering the main track.  When the switch is opened, it shunts the block signal system, causing signals approaching the block that the switch is in from both directions to go red.  The 5 minute wait is to allow any approaching train to reach their next block signal and observe that there is an obstruction ahead.  Depending on where the approaching train is, their last signal may have been green, the next one red.  If the approaching train is already beyond the last signal before the switch, the 5 minute wait allows the crewmember at the switch to see the approaching train and line the switch back for the main track.

There are conditions where the 5 minute wait isn't required.  That's for another discussion.  First, grasp the 5 minute wait before entereing tha main track.  That's how they teach new-hires on the railroad I work for.  You need to understand the basics before tackling the technicalities.

Jeff     

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Posted by faraway on Saturday, April 28, 2018 6:49 PM

Jeff, thanks for the explanation. it is much simpler than expected :-)

Reinhard

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Posted by dehusman on Sunday, April 29, 2018 1:12 PM

Actually the answer to the original question was pretty simple.  They would flag.

When the train is about to arrive at the station they drop a flagman, the train pulls into the siding, while they secure the train the head flagman goes out ahead, they open the switch and wait 5 minutes, they run around the train, get back in the siding, call in the flags and they are done.

On some roads, they might leave the entering switch open to "hold" the signals.

Dave H. Painted side goes up. My website : wnbranch.com

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Posted by gregc on Sunday, April 29, 2018 2:50 PM

considering the rules described for entering a siding,  I have a difficult time imagining a model railroad that truly implements a prototypical signaling system or an operating session that accurately follows a rule book.

i've seen Bruce Chubb's Signal series describing turnout locks and keys

greg - Philadelphia & Reading / Reading

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Posted by dehusman on Sunday, April 29, 2018 8:43 PM

gregc
considering the rules described for entering a siding, I have a difficult time imagining a model railroad that truly implements a prototypical signaling system or an operating session that accurately follows a rule book.

In ABS the rules for entering a siding are very simple.  Stop.  Line the switch.  Enter the siding. 

In ABS the rules for leaving a siding are very simple.  When you have authority, open the switch.  Wait 5 minutes.  If its clear, go.

In CTC the rules for entering a siding are very simple.  You obey the signals.

In CTC the rules for leaving a siding are simple.  You obey the signals.

But that's not what you asked about.

Dave H. Painted side goes up. My website : wnbranch.com

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