Assertion: powered locomotive | /r/HasProperty | serious contender
Facets:
value: because of its obvious advantages
type: CAUSE
value: for half a century
type: TEMPORAL
value: for the top spot in transportation
type: TRANSITIVE-OBJECT
Source sentences:
text: For half a century the air-powered locomotive was a serious contender for the top spot in transportation because of its obvious advantages: simplicity, safety, economy, and cleanliness.