Kato Unitrack · N scale · 24 pieces
Oval + Passing Siding — Kato Unitrack N scale plan
A running loop with a siding so two trains can pass.
- Board
- 1,829 × 838 mm
72 × 33 in - Track footprint
- 1,626 × 630 mm
64.0 × 24.8 in, centerline - Pieces
- 24
2 turnouts - Geometry
- Closed
0 open ends
What it teaches
An R315 oval with a passing siding on the near straight. That straight runs through a facing #4 turnout and a trailing #4 turnout — the second is mated by its main exit, so it faces the other way — which puts both diverging legs on the same side, pointing at each other. Each leg reverses through an R481-15 curve down to the 33 mm track center, and between them the siding runs 498 mm: S248 + S186 + S64, an exact seam.
The oval still has to close on its own. Through the turnouts the near straight is 126 + 3 × 248 + 126 = 996 mm, and the far straight matches it piece for piece with 3 × S248 + S124 + 2 × S64 = 996 mm. Change either side without the other and the loop opens.
The two turnouts are sold singly and are most of the cost; the packs of S124, S186, S248, S64 and R481-15 each leave spares, which is why the whole-pack figure is above the per-piece one.
How the siding lands on the 33 mm center →
Parts list
Grouped by the Kato part number you actually buy — a curve's left and right hands are one part. Quantities, pack sizes and prices are the ones RailMind's parts list computes for this plan.
| Kato part | Piece | Qty | Each | Sold as | Buy | Cost |
|---|---|---|---|---|---|---|
| 20-020 | S124 | 1 | $2.00 | 4-pack | 1 pack (4 pcs, 3 spare) | $8.00 |
| 20-010 | S186 | 1 | $2.25 | 4-pack | 1 pack (4 pcs, 3 spare) | $9.00 |
| 20-000 | S248 | 7 | $2.50 | 4-pack | 2 packs (8 pcs, 1 spare) | $20.00 |
| 20-030 | S64 | 3 | $1.88 | 2-pack | 2 packs (4 pcs, 1 spare) | $7.50 |
| 20-120 | R315-45 | 8 | $2.50 | 4-pack | 2 packs (8 pcs) | $20.00 |
| 20-160 | R481-15 | 2 | $2.06 | 4-pack | 1 pack (4 pcs, 2 spare) | $8.25 |
| 20-220 | #4 Turnout L | 1 | $37.50 | single | 1 | $37.50 |
| 20-221 | #4 Turnout R | 1 | $37.50 | single | 1 | $37.50 |
| Estimated total, per piece | $126.50 | |||||
| Buying whole packs — 9 packs + 2 pieces | $147.75 | |||||
Approximate US retail per piece — Kato sells most track in packs, and street prices vary. Use as a planning estimate. The per-piece total is what the pieces cost; the whole-pack total is what you pay at the counter when a pack leaves spares.
Build it
RailMind ships this plan in its example gallery. Open it, edit it, and print it at true size — tiled across Letter or A4 with registration marks — to lay the track over. The parts list above is the one it produces, and it will check it against the track you already own.
iPad only · iPadOS 18 or later · free to build a starter layout, one US$29.99 purchase to unlock every piece.