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.
Safety Valve wrote: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!
Joe Fugate Modeling the 1980s SP Siskiyou Line in southern Oregon
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.....
Jeff But it's a dry heat!
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.
Bear "It's all about having fun."
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.
selector wrote: steamnut wrote: 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?
steamnut wrote: 2. Capacity in cars of all sidings that accept cars. Multiplying this number times one plus the average
2. Capacity in cars of all sidings that accept cars. Multiplying this number times one plus the average
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".
steamnut wrote: selector wrote: steamnut wrote: 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:
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.
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
1+1 = 2.
What are we gonna do with just two cars on a siding built for one?
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 FORMULASWhere 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 YOUOne 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
baltimoreterminal wrote: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?