The C-TRAK Standards


The beauty of C-Trak is, that it’s not a formal standard as far as measurements go, more a way of thinking. The most important thing is that there should be at least one C-track compatible segment that can connect to the next module. Only if more railroaders would like to connect to modules from others, that some adjustment is necessary.

In order to keep modules easily manageable and flexible a size of around 50 x 50 cm (2 x 2 ft). This is the reason that a ’basic’ straight module is a square of 532 x 532 mm, consisting of 1 straight of 188 mm and two straights of 172 mm. The 188 mm piece is interchangeable for a switch/turnout. The corners are based on Radius 1 (360 mm) and Radius 2 (437,5 mm). Distance between the tracks (centerline) is 77,5 mm, which is standard for all Märklin C-track. The moulded railbed has a width of 40 mm. By keeping the connecting rails equidistant from the edges, modules can be clicked together like domino.

The theoretical measurements of a basic module are as follows:

Width 172 + 172 + 188 mm 532 mm
Depth 172 + 172 + 188 mm 532 mm
Height 100 mm (including adjustable legs) 100 mm
Distance from edge to centerline of track 1 532 – 360 mm 172 mm
Distance from edge to centerline of track 2 532 – 360 – 77,5 mm 94,5 mm
Distance from edge to bedding track 1 532 – 360 – 40/2 mm 152 mm
Distance from edge to bedding track 2 532 – 360 – 77,5 – 40 /2 mm 74,5 mm

It all looks very theoretical, but actually building modules is not hard. A Module should not bee to large, so the rails can not be clicked together anymore, so with most measurements: rather a little bit smaller than larger. When using double track, the distance between the tracks is very important. However this is easily constructed using switches/turnouts as a guide.
There are several ways to construct modules. The most common is a box made from plywood, with or without a filling with foamboard. See Building elsewhere on this site.

The width of is free, as long as modules can be transported easily. Preferred is a width constructed out of complete track sections. A width of 720 mm for a straight section can certainly work.

The depth of the modules doesn’t have to be fixed either, unless working with corners. Use 90 degree angles to work out the depth needed for the two connections which are not in one line.

The height of the modules is 10 cm (4 inches). The modules can be filled with foam to work out contours in the landscaping (e.g. tunnels and bridges). When the modules are left hollow, they can be stackable when in storage, because a lot of scenery (buildings, trees etc.) will be covered by the next module. When used at home, any other height will work just fine, but to be able to connect modules of different owners at events, the railheight should be at max. 10 cm. Because track sections are actuallu 10.3 mm high, the top of the rails should be at 110 mm. To be able to chanche the height a little bit, legs with set screws can be used.

Electrical connections

When using trains from the Märklin my world program, no wiring is required. The trains run on batteries, so no connection with mains or any other power source is required. They will run on the standard C-track and on plastic track. When other (AC or DC) rolling stock is used, trains need current pickup from the rails. Because of the Märklin 3-rail system for AC, constructing layouts with shorts is impossible. The electrical connection between the rail sections is very good, so when running trains with a decoder just 1 feeder rail should (theoretically) be sufficient. When using multiple trains and analogue train control, things get more complicated, because some modules need to be switched off. Because the ease of use and the fun of playing with trains, digital- or infrared control is preferred.