Single straight
A TT single is sized so that two-and-a-half Tillig 166 mm straights — that is, 415 mm of rail — sit on a 413 mm module box with a 1 mm overhang at each end. Track centres come down to 43 mm, reflecting TT's smaller loading gauge, and the front-of-module setback is described as an outer-line offset rather than a setback to the front rail.
| Scale ratio | 1:120 | Between Z (1:220) and N (1:160) |
|---|---|---|
| Track gauge | 12 mm | Standard TT gauge |
| Length × depth × height | 413 × 400 × 70 mm | Module box outer dimensions |
| Track length | 415 mm | 1 mm overhang at each end |
| Track centres | 43 mm | Between the two parallel running lines |
| Outer-line offset | 86 mm | Centreline of outer track from front face |
| Track system | Tillig Bedding Track | Not Kato — the only non-Kato T-TRAK variant |
| Skyboard | Optional | Height not specified by the standard |
| Box height | 70 mm | Same as N and HO standards |
Multi-length and corner modules
Like the other scales, TT supports doubled-up straights and a square-format outside corner. The double straight is built from five Tillig 166 mm straights end to end (giving 830 mm of rail) on an 828 mm box. The outside corner is a near-square 481 × 481 mm footprint sweeping a 90° arc, made from three 30° Tillig curve sections per running line.
| Single straight | 413 × 400 | Track 415 mm |
|---|---|---|
| Double straight | 828 mm long | Five × 166 mm = 830 mm rail |
| Outside corner | 481 × 481 mm | 90° sweep |
| Inner radius | 353 mm | Three sections of 30° |
| Outer radius | 396 mm | Three sections of 30° |
Tillig parts list
The TT addendum lists Tillig Bedding Track parts by catalogue number. Brown ballast is the standard finish for the running lines; grey alternatives are listed where Tillig publishes one. Flex-track is permitted on transition modules where Bedding Track sectional pieces would not give a clean fit.
- #83712Straight, 166 mm, brown ballast×2
- #83713Straight, 83 mm, brown ballast×1
- #83701 / #83702Grey-ballast straight alternativesoption
- #83717 / #83780Curve 30°, 353 mm radius, brown ballast×3 each
- #83706 / #83770Grey-ballast curve alternativesoption
- #83820 / #83821Turnout, RH / LHpreferred
- #83594Rail joiner with solder tagfeeder
- #07911TT rerailer×1
- #3495Flex-track, wood-sleeper, 664 mmtransition
- #83134Flex-track, concrete-sleeper, 520 mmtransition
Tillig is supplied in Australia through Orient Express in South Australia, who carry Bedding Track and turnouts in both ballast colours. OzRail produce flat-pack laser-cut ply baseboards for T-TRAK; specify TT when ordering and they'll cut to the 413 × 400 mm single envelope. Modelling standards for TT in this guide adapt the BBMRA conventions via the NMRA, with all dimensions metric-converted at source so you don't have to translate them at the workshop.