Well, your timer isn't a Timer, it's just a number. And I don't see you calling timedSpawn anywhere.

This is definitely frame script, so I'm assuming this frame is being looped a lot. I wouldn't do it that way, but it's not wrong per se.

What I'd do is set up an actual Timer, and use a variation of timedSpawn as a listener on TimerEvent.TIMER. Moving the barriers could be done on an enterframe listener. Definitely change the this["bar"+i] stuff to use a proper array.