Assertion: tank's engine | /r/HasProperty | started
Facets:
value: every half hour
type: TEMPORAL
Source sentences:
text: When the engine in natural gas vehicle (NGV) is started, the LNG is heated, converting it back to a gas.
text: Operating in sub-zero temperatures, the 8th Hussars learnt the rigours of winter warfare: their tanks had to be parked on straw to prevent the steel tracks from freezing to the ground, with engines having to be started every half hour, with each gear being engaged in turn, to prevent them from being frozen into place.