Choosing N scale track: Overview

Edit from the future (2021): the price situation now is radically different than it was when I wrote this in 2009.  Peco is no longer at such a large disadvantage and has gained in popularity.  Please check your own prices when you read this.

Once a modeler chooses N scale he/she then has to choose which brand (e.g. Atlas) and line (e.g. Code 55) of track to use. This decision has to come fairly early in the planning process as different brands/lines of track and switches have different geometries, thus impacting the layout design. This post provides an overview of what's available in the U.S. and Canada. In a later post I'll go into more detail on the topic of the different lines of flex track/switches, where there is a lot of choice and a lot of factors to consider. N scale track can be grouped into 4 categories. I'll list them here in order from beginner to most advanced:

1. Roadbed Track & Switches
2. Sectional Track & Switches
3. Flex Track & Switches
4. Hand-laid Track & Switches

Note that Atlas and Peco offer lines of track that include both (2) and (3). When choosing your type of track these are the factors to consider. Ease of Use and Time to Install. This factor can vary tremendously from one category to the next. At the extremes consider that a sizeable roadbed track layout can be put together by a beginner in an hour or less, which is about as long as an expert needs to assemble a single hand laid switch. Appearance. In general, the trade-off for ease-of-use and time-to-install is appearance. The more time you invest in installing your track, the higher the potential quality of the appearance, depending upon your implementation. Nothing looks as sharp as quality hand-laid track, while no amount of scenic detail can fully hide the unrealistic plastic appearance of roadbed track. Price. In general, the most expensive category is roadbed track and each successive category is cheaper. There are, however, exceptions to this rule. Some sectional switches can be quite pricey, and many people who handlay track invest a lot in specialized handlaying tools and materials. Flexibility. With handlaid track you can create any configuration, curve, spiral, or switch geometry you need. With roadbed track you are limited to the pieces the manufacturer offers. Sectional track is a little more flexible than roadbed track in that you can cut pieces. Flex track is equivalent in this regard to hand-laid track except for the switches. Operational Reliability. All categories of track offer anywhere from poor to excellent reliability depending upon brand and installation quality. Within each category certain brands are better than others. So, with those decision factors in mind, here is a survey of each category of track: Roadbed Track includes a built-in plastic roadbed underneath the ties. The roadbed adds stability, but the main advantage is that you "click" one piece of roadbed track to another, so assembly as fast and the track stays locked together. The different brands of roadbed track are not compatible with one another, but you can construct a "transition" track between two makes if so desired. Each manufacturer offers a variety of lengths of straight track, plus a variety of curves in different lengths and radii, plus switches and special purpose track like crossings. Roadbed track is the preferred choice for starter sets and newcomers to the hobby, especially children. It's also popular for those modelers who prefer operations to construction and aren't overly concerned with appearance. The quick setup feature also makes it popular among those who need to tear down and rebuilt layouts frequently. And of course, all roadbed track features insulated switch frogs for ease of use. Historically all roadbed track has been code 80, and Kato has been the most popular manufacturer due to both their large variety of track and their reputation for impeccable operations reliability. Bachmann offers a smaller line of cheaper roadbed track that tends to get less favorable reviews for reliability, especially the switches. Life-like train sets include their own roadbed track, and apparently you can order extra pieces, but the selection is very limited. This past year Atlas has introduced a line of code 60 roadbed track that is clearly intended to compete with Kato for the lion's share of this market. Early reviews are that Atlas wins on price and appearance, but I have no experience with it. Sectional track is similar to roadbed track, but without the roadbed. The track consists of plastic ties and rails, and each manufacturer offers a variety of curves, straights, switches, and special track. Connections are purely by rail joiner, so if you use sectional track you'll want to at least pin it into place on a board, and most people install the sectional track on top of a roadbed material, like cork, then glue scale ballast on top to complete the effect and hold the track in place permanently. Because the connection is by rail joiner different makes often work interchangably with each other, if the rail size is the same, and even if they don't it's usually not hard to build a transition track between two makes. Makes that work together: Peco 80, Atlas 80 and Peco 55; Atlas 55 with Micro-Engineering flex track. Sectional track was available decades before the introduction of roadbed track 20 or so years ago. Many people, myself included, thought that sectional track would eventually be completely replaced by roadbed track, but it turns out that a lot of modelers like sectional track. A well-scenicked layout with sectional track can look very nearly as nice as one with flex track, but avoids the extra work and skills that flex track requires. There are apparently enough of these modelers that when Atlas released their new code 55 line 4 or 5 years ago they included a huge variety of sectional pieces, and they have been a big seller. Atlas flat-out dominates the sectional track market in North America, with code 80 and code 55 lines. Peco, a UK firm, once was very popular but has lost most of their market share due in large part to exhorbitant prices, recently made worse by the weak dollar. A few other makes have been available in the past, such as Shinohara (code 70) and Model Power, but their market share is almost non-existent now. For modelers building new sectional track layouts the choice is likely to be between Atlas code 55 and 80, although Peco code 55 and 80 may be an option for a few. I'll cover the differences between these lines of tracks in my future post on flex track, since all of these sectional track lines include compatible flex track as well. Flex track is a section of track 29-36" long (length depends on the manufacturer) that can be bent to shape. With flex track you can duplicate anything that you can do in sectional track, plus you can build curves of radii that are not available in sectional track, and even create curves of changing radii, such as spiral easements. Flex track is considered better in appearance than sectional track, in part because curves and spiral curve transitions can look more realistic, and in part because sectional track has too many rail joints and has funny looking partial ties at both ends of each track piece. With the exception of Micro-Engineering code 40 track, all flex track lines include compatible switches. In addition, as noted above, sectional track lines from Peco and Atlas offer compatible flex track. So, there is a large selection of flex track lines to choose from - more choice than available for sectional or roadbed track. Since it is not difficult to connect the different types of flex track (using a transition track if necessary) many modelers do just that. For example, using larger rail for main lines and smaller rail for branch lines and sidings. Flex track does require more work to install than sectional track. When laying sectional track the curves and straight lines are already built in. With flex track you have to mark curves and straights onto the roadbed, then carefully adjust the track to match the marks. Spiral easements -- in which the curve gradually transitions from a tangent to a curve or from one radius curve to another -- require more skill to create than constant radius curves. Flex track often has to be precisely cut to fit, with the rails often of different lengths due to curves. This task is harder in N scale than HO because there is less room for error. Then there is the fact that around curves flex track joints need to be soldered to keep the curve steady and without dents. None of these skills are hard to learn, but taken together one can understand why some modelers prefer sectional track. I will review the different lines of flex track in a future post. Hand-laid track is preferred by those who want the absolute best possible appearance. It's not nearly as common in N scale as it is in HO (the size factor makes it harder to assemble the smaller N scale parts together by hand), but it's not rare either. While there are those who hand lay both the track and the switches, its become more common recently for modelers to hand lay the switches in combination with their preferred flex track, usually choosing Micro-Engineering for appearance reasons. The advantages of hand laid switches are many. First, if done well the appearance can be nearly identical to the prototype. The difference is noticable enough that visitors with any model railroad knowledge at all will see and admire it. Second, custom switches can be built for any situation. Need a switch with a #9 frog, or an outside switch on a 28" radius curve, or a crossing of a curved track and a straight one? None of these are available unless built by hand. Price is also an advantage, at least theoretically, as you are just buying rails, ties, spikes and/or glue and/or solder. In practice many modelers who hand lay track invest in specialized tools and jigs, or even buy partially assembled switches that have the rails and a few key ties in already in place -- all of those things save time and help make for reliable switches, but also cost money. The down side is that this is a lot of effort and time. And while proponents of hand-laying are correct to say that anyone can learn the skill, it's a skill that takes time to learn to do well. One noted hand-laying proponent, the prolific model railroad author Tony Koester, says that it takes him about an hour to assemble each of his hand-laid HO switches. (Tony's method is described in his Model Railroader book, Trackwork and Lineside Detail.) Others, such as the makers of Fast Tracks jigs for handlaying switches, say it can be done faster. I seriously considered handlaying my switches until i realized how long it would take to build the 130+ I will have on the main layout. At the rate of one switch per hour, and maybe 4-5 hours per week on the layout, that translates to at least half a year just assembling (not installing) switches. So I bought mine. But for those with smaller layouts, or with more time, who place an absolute premium on appearance this is your best option.

Frogs: Dead or Alive

A "frog" is the part of a switch or crossing where rails from separate tracks meet. In model railroading, frogs can be of two types: "insulated" (a.k.a. "dead", "plastic", or "insulfrogs") and "live" (a.k.a. "metal", or "electrofrogs").

Different brands/lines of N scale switches either have live or dead frogs, or in the case of Peco code 80, both. The difference is important enough that I'll refer to it a few times in future posts, so I'm covering it as a separate post here.

Here is a diagram of a switch with an insulated frog (yes, I made this myself):




The parts in the center colored in black are plastic -- or any other non-conductive material. The rails on the top (blue) are one polarity, no matter which way the switch is set, and the rails on the bottom (red) are the other. In order to keep the rails powered correctly the switch will have hidden wires, usually underneath the switch ties, connecting the rails as shown in the dotted lines.

By comparison, here is a diagram of a switch with a live frog:



All the rails, including the frog, are metal. Even though there is an apparent electrical gap between the rails at the frog itself, they are electrically connected across that gap.

Electrical power distribution is a bit non-obvious for live frog switches. For the moment, ignore the box on the right of the diagram labeled "SPDT" and the lines connected to the box. When you open a live frog switch out of the box the SPDT box won't be there. Instead, in the out-of-the-box situation the frog rails and all the inner rails will get their power from where the rail point touches the outside rail (in this diagram look immediately above the word "Rails" in red). Thus, when the switch is thrown the frog and inner rails will switch polarity from red to blue or vice versa.

The potential problem is that the electrical connection between the point and side rails can be tenuous -- and can get worse over time with dirt or corrosion. Many modelers choose to supplement the power to the frog and inner rails using an SPDT switch, as shown in the diagram -- and often this SPDT is built into a switch motor such as the Tortoise or even with a manual switch controller like the Blue Point.

The other issue is that the live frog switch always has both rails in the non-selected direction at the same polarity. Now, this can be useful in the DC world as a means of controlling multiple engines on the layout. A spur or single-ended siding that is attached to this switch gets no power unless the switch is set pointing in that direction. This function is called "power routing" and thus an alternate name for live frog switches is "power routing switches". (Note that the corresponding alternate name for dead frog switches is "all live" switches -- meaning every direction has both power polarities -- but the use of the term "all live" for a "dead frog" switch is so confusing that I avoid it.)

For most DCC layouts, which already have multiple engine capability, power routing is useless. DCC operators prefer the ability to move their engine on the spur or siding for tasks like car positioning -- even if the switch is set against them. Thus, DCC modelers will tend to run separate wire feeders to all track that is attached to the live frog switches, then add insulated gaps next to the frog rails to prevent shorts.

Except for power routing are there any other advantages to live frog switches? Well, there are two. First, they can be more operationally reliable. This is because the insulated frog creates a power gap when one of the wheels of an axle is in contact with it. With most modern locomotives that get power via all wheels this is not a problem, but with older locomotives or sometimes with short switchers with dirty wheels this can cause engine stalls. This can be easily solved by keeping wheels clean.

The second advantage is that the all-metal frog looks more realistic than plastic frog switches, even after they are painted and weathered. In a well maintained DCC layout this is your only real advantage of live frog switches.

So, yes, if you've followed this far you've realized that live frog switches have one advantage -- appearance -- and yet each live frog switch requires the addition of an SPDT switch, one extra feeder, and two insulated gaps. So is the hassle of all that extra work worth the marginally better appearance?

Unfortunately, many of us don't get the choice. If you choose code 55 rail all the switches have live frogs. Which is why my main layout is full of live frog switches.

More mid-tier gluing

Here's where the middle tier is as of tonight:



I did a switch inventory and realized that I have no right switches left. I'm doing a count of Atlas switches needed to complete the lower deck (not tier) of the layout, and will send an order in tonight. There is enough work to keep me busy until they arrive at the end of the week.

I've run out of track salvaged from the first staging attempt, not counting 3 switches. There was about 12' of flex track that had been nailed to the lower tier and was too damaged when removed to be reused -- I tried but it was apparent that it would not operate reliably. I'm starting to use new flex track again with new rerailer track. I'd forgotten how much easier fresh track is to work with. Re-using salvaged track has the advantages of already having feeder wire and rail joiners attached, but the track itself was harder to position and shape as it keeps wanting to go back to its old shape.

I have a bunch of flex track left over from my 2002 N scale layout, and I've used a few sections of it here and there, but I'm putting it aside from now, for two reasons. First, it needs a very intense cleaning to be usable. Second, as noted above, re-used track is harder to position and shape into place, and this very old track is almost brittle. I'd planned to reuse all the 2002 track (about 110' of flex track), thus saving lots of $$$, but I think this is an example where the savings in time may be worth the extra money. I'll include some new flex track in with my switch order tonight.

Mid-tier gluing progress

Have made decent progress gluing down new track on the middle tier. Here is a photo as of tonight:


I've nearly used up all the track salvaged from the first staging attempt. The salvaged track mostly consists of two sections, usually a piece of flex track and a rerailer track, soldered together with feeder wires attached at the rail joiners. This is why you see so many wires dangling above the middle tier in this shot.

It will probably take a few more days, possibly a week or so, to complete the middle tier. There are 8 switches to install, each which require a lot of time, and I've yet to connect the feeders for any of this new track. I plan to start work on the power cabinet sometime in this next week as well.

Short solved -- and more

I previously mentioned that there was an electrical short somewhere that affected the middle and lower tiers. I'd spent probably an hour or so trying to find it with no luck, so I stopped looking on March 28th and focused on the upper tier.

Today, with the middle tier ready for new track, I started the search afresh and found it within a few minutes. The guilty bugger was the staple on the left shown in this picture:


As often is the case, when you set a problem aside then revisit it later you find a new approach that works. In this case I realized that, having looked at everything 3 or 4 times, the problem almost had to be a staple that penetrated the insulation on both wires. Then I realized I could find it easily by using the multi-meter and checking for resistance between each staple and the track. Sure enough, this one registered loud and clear on the meter, and the repair took a minute.

Once that was done I started putting down new track. This picture shows the glue drying on two new track sections:


A close look on the left side of the picture reveals that there is a second layer of the blue roadbed on top of the first. As I noted in my last construction post, the new plywood I'm using is about 1/8" thinner than the old, and this caused the transition from one to the other to be uneven, even after I shimmed it. The second layer of roadbed seems like it causes no problems, however in order to keep the track as smooth as possible I'm letting this dry in place, without weights on it. This is an experiment -- if it works I might use the same technique for the rest of the staging track.

Next up: lots more track installation on the middle tier.

Choosing a scale

[Revised on April 24]

I previously talked about the difference between Gauge and Scale, and in that post linked to a long but incomplete list of known scales. In this post I'll talk about choosing a scale. Some of the points in this post will be referenced in later posts on the design of the current layouts.

Let's suppose you wanted to build a layout with an American standard-gauge prototype. If you walked into a large multi-scale hobby shop like Caboose Hobbies these are the scales you'd find that have that kind of off-the-shelf equipment available:

• Z scale (1:220)
• N scale (1:160)
• HO scale (1:87)
• O scale (1:48)
• H scale (1:32)
• 1:29 scale (using H scale track)

Now, this is not a list of every known scale. But it is a list of scales that are popular enough to have several manufacturers that produce off-the-shelf American standard gauge prototype products for them.

If you were choosing from this list of scales you'd probably be able to eliminate 3 or 4 possibilities right away, depending upon your preferences. The factors that influence most people's choice of scale are these:

1. Availability. The most popular scale, HO, has a huge variety of items available. Less popular scales like O and Z have a very restrictive selection. If you want to model a particular road name, or era, or just have a hankering for certain types of locomotives, you may find that not every scale has the off-the-shelf equipment that you like.


2. Price. HO and N are the lowest cost on a price-per-item basis. This is partly due to popularity (economies of scale, plus competition), and partly due to the fact that it's more expensive to build models that are very large or very small.


3. Experience and/or existing equipment. For example, if you had an O scale layout as a kid you may lean towards using O scale again as an adult, especially if you have some old O scale equipment that can be reused. Similarly, if you have friends running N trak modules you are more likely to choose N so that you can interoperate with them.


4. Space. One of the frustrating things about model railroading is that unless you are very lucky you never have as much space as you want. This makes sense when you realize how huge the thing is that we are trying to model. A typical modern freight train is at least a mile long -- and a mile is over 60 feet in HO scale! Or suppose you just want to run an 8 car commuter train, but that is almost 9 feet long in HO -- not easy to fit on a 4x8 table! Then there are the curves -- the famous horseshoe curve on the old Pennsylvania Railroad is one of the tightest curves on a class 1 mainline in the U.S., but if you were to model it accurately in HO scale you'd need a half-circle with a diameter of over 14 feet! For these reasons it is not surprising that modelers looking for more realism have flocked to N and even Z scale. Not only can you squeeze a layout into a much smaller space, you can also use a larger space to create a more realistic setting.


5. Size. The counterpart to "space" is the size of the equipment you use. For some modelers, weakening eyesight or dexterity motivates them to take up a scale such as O or even to model a large scale indoors. For others the frustration of trying to do electrical or detailed modeling work on N or Z scale has pushed them to HO. Size vs. Space is always a major trade-off in choosing a scale.


6. Aesthetics. What do you think looks better? Some modelers love the appeal of large, chunky O scale stock rolling across the layout. Others like the great detail they can put into large scale models. Some love to create panoramic views of mountains, canyons, or just large freight yards in a way that's only possible in the smaller scales. But as most modelers choose HO, perhaps most modelers like a compromise of all of the above.

With those scale choosing criteria in mind, here's a quick review of the scales.

Large (H and 1:29) I explained how all large scales use the same gauge of track in a previous post. H and 1:29 are the scales you would use if you wanted to model standard gauge.

The main advantage of large scale is that it is intended primarily for running outdoors. Most large scale modelers do so outdoors, in a specialty of the hobby called "garden railroading". For many of us (and I am one) there is a special appeal of railroading outdoors. First, there are all the tactile sensations of just working outdoors. Second, while indoor railroading tends to be less social -- usually only other modelers want to hang around your layout -- outdoor railroading invites the world to join. Even if you don't like railroads you may still love the garden aspect, or working with ponds and streams, or just being outdoors.

Of course, there are disadvantages to outdoors. The environment is always changing, the weather may not cooperate, and you may not have a suitable yard to build in. It's not for everyone.

One more advantage of large scale is that the very large equipment just has a certain appeal. I mean, it's HUGE compared to the other scales. This is why a few people who don't like outdoor modeling still use large scale indoors.

The disadvantages of large scale are simple: price, the space required, and the time required. Engines commonly run in the thousands. Although entry level diesels can be had for under $200 the lack of detail relative to a $75 HO diesel is noticable. Track has become exhorbitant. And depending on how you construct your layout you may find yourself spending tens of thousands in landscaping. There are those who have successfully built very low cost garden railways, but they always make significant compromises and spend a very long time building a lot from scratch.

Meanwhile, big trains mean you need a lot of space to run them. And if you are building outdoors, the time required for construction is much more than if you build a comparable layout indoors.

Garden railroading, I'm told, is the fastest growing segment of the hobby. But it's not for everyone.

O scale (1:64) There are really two types of O scale. One is the standard 2-rail model train. The other is Lionel. Lionel was the leading classic toy train for most of the 20th century. Lionel trains weren't that realistic -- they used a 3 rail electrical system, the rails didn't look anything like the prototype, and the locomotives and rolling stock were more like caricatures than the real thing, with absurdly large trucks and disproportionate dimensions. But for a long time they were the most accessible toy trains around. Today an old Lionel set in good condition is worth quite a bit of money as a collector item. This isn't true of most other model trains, which lose value as better quality trains are developed.

If you model Lionel you're in a special part of model railroading called Classic Toy Trains, which even has its own magazine. Otherwise, if you're modeling 2-rail O scale you're in the main branch of model railroaders.

2 rail O scale has always been a minority scale, but as with the rest of the hobby it has gained in popularity in recent years. It is more expensive than HO, and availability is limited, but if you are interested in O you can look at O catalogues (Walther's offers one, and most train shops carry it) to see if the available equipment is sufficient for what you want.

HO scale (1:87) This has been the majority scale since shortly after its introduction in the late 1930s. No one knows exactly what percentage of modelers choose HO, but it's probably around 75%, and higher for first-timers. (There have been various surveys, but none of them have a truely random sample, so 75% is a rough averaging of published figures.)

If you choose HO you've got lots of company. Almost every prototype that has ever been has been modeled by some manufacturer in HO, and the most popular are available from several manufacturers. New releases come out in HO first, and then sometimes in other scales. Your selection of structures, scenic material, track, and books dwarfs all the other scales. All this availability also means the best price competition -- you'll pay less per item than any other scale except perhaps N. When you read articles in popular magazines that are allegedly for "all scales" you'll find that 80-90% of them are in HO.

N scale (1:160) N scale came out in the 1960s in answer to those who were frustrated with the space issue mentioned above. TT scale (1:120) had been invented previously, as a smaller alternative to HO, but it never really took off.

Early N scale equipment didn't look or run very well. There were even problems with consistent scale, and today some items labeled as N scale from other countries are actually 1:150 (Britain) or even larger (East Asia).

But by the early 1970s N was sufficiently improved that it began being taken seriously. Then in 1973 the N trak module standard was invented and showcased at its first convention. The idea of running 150 car trains on a model railroad was an instant hit, and N trak grew rapidly in popularity.

In 1978 a landmark series of articles in Model Railroader described how to build a portable version of the Clinchfield in N scale and this was hugely influential. Then in 1981 Bill and Wayne Reid started publishing their articles of their large, incredibly detailed N scale layout based on a Pennsylvania and Maryland prototype. N scale was now considered a serious scale and through the 1980s and 1990s Model Railroader made a point of promoting N scale in virtually every issue. (They no longer do this, probably because there are now two N scale-only magazines that are widely read).

MicroEngineering and Micro-Trains entered the N scale market, making much better looking equipment available, and as of today most HO scale manufacturers have followed suit. The old questions about N scale electronics have been addressed -- equipment built in this century runs as well as does HO scale equipment.

So, today, N scale is a distant #2 to HO, but is gaining steadily. Pricing is similar -- although it must be admitted that an N scale layout will cost more than the same size HO scale one because you'll probably buy more equipment. Availability is now very good in N scale, such that the most well known locomotives and equipment are available in both scales, but HO scale is still ahead both in terms of the more obscure prototypes and also in terms of the wider range of road names and numbers available.

N scale has the space advantage described earlier. In terms of the "size" criteria, well, this is where HO wins hands down. HO track and HO locos and rolling stock are much easier to work on than N scale equivalents due to their size. This is especially true of DCC decoder installs, but also of other general maintenance and installation tasks. A similar comment can be made about most other tasks that are affected by size, from de-coupling to reading numbers on the cars.

This isn't to say that smaller size is always a disadvantage. N scale is about 54% the size of HO in one dimension, but in 3 dimensions (i.e. volume) N scale is about 16% of the size of HO. This means that voltage requirements are far lower, as is weight, and both of these are to our advantage during construction.

Z scale (1:220) Märklin introduced Z scale to Europe in the 1970s. Why did they choose a scale only a bit smaller than N? Possibly because their 3-rail HO was already proprietary and they liked having a line of trains that didn't interoperate with anyone else.

Whatever the reason, Z scale sold sufficiently that Märklin introduced U.S. prototype equipment into the states in the early 1980s. It was not very realistic -- rails were ridiculously huge, couplers were almost half the length of the cars, wheels too big, etc. But it was promising. In 1983 the great layout designer John Armstrong wrote a tremendously well-thought out article on how to design a Z scale layout, and later it was included in a layout book. This, combined with the introduction of much more realistic Z scale items by Micro-Trains a few years later, made Z a viable scale in the U.S.

Today Micro-Trains is still the main supplier of U.S. Z scale. Z scalers often supplement by picking up European models and Americanize them for their layouts. DCC manufacturers have made Z scale decoders for over 10 years now, and newer Z scale locomotives are not difficult to convert to DCC -- all or almost all Z scale locomotives are diesel.

Z is most commonly chosen by those who have only very small space to work with. You can really get a nice layout into a small space with Z. However, recently the trade magazines have showcased a few very large Z scale layouts which are designed to really exploit the "space" advantage noted above. One that was recently featured was of a Swiss line and the use of Z allowed the modeler to duplicate how the monsterous Alps just dwarf the tiny trains that snake through them. If you are willing to select a road name and era that matches the equipment available in Z you can do some terrific modeling.

Settling on a choice of scale. So, if you were to walk into a large train shop and look at all the available scales, which would you choose?

You could find starter sets in all of the above scales, but the selection would vary greatly. At Caboose Hobbies there is one very long aisle (60 feet? 80 feet?) almost exclusively taken up with HO starter sets, from the cheap to the better quality. There is a good selection of N scale as well, but not so much of the other scales.

If you're thinking outdoors you'll take large scale. If size is your most important criteria, O or large scale is your likely choice. If space is the main factor, you'll be over at the Z area of the store.

But the vast majority of newcomers choose HO. N scale is in second place, but it's a distant second -- maybe 1/4th of the number of people who choose HO. So, if I knew nothing about you I'd have to suggest you choose HO simply because that's the default. But if you asked me why some people choose N, here's what I'd tell you.

Consider a typical HO 4x8 layout. Yes, you can squeeze the same layout in N scale in a space smaller than 3x5, and that's one advantage. But suppose you took that same HO layout plan and duplicated it in the same size for N. Instead of ridiculously tight 18" HO curves you'd have respectably broad 18" N scale curves -- that is, the trains would look a lot more realistic as they went around the layout. Instead of having to run pathetically short train consists of 8 or 10 cars you could run almost plausible consists of 16 or 20 N scale cars. Go outside the 4x8 and the advantages are even greater. Longer trains, wider curves, larger yards, all in the same space.

For example, suppose you wanted to run the classic passenger train, the California Zephyr. Kato makes a great model of this in HO and N. It's 11 cars long. With 3 locomotives pulling it is about 7' in N scale but closer to 14' in HO scale. In most room size layouts you can fit a couple nice 7' long stations in without having to make them go around a corner curve. You won't be able to do that with 14' stations in HO.

So that's my $.02 on the choice of scales. And I didn't try to hide it, but you can see from this write-up why I like N and large scale.

Mid-tier subroadbed complete

Finished cutting and installing the middle tier subroadbed. Here's a picture from the staging side of "the window":


I did complete about half the blue roadbed as well. This picture is from the other side, and includes a few flat objects on the just-laid blue section to keep it in place while drying:


Nothing special about this contruction step except that I discovered this 1/2" plywood is about 1/8" thinner than the 1/2" plywood I used previously. How can that be? Well, I knew this was really only 15/32", but it seems that the other stuff was actually closer to 5/8", or maybe 19/32". And I'd forgotten that I'd done that.

Oh well. I did a little shimming under the one end of the new subroadbed to keep the tracks even. The slight grade won't affect this area, since it was flat anyway.

Tomorrow I'll finish the roadbed. Then my next task will be to clean up the office/train layout area -- I've let it go this past month due to all the other activities. And I need my hobby desk usable again so that I can start prepping all those switches.

Mid-tier alcove bridge

Not much new to report. I've started building the plywood subroadbed for the rest of the middle tier of staging. Just one picture to add:


Previously I mentioned that there is a 3' 9" wide alcove that the staging tracks have to span without supports because I will later want to be able to crawl under the track to get into the alcove. In that previous post I had a side picture of the upper tier alcove bridge. This picture above shows the underneath of the middle tier alcove bridge before it has been installed, so provides a better view of the bridge construction. (Note that the bridge is temporarily resting upside down on another part of staging -- this is not where it will be installed.)

There's not much to this construction. Two L-girders are attached together with nuts and bolts to provide a level surface, then the L-girders are attached to the underside of the plywood with #8 metal screws and washers. The plywood is strong enough to hold a whole slew of N-scale trains but it will tend to warp/bow unless something keeps it flat and level -- the L-girders provide that service and also provide some vertical strength in case some doofus like me stumbles and lands on the bridge.

Next step is to finish the subroadbed and add the blue roadbed -- I can complete both tomorrow if I can get a free hour to work on it.

Upper Tier completed

Here's a picture of the upper tier with all track in place and tested. There is even a test train on the track:


One note about this construction is that I've made some improvements in the track installation techique. I learned, during the prepping of the Atlas switches, to file down rough edges in the switch rails that can catch wheels and cause derailments. Having done that procedure now for 24 switches I automatically paid more attention to the rail joints in this new section of construction, using the diamond files and even the rotary tool to make all rail connections super smooth. During testing I found that the newly installed track resulted in very smooth operations -- even better than what I found on the previously installed track. At some point I'll go back and apply those lessons to the rest of the staging track.

The only other construction note is that I compromised a bit on the wiring standards. The most recent construction consisted entirely of track re-used from the first staging attempt, usually in groups of 2 or 3 track sections soldered together and with the original feeder wires intact. As a result, I ended up with a few single sections of track with no feeder wire. Instead of adding an extra pair of feeders I just soldered these to one of the adjacent track sections. Throughout this process I've been using the multi-meter to test for shorts and I've found that there is virtually no resistance between adjacent rails soldered together, so I expect no troubles with this compromise. In fact, I'm beginning to think that my feeder-to-every-other-rail-joiner stategy may be overkill.

Once everything was completed, cleaned, and tested with the DC SD90MAC locomotive I hooked up the Digitrax and tested a long train on both grades. Here's a picture from part of that test:


The train in question is 33 Athearn Bethgon Coalporters, which are harder to pull than most other cars due both to weight and higher resistance wheels. With the two locomotives this train is almost 13' long -- over 2000' scale feet -- and would justify two or three lead engines in normal operation.

I found that two Kato diesels (SD40-2, latest release) pulled this up the 0.9% approach grade (the upper tier staging entry track near the wall) without any noticable affect on speed. Just for grins I tested the same train up the short 3.5% grade in the upper tier staging yard (as shown in the photo) and they got up just fine, albeit with some speed degradation.

Alas, when I tried two Atlas diesels (SD60M) they struggled mightily with just the 0.9% grade, making slow progress at full throttle and lots of wheel spinning.

This matches my previous experience with Kato and Atlas diesels from my 2002 test layout, although at the time I attributed the difference to the fact that the Atlas diesels I had then being only 4 axle (dash-8s) versus the 6 axle Katos (C44-9W). But, the Atlas SD60M also has that problem and it has 6 axles. Fortunately, most of my mainline modern freight diesels are Kato (17) versus only 4 for Atlas. For now I'll stick with Kato until I do some research and see if the Atlas problem can be solved easily. If not I can get by with assigning the Atlas engines to lighter duty work.

Finally, a note about time -- mostly because when I re-read these posts later I'll wonder why it took 3 weeks to finish the last section of the upper tier. My last post on upper tier construction was on March 28. One factor is that there was a lot of work required in this small space. 8 switches, reusing already soldered track, and fitting a lot of track into a conjested space all required extra time and attention. But the main factor is that I didn't have a lot of time the past 3 weeks due to lots of work at work and at home (prepping for 2 birthdays, Easter, some financial matters including the IRS, and several snowstorms that required driveway attention).

I may get more free time in coming weeks, but as the (hopefully) last Spring snow melts the outdoors is beckoning -- first the spring thinning of our little patch of forest, then the outdoor railway, which will generate a few posts of its own. I resolve to keep making weekly progress on the N scale layout, however. The next step is the middle tier of staging.

(not so) Secret Codes

In past posts I've mentioned Code 80 and Code 55 track. In model railroading, "Code xx" simply means the height of the rail above the top of the ties (a.k.a. "sleepers" in the British Commonwealth) in thousandths of an inch. For example: Code 80 track has 0.080" high rails.

"Why should I care about rail height?", you may ask. And many model railroaders happily build their layouts without ever worrying about rail height. However, it's just one more aspect of realism that a modeler may or may not be concerned about.

The problem is that most model train track has rails that are ridiculously big, and although most people don't notice at first glance, if you are looking at a detailed model of a railroad scene the oversize rail can often ruin the illusion.

In the prototype (a.k.a. "real life"), modern rails in the U.S. tend to all share the same flat-bottomed profile, as shown at the link. However, rail sizes can vary greatly. By convention, the rail size metric used is "pounds per yard" of rail. At one extreme, the early DRG narrow gauge lines used 30 lb. rail -- which is about 3 1/8" in height. At the other extreme the Pennsylvania Railroad (PRR) once used 155 lb rail for their main lines -- the heaviest rail in common use, and about 8" in height. Modern class 1 (the busiest main lines) rail tends to be in the 100-132 lb range (6-7 1/8" high), although some heavier rail (140 lb) is starting to be used. It's typical for a railroad to mix rail sizes -- sidings, spurs, branches and yards often have smaller rail -- often 80-90 lb or less.

How does that compare to the model? Well, in N (1:160) scale Code 80 was long the N scale standard, and is still the most commonly used rail. Code 80 is equivalent to over 13" high rail -- about double the size of a modern main line. Code 55 is now the preferred rail for N scalers more interested in the details, but even that translates to 8.8" rail height -- bigger even than the PRR. Code 40 track is available for those that want absolute accuracy, as code 40 is equivalent to about 6.4" high track (roughly 110 lbs/yard), but if you use code 40 you have to hand build your own switches. Some modelers choose code 55 for the main lines and code 40 for spurs and sidings.

How much difference does it make? Well, compare a photo of a prototype locomotive to its N scale equivalent sitting on code 80 track and you'll notice the difference right away -- of course, that's probably because you'll be looking for it. In practice, most people don't notice, especially if you "weather" your track by painting a rust color on the sides of the rails and do a good job with the ties and ballast. I have heard from one N-trak modeler who often takes his N-trak modules to conventions and he reports that no one noticed (or at least no one commented) when he converted to code 55 from code 80. However, he gets lots of comments when he makes other changes to the details.

Still, I am using code 55 on my main layout, in large part because code 55 track products look a lot better overall, not just the rail height, than do the code 60, 70 and 80 N scale products.

For the record, the reason N scale track manufacturers initially chose code 80 was operations reliability. As with all model train scales, oversize rail and wheel flanges were chosen to minimize derailments. Today, modern plastic and metal manufacturing techniques are much more precise than they were in the past, so we can acheive even better operational reliability without the oversized rails and flanges. Even so, there are potential operational issues with certain brands of N scale code 55 track, and I'll cover that in a later post on track brands.

For those interested in more details on rail heights and sizes in the prototype and in the model scales, here is a good site.

For those interested in very high accuracy model railroading, what is commonly called "fine scale" modeling, the Proto 87 site is worth a visit. The term "Proto 87" simply means trying to precisely and accurately model the prototype in HO (1:87) scale. In addition to getting the rail size right, they also try to model exact replicas of (for example) switches and wheel flanges. This type of modeling is not for everyone, as there is a lot of extra effort required. But its a lot of fun to look at the results of a successful Proto87 modeler.

Outdoor model train scales

In the earlier post on gauge and scale I mentioned that the "large", outdoor scales range in size from 1:20.3 to 1:32. While these may seem like random numbers, there is a very logical reason behind them, dating back to the early history of model trains.

Some of the earliest model trains in the late 1800s were made by Märklin in Germany. They built three sizes of trains and named them "1", "2", and "3" gauge. All three were on the large size, reflecting the technology at the time. "1" gauge is 45 mm between the rails, about 1.77 inches.

When Lionel started making electric toy trains in the early 1900s in the U.S. they decided to name their gauge "0", pronounced "zero", because it was somewhat smaller than "1" gauge. However, people reading "0" (zero) thought it was the letter "oh", and so "O" has forever been the name of 1:48 scale. The smaller O scale trains quickly surpassed the larger 1 gauge trains in popularity because they took up less space. While "1" gauge trains continued to be produced in smaller quanitities, "2" and "3" stopped being produced.

Later in the 1930s Märklin came out with an even smaller scale, 1:87, and named it "half-oh", or "HO" for short (even though it was quite a bit bigger than half of 1:48). HO quickly leaped ahead of O in popularity, as many other manufacturers followed Märklin's lead. "1" became an almost forgotten gauge.

Fast forward to the late 1960s when a family named Lehman in Germany decided to build electric trains that could run outdoors. They chose "1" gauge track and named their new company LGB for Lehman Gross Bahn -- which translates literally to "Lehman Large Trains". For their initial line of trains they chose to model European prototypes that used a 1 meter narrow gauge. A 45 mm gauge track, when used to model a meter gauge prototype, yields a scale of 1:22.5. This soon became known informally as "G" scale. However, "G" was never officially recognized as a scale, and today people often mistakenly use the term "G" for any train running on "1" gauge track.

LGB trains were a hit, first in Europe and then in the states. In the 1970s LGB introduced more trains, including models of standard gauge European trains and 3-foot narrow gauge U.S. trains. LGB was vague about the scale of these new models, in part so that the cars from one size prototype wouldn't look out of place in the same train with others, and this resulted in a lot of confusion. (Today some modelers feel that LGB's failure to provide accurate scale info with their models ultimately contributed to their sales decline and their recent bankruptcy.)

In the 1990s and 2000s many other manufacturers entered the large scale train market and fortunately almost all of them provided specific scale info. For "1" gauge models based on a 3-foot U.S. narrow gauge prototype the scale of 1:20.3 is correct. The NMRA has recognized this as "F" scale . For "1" gauge models based on standard gauge the correct scale is 1:32, which is now recognized as "H" scale. It's easy to remember these letters because F-G-H are all "1" gauge scales, based on 3 ft gauge, 1 meter gauge, and standard gauge prototypes respectively.

Unfortunately, before H scale was established Aristocraft introduced a line of "1" gauge products based on standard gauge prototypes in 1:29 scale. As such the trains were somewhat larger than they should be given the wheelbase of the trains. Aristocraft chose 1:29 apparently because this allowed the LGB narrow gauge boxcars to look correctly proportioned next to Aristocraft product. USA Trains copied this practice, and their product line became very popular due to their lower prices and US prototypes, so other manufacturers followed their lead. Today large scale modelers now have to be aware that some standard gauge product is 1:29 scale and some is 1:32, and to try not to mix them because they will look funny together if you do.

Just to complete the confusion, a lot of the non-train models that are available for adding scenery to your outdoor layout are 1:24 scale, which kinda-sorta works with some of the other scales if you don't look too closely, or if you separate the 1:24 models from the trains visually.

One other point to note is that although all the "1" gauge trains will run on the same track, there are still separate lines of F, G, and H scale track. That's because while the rail gauge is the same, tie sizes vary greatly between scales.

Now, having said all of the above its worth noting that Garden railroaders tend to be a lot more relaxed than indoor modelers about prototypical accuracy. Many happily run trains of mixed scales. Others may run all their narrow gauge trains one day and all their standard gauge the next. And despite such sacreligious behavior they amazingly still get their layouts featured in Garden Railway magazine! :)

For my outdoor layout I have chosen a U.S. 3 foot narrow gauge prototype, so my scale is F (1:20.3). Actually, to be precise, my scale is Fn3, reflecting the 3 foot narrow gauge. However, the "n3" is usually not mentioned since virtually everyone in F scale is doing narrow gauge.

Design influences: third layout

I started my 3rd layout late in 1989, almost 9 years after my second layout was built and dismantled. I was newly married, and my wife, noting my intense interest in both real and model trains, suggested I build a layout. I immediately adopted her suggestion, of course, as I did not want to be disagreeable early in our marriage. ;)

Popular layout design theory holds that there are three decisions you need to make before you get started designing the layout: theme, scale and site, though not necessarily in that order. For my third layout the theme was a given -- European passenger trains. I'd moved to central Germany in 1987 and had traveled western Europe extensively for work and tourism while I was there. Europe had, and still has, a plethora of wonderful passenger rail. Furthermore, shops with European model trains were plentiful, with virtually one in every decent sized shopping district plus large model train departments in most of the big department stores. In 1989 I had one of each within 3 blocks of my apartment. Given that I was in the center of all this, and that I loved passenger trains, no other option was even considered.

As to scale, I was predisposed to HO but had to do some research before deciding. I visited a couple of local shops and found that German model trains were different in many ways from those in the U.S. In the U.S., with the special exception of Lionel Toy Trains, a wide variety of manufacturers will make interoperable equipment for the same scale. In Germany, at least back in 1989, modelers tended to stick predominantly to one manufacturer. I think this was mostly because the largest manufacturer, Märklin, set the tone with their distinct HO product line. Märklin HO has proprietary couplers and a unique 3-rail track system, with the third "rail" fairly well disguised as metal bumps in the center of the ties.

So the first question the train shop owners asked me was "which brand of model train are you using?" I hadn't decided, so in response I reviewed a few product catalogues and settled pretty quickly on Märklin HO. I suppose part of my rationale was the apparent quality of their product and the relative breadth of the their product line. But the main reason was that in 1988 Märklin had introduced their "Digital" line, which was what we now know as DCC. Such a product rollout was and example of the key advantage of a proprietary model train brand. While the rest of the model train industry would spend the next 15 years or so evolving the standards and practices to make DCC practical and universal, Märklin was able to provide all the necessary components all at once, out of the box. No messy decoder installs or debugging of weird timing problems between different manufacturers. It was literally plug-and play back in 1988.

Having decided on theme and scale I now needed to pick a site, and that was a bit of a challenge. We lived in a 61 square meter, one-bedroom apartment. Not small for two people, but not very accomodating for a model railroad. I knew the layout would need to be portable in sections, both because we would eventually move out of the apartment, and also because I would need to put it away in the storage locker when we entertained. I eventually settled on a 3x1 meter portable layout concept consisting of three 1x1 meter sections. This is roughly 32 square feet -- about the same as an American 4x8 layout, but somewhat longer and narrower.

With theme, scale and site decided I then needed a layout design. I quickly found that it was going to be very difficult to squeeze an interesting passenger layout into such a small space. When you start any layout design it's helpful to figure out the key constraints and requirements at the start, what the great layout designer John Armstrong called "Givens and Druthers". For me they were:

1. Train length. I wanted to run trains of up to 5 passenger cars. The longest train measured 160cm with the locomotive.


2. Curve radius. It was a given that any curves were going to be of the tightest possible operational radius, and hidden in tunnels because they would look so unrealistic. This turned out to be about 40cm radius if I recall correctly, or about 15".


3. Stations. Passenger train layouts need stations. At first I was open to a minimum of one station, either a through style or a stub terminal style. After sketching a few designs, though, I realized that I needed a minimum of two stations to keep it interesting, and ideally one of each style.


4. Realism. The setting should be at least possible, if not plausible. This implies that the trains would need to exit through a tunnel somewhere to go "off stage", which would represent the "rest of the world". I had not heard the term "staging" back then, but the requirement for staging was clear. It also meant that oval designs or twice-through-the-same scene designs were out of the question.

I sketched all kind of layouts but just couldn't find a solution that I liked. The best I could come up with was a layout with a 3-meter-long view block lengthwise down the middle. On one side would be the stub terminal, then the train would go through a curved tunnel to the other side where there would be a through tunnel. Then the train would go through another curved tunnel to an under-layout staging area.

But this design concept had at least three problems. First, the overall run for the train was very short, making it less interesting to operate. Second, there was the problem that trains would still be exiting the first station while simultaneously entering the second. Finally, this design requires walking around the layout to follow the train, which is acceptable in theory, but in practice is difficult given that Märklin did not yet have walk-around controls.

I bought some German layout books seeking inspiration, but found no answers. I dug out my old copy of the "101 Track Plans" book that I used for my second layout, but still nothing satisfied. I eventually got so frustrated that I seriously considered switching to N scale, even sketching some N scale plans for the same space. Finally I found my solution by looking "one last time" at a Märklin layout design book. Most of the Märklin layouts in that book eschewed realistic operations, but one design stood out:


To see why I liked this, ignore the logging and industrial elements in this picture and focus just on the layout of the main line. The railroad starts at the stub terminal at the top of drawing, which is at the top of the hill, then winds its way down slope, making two horseshoe turns with the second turn in a tunnel, and arrives at a through station. From there it goes into a tunnel that goes to "the rest of the world", a.k.a. "under layout staging".

I might not have seen the passenger possiblities here if my wife and I had not been making frequent visits to Switzerland, where I'd noted the following about Swiss mountain railroads: 1) The Swiss have a lot of tunnels, and often in places where Americans would have chosen a large cut; 2) There are a few mountain towns in Switzerland that are accessible only by train or hiking path; 3) There are some places where two stations are quite near each other, separated as much by elevation as by horizontal distance; and 4) compacted, complex trackwork is common throughout the Swiss mountains as they often have to squeeze track into small spaces.

So, I could see this track layout working with a Swiss mountain theme. The track distance between the two stations allows for a longer run that addresses the concerns stated earlier. The two stations would be separated mostly by elevation and in a mountain town that was accessible only by train. I would not include the industry shown on the Märklin drawing, but would allow a "goods track" at each station for local freight deliveries (what in America we would call a "team track"). For even more fun the theme would be a ski village in winter. And the whole layout could be viewed and operated from one side.

The next step was to compress the layout design from the 3.0x1.7 meter space shown in the drawing to my 3x1 meter space. This wasn't hard as I didn't need the space that was set aside for industry. As I drew the detailed design it I re-routed the main line and made a few changes, most significantly adding a turntable to the stub terminal. This was totally non-realistic as the Swiss converted to electrical railroads for their mountain tunnel lines very, very early (the first decade of the 1900s I believe), but I wanted the flexibility of running steam. I later gave the railroad a specific date of Boxing Day (day after Christmas), 1956, and planned to string electric catenary. The idea was that the catenary would be new, so new that the viewer couldn't tell whether it was yet operational. I could then run steam, diesel or electric depending on my whim.

I built the layout in early 1990 using a German language model railroad how-to book as a guide. The methodology they used worked, but I don't recommend it because it's not very conducive to later revisions of the layout. The Märklin turntable I'd included in the layout plans was announced but would not be available until 1992, so I ran trains without it for the first year. The digital system worked great, and I built a few models and a bit of scenery.

By 1991 I just left the layout in the storage locker, as moving it in and out had become a pain. In late 1991 I took a job in California, and in early 1992 we moved into a new house. The layout was setup in one of the bedrooms. This picture shows it shortly after things were unpacked and I had gotten the trains running:


Unfortunately, this amazingly is the only photo I have of the layout today. Alas, the angle is not good for seeing the track plan, the scenery is not in position, and there are even random items piled on the layout in places. I think I took this picture as part of a series showing each room in the house after move-in. Furthermore, the turntable was not yet in place. However, as it is the only photo I have I'll have to use it to describe the layout, and how it differed from the Märklin drawing that inspired it.

The top tier was the stub terminal -- this level had no slope. There were three tracks for passenger trains and one short track, on the side farthest from the camera, for goods cars. The space for the turntable and a few locomotive tracks was on the right -- I would add the turntable to the layout later in 1992. Two double-slip switches connected the turntable to the passenger tracks. There was an escape crossover near the end of the two longest passenger tracks, to allow for backing steam locomotives back to the turntable, turning them, and attaching them to the other end of the train for the return journey.

The middle tier was on a 4-5% grade connecting the two stations, with the left half of this tier in a tunnel. I added a siding to the middle tier between the curves, and this proved very useful in operations. The inspiration for adding a siding partially in a tunnel came from the line between Grindlewald and Wengen in Switzerland.

The lower tier was on a 1-2% grade with a two-track through terminal. A short goods track was also included on the left side. Curved Märklin switches were used at both sides of the lower tier so that the station tracks were long enough to accomodate the passenger trains.

The underneath staging level consisted of a double-track reverse loop. Because of Märklin's 3-rail system no auto-reverse mechanism was needed. Staging could accomodate up to 4 trains.

Operations consisted of a tight holiday schedule of regional, local, and worker passenger trains, with two runs for goods cars placed at gaps in the schedule. To add operational interest special events, such as late trains or a non-functioning engine, were introduced at random intervals.

I continued to run trains and enhance the layout occasionally through the end of 1993, when our first child, Paige, was born. During that time I'd converted the layout from being in 3 sections to one large section, in order to make continuing construction easier. Work then essentially stopped on the layout until late 1995, when the arrival of our second child, Daniel, meant the layout had to move into storage. I built a special holding platform for it high in the garage and packed it all away as carefully as I could, and it sat there for many years.

In early 2002 I found that my train-obsessed son was climbing up a ladder in the garage, lifting the layout dust cover, and spending hours staring at the the layout. He had his own HO trains (supplemented by my old American HO trains that had been converted with modern couplers) on an oval layout on a flat board. But he was fascinated by the mountain layout with the slopes and bridges. We decided to swap the two layouts -- the Märklin one went in the garage spot where his had been, and his went where the Märklin one had been stored. We then revived the Märklin layout and ran trains for several months.

It all ended when I decided to start a new layout in N scale. The Märklin layout went back into storage and was dismantled for our move in 2005. I have a tinge of regret about that, but I'd realized that I never was going to have time to finish the Märklin layout given a) my new interests in N scale and large scale and b) that I'd lost interest in Märklin 3-rail.

So, what were the lessons learned from the 3rd layout?

1. Yes, I love passenger trains. More specifically, I loved the drama of the trains coming in and out of the stub terminal and crossing over the double-slip switches. The stub terminal was my favorite part of the layout, especially with the abundance of operational possibilities after the turntable was added.
2. Double track is cool. This layout was single track operationally, although with two stations and a siding most of the actual main route was double track. I did this because single track is recommended for layouts because it increases operations activity due to having to accomodate meets between trains in opposite directions. But as I looked at the staging part of the layout, with the double-track curve, there was something about that "boulevard of steel" that made me want to emulate that on the main line with my next layout.
3. Digital is cool. Märklin digital, less so. For one it's ridiculously expensive, and for another many of the operations were very difficult due to limitations of Märklin controls.
4. I can do without turntables. Oh, they are fun and cool to look at, but the huge amount of work required makes me question the fun/work ratio. I haven't planned one since, although my outdoor layout will probably have two for prototype reasons.
5. I'm ready for a really big layout. After this layout was done I felt I'd done as much as I could with small space compromises, and that what I really wanted were long trains over very long runs and curves that weren't so tight that they had to be hidden in tunnels.
6. I want more realism than what this layout offered. Given the space I had it was the best I could do, but some of the pretenses required to create interesting operations were really stretching the term "realistic". Another reason to go big with the next layout.
7. I discovered that my modeling interests tend to be influenced heavily by where I live. When I built this layout I was surrounded by European trains and couldn't imagine modeling anything else. I think that part of the reason my interest waned in 1994, apart from the thrill of a baby in the house, was that European trains were becoming a distant memory to me -- and when I revived the layout in 2002 the European trains seemed no more realistic to me than the Thomas the Tank Engine trains my kids had. However, at that same time I'd become very interested in local railroads like the Southern Pacific and the old narrow gauge South Pacific Coast.

All of these lessons would factor into my current layout. Unfortunately, in 2002 I still didn't have the space to go "big", so my 4th layout would have to incorporate some, but not all, of these learnings.

Gauge vs. Scale

In model train conversations it's common to hear the terms "gauge" and "scale" used interchangeably, as in "HO gauge" as a synonym for "HO scale". This is especially true for model railroading newcomers. While this causes no harm, as everyone understands what is being said, the two terms have different meanings:

Scale -- The size of the model relative to the prototype.

Gauge -- The distance between the two rails.

For example, N scale is 1:160, which means it is 160th the size of the prototype. If a prototype freight car is 80 feet long, in N scale it would be 160th of that, or 1/2 of a foot long.

In terms of gauge, prototype standard gauge is 4 ft 8.5 in between the rails, which translates to 9 mm between the rails in N scale. ("N" was chosen for the name of 1:160 scale because of the Nine mm rail gauge. )

So, if you say something is HO gauge what you are saying is that it is 1:87 (HO) scale and standard gauge. Similarly, the term "HOn3" means a model that is 1:87 scale, but representing a prototype narrow gauge of 3 feet. The "n3" of "HOn3" means: "narrow gauge, 3 feet". There is also an Nn3 -- 1:160 scale and a narrow gauge of 3 feet. Another popular example of modeling narrow gauge is On2.5 gauge -- which is O scale (1:48), narrow gauge of 2.5 feet.

The National Model Railroad Association (NMRA) has their own web page on scale and gauge which covers this topic in detail, including a list of scales common for indoor model railroads.

Although many model railroad scales have been established they clearly do not enjoy equal popularity. The most popular scale by far is HO, with N a distant (but growing) second, and the other scales further behind. TT scale (1:120) is virtually dead, killed off by the introduction of N in the 1960s. OO scale (1:76.2) is very popular -- perhaps the most popular -- in Britain but is almost unheard of elsewhere.

The NMRA web page I linked to does not, for some reason, list the "large" scales, from F (1:20.3) to H (1:32). These scales are commonly referred to as "outdoor" or "garden" railway scales because, although you can run them indoors, they are mostly used outdoors.