The geometry-finisher. A half curve turns 11.25° — half the arc of a standard curve, thirty-two to a full circle — at Setrack's No.2 radius of 438mm (17.25in), and it exists to make plans work: squaring up the geometry after a turnout (Setrack points diverge at exactly this angle, so a half curve brings the diverging road parallel), easing gentle S-curves into sidings and loops, and providing the half-step that makes an oval fit the baseboard when full curves overshoot. Code 100 nickel silver, rail joiners fitted.

The Radius System

No.2 radius is the middle way of Setrack's curve family — inside it, No.1 (371mm) for the tightest train-set circles; outside, No.3 and No.4 for sweeping outer loops and double-track spacing. Standard curves (ST-225 at this radius) do the main circling; half curves do the fine-tuning. Runs everything Code 100 runs — vintage deep flanges included — and connects freely with Hornby and Bachmann sectional track, sharing the same geometry standards.

Track That Grows With You

Fully compatible with Peco Streamline Code 100 — and if the 438mm/11.25° numbers sound familiar from our Streamline listings, they should: Peco's SL-U77/U76 small-radius curved turnouts were adapted from this very Setrack geometry, so mixed Setrack-and-Streamline plans share their maths. SL-11 insulated joiners for section breaks; ST-280 nails for pinning down.

Specifications

Brand: Peco
Part Number: ST-227
Range: Setrack, Code 100
Gauge: OO/HO (16.5mm)
Radius: No.2 — 438mm (17.25in)
Angle: 11.25° (32 per circle)
Rail: Nickel silver, Code 100
Companions: ST-225 standard curve (same radius); SL-U77 curved turnout (same geometry)