Switch radius determines the diverging route geometry and directly affects operating speeds and maintenance requirements.
Standard Switch Configurations
| Turnout Number |
Radius (m) |
Speed (km/h) |
Application |
| 1:24 |
2500 |
160 |
High-Speed |
| 1:18.5 |
1200 |
130 |
Main Line |
| 1:16 |
760 |
100 |
Secondary |
| 1:12 |
500 |
80 |
Branch |
| 1:9 |
300 |
50 |
Yard |
| 1:8 |
190 |
35 |
Industrial |
| 1:6 |
150 |
25 |
Sidings |
Speed Capabilities
| Radius (m) |
Straight |
Diverging |
Trailing |
| >2000 |
300 km/h |
160 km/h |
180 km/h |
| 1200-2000 |
250 km/h |
130 km/h |
140 km/h |
| 760-1200 |
200 km/h |
100 km/h |
110 km/h |
| 500-760 |
160 km/h |
80 km/h |
90 km/h |
| 300-500 |
120 km/h |
50 km/h |
60 km/h |
| 190-300 |
80 km/h |
35 km/h |
40 km/h |
| <190 |
60 km/h |
25 km/h |
30 km/h |
Geometric Requirements
| Parameter |
High-Speed |
Main Line |
Yard |
| Lead Length |
54-72m |
27-42m |
12-18m |
| Switch Angle |
1:24-1:32 |
1:12-1:18.5 |
1:6-1:9 |
| Curve Entry |
Spiral |
Transition |
Direct |
| Cant |
0mm |
0-20mm |
0mm |
| Gauge Widening |
+0/-1mm |
+2/-1mm |
+3/-1mm |
Maintenance Tolerances
| Measurement |
New |
Warning |
Limit |
| Gauge |
+1/-1mm |
+2/-1mm |
+3/-2mm |
| Alignment |
±2mm |
±4mm |
±6mm |
| Cross Level |
±1mm |
±3mm |
±5mm |
| Stock Rail Wear |
0mm |
8mm |
12mm |
| Switch Rail Wear |
0mm |
6mm |
10mm |
| Element |
Standard |
Tolerance |
Check Method |
| Entry Spiral |
1:50 |
±1:100 |
Survey |
| Exit Spiral |
1:40 |
±1:80 |
Survey |
| Flangeway |
44mm |
+2/-1mm |
Gauge |
| Check Rail |
1393mm |
±2mm |
Gauge |
| Switch Throw |
115mm |
±3mm |
Measure |
Regional Standards
UIC/Europe
| Type |
Radius (m) |
Application |
| EW60-500-1:12 |
500 |
Main Line |
| EW60-300-1:9 |
300 |
Secondary |
| EW60-190-1:9 |
190 |
Yard |
| EW60-760-1:14 |
760 |
High-Speed |
| EW60-1200-1:18.5 |
1200 |
HSR |
AREMA (North America)
| Number |
Radius (ft) |
Application |
| No. 20 |
3250 |
Main Line |
| No. 15 |
1500 |
Secondary |
| No. 10 |
725 |
Branch |
| No. 8 |
491 |
Yard |
| No. 6 |
284 |
Industry |
Installation Requirements
| Parameter |
Value |
Tolerance |
| Base Level |
0mm |
±2mm |
| Alignment |
0mm |
±2mm |
| Gauge |
1435mm |
+2/-1mm |
| Superelevation |
0mm |
±1mm |
| Support Spacing |
600mm |
±25mm |
Critical Dimensions
| Location |
Measurement |
Tolerance |
| Switch Toe |
3mm |
+1/-0mm |
| Switch Heel |
Full gauge |
±1mm |
| Stock Rail |
Profile |
±0.5mm |
| Crossing Nose |
14mm |
+1/-0mm |
| Check Rails |
44mm |
+2/-1mm |
Performance Monitoring
| Aspect |
Method |
Frequency |
| Geometry |
Track Recording |
Monthly |
| Wear |
Digital Gauge |
Weekly |
| Movement |
Switch Monitor |
Each Operation |
| Forces |
Load Cells |
Continuous |
| Temperature |
IR Sensors |
Continuous |
Wear Limits
| Component |
Warning |
Action |
Replace |
| Stock Rail |
8mm |
12mm |
14mm |
| Switch Rail |
6mm |
10mm |
12mm |
| Wing Rail |
7mm |
11mm |
13mm |
| Crossing Nose |
9mm |
13mm |
15mm |
| Check Rail |
5mm |
8mm |
10mm |
