Looking at a row of TTrak modules you see the long straight mainlines heading down the front of the table. But it's -boring-! I wanted something that would let me have scenery in front of the tracks as well. So I built a pair of double-wide modules as 'swing' or offset modules.
The track swings from the front of module 1 to the rear; module 2 reverses the swing; it's a mirror image of the track on the 1st module. The track at the rear of the modules is spaced the same distance from the back of the module as the normal distance from the front of the module. Any standard module(s) can be spun end for end and inserted between the swing modules. This makes it important that your modules look good from the back as well as the front!
For each offset module you'll need the following track. Note that these lists are for EACH track-- the 2nd track is assembled the same as the 1st, but flipped end-for-end (the track plan is symmetrical). The pieces I used, in order, are:
Basic 25mm |
Alternate 33mm |
Alternate 33mm |
Track Spacing |
Track Spacing |
Track Spacing |
|
-------------------- |
-------------------- |
-------------------- |
|
2x64mm R481-15 2x64mm 1x62mm R481-15 1x62mm
The center of each track
|
62mm R718-15 124mm R718-15 64mm
|
For 12" Deep Modules - - - - - - - - - - - 29mm 2-R481-15 124mm 2-R481-15
|
The first two columns describe the track for standard 8-1/4" deep double-wide modules. Column 1 uses the Basic 25mm track spacing-- these are the modules I've built. Column 2 uses the Alternate 33mm track spacing.
The third column also uses the Alternate 33mm track spacing for an offset module to be used with a 12" deep double-wide module. This was designed at the request of Steve Jackson (who designed the junction modules, below). The curves are similar to the 'Original' standard offset module. The track is actually 3 or 4mm longer than the 620mm it should be for a double-wide module. However, this is less than 1/4" and should be 'fudgeable.'
Having the track move back and forth breaks up the long straightaway and provides an excuse (and a place) for more scenery in front of the tracks.
The curves on all versions are nice and broad; I think most equipment will handle them easily. The center section of the 'original' version is 190mm long (not quite 7-1/2").
The 33mm center-to-center versions have 124mm straight sections (not quite 5") in the center. The shallow version has curves that are about 9" broader than the other 2 versions.
These central straight sections should avoid most S-curve problems.
Although the revised TTrak standard allows you to use Kato's standard 33mm track spacing (the TTrak Alternate track spacing), you can 'cheat’ and use the Kato crossover and truss bridges with modules using the Basic 25mm track spacing. If you build a double-wide module, you just have to swing the tracks from 25.4 mm center to center out to 33 mm center to center-- that's 4 mm sideways for each track (not quite a quarter inch). You should be able to "cheat" on the alignment, or, use a couple of short sections to get a bit more play to get a 'straight curve' that lets you slip the crossover or double bridge into your module.
I've been violating the module size standard since I first thought about building a module-- I went right to designing double-wide and even a quad-wide module. I thought that a single-wide module didn't give enough space to -do- anything!
I've changed my mind (partly). It's like Haiku, or a Limerick-- You are given the standard shape of the thing. It's your job to be creative within that shape. More of a challenge to be creative and still fit the pattern. Like -this- limerick-- (I don't make 'em up; I just remember 'em!)
The 'Basic Corner' for T-Trak specifies Kato 20-170 curved track: 8.5" radius (216mm). These are constructed on 12-1/4" square modules. Unfortunately, larger engines have problems with curves this tight.
Larger corners which conform to the T-Trak specifications, but have wider radius curves, can be built:
| Corners for Basic Track Spacing | |||
| Module Size (Square) | Kato Track Part# | Radius | Radius (mm) |
| -------------------------- | ---------------------- | ------------- | ----------------- |
| 12-1/4" | 20-170 | 8.5" | 216mm |
| 13-1/2" | 20-100 | 9.8" | 249mm |
| 14-13/16" | 20-110 | 11.1" | 282mm |
All of the above use 3 short sections of track from the Unitrack 20-945 Short Piece Assortment: 45.5mm / 1-3/4" straight at either end of the outside track, and a single 29mm / 1-1/8" straight between the two curved inner sections. This allows you to use the same radius track for both the inner and outer tracks.
You can also use flextrack for the corners and use short sections of straight Unitrack at the interfaces. This maintains the locking action of the Unitrack rail joiners between modules.
A layout with the largest of these corners will just fit on a 30" wide table. This would put all of the modules right at the edge of a 'standard' 30" table-- I suggest one of those under-the-carpet no-skid pads to make sure things don't jiggle off the edge!
The 282mm / 11.1" radius should be able to run most N steam engines and all N diesel engines. The 249mm / 9.8" radius can handle most diesel engines and some steam; the Kato Mikado handles the 9.8" curves acceptably; the Bachmann 2-8-0 Consolidation does also. The Kato RDC cars look a little funny around the 249mm / 9.8" corners-- the cars are long, and there's quite a bit of overhang.
| Corners for Alternate Track Spacing | |||
| Module Size (Square) | Kato Track Part# | Radius | Radius (mm) |
| -------------------------- | ---------------------- | ------------- | ----------------- |
| 14-3/8" | 20-120 (outer track) | 12.4" | 315mm |
| 20-110 (inner track) | 11.1" | 282mm | |
| -------------------------- | ---------------------- | ------------- | ----------------- |
| 13.1" | 20-110 (outer track) | 11.1" | 282mm |
| 20-100 (inner track) | 9.8" | 249mm | |
| -------------------------- | ---------------------- | ------------- | ----------------- |
| 11.8" | 20-100 (inner track) | 9.8" | 249mm |
| 20-170 (outer track) | 8.5" | 216mm | |
These track selections are for corners using the Alternate (33mm) center-to-center track spacing. This spacing does not require the 3 short straight sections of track.
The largest alternate corner should be able to handle almost any equipment you have. A layout with these corners will just fit on a 30" wide table. This would put all of the modules right at the edge of a 'standard' 30" table-- I suggest one of those under-the-carpet no-skid pads to make sure things don't jiggle off the edge!
The medium-sized alternate corner should be able to handle large equipment, but will suffer with more 'overhang' on the curves.
The smallest alternate corner should be restricted to short length equipment, and 4 axle diesel locomotives.
The medium and small corners will be more restrictive on the inner track than the outer track.
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Track for Modules
Offset Modules
Crossovers & Bridges
Small Modules
Bigger Corners
Church Photos
