the minimum?

  I think the bare minimum is the distance I can see when railfanning a location. So about two miles if a flat open area or maybe a bit less in a mountainous location. At Tehapaci for instance I can park at the loop and see trains coming up from Woodford ,around the loop and disappearing around the hill. So a layout with the Woodford siding,the climb to the loop and the loop siding would give enough run to have meets at the sidings and watch the trains re-start and fight the grade. Staging on each end of the modeled area could connect off scene to provide lots of trains for the session. My S scale layout has about 100 feet of mainline run which seems like enough running slow and working the industries but would be pretty short if I were just high balling around it. If mainline running was the goal I'd probably have gone around the room twice to double the run .......DaveB

How much space do you have available?

How long are the trains you want to run?  What is the terrain that you are running through?  I think the best that I have seen in ho scale is the Tehachapie layout at the San Diego Model Railroad Museum built by the La Mesa club.  They can run multiple trains with 100 cars or more in each train.  Most of the trains that I have seen them run are using 40-50 foot cars.  The limiting factor there is the length of the passing sidings. 

I was invited to run a train there when I was visiting one time and one of the guys invited me to run after I had been there all morning and came back after lunch.  The operators' aisle is 320 feet long!

If you don't have the space for a long enough mainline, the trick is to have a view block of some sort that keeps you from seeing both ends of your long train at the same time.  The limiting factor for most of us will always be how much space you have for a model railroad.

Minimum

Minimum?  Very subjective and it depends, but you already know that.

Staging to staging, 4-5- train lengths, main-siding-main-siding-main.  You leave staging and you have two options for meeting points.

Also depends on what the trains DO.  For example a through freight on my layout starts out in a yard.  The crew has to get their engine, hostle it to the train, depart, run to the first siding, they might have a pick up there, then run to the next major station where they might have a set out and pick up.  Then they will run to the next siding, which is also a junction with a branch so they might pick up there.  When they get to the final terminal they yard their train and turn their power, they may turn back on another train.

That is all in about 14-15 train lengths (Terminal-main-Siding-main-main-Terminal-main-main-main-Siding-main-main-main-Terminal).

Plus a NWD Thru train out of origin will have 2 blocks and a SWD Thru train out of origin will have 3 blocks so when they pick up, if they pick up in block that will take longer.

Its not only how long the run is and how many sidings, its what the train have to do along the way that contributes to operations. 

If I had the space available,

If I had the space available, I would want a run between two towns to be long enough so that neither town can be seen from the other.  During it's run, the train should be out of sight of both towns for at lest 4 to 5 train lengths.

Probably not a lot of layout's out there that can achieve this for all of the yards and towns on the layout.

gs

Time, is what makes a layout seem bigger than it is.

If it takes you 5 minutes or more to get from point A to B.  You have it.  Any time over 3 minutes makes you feel like you have gone some place.  Not as much a distance thing,  it is a time thing.

running at 20mph or less.  I takes a long time to get from point A to B on my layout.  Run the Amtrak and you have just done the entire layout in around 2 or 3 minutes.

Talking real time,  not fast clock time.

Depends on era.

For modern railroads you would need a lot of space because cars are longer, trains are longer and require much larger curves to operate reliably. I would have to do a nolix to have modern trains fit my 11’ x13’ space or model a small short line. A decently long train would wrap 75% to 100% of the way around the room to represent a mainline regional or class 1 train.  Even then it would actually be condensed to about 20-25% compared to prototype. Don’t blink or you will miss it.  
 

I model 1925. There were longer trains on the heavy mainlines back then too but many routes had a medium level of traffic and a 15 car train looks respectable and fits in 10’-11’ of track. 
I can run 2 trains since I have 2 passing sidings on a circle of track, but I can’t really replicate true mainline procedures. The closest I can get is one train comes in from staging and then the opposing train arrives from staging. I currently only model 1 location. 

Limited space is why I enjoy

Limited space is why I enjoy the folded loop config with a central operating pit.  You can double the main in many instances, or at least have two 10+ foot sidings, and it becomes a looped point-to-point.  Although it comes back to the same place it started, but...nothing's perfect.

A doubled main affords the operator flexibility in purpose and desired effect, but it extends the run to twice the nominal single loop distance.  In my case, a single loop at passenger express speed would take about 55-60 seconds in my 9' X 18' space.  With a folded loop, I get to see the backdrop behind the train everywhere and the trip, again timed AT speed, is now about 2 minutes.  In scale, it's only about 3.5 miles (haven't really figured it out, just a guess), so it is highly compressed, but there's no reason I can't run another loop, folded, and extend that out to a satisfying 4 minutes.  With a drag freight, I can go back to the house and get a coffee or a beer and not miss a mile's worth of movement. 

  "A doubled main affords

and with the right type of scenery one can even design a three times around the room plan and get even more running length....DaveB

Naturally how much space you

Naturally how much space you have is going to limit it somewhat.  I'm working with what I got and feel I have a mainline that will sort of do the job.  Two 21' sidings and mostly visually separated from each other, granted, runs aren't very long.  Staging for around 10 fairly long trains, a main yard and a branch line that will run below around part of the layout.

Dave1905 has excellent points

Dave1905 has excellent points in his post as does AZ Baja. I would suggest it depends on what you are modeling and how you are doing it. For example in my plans for a layout the area modeled will represent less than 10 actual miles of mainline and include a yard and engine terminal along two miles of that location. I also like long trains that are 50 to 100 cars in length. The entire modeled portion of the line will be urban with heavy industry and slow speed with lots of switching. I am planning on 3 to 4 blocks for the entire modeled portion of the line and no fast clocks. Staging will be return loops at each end so trains can return from the direction they left.

Through trains will stop for motive power or crew changes and nothing else. Trains coming to the town will terminate and the cars will then be sent out with locals/switchers to be delivered. Their pick ups will be made up into trains leaving the terminal to the division points.

This does a few nice things, makes signals easier, eliminates the issue of trying to switch via fast clock, and allows for lots of traffic with trains much closer to prototype length.

For me the length of run should be at least 3 to 5 times the length of your train. In case you are wondering a 160 car train at a slow mainline speed of about 40 mph, give or take, takes about 5 minutes to pass a given point.

Here is a video for you to evaluate this, I ran the train on our club layout, which is in a space approximately 24x52 feet. It is one deck and HO scale. A two deck layout could easily put the same amount of run in half the length as the club layout is not a great design for long run.

Old School Tools

Interesting discussion, and maybe not a subject given enough attention. Completely OT, but a surprise and pleasure to see Jim Fitch using Old School Tools. 

Depend of space

I'm happy to see I'm not  the only one who use compass and pencil to drawn my plan…..and a old squared paper.

My design for my N scale layout plan  use a train length of 20 cars plus caboose and locomotives.

This mean I have space on hand which allow this length, it seems to me available space is connected with the length of running train.

Since the layout is set in Virginia, the track has level grades and numerous S curves to be eyes catching.

The 20 cars length  is set in a 1935 area, so the hopper are 33' and 40' boxcars for the most

The medium length  of these cars is 8 cm, a small 3" in N scale so my train are around 170 cm long  plus a locomotives or around 66" plus a steam locomotive

I work with a standard length  train for the plan of 78" so I have place in siding or in yard track.

This mean any yard which can receive such trains eat 78" in a minimum ladder design, which is already a long space even in N scale.

I also design distance between towns and village with this length and try to use a minimum  ratio of 3 length train between town so the run is quiet realistic, scenery also help to make the feeling of greater distance between towns

Yard, siding and some easement to move trains are designed with this 20 cars train in mind where necessary.

Course some area like small town or industry allow only smaller train to go there, this enhance operations too.

So for me, the length of a train is connected with the space you have on hand.

This is a non sense to run a long train where you see the locomotives and the caboose in the same scene

Considering space is also important about the kind of locomotives you use, big space allow you to use big power, small space are better looking with small locomotives.

 I also like long trains that

So do I, but don't have the luxury of having enough space to do that and I imagine most don't.  But maybe that is one of the advantages of living in the state where you can't see the top of their hats!  Space.  I lived for a while in Friendswood Texas near the space center for a while in the late 80's but the economy was lousy for geologists at the time so I ended up having to move.  But having a large space is something most of us don't take for granted.  Consider yourself blessed!

I'm hoping I can manage 30 car trains however, and the odd longer 40 car train.  

I used software to make maps and figures for my masters thesis in the 1990's so am not dead set against it, but I don't have a large enough computer screen at home and find I can visualize layout elements better after having drawn the boundaries of a layout area/room on graph paper to a scale.  It works for me.  Many these days seem to be using smaller screens for home use like iPads, smart phones and laptops, and those kinds of devices don't lend themselves to layout design - too cramped.  I'd have to go out and buy a larger monitor and it hasn't been a priority so far.

xxx

Interesting Thread

Finding lots of good thought points in this one, with pleasant, open minded discussions.

Some personal observations/opinions...

"Selector" said...

It is indeed a good platform for increasing running length, albeit with a few compromises that must be accepted. About 40 years ago, I was in a situation that I had one average-sized bedroom as a location for a layout. At the time I wanted model a freelanced short line, but I also wanted a bit of running. SO, while browsing my dog-eared book "101 Track Plans"... this one caught my eye, as the main portion was smaller than my room I had to work with:

I expanded the width and flipped the yard into the center of the layout, giving me an around the wall w/center peninsula. I increased the bench widths around the wall to 24", and made the peninsula about 48" in width with a dividing backdrop down its center, thus one side of the peninsula was one end of the layout (with interchange) and the other side of the peninsula was the town at the end of the branch. I employed connections on the lower level and upper level trackage so I could operate it in continuous fashion, if desired. However, the main line run was ample enough that it gave me a decent run from interchange terminal to the end of branch by using one (upper) of the connector tracks. Lastly, as would be expected, I personalized the industries and yard and thus the plan was not track for track, but the overall look and concept was retained.

Sure, there were compromises out the wazoo, but I had a TON of fun operating the layout and it was CERTAINLY better than the "no layout" option.

Jim Fitch said this about "old school" trackplanning:

As it does for me, too. Having tried a few of the free layout design software that was available at the time, I returned to "old school". I just liked the tactile feel of using templates, a compass, french curves, etc. I also found it easier to visualize changes using paper n' pencil. Paper n' pencil track planning was a thoroughly enjoyable experience for me during the "down times" that I was without a layout. Nothing like sitting there at the table on a cold winter night, hot cup of coffee sitting beside me, and cogitating and scribbling on a track plan.

Run distances vs time:

Interesting that some of you have come to the conclusions I have come to over my decades of doing this "model railroad" thang.

Run distances...

I have about 135' of mainline and all sections of main between towns are longer than my "standard" train length of two 4-axle diesels, 16 40'-50' cars, and a caboose. (Said train length fits all the four pass tracks as well as the main stage tracks.) Most of the towns have much more than a train length between them. Being that the layout is a partial dual level, and the peninsula is divided by a back drop, I like the "isolated" feeling of the visuals.

Time...

I concur that distance can be enhanced through the use of fast time. I will eventually have a dedicated fast clock on my current layout, and I suspect that I'll end up using 12:1 as my ratio again. Running non-stop at about 25 or so scale MPH results in about 7 mins 30 secs of run time from stage to stage. In 12:1 that equates to about an "hour and a half."

SO, some of my experiences over the decades seems to mirror what others have experienced. I guess some things are somewhat "givens" when it comes to mainline length, town separations, fast time, and such.

Andre

Not one simple answer

There is not one simple answer.  
 

One trick that helps with the illusion of distance is view blocks.  This can be as simple as trees that block all or part of the train as it moves from point-A to point-B.

Joe

Type of trains

The type of trains can have a lot to do with making the layout feel "longer".  Passenger trains, intermodal trains and unit trains tend to just breeze right through at a high rate of speed.  Shorter trains, locals, drag freights, low end general merchandise trains that block swap or do station work (pick up and set out blocks) will all make the layout seem longer because the work and thier general speed will make them take longer to get across the layout.

You asked for a number

Okay from experience and keeping in mind that I'm a lone wolf, I had a large layout with 180 feet of mainline. Out of that 180 feet I had 17 feet of yard and 10 feet for the last town on the layout. I started out modeling the Colorado Midland and actually built in 4% grades like the prototype had so I had to use helpers to the first station. So, running with a helper and cutting it off at the first water stop and then a second water stop at the crest and finally one more on the way down just because, I could use up a half hour getting over the line easily, with no switching.

The only problem I had was that if I went down to work on the layout I'd first decide to run just one train, but then when i got to the last station I felt I just had to turn it and run it back. I got very little work done on the layout that way. Running steam, with helpers, up steep grades means slow speeds and later when I switched from HO to On30 it still took me just as long, so I felt that length was perfect for me. Obviously for some that's not near enough and for guys that don't have a 24X27 space that's more than they can ever get but I loved it.

I've since moved and had to dismantle that layout and now have to fit what i want into a 13X39 foot room and am having trouble duplicating the twisting and turning mainline I once had and will settle for 140 to 150 feet of mostly tangent run. I'm much older and don't have the desire to rebuild the mountains either but there will be more switching so I'm sure that I'll easily need that half hour to go from end to end. And then back.  .

Anyway, that's my experience, Sam

The Midland...

THAT read as if you had built your own model railroading paradise!

When one's own creation (their model railroad) can capture you and draw you into it in such a manner as you described... well... that's what it's all about.

Also, sounds like you had a dandy of a representation of the CM. (The CM is one of my favorites, if not THE favorite, of my Colorado routes of interest.)

I have unwittingly emulated what you had: That is, a significant ruling grade was intentionally designed into my trackplan for the same reasons: Helpers and actual tonnage restrictions. So far, it's paying off handsomely.

Perchance any pictures of your CM layout? Trackplan? Inquiring minds (mine) want to know! Feel free to email me (through this forum) so as not to clutter this thread with a diversion.

Andre

Interesting topic

And some interesting points. Several things I've never thought about before.

And I'll third the pleasure at seeing Jim's old school drafting tools. All of my layouts ( 9, I think ) have been drawn old school, I have two pads of graph paper next to me as I type with various incarnations of the next three layouts on deck...

How about doing laps to

How about doing laps to extend the mainline run?  What are your thoughts on this concept?

Regards
Shelton

Laps

Depends on what type of operation you have and what you mean by "laps".

Assuming by "lap" you mean  you have a circular loop of track with stations along it and you make an orbit or orbits of the loop between working a station, if you are operating alone, one train at a time, that can be an effective way to lengthen the run.  On the other had if you are operating multiple trains in both directions with a single track, you can run into problems because every train will meet every other train on every orbit.  A train leaving "New York" will have to meet the train that has just left "Chicago".  Lets say there are 4 stations on the loop, so a train makes 5 orbits to complete the run.  That means the my train will meet your train up to 5 times.  That pretty well rules out train orders or schedules since its would be tough to keep track of which orbit everybody's on.  You would have to use some sort of modern system where you authorize how far to go rather than how to proceed based on the trains.

Assuming by "lap" you mean separate loops around the layout (2,3,4 times around the room), that also works but as the number of laps increase it becomes more and more difficult to separate them visually.  You can use a nolix and have up to about 4 loops.

Minimum length of mainline

Lars

If you haven't already subscribe to MRH Running Extra.  Jim Six has a column on the limited modeler.  He covers a lot of ideas for the one town layout concept.  Don't focus on how much mainline you can have but rather have the mainline as a prop supporting the rest of the layout.

How about doing laps to

Hard to do laps on a point to point layout.   Like my layout

Or in my case,  I can set my layout to do laps, but it is only in one direction (Turnout with crossover configuration will not let it make laps the other direction)  Doing this runs it through the staging Helix, staging and everything else.   adding 20 some minutes to a run...But do people actually want to run up and down the staging Helix and inside staging area etc. to gain extra run time?

With the layout I built, I

With the layout I built, I have an outer loop and an inner loop.  The outer loop has a yard and station and the inner loop is used to create the distance between the main yard/station.  I know this gets boring fast, however I can also run this point to point in that we leave the main yard, run once in the inner loop and then come round back to the main yard.  Now with sound decoders, I need to run multiple laps in the inner loop so as to realistically go through the "notches" so to speak - still its fun kinda.

Regards
Shelton