|
Relationships
|
|
|
|
| Parents |
内部属性 |
Any Attribute of an Entity that is an internal property of the Entity, e.g. its shape, its color, its fragility, etc.
|
| Instances | BroadGauge | BroadGauge is the attribute of any Railway that has a TrackGauge wider than StandardGauge. |
| | DualGauge | DualGauge is the attribute of any Railway that has three parallel rails, thus allowing two different gauges of rolling stock to travel over it. |
| | NarrowGauge | NarrowGauge is the attribute of any Railway that has a TrackGauge narrower than StandardGauge. There are several common track widths among NarrowGauge railways. |
| | StandardGauge | StandardGauge is the attribute of Railways having the standardized track width that is used in North America and most Western European countries. The standard is typically a distance of 4 ft., 8-1/2 inches (1.44 meters). There is some variation within which usage is compatible, e.g., 1.35 meters. Standard gauge originated in England and was mandated by the U.S. Federal government for the U.S. Transcontinental Railroad. It is also used in Canada, Great Britain, and most of Western Europe (but not in Ireland, or Spain and Portugal. |