Fugate's Trackplan Analysis

[jfugate]

Joe my plan features the B&O, Baltimore Division, which was double track main line.  Could you elaborate on adapting the formaulas for a double track main line layout?  Thanks, Travers, BaltimoreTerminal, 8-3-07

Travers:

For double track mains, one approach is to pick one main as main trackage and consider the other track to be passing sidings. Every-so-often you will have crossovers between the two mains -- these crossovers mark the ends of the passing sidings. In effect, the other main is nothing but passing sidings that parallel the main. The result on the formulas will be that a double-track main will allow you to run lots of opposing trains.

For this to work, the crossovers must allow the train to change mains, run on the other main for a while, and then the next crossover must allow the train to cross *back* over to the original main it was on. In other words, your crossovers should alternate the crossover direction. If the next crossover doesn't alternate, then it's connecting trackage in the middle of a "passing siding", not the other end of a "passing siding".

If your dispatching threshold numbers are much larger than your desired train length, the formulas will be suggesting that you don't have enough *alternating* crossovers between the two mains. Putting in more altenating crossovers will have the effect of shortening the passing sidings (the other main) and give you more flexibility during operations. It will give the dispatcher more places to have a faster train overtake a slower one, for example.

The other way to handle the second main is to make some parts of the second main between alternating crossovers into passing sidings, and make other parts of the second main into connecting track. The result (again) will be that you can run lots of trains -- which is what a double track main will allow. Taking this approach reflects how you actually plan to use the track and won't skew the mainline numbers.

Does that make sense? 

[baltimoreterminal]

Joe,

Thanks for your contributions to the hobby, and giving back to the community.

The track plan analysis stats give you metrics on a layout design. They make you aware of important track relationships and use rule-of-thumb values based on widely accepted best operational practices.

And as I see it, give the layout designer an opportunity to judge how the current plan will handle operation, before cutting the lumber.  (You know the old; 'measure twice, cut once')

UNDERSTANDING THE LIMITATIONS OF THE FORMULAS
Where the formulas tend to break down is for layouts that have multi-track parallel main lines. For this kind of layout you need to pick one mainline as "main" trackage and then if you have crossovers between this "main" and the other mains, consider the other mains to be some combination of passing siding and connecting trackage. If you don't do this, the formulas give you very skewed results that are of little value.

MAKING THE FORMULAS WORK FOR YOU
One of the beauties of the formulas is you can elect to analyze the design in different ways by assuming different usage of certain trackage. For instance, if like me you have lots of varying lengths of passing sidings from real short to real long, you can elect to not use the shorter passing sidings for passing, but simply as runaround trackage for switching -- in other words make them connecting trackage -- and then see how that changes the operational characteristics of your design.

 

Joe my plan features the B&O, Baltimore Division, which was double track main line.  Could you elaborate on adapting the formaulas for a double track main line layout?  Thanks, Travers, BaltimoreTerminal, 8-3-07

[Anonymous]

1+1 = 2.

What are we gonna do with just two cars on a siding built for one?

[selector]

Okay, fellas, thanks for straightening me out.  I had to default to grade school math and know that anything times one yields the same old thing.  It makes sense now.

-Crandell

[jfugate]

2. Capacity in cars of all sidings that accept cars. Multiplying this number times one plus the average

  Steamnut, did you miss something, or have I?

Selector, if you use only the average number of servicings as your multiplier, you are missing the number of cars that start the session already in the siding, that is the reason for the "one-plus".

Yes, the proper color emphasis should be:

2. Capacity in cars of all sidings that accept cars. Multiplying this number times one plus the average

You need to compute the average and add one to it. Perhaps a better wording would be:

2. Capacity in cars of all sidings that accept cars. Multiplying this number times the average ... plus one.

Nothing like having new eyes look at something to find the improvements.

[steamnut]

2. Capacity in cars of all sidings that accept cars. Multiplying this number times one plus the average

  Steamnut, did you miss something, or have I?

Selector, if you use only the average number of servicings as your multiplier, you are missing the number of cars that start the session already in the siding, that is the reason for the "one-plus".

[jfugate]

Regarding all this discussion about analysis versus actual experience ... it is worth noting the formulas used in my analysis methods are not completely my own but an extension of the work done by Dr. Roy Dohn, who consulted with many people, not the least of which was the late John Allen of Gorre & Daphetid fame.

So much experience has been encapsulated into these forumlas and for a newcomer, I think the "encapsulated experience" these formulas give is invaluable.

[bearman]

Fugate: "Let's dispell any such notion right now..."

Oopsie! As I indicated in another post, I used your method to analyze and select between two final track plans.  In both cases, the limits to the method, e.g. double track main, that you describe are not part of my layout.  I scoured the net looking for some sort of way of objectively analyzing my final decision and ran across yours, and, from the posts on this thread, I believe that it has been validated w/in the limits you describe.  And I agree, I believe that I have avoided the mistakes that plagued my first attempt at a RR. 

 As an aside, I think that w/more work, the method lends itself to a linear programming solution, the work being that necessary to set up the equations to the point where you plug in the variables, and decide what to maximize and what to minimize and then voila, the metrics which define how much track and of what type to suggest the operation that someone wants in their layout.  Not that I am going to do it, I've had enough of those in college and grad school and early in my professional career and now that I am in mgt, I don't have to futz aroundwith matrix algrebra.

[Vail and Southwestern RR]

There is no doubt that the best way to find out if it works is to run it.  But I'm glad Joe came up with his analysis 'package' to give me a chance to think about things and see if I had totally overlooked something.  As it turned out, I didn't change much (maybe nothing, but I've slept since then), but even that was good.  After the time (months, years, lifetimes, generations) it takes me to get the thing built it is nice to know it might actually work before I get there.  Someday.....

 

[jfugate]

When the day dawns on that layout and it's time to run a train, many truths will reveal themselves. You can analyze and paper over and plan to the most microscopic ad-nauseum but for me, the best way is to actually go try it.

Boy is that the truth. The best thing I ever did was to start attending serious layout op sessions -- nothing will teach you better about the hobby and operations than actually doing it.

I quickly found out what I did and didn't like about layout operation, and was able to then design a layout that emphasized the things I liked over those I didn't like.

It could be prototype operation will be, like it has become for me, the overarching goal of the hobby and so you can design a layout that supports that goal. Or you could find out it's not your cup of tea at all, so then you know designing a railfan's layout (lots of track everywhere to support lots of trains running) will make you happy as a lark.

In this case, the experience comes by getting up out of that armchair!  

[Anonymous]

When the day dawns on that layout and it's time to run a train, many truths will reveal themselves. You can analyze and paper over and plan to the most microscopic ad-nauseum but for me, the best way is to actually go try it.

Mistakes? Sure.

An example will be a tiny Coaling tower that is much smaller in cubic capacity to the PRR Duplex 4-4-4-4 that it's trying to coal up. That one has been replaced with a BIG coaler, worthy of it's 250 ton capacity. Now I need to find space for it before I try to build such a monstor.

[dknelson]

I make mistakes when working on the layout just like the rest of you.

Speak for yourself...

Sounds like *you're* the god then ...

Maybe he meant -- and this would describe me -- nobody makes mistakes like mine.  I strive to someday lift myself up to the level of Fugate-type mistakes but currently dwell in the muck of Nelson-type mistakes. 

Dave Nelson

[SilverSpike]

I make mistakes when working on the layout just like the rest of you.

Speak for yourself...

Sounds like *you're* the god then ...

 

LOL!!!

Joe, you took the words right out of my mouth! That's exactly my response when I read that one!

 

[jfugate]

I make mistakes when working on the layout just like the rest of you.

Speak for yourself...

Sounds like *you're* the god then ...

[mononguy63]

I make mistakes when working on the layout just like the rest of you.

Speak for yourself...

[jfugate]

I'm not suggesting Fugate is some sort of god ...

Let's dispell any such notion right now ... I put my pants on in the morning just like everyone else and every day I make mistakes when working on the layout just like the rest of you.

My main goal in sharing with my fellow modelers is to help us all make only new mistakes.

It's like I tell my kids: good judgement comes by experience -- and experience comes from poor judgement. No reason why that poor judgement has to be *your* poor judgement. The really wise people in the world learn from everyone else's poor judgement instead of their own whenever possible.

So by sharing my experience I'm giving you insight into the stupid mistakes I've made in many cases. Sometimes though, I'm smart enough to learn from the other guy's mistakes ...  

[jfugate]

Time to weigh in on this discussion ...

The track plan analysis stats give you metrics on a layout design, they aren't meant to somehow alert the layout design police to come knocking! They make you aware of important track relationships and use rule-of-thumb values based on widely accepted best operational practices.

UNDERSTANDING THE LIMITATIONS OF THE FORMULAS
Where the formulas tend to break down is for layouts that have multi-track parallel main lines. For this kind of layout you need to pick one mainline as "main" trackage and then if you have crossovers between this "main" and the other mains, consider the other mains to be some combination of passing siding and connecting trackage. If you don't do this, the formulas give you very skewed results that are of little value.

MAKING THE FORMULAS WORK FOR YOU
One of the beauties of the formulas is you can elect to analyze the design in different ways by assuming different usage of certain trackage. For instance, if like me you have lots of varying lengths of passing sidings from real short to real long, you can elect to not use the shorter passing sidings for passing, but simply as runaround trackage for switching -- in other words make them connecting trackage -- and then see how that changes the operational characteristics of your design.

To Brakie's point -- the formulas capture what amounts to the "unchangeable rules of operation" in them -- the "laws of physics for layout operation" if you will. How you define your design's trackage types is where your judgement comes in and you are free to change track types around to see what it does to your design's operation characteristics.

NEWCOMERS ESECIALLY CAN USE THESE FORMULAS
Once you become more experienced in the hobby, analyzing track plans using the formulas will be less useful because you can just look at a track plan and tell something of its operational potential. But for newcomers who don't have all this layout operation experience, the formulas provide a quick way to draw on this expert knowledge and apply it to a track plan to assess its operational potential. 

[tomikawaTT]

Having just run a rough cut on my under-construction layout, I can see that the Fugate Formula might be useful for analysis of competing layout designs but is rather less useful if the layout has been specifically designed to meet the requirements of running the prototype's timetable with prototypical consists.  In my case, train length came FIRST, and everything else was sized to fit around it.  Also, since my prototype didn't switch wayside industries the way most American model railroads do, most of my trains run through with nothing but an engine change - and possibly not even that.

I see one item that Joe didn't address, which can be critical.  Granted that it's nice to cram a lot of layout into a space, but that space also has to be able to allow operators to function - throw switches, couple and uncouple, or just watch the train to make sure that locomotive and throttle setting are on the same page of the book.  Having to squeeze past one another or bump butts with the guy switching across the aisle gets old in a hurry!  (Lone wolves who do it all themselves can smile here - but how many of them are trying to run a 140+ train/day timetable?)

If I had nothing better to do, I could run a complete, detailed Fugate analysis on the layout, which would be of only marginal value to someone trying to do what I'm striving to do and no value to me at all.  Thanks, but I'd rather spend the time laying track.

Chuck (modeling Central Japan in September, 1964)

[bearman]

"That is exactly why I was trying to define an Algebra rather than just a formula.  That way one could change the end criteria, work backwards through the formulas thus solving for the variables to make that given end criteria happen"

Gandy - I hear you.  I suspect, however, that algebra won't work but a linear program, matrix algebra I believe, might, where you have a series of equations that you solve based on minimizing or maximizing the different variables.  Unfortunately, solving a linear program by hand becomes a big mess after the third equation which is why we have computers. 

[IRONROOSTER]

Hey, if it works for you, use it.  There will always be controversy in this hobby because there are many ways to do things and there are many different goals.  Personally, I like having lots of choices and ways of doing things - keeps the hobby from getting stale.

Enjoy

Paul 

[bearman]

I truly did not believe that I was creating a controversy when I started this thread.  I would point out that I used the method as a tool in making a decision between two rather different track plans, and I also used it as a tool in an attempt to ensure that I would be able to operate my layout the way that I wanted.  For example, I wanted to run two locomotives (and up to two switchers) and before I spent the big bucks I was able to validate this requirement.  Additionally, I wanted to run a train(s) up to 7 cars long and the plan I chose again using this tool will allow for trains up to 10 cars.  Finally, I wanted to make sure that the main yard was big enough and using Fugate and the 80% rule-of-thumb approach, again I was able to validate my minimum requirement.  In other words, as someone else has posted, I do not intend to operate the layout at the maximum, I want to ensure that I can operate the layout the way I want it to operate.

I'm not suggesting Fugate is some sort of god, but I have visited his site on more than one occasion for information, and I have learned something about ballasting from his video.  I have also visited the sites of any number of the posters on this forum and have, again, learned a lot from you guys as well.  Finally, I would like to point out that sometimes I get the same answer to a question from more than one site, and in these cases I appreciate being able to get a "second opinion" whcih validates the initial answer.

[steinjr]

  I just took the time to measure on my plans and do the calculations. I was surprised at how accurate the statistics actually describe operating potensial - it matches pretty well what I had figured out counting on my fingers and toes

 Her is the MTRY layout:

 Here is the stats calculated by the method Joe Fugate describe (to the best of my knowledge - the measurements may be off by a couple of percent, but shouldn't make a huge difference)

Room area   : 6.5 x 11.5 feet = 74 square feet
Layout area : 44 square feet (59%)
Number turnouts : 30

Mainline track: 48 feet (96 cars)
Passing tracks: 11.3 feet (22 cars)
        Roseville siding : 6 feet (12 cars)
        Yard track 1(A/D): 5.3 feet (10 cars)
Staging tracks: 12.6 feet (25 cars)
Service tracks: 0
Storage tracks: 33.9 feet (67 cars)
         Yard tracks 2-6: 18.1 feet (36 cars)
         Industry sidings: 15.8 feet (31 cars)
Connecting tracks: 24' (48 cars)
         Switches: 264cm (12 switches not already counted as part of main line x22cm) 
         Yard lead: 118 cm
         Flour mill runaround: 2 feet
         Other connecting track: 294 cm

Passing sidings: 2
Passing train length: 12 (max)/11 (avg)/10 (min) cars
Staging tracks: 2
Staging train length: 13 (max)/12 (avg)/ 11 (min) cars

Maximum number of cars: 105*0.8 = 82 cars
    storage: 67
    staging: 25
    passing/2: 11 
Number of cars moved: 124 * 0.4 = 50 cars
   staging: 25*2 = 50
   passing: 26
   connecting: 48
Average train length: 11 cars (avg passing)
Trains: #cars moved (50) / avg train length (11) = 5 trains (really just under 5)
Dispatching threshold: (3x10 +2x11 +12)/6 = 10 car trains

 I was planning to use trains of maximum length 1 short engine, 8 cars and a caboose. Which is pretty much the same as 10 cars in length, when you use short engines (less than 5.5" long).

 Smile,
 Stein

[Gandy Dancer]

I think his[Joe's] formula on the whole achieves that goal, and thus might arguably be considered a yardstick for potential operating interest. But maximum operation isn't my goal, and I believe from extensive anecdotal experience, that it also isn't the goal of the majority of MRs.

That is exactly why I was trying to define an Algebra rather than just a formula.  That way one could change the end criteria, work backwards through the formulas thus solving for the variables to make that given end criteria happen.

[wedudler]

Nice idea. It will take some time for me to do all the measurements.

Wolfgang 

[selector]

2. Capacity in cars of all sidings that accept cars. Multiplying this number times one plus the average

  Steamnut, did you miss something, or have I?

[Vail and Southwestern RR]

I haven't seen Joe's layout analyze since that will be his observation based on his perferances..I prefer to analyze my layouts with my own preferences.We get the same results.A layout that fits our personal preferences based on our givens and druthers.

For not even having looked at it, you made a lot of assumptions here, Brakie.  It's just a tool, and it may or may not be useful to you.  What it can do is make sure that you have thought about some things that you may not have.  You can decide to use the information in any way you want, or ignore it completely.  But my feeling was that it was not a measure of 'good' and 'bad', but rather a objective(as much as possible) method to help determine the operational possibilities and/or limitations of a layout before it is built.  I guess if I knew everything about layout design and operation, I wouldn't need to read books and use tools like this.  For now, I'll take advantage of all of the experience and expertise I can find, and then make my own choices.

[steamnut]

Joe's comments are always interesting and thought-provoking, and he is a shining example of those who expend time and effort to "give back" to the MR (model railroading) community.

But I, personally, don't find his proposed formulaic approach helpful - even though I am very mathematically inclined and use math and formulas extensively in other ways in my MR planning and building.

Above all, his analysis is aimed at establishing the MAXIMUM operation that can possibly be squeezed out of a given layout. I think his formula on the whole achieves that goal, and thus might arguably be considered a yardstick for potential operating interest. But maximum operation isn't my goal, and I believe from extensive anecdotal experience, that it also isn't the goal of the majority of MRs. For one thing, I personally prefer more relaxed operating; for another thing, I model (more or less - I've played with the reality to some extent) a prototype short line whose physical plant always exceeded its actual business. I'm not convinced that his formula has a lot of meaning for those whose operating goals are different.

However, there ARE some statistics and relationships that I believe to be very important in layout planning, but you really don't need a bunch of formulas, just some careful measurements, simple math and logical thinking. While Joe also measures the same statistics, where I fall out with him is the idea that this should (and arguably even can) be extended to a cut-and-dired holistic mathematical determinant.

1. Max / avge / min length of passing sidings in terms of (number of cars PLUS typical locomotive length [Joe's formula ignores the space taken up by locomotives]). Assuming that you want to run more than one train at a time, this is the single most important determinant of typical operational train lengths. I say "typical" because its not as simple as that; a train longer than any passing siding can be easily operated as long as it does not have to meet any OTHER train that is also longer than any passing siding. And if you are really into challenges, two trains that are both longer than the passing siding can pass each other using the maneuver called "sawing". While speaking of passing sidings, I'll note parenthetically that a good track plan also needs run-around sidings, which in most cases should not be double-counted as passing sidings.

2. Capacity in cars of all sidings that accept cars. Multiplying this number times one plus the average number of times you expect to service the sidings during a session gives you the approximate number of cars that will be moved around between points ON the layout (but does NOT count the cars that may be in through trains). Comparing this figure with Item 1, typical train lengths, also gives you a quick estimate of how many trains per session will be required to service your local industries.

3. Total main line run expressed in terms of the number of trains of MAXIMUM operational length that it can hold can usefully and easily be used to calculate the maximum number of trains you want on the layout at one time. To do this, you must decide on the minimum number of train lengths that you wish to SEPARATE each train. So lets say your main line run could hold 12 maximum-length trains, and your personal sense of aesthetics says you want three train-lengths BETWEEN each train. Then your total effective train length is actually four train lengths (one actual train plus the empty track for three more), and you will enjoy seeing a maximum of three trains on the layout at one time (12/4), while a working maximum (a nose-to-tail situation around the whole main line would lead to gridlock just like on highways) is probably 40% of the theoetical maximum, or between four and five trains (.4 * 12 = 4.8).

Measuring these three items objectively (especially actual passing length versus nominal siding length) is an excellent means of evaluating a plan in terms of your own goals. 

[bearman]

I believe the first two posters in this thread have a difference of opinion as to the criteria that Joe decided were the most germane or decisive with respect to judging the operational suitability of a given track plan. 

Actually, I am not that bright at all to be able to discuss the necessary criteria.  I was just wondering what other people thought about the method.  I ended up using it when it came down to making a final decision on which of two different track plans I would build.  From what I understand, Fugate took someone else's work and expanded on it.  I would be more than pleased to look at any other method just for kicks (since I already am building my layout) simply because I am interested in an objective evaluation of a situation which is inherently subjective.

Gandy-Check it out if you like, especially since it sounds like you have an interest in measuring something which it appears most people believe can't be measured.  The real point being that if I aware of Fugate's method, or any other method for that matter, before I started on my first layout, there are several design mistakes that I could have avoided.

 

[selector]

I believe the first two posters in this thread have a difference of opinion as to the criteria that Joe decided were the most germane or decisive with respect to judging the operational suitability of a given track plan.  Once "we" can agree that the criteria are acceptable, have face validity that is, and that they are genuinely the best set of criteria, the definitive ones, for evaluating an operational component, then we can all do our calculations (no control for measurement biases unfortunately...we'll all be subjective in that regard) and report back.