Kaworu stopped it before it was completed. (he threw the lances into Unit 1, to stop it)
Yeah, that was very frustrating.
But why did Kaworu do that? We never got an answer of why he stopped it. His whole plan to pull a fast one on Gendo in 3.33 makes no sense, why in God's name would Gendo trust him after he stopped the very thing he wanted. Am I missing a huge chunk here?