Mann vs. Machine Map Tank bug.

So, im making a MVM map, i set up the train path. And everything is going fine, though, when he reaches the end and drops in the bomb, nothing will happen.
I looked at the pop files for lots of maps. And their tanks always had "OnDropBomb boss_deploy_relay trigger" or something around that. Though, decompiling the map, there is no "boss_deploy_relay" in it.

Can anyone explain what i have to do? :/