Table 3 Thresholds for maintenance of some lines of Beijing subway (unit: mm)
Type | Item | Planned maintenance | Regular maintenance | ||
|---|---|---|---|---|---|
Line | Gauge | Main line | Other line | Main line | Other line |
Horizontal | +4, −2 | +5, −2 | +6, −3 | +7, −3 | |
Vertical | 4 | 5 | 6 | 8 | |
Direction (line) | 4 | 5 | 6 | 8 | |
Twist | Â | Â | Â | Â | |
 Transition curve | 4 | 5 | 6 | 8 | |
 Branch line and circular line | 4 | 5 | 6 | 8 | |
Turnout | Gauge | Â | Â | Â | Â |
 General place | +3, −2 | +3, −2 | +4, −3 | +4, −3 | |
 Sharp end of switch rail | 3 | 4 | 5 | 7 | |
Horizontal | 3 | 4 | 5 | 7 | |
Vertical | 3 | 4 | 5 | 7 | |
Direction | Â | Â | Â | Â | |
 Line | 3 | 4 | 5 | 7 | |
 Offset | 2 | 2 | 3 | 3 | |