On a single track mainline, with passing sidings, and two way traffic. The answer is a train can onlu move if it has an empty track in front of it, and an empty track to stop on.
If you had both tracks at each passing position occupied, with one east bound and one west bound train at each, then all east bound trains could move up one siding, and then all westbound move up one siding. Great care needed, and very boring.
fwrightThought some more about the original question. I think the underlying question is, "How does one achieve the maximum train density on a given layout?" And what are the limiting factors?
On my layout, well it's only plywood wired and ready for track--but I can see it all operating in my head. You can run 4 trains, all of them working. There is a yard switcher, a lumber switcher moving boxcars to fill orders, there is a mainline train, either freight or passenger, and the freight drops off and picks up cars, and there is the logging train coming out of the mountains to drop logs at the mill.
The limitation is space. It's roughly 8x12 and eventually everyone will need to be in the same place in the center at once. Practically speaking, two operators can work at once.
Chip
Building the Rock Ridge Railroad with the slowest construction crew west of the Pecos.
Thought some more about the original question. I think the underlying question is, "How does one achieve the maximum train density on a given layout?" And what are the limiting factors?
I thought the history of the prototype might give some answers. Railroad infrastructure - land, roadbed, track, maintenance, people, buildings - is very expensive. The best way to get a profitable return is to maximize density on limited infrastructure. Railroads have been working on this for over 150 years. Model railroads are very similar in this regard - infrastructure (the layout) is expensive in terms of space, time, maintenance, and costs. Time, maintenance, and costs are non-linear - they go up as the square of the space. Space for model railroading and land for railroads is generally hard limited - there is a gigantic step increase in cost to go above what is on hand.
Narrow gauge was an attempt to reduce cost of infrastructure to a greater degree than the capacity. It failed.
But the right answer proved to be increasing density of trains (increasing capacity) on a limited infrastructure.
Early railroads were a "see and avoid" solution. The engineer was responsible for not crashing into another train. Very much how a DCC layout operates today.
The next step was the addition of timetables and operating rules to assist the engineer. This allowed a substantial decrease in following distances for trains, and prearranged meets reduced waiting times. Both helped to dramatically increase train density. But limited communications didn't really allow for centralized dispatcher control, and therefore things would fall apart when somebody got significantly behind schedule. Happens all the time in model railroad operations.
As communications improved, trains could be run even closer together as long as the dispatcher could control the track. Signalling systems and station/train position reporting gave the dispatcher command and status respectively. There are some model railroads that reach this point.
In modern railroading, blocks have become shorter and status is reported on a full-time basis to the dispatcher to allow the dispatcher even tighter control and the closest practical train spacing for a given track arrangement. Algorithms have been written to allow computerized dispatching. And so even greater train density has been achieved.
The density gains in the late 20th Century have been so great that most of the double track from the early part of the century has disappeared.
just my thoughts
Fred W
It depends on what you consider "operating" as well. Is the operator, to use John Armstrong's terms, the "Spectator", the "Engineer", or the "Dispatcher"?
A "Spectator" layout with lots of automation (and a dispatcher) can support a very high density of trains. What is being sought is the sight of a train or trains going through a scene or scenes. DCC is not all that helpful for high density operations because of its "see and avoid" mentality.
A "Dispatcher" layout can also be high density (to make the Dispatcher work). But again, high density of trains on track requires not just engine control, but track control and blocks. Just like prototype light rail systems.
An "Engineer" layout tends to be lower density, with number of trains limited by passing tracks or other temporary "get off the main" devices. Without a dispatcher and some kind of operating rules, density has to be limited to practice "see and avoid". Direct engine control via DCC or similar supports the Engineer experience. Meets and passing are arranged between the engineers for the 2 trains.
It's been interesting to operate a large modular HOn3 single track layout. Operations in Engineer mode (which most of us prefer) can quickly grind to a halt if train density gets too high. Spectator operations can go to a higher density because all the engineers are just running a train for show. The density could go even higher with some run rules and a dispatcher coordinating.
I built several DC cab control powered layouts before I finally tried DCC. None of these layouts were very big and I usually operated alone. Trying to "run" two trains by myself usually meant just running two trains around the layout while I performed the "toggle switch two-step" to keep them from running into one another. While visitors were impressed that I could run two trains, I was not able to teach a second operator how to take over one of the trains using the cab control system. Part of the problem was that I used a central control panel with Atlas components layed out in straight lines. Having to match the component number to a numbered block of rail often took longer than it took the train to travel that block with obvious results. DCC made all of this so much easier and more fun, too! DCC wiring is much simpler as well.
Hornblower
I wired my layout with multiple cab control on separate control panels for different sections of the layout. I can run a continuous train, with other operators running staging trains separately on different parts of the layout. The layout is wired so that the main control panel can operate trains on any part of the layout, including the upper level.
Marlon
See pictures of the Clinton-Golden Valley RR
cuyama gregc but i think there's room for improvement when you have ~half your engineers waiting for a train out of the same staging yard, but wonder if it gives the dispatcher a break. Dave H. provided good suggestions. In addition, many layouts now stage some trains out on the layout as if "en route". This reduces the congestion in staging and active yards and puts more crews to work at the session start.
gregc but i think there's room for improvement when you have ~half your engineers waiting for a train out of the same staging yard, but wonder if it gives the dispatcher a break.
Dave H. provided good suggestions. In addition, many layouts now stage some trains out on the layout as if "en route". This reduces the congestion in staging and active yards and puts more crews to work at the session start.
I do this, been doing it for years.
My operational plan includes one or two freight trains in the yard ready to depart, several passenger trains already in the station, and, there are cutoff tracks that bypass the staging all together, they appear as a junction at each end of the visable mainline and provide two more staging spots during an opps session.
My very first layout, built for me by my father in 1967, had hidden staging. And with power routing TruScale turnouts you could operate it blind. Throw one turnout, drive the train in slowly, it would stop when it hit a dead spot controlled by contacts on the Kemtron switch machine for the turnout. Throw the second turnout, flip the block toggle and pull the other train out.
People were amazed, one train went in the tunnel, a different one came out the other end. Guess my father was ahead of his time in model railroading.......
Sheldon
gregcbut i think there's room for improvement when you have ~half your engineers waiting for a train out of the same staging yard, but wonder if it gives the dispatcher a break.
Layout Design GalleryLayout Design Special Interest Group
True.
Next step is to figure out why everybody is bunched at the same place.
Is it that several trains were scheduled to converge on the same place at the same time?
Were they scheduled at different times and they didn't run to schedule?
Or... is the one train everybody is waiting on scheduled at the wrong time?
Or. is the dispatcher prioritizing the wrong train (holding 3 trains to run one)?
Lots of options, lots of ways to adjust the problem.
Dave H. Painted side goes up. My website : wnbranch.com
thanks
i understand running railroad like airlines, landing 2 mins apart is unrealistic and unsafe (yes, i'm a firmware guy use to controlling thing in nanosec).
i understand that a tight schedule is totally messed up if theres a model train derailment.
but i think there's room for improvement when you have ~half your engineers waiting for a train out of the same staging yard, but wonder if it gives the dispatcher a break.
i believe a well thought out schedule can results in rational throughput and smooth, uneventful operation. maybe people want some chaos (entertainment)
greg - Philadelphia & Reading / Reading
Routes:
You said you had trains waiting for other trains at junctions and interlockings. That implies that you have trains taking different routes through those interlockings or junctions.
Line every main track switch between Yard and Bank for the normal route. Any time you line a switch (other than a crossover move) is a different route. Yard-Latham-Dell-Shore-Nassau-Bank-Cliff is a "route". Any other combination of statins, or any other order of stations is a different route.
gregci think (model) trains could be scheduled such that when sharing trackage, they arrive at a junction just as it clears from a previous train.
Yes, but that's not going to have a high degree of success because any pertubation will cause the schedule to fail.
Real railroads don't work that way.
My observation is that you like things wound really tight. Based on other threads you have had, you really, really, really sweat the details. You do not seem to like things "loose".
Unfortunately, this is one of those situations where a "loose" solution might work better than a "tight" solution. You do exactly what the prototype does, work at the 70% percentile. That puts trains early more than late, which gives them a bit of slack, so if they do get delayed its not a big deal.
On the line between Kansas City and St Louis, we had 2 pair of Amtraks a day. The line was conventional double track St Louis to Jeff City and effective double track Jeff City to KC. Trains went west on the Sedalia Sub and east on the River Sub, parallel routes 20 miles apart. Amtrak operated in both directions on the Sedalia Sub. Because of the volume, we had to start putting trains in sidings as far back as Jeff City, 125 miles away from KC, BEFORE Amtrak left KC. The 8th or 9th train from Kansas City would have to wait for Amtrak to run all the way from KC to Jeff City before it could leave Jeff City. Not suggesting that for your club, but just as an example even with a "tightly" scheduled train, delays can happen.
It might also help if you backed off the train density a tad, minimizing the conflicts.
Which, to Cuyama's point, brings us to simplifying the routing. Just use the through route between Yard, Port and Cliff, remove Hyde, Radstock and Richards from service and spike the switches at Dell execpt for the crossovers.
Cliff to Green Mountain becomes staging and you run staging to yard or staging to port. Hugely simplifies the operation. Then you have a straight double track main with a short stretch of single track through Spikes Peak. Simpler to operate.
13?
an alternate route is separated track between two endpoints, right?
don't understand why you consider a reversing loop an alternate route
yes, trains can originate and return to hyde, but hyde is hidden and is really two separate, westbound and eastbound staging areas with specific tracks for long (80) coal trains.
port complicates things. one (D, E) track is hidden storage for a circus train. i guess the other is an alternate route.
can you be specific?
dehusmanThere are 4 reversing loops and two "ovals" plus the "main line". I found at least 6 or 7 routes a train can take out of Hyde, plus at least three involving Cliff and three more involving coming off the branch.
+1
gregci'm not aware of alternate routes?
There are 4 reversing loops and two "ovals" plus the "main line". I found at least 6 or 7 routes a train can take out of Hyde, plus at least three involving Cliff and three more involving coming off the branch.
cuyamaI suggest you look at removing some of the junctions and alternate routes
i'm not aware of alternate routes?
As I understand the diagram, one of the problems you have is the many junctions and alternate routes. These create "friction" that makes it hard to move more trains in a given time.
gregc i think (model) trains could be scheduled such that when sharing trackage, they arrive at a junction just as it clears from a previous train.
That probably won't work consistently. All it takes is one club member to decide he needs to go get coffee to make his train a few minute late and jam up the schedule.
If you want to increase capacity, I suggest you look at removing some of the junctions and alternate routes from service temporarily during formal op sessions. That would reduce the number of interactions for each train and ease scheduling. After all, real-life trains can’t teleport directly from New York to Chicago; they run linearly through the intervening country.
In that space, a different track plan could support many more trains in motion, but of course it can’t be changed now. I’ve operated and worked with ops plans for much smaller spaces that handle more trains at once with less friction.
It may be counterintuitive, but fewer trains running at one time may increase the throughput and allow more trains to be run overall in a given time. A jam-packed schedule with lots of dependencies is very hard to maintain and any missed meets and passes will snowball into much bigger problems.
Byron
dehusmanHere's my take on the operation, if I had to overlay some concept on the existing plan. Kind of a Jersey side of New York kinda theme with Port and Yard representing New York City/Jersy City/Port Reading and Cliff kind of a Maybrook type destination, with Hyde representing Wilkes Barre/Scranton and Phillie. The RDG runs Phillie to Port, the CNJ (or LV) runs Scranton to Yard and Port, the NH (or LV) runs Yard to Maybrook.
that's an interesting analogy to the extensiveness of the layout.
but i keep thinking of the explanation of car exhaust headers, that hot dogs of gas exit the cylinder and each reaches the header manifold just as the previous hot dog leaves the manifold. i think (model) trains could be scheduled such that when sharing trackage, they arrive at a junction just as it clears from a previous train.
scheduling trains is one challenge, but another is can a dispatcher keep up with such a schedule. yes, this is an unrealistic artifact of a model railroad trying to maximize operations over a limited amount of time.
i'm reminded of gomez adams switching turnouts just as a train completely crosses one and another train reaches it.
it makes sense that the schedule should not only optimize train throughput but dispatcher capacity as well. currently, that workload is shared with tower operators. consequently, the lack of tower operators impacts remote operation.
but there's discussion of integrating tower capability with the dispatcher (more hardware and software). perhaps, as sheldon suggested, a way of having multiple CTC operators managing different parts of the layout.
while i'm sure some think i sound disgruntled, the tread is making me aware of and thinking thru aspects of operation i'm unfamiliar with and may take for granted.
so thanks
If you want to do west coast, then make substitute LA for New York and assign the routes to the UP, SP and ATSF instead of the RDG, CNJ and LV.
gregcthat's the track plan.
Wow. Its reverse loop to reverse loop with a more or less two ovals and a reverse loop dropped in the middle.
I could see where that would be very challenging to operate and if you just ran trains on individual routes, it could get balled up really fast.
If you wanted to operate prototypically you would have to operate the main truck line and the other loopy ovals would have to be connecting lines that feed trains into the main trunk.
Not sure how that would work since it seems like most of the staging is in the middle. If there was staging in each of the end loops, I would try to run it as four major routes: Yard to A-Hyde, Port to A-Hyde, Cliff to F-Hyde, and Yard to Cliff. The routes would overlap on the Dell to Shore portion.
Here's my take on the operation, if I had to overlay some concept on the existing plan. Kind of a Jersey side of New York kinda theme with Port and Yard representing New York City/Jersy City/Port Reading and Cliff kind of a Maybrook type destination, with Hyde representing Wilkes Barre/Scranton and Phillie. The RDG runs Phillie to Port, the CNJ (or LV) runs Scranton to Yard and Port, the NH (or LV) runs Yard to Maybrook.
The constraining factors are the staging at Hyde, the single track, the ability of the end loops to originate and terminate trains and the ability to pump trains between Dell and Shore.
The diagram is so small I can't make out the details of the text description or the individual tracks, so if there is a operating concept, I am unable to read it.
dehusmanThe only thing I've seen is a picture of a decades old layout Without any information any discussion is purely in the abstract.
Without any information any discussion is purely in the abstract.
that's the track plan.
ATLANTIC CENTRALIn the same layout space, true separate double track continuous double track loops with thru staging would allow trains in both directions to enter and leave staging without waiting for trains traveling in the other direction.
i believe the layout has examples of all of the above. it has 3 loop staging areas with separate entrance/egress, it has double track mainline but single track to 1 staging area.
i would say it models various realities of existing railroads that have existed for over a 100 years and of course are not optimal for current needs.
dehusman Is there a track plan or any kind of information on the layout we are discussing? If there has been, I haven't seen it. The only thing I've seen is a picture of a decades old layout and string line of a small DRGW layout. Without any information any discussion is purely in the abstract. Poor scheduling can bottleneck things. But then again poor execution of a good schedule can bottle neck things. A poor track design can bottle neck things. A poor yard operation can bottle neck things. A poor communications method can bottle neck things. Poor operating practices can bottle neck things. It could be any one, any combination or all of the above. Who knows?
Is there a track plan or any kind of information on the layout we are discussing? If there has been, I haven't seen it. The only thing I've seen is a picture of a decades old layout and string line of a small DRGW layout.
Poor scheduling can bottleneck things.
But then again poor execution of a good schedule can bottle neck things.
A poor track design can bottle neck things.
A poor yard operation can bottle neck things.
A poor communications method can bottle neck things.
Poor operating practices can bottle neck things.
It could be any one, any combination or all of the above. Who knows?
It is my understanding that Greg is refering to the Pacific Southern Railway, where I believe he is a member.
gregc dehusman Do you want every operator to have a train to run as soon as the op session starts? (expect) no dehusman Do you expect to have every operator operating a train at every moment? every operator that would like to, within reason. of course some may only run a train or two and chit chat the rest of the time. but it seems poor scheduling on larger layouts can result in bottle-necks.
dehusman Do you want every operator to have a train to run as soon as the op session starts?
(expect) no
dehusman Do you expect to have every operator operating a train at every moment?
every operator that would like to, within reason. of course some may only run a train or two and chit chat the rest of the time. but it seems poor scheduling on larger layouts can result in bottle-necks.
OK Greg, the bottleneck problem is the track plan.
Recycling trains at the ends of the mainline looks to be a problem.
Having the staging in the middle of the mainline that short circuits the mainline does not seem like a good plan.
And loop to loop double track mainlines are not really double track in terms of traffic volume.
I have long argued against point to point or even loop to loop layouts as requiring too much setup and turn around time at the ends of the mainline.
In the same layout space, true separate double track continuous double track loops with thru staging would allow trains in both directions to enter and leave staging without waiting for trains traveling in the other direction.
I realize it was typical back in the day, but that layout has the mainline running around and around thru the same scenes a bit too much.
They should have used some of that open floor space........
It can be so simple and so effective, take the mainline once around the room visably, then take it once around the room hidden with staging all along the hidden part.
A west bound train runs the visable length of the main, disappears, parks in staging, another takes its place, reappearing as a new west bound train at the east end of the mainline.
And likewise in the other direction.....
Then you ad in yards, juctions, branch lines, etc.
In my case I only have one visable yard, one major passenger station, one engine terminal, one wye junction, etc, etc.
The only feature that is really modeled more than once are rural commuter stations, there are three of those.
dehusmanDo you want every operator to have a train to run as soon as the op session starts?
dehusmanDo you expect to have every operator operating a train at every moment?
riogrande5761I was also recommended that I may want to power block the staging so I can "turn-off" track power to each staging track if I wanted. Reason being DCC engines may be sitting there with sound and pulling power when not in use.
DoughlessYou can have 50 different trains waiting in staging, or a train waiting on a passing siding somewhere, but my rules are that only one train at a time moves on the layout.
I was on another forum, which I believe GregC is on, and I was getting some advice on setting up my DCC system for a layout I am working on. How many boosters, and how many power districts etc. Layout is to have 11 staging tracks so potentially 10 or 11 trains in staging.
https://model-railroad-hobbyist.com/node/38407
Conclusion was that I could run several trains and probably will only need one booster, or at most two. Part of the topology involved the used of PSX circuit breakers and divide the layout into power districts etc.
I was also recommended that I may want to power block the staging so I can "turn-off" track power to each staging track if I wanted. Reason being DCC engines may be sitting there with sound and pulling power when not in use.
Follow the above link if you want to wade through the discussion but it was very informative.
Rio Grande. The Action Road - Focus 1977-1983
gregcthe club may have 6+ engineers besides a dispatcher and 3 tower operators. i've had to wait at signals for 5 mins. 2-3 trains will be scheduled over a single track branch, as well;
Finally we are getting to your real question.
engineers standing around waiting for their train to be cleared out of staging thru the single track while one is coming into staging over the single track
This harks back to the "turn time" that I mentioned earlier. Also applies to single track helixes. The constraint on the spacing of trains is the turn time into staging.
The question then becomes what do you want the operation to feel like?
Do you expect to have every operator operating a train at every moment? Do you want every operator to have a train to run as soon as the op session starts?
I will operate (after phase 2 is in service) with a crew of 4 yardmaster/yard engines, 3 or 4 road jobs and a dispatcher. After I generate the line up of trains (using a string chart), I then schedule the operators. Which trains will operator A run, which will operator B run, etc. I then adjust the schedules/line up to match the operators.
Real railroads have crews that take 8-12 hours to get someplace. Our crews take way less time so its a completely different dynamic. I have only operated on one layout where I had one train (as opposed to switcher), a turn, that took the entire op session to run.
gregc i assume no one would be pleased if i were assigned a train and had 5 min conversation with someone before pulling out during an op-session.
i assume no one would be pleased if i were assigned a train and had 5 min conversation with someone before pulling out during an op-session.
That's what happens when you have a friendly operating session. If you had everyone running a train without conversation or friendly banter, no one would want to run trains.
My layout is 20' x 20', 2 levels, double track main with staging on lower level. I dispatch with manual controlled signals. I have one yardmaster and my optimal operating session is to have 4 operators. It can get crowded, and some trains will have both engineer and brakeman.
100 operators? I've seen modular layouts bigger than your original post and they don't have that many operators. How long would an operating session last with that many operators?
Neal