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Classifying Your Modules Or Layouts

Reprinted from September/October, 2002, Volume 8, #5 issue of Ztrack Magazine, Copyright 1999, Ztrack, all rights reserved.

by Robert Kluz

The recent National Train Show in Ft. Lauderdale showed how a little ingenuity and a lot of hard work allowed modules of different standards to be assembled into one working layout. Though each club built the modules independently, the connections were made possible due to bridges between the sections. These bridges allowed the track to conform to the different standards.

Though integration was possible, some trains could not navigate the length of the layouts. Why was this? The answer is in the history of Z scale and the enemy of long trains... curves.

Many of us designed our layouts and modules based not on a standard of radius curve measurements, grades and height clearances, but based on what our locomotives could traverse. For years, the standard locomotive for North American modelers was the F7 locomotive. This sprite mid-sized diesel could handle very tight radius curves. As modelers, we designed our layouts according to the limitation of the F7s (comparable to class 111 electrics or 218 diesels for European operators) without much thought of larger engines. This standard would reign for nearly fifteen years.

The change would come in the form of American Z Lines and their C44-9 release. The C44s were much longer and could not use the same tight radius curves that the F7s ran so well on. Suddenly, operators wishing to run the new generation of diesels found that their curves were too tight for the long three axle truck locomotives. Again this concern would arise for the Alco PA1 and E8 releases from AZL. Interesting enough, Märklin in 2000 released the model of the ICE 3 (88712). This was the first mini-club set released by Märklin with a minimum radius standard greater then the minimum standard radius offered in Märklin's sectional track line. The minimum radius standard is based on the 8510 track section with a 145mm (5 3/4") 45o curve. The ICE 3 requires a minimum of 195mm radius which equates to the 8520 curved track (7 11/16" for 45o curve).

In talking with members of the module clubs, the concerns of radius became a real issue. As more Z scale modules and layouts are built around the country, how can we categorize them so we can easily understand the limitations and specifications of the track work? This is an important question to ask, especially when it comes to module assembly were modules may be assembled for the first time, ever.
The solution came in the form of a simple classification system. This system can be used no matter which module specification or style of layout you are building. It is intended to maintain consistency across your layout.

The basis of the classification is the main line. Branch-lines can be classified as well, though for module operators, main line standards are most important. The classification was created around the Märklin standard track sections. The following classifications have been proposed:

Class A :
All radius curves utilize flex track. Minimum radius for 180o is 18" though greater is preferred. Track should accommodate long locomotives such as C44s or large steam locomotives (Big Boy). Height clearances should accommodate tall cars such as double stack intermodals (roughly 1 1/4").

Class B:
Minimum radius curves equate to Märklin's 8530 track, or 440mm (17") for 180o. Track should accommodate large locomotives such as C44s or PA1s. Large steam locomotives may have problems. Height clearances should accommodate tall cars such as double stack intermodals (roughly 1 1/4").

Class C:
Minimum radius curves equate to Märklin's 8520 track, or 390mm (15 1/4") for 180o. Track should accommodate all mid sized locomotives such as F7s. Larger locomotives such as C44s or PA1s will likely have difficulties navigating. It is recommended that height clearances accommodate tall cars such as double stack intermodals (roughly 1 1/4").

Class D:
Minimum radius curves equate to Märklin's 8510 track, or 290mm (11 1/3") for 180o. Track should accommodate mid sized locomotives such as F7s. Smaller locomotive such as 0-6-0s and switchers preferred. No minimum clearances.

These classifications are still open for revision and modification. Individual needs will ultimately dictate height clearances. Catenary operations are popular in Z scale for European modelers. It is likely, more catenary masts will be appearing on North American layouts due to releases such as FR's New Haven electric and a Marklin GG1.

When classifying your layout or module, the classification must be based on the minimum of your radius. For instance, if you use all flex track, 18" plus curves, but one curve is using the 17" Märklin 8530 track, the layout or module must be classified as a Class B.

For module clubs looking to combine modules from individuals and other clubs, this system gives a quick reference point for connectivity and operation potential. A complete module setup will have an overall classification based on the minimum class of a module or modules. Again, if all modules are Class B, but one is a Class C, the module setup in general must be classified as a Class C.

For planning, a use of such classifications will make setup and assembly much easier. By organizing and combining modules of the same class, operators know what equipment will work dependably on the setup. This is important in a show environment where audiences are waiting to watch trains run.

Grades were not discussed within the classifications. As a general rule, if long heavy trains are your goal for operations, grades on your mainline should be kept to a minimum if not eliminated all together.

For those currently in the planning and building stage of layouts or modules, I have one recommendation. Keep your future needs in mind when building your layout. By building the largest radius curves you can, you will allow for greater operation potential, even if you do not own or the locomotive has not been released yet. For instance, can you imagine a Big Boy in Z scale? It would be incredibly long. How many of us could even run such a locomotive on our layouts?

Planning ahead will ultimately save you time and frustration if that must have locomotive is just too much for your current layout. I can speak from experience as I have recently rebuilt a hidden tunnel section of my layout. The curves in the tunnel could accommodate my large fleet of mid sized locomotives (such as German class 110, 111 electrics) but large steamers and large modern diesels such as the C44s experienced difficulties. By adding a turnout in the mountain, a single line extends off the top of the loop and bypasses the tight radius curves. This has allowed for much better operation. Even then, my layout is still more of a Class C layout then a Class B. I am working to find ways to upgrade the layout so trains such as the ICE 3 can find a home. So what classification is your layout or module? There is no wrong answer. Again, build a layout for your needs, but keep in mind your future wishes.