T-TRAK Module Basics

Straight Modules - Single, Double, Triple, Quad
Corner Modules - 90°, 180°, and 90° inside corner
Junction Modules

Basic Modules


The minimal standards in T-TRAK permit the flexibility to build modules of all shapes and sizes; however, there are some basic modules that are essential building blocks in any layout. T-TRAK modules fall into three main categories: straights, corners, and junctions. Pictured to the right is a single. Single modules are 308 mm wide with 310 mm of track. The track arrangement is usually a 186 mm and a 124 mm section for each line or a 248 mm and a 62 mm. Click here for a list of single modules on the T-TRAK Wiki.

Track: 2 Kato 20020 and 2 Kato 20010 (click image to enlarge)

The double module is 618 mm wide with 620 mm of track (double the track length of a single). Track arrangement for the double can be accomplished with two pieces each of 186 and 124 mm track sections (for each line). It can also be built with two pieces each of 248 and 62 mm track. Another common arrangement for doubles is using two pieces of 248 mm and one piece of 124 mm for each line. As previously stated, any arrangement which yields 620 mm of track for each line is acceptable. Click here for a list of double modules on the T-TRAK Wiki.

Track: 4 Kato 20000 and 4 Kato 20040 (click image to enlarge)

The triple module is 928 mm wide with 930 mm of track (triple the track length of a single). Track arrangement for the triple can be accomplished with numerous ways as long as track length for each line is 930 mm of track. Obviously, it can be accomplished using three times the pieces required for a single.
Longer modules can be created but often it is easier to construct a set of smaller, standard-sized modules to depict the desired scene. Using this technique, long sidings or yards can be constructed and still remain portable. Click here for a list of triple modules on the T-TRAK Wiki.

Track: 6 Kato 20000 and 2 Kato 20010 (click image to enlarge)

The most common 90° corner consists of a module 365 mm long on each side. Track consists of two pieces of 282 mm radius and two pieces of 315 mm radius. These radii permit a double row of modules on a single folding table. Click here for a list of corner modules on the T-TRAK Wiki.

Track: 2 Kato 20110 and 2 Kato 20120 (click image to enlarge)

The 180° corner, also known as an end cap, measures 365 mm in length and 730 mm in depth. It functionally replaces two 90° corners and requires four pieces of 282 mm radius and four pieces of 315 mm radius. While end caps are convenient in that they reduce the number of modules, using them exclusively limits layout designs to ovals. Click here for a list of 180° corner modules on the T-TRAK Wiki.

Track: 4 Kato 20110 and 4 Kato 20120 (click image to enlarge)
The inside corner is not as common as other module types but is required for L-shaped layouts that consist of a double row of modules. Refer to "The Unofficial T-TRAK Handbook" (see Links) for module dimensions as they can vary depending on the depth of straight single modules. However, as a rough rule and assuming standard radii corners and 33 mm track spacing, an inside corner module with square dimensions greater than 410 mm and less than 675 mm should work for a base module. Track placement will not necessarily be aesthetically correct but it will fit. There are two known working track configurations for an inside module. One configuration is the the same as the 90° corner with the addition of a 29 mm track piece between the two 45° track pieces. The other configuration consists of two 30° 348 mm radii easement pieces to two 15° 315 mm radii pieces for the inner (white) line. The outer (blue) line consists of two 15° 315 mm radii plus two 15° 282 mm radii plus another two 15° 315 mm radii. Click here for a list of inside corner modules on the T-TRAK Wiki.

Track: 2 Kato 20130, 6 Kato 20121, and 2 Kato 20111 (click image to enlarge)

The T-Junction is a special module but has become very common in larger layouts as it permits more complex module arrangement as well as increasing the number of loops on a layout. The geometry of the T-Junction was derived by Steve Jackson in 2004 based on the geometry of a typical corner. The track of the T-Junction consists of four pieces of 45° 282 mm radius track for the two inner curves. The straight track is 597 mm in length. This is not a standard length for Kato Unitrack so either requires their special expansion track or cutting track to the appropriate length. The expansion track between two 248 mm pieces are depicted in the picture at right. Click here for a list of junction modules on the T-TRAK Wiki, however, please note that not all of the listed junctions are T-Junctions.

Track: 4 Kato 20110, 2 Kato 20000, and 1 Kato 20050 (click image to enlarge)

Detailed information regarding electrical connections techniques, other than the standard wiring polarity and the use of Kato connectors, as well as various module construction methods, can be found on The T-TRAK Wiki and The Unofficial T-TRAK Handbook. Refer to the Links page for web addresses.