When using siege vehicles, always move as a Eve isk group, especially if you're only piloting a Catapult, players will easily destroy a vehicle as they're simply not as well equipped to deal with personnel. A Catapult's Flame Breath deals good damage against players, but players can very easily outmaneuver the vehicle. Moving as a group will also allow you to concentrate fire on one spot, which is critical because offense is running on a timer.