Todd said:
"Not nessecarly a coaster with no complete circut is a shuttle"
A shuttle has to do with the lift and drop mechanism. A boomerang is a shuttle because it is lifted and droppped into the course of the ride, look up the term shuttle in any dictionary. It is otherwise defined as a non-continuous coaster.
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Oooooh, my freekin' head.... Too many G's Too many G's! No, no, Too much Beer before the G's! Home Park: Knott's Berry Farm