Topic summary
Narrow Gauge

Extracted from the Wikipedia article Narrow-gauge railway.
Fastest trains
Narrow gauge's reduced stability means that its trains cannot run at speeds as high as on broader gauges. For example, if a curve with standard-gauge rail (1435 mm) can allow speed up to 145 km/h (90 mph), the same curve with narrow-gauge rail (1067mm) can only allow speed up to 130 km/h (81 mph).